THE INTERNATIONAL SCIENTIFIC SERIES. 

VOLUME XV. 

THE INTERNATIONAL SCIENTIFIC SERIES. 

_Works already Published. _

 I. THE FORMS OF WATER IN RAIN AND RIVERS, ICE AND GLACIERS. By J. Tyndall, LL. D. , F. R. S. With 26 Illustrations. Price, $1. 50. 

 II. PHYSICS AND POLITICS; or, Thoughts on the Application of the Principles of "Natural Selection" and "Inheritance" to Political Society. By Walter Bagehot. Price, $1. 50. 

 III. FOODS. By Dr. Edward Smith. Illustrated. Price, $1. 75. 

 IV. MIND AND BODY: the Theories of their Relations. By Alexander Bain, LL. D. Price, $1. 50. 

 V. THE STUDY OF SOCIOLOGY. By Herbert Spencer. Price, $1. 50. 

 VI. THE NEW CHEMISTRY. By Professor Josiah P. Cooke, of Harvard University. Illustrated. Price, $2. 00. 

 VII. ON THE CONSERVATION OF ENERGY. By Professor Balfour Stewart. Fourteen Engravings. Price, $1. 50. 

 VIII. ANIMAL LOCOMOTION; or, Walking, Swimming, and Flying. By Dr. J. B. Pettigrew, M. D. , F. R. S. 119 Illustrations. Price, $1. 75. 

 IX. RESPONSIBILITY IN MENTAL DISEASE. By Dr. Henry Maudsley. Price, $1. 50. 

 X. THE SCIENCE OF LAW. By Professor Sheldon Amos. Price, $1. 75. 

 XI. ANIMAL MECHANISM; or, Aërial and Terrestrial Locomotion. By C. J. Marey, Professor of the College of France, Member of the Academy of Medicine, Paris. 117 Engravings. Price, $1. 75. 

 XII. HISTORY OF THE CONFLICT BETWEEN RELIGION AND SCIENCE. By John W. Draper, M. D. , LL. D. Price, $1. 75. 

 XIII. THE DOCTRINE OF DESCENT AND DARWINISM. By Oscar Schmidt, Professor in the University of Strasburg. Price, $1. 50. 

 XIV. THE CHEMISTRY OF LIGHT AND PHOTOGRAPHY; in its Application to Art, Science, and Industry. By Dr. Hermann Vogel. One Hundred Illustrations. (_In press. _)

 XV. FUNGI; their Nature, Influence, and Uses. By M. C. Cooke, M. A. , LL. D. Edited by Rev. M. J. Berkeley, M. A. , F. L. S. With 109 Illustrations. (_In press. _)

 XVI. OPTICS. By Professor Lommel, University of Erlangen. (_In press. _)

THE INTERNATIONAL SCIENTIFIC SERIES. 

FUNGI:

THEIR

NATURE AND USES. 

BYM. C. COOKE, M. A. , LL. D. 

EDITED BYTHE REV. M. J. BERKELEY, M. A. , F. L. S. 

NEW YORK:D. APPLETON AND COMPANY, 549 AND 551 BROADWAY. 1875. 

PREFACE BY THE EDITOR. 

As my name appears on the title-page of this volume, it is necessarythat I should exactly state what part I had in its preparation. I hadno doubt originally engaged to undertake the work myself; but finding, from multiplicity of engagements and my uncertain health, that I couldnot accomplish it satisfactorily, I thought the best course I couldtake was to recommend Mr. Cooke to the publishers; a gentleman wellknown, not only in this country, but in the United States. The wholeof the work has therefore been prepared by himself, the manuscript andproof sheets being submitted to me from time to time, in which Imerely suggested such additions as seemed needful, subjoiningoccasionally a few notes. As the work is intended for students, theauthor has had no hesitation in repeating what has been stated informer chapters where it has been thought to prove useful. I have nodoubt that the same high character will justly apply to this as to Mr. Cooke's former publications, and especially to his "Handbook ofBritish Fungi. "

 M. J. BERKELEY. 

SIBBERTOFT, _November 23, 1874. _

CONTENTS. 

 PAGE I. NATURE OF FUNGI. 1 II. STRUCTURE. 17 III CLASSIFICATION 64 IV. USES. 82 V. NOTABLE PHENOMENA. 105 VI. THE SPORE AND ITS DISSEMINATION. 119 VII. GERMINATION AND GROWTH. 137 VIII. SEXUAL REPRODUCTION. 163 IX. POLYMORPHISM. 182 X. INFLUENCES AND EFFECTS. 209 XI. HABITATS. 233 XII. CULTIVATION. 253 XIII. GEOGRAPHICAL DISTRIBUTION. 266 XIV. COLLECTION AND PRESERVATION. 287 INDEX. 295

LIST OF ILLUSTRATIONS. 

 FIG. PAGE 1. Agaric in Process of Growth. 17 2. Section of Common Mushroom. 21 3. Sterile cells, Basidia, Cystidium, from _Gomphidius_. 21 4. _Polyporus giganteus_ (reduced). 23 5. _Hydnum repandum. _ 24 6. _Calocera viscosa. _ 24 7. _Tremella mesenterica. _ 24 8. Basidia and spores of _Phallus_. 28 9. Basidia and spores of _Lycoperdon_. 29 10. Threads of _Trichia_. 31 11. _Arcyria incarnata_, with portion of threads and spore. 33 12. _Diachæa elegans. _ 34 13. _Cyathus vernicosus. _ 34 14. _Cyathus_, Sporangia and spores. 35 15. _Asterosporium Hoffmanni. _ 36 16. Barren Cysts and Pseudospores of _Lecythea_. 36 17. _Coleosporium Tussilaginis. _ 36 18. _Melampsora salicina_, pseudospores of 36 19. _Cystopus candidus_, conidia of 38 20. _Xenodochus carbonarius_, pseudospore. 38 21. _Phragmidium bulbosum_, pseudospores. 38 22. Pseudospores of _Puccinia_. 40 23. _Thecaphora hyalina_, pseudospores. 41 24. _Æcidium Berberidis_, peridia of 41 25. _Helminthosporium molle_, threads and spores. 42 26. _Acrothecium simplex. _ 44 27. _Peronospora Arenariæ. _ 44 28. _Polyactis cinerea. _ 47 29. _Peziza Fuckeliana_, with ascus and sporidia. 47 30. _Penicillium chartarum. _ 50 31. _Mucor mucedo_, with sporangia. 50 32. Small portion of _Botrytis Jonesii_. 54 33. Section of cup of _Ascobolus_. 57 34. Asci, sporidia, and paraphyses of _Ascobolus_. 59 35. Perithecium of _Sphæria_. 61 36. _Uncinula adunca_, conceptacle with appendages. 62 37. _Agaricus nudus. _ 66 38. _Scleroderma vulgare_, Fr. 69 39. _Ceuthospora phacidioides. _ 69 40. _Rhopalomyces candidus. _ 74 41. _Mucor caninus. _ 75 42. _Sphæria aquila_, cluster of perithecia. 78 43. _Morchella gigaspora_, from Kashmir. 99 44. _Cyttaria Gunnii_ 101 45. Spores of Agarics 121 46. Spores of _Lactarius_ 121 46a. Spores of _Gomphidius_ 122 47. Spores of _Polyporus_, _Boletus_, and _Hydnum_. 122 48. _Diachea elegans_, capellitium of 123 49. Spore of _Hendersonia polycystis_. 126 50. Spores of _Dilophospora graminis_. 126 51. Spores of _Discosia_. 126 52. Spore of _Prosthemium betulinum_. 126 53. Spore of _Stegonosporium cellulosum_. 126 54. Stylospores of _Coryneum disciforme_. 126 55. Spores of _Asterosporium Hoffmanni_. 126 56. Spores of _Pestalozzia_. 126 57. _Bispora monilioides_, concatenate spores 126 58. Pseudospores of _Thecaphora hyalina_. 128 59. Pseudospores of _Puccinia_. 128 60. Pseudospores of _Triphragmium_. 128 61. Pseudospores of _Phragmidium bulbosum_. 128 62. Winter spores of _Melampsora salicina. _ 128 63. Spores of _Helicocoryne_. 129 64. Sporidium of _Genea verrucosa_. 130 65. Alveolate sporidium of _Tuber_. 130 66. Asci, sporidia, and paraphyses of _Ascobolus_. 131 67. Sporidium of _Ostreichnion Americanum_. 132 68. Ascus and sporidia of _Hypocrea_. 135 69. Sporidium of _Sphæria ulnaspora_. 135 70. Sporidia of _Valsa profusa_. 135 71. Sporidia of _Massaria foedans_. 135 72. Sporidium of _Melanconis bicornis_. 135 73. Caudate sporidia of _Sphæria fimiseda_. 135 74. Sporidia of _Valsa thelebola_. 135 75. Sporidia of _Valsa taleola_. 135 76. Sporidium of _Sporormia intermedia_. 135 77. Asci and sporidia of _Sphæria_ (_Pleospora_) _herbarum_. 135 78. Sporidium of _Sphæria putaminum_. 135 79. Basidia and spores of _Exidia spiculosa_. 139 80. Germinating spore and corpuscles of _Dacrymyces_. 140 81. Germination of _Æcidium Euphorbia_. 142 82. Germinating pseudospores of _Coleosporium Sonchi_. 144 83. Germinating pseudospore of _Melampsora betulina_. 144 84. Germinating pseudospore of _Uromyce appendiculatus_. 145 85. Germinating pseudospore of _Puccinia Moliniæ_. 146 86. Germinating pseudospore of _Triphragmium Ulmariæ_. 146 87. Germinating pseudospore of _Phragmidium bulbosum_. 147 88. Germinating pseudospores of _Podisoma Juniperi_. 149 89. Germinating pseudospore of _Tilletia caries_. 150 90. Pseudospore of _Ustilago receptaculorum_ in germination, and secondary spores in conjugation. 151 91. Conidia and zoospores of _Cystopus candidus_. 151 92. Resting spore of _Cystopus candidus_ with zoospores. 152 93. Zygospores of _Mucor phycomyces_. 158 94. Sporidium of _Ascobolus_ germinating. 161 95. Zygospore of _Mucor_. 164 96. Zygospore of _Rhizopus_ in different stages. 166 97. Conjugation in _Achlya racemosa_. 169 98. Conjugation in _Peronospora. _ 171 99. Antheridia and oogonium of _Peronospora_. 172 100. Conjugation in _Peziza omphalodes_. 176 100a. Formation of conceptacle in _Erysiphe_. 176 101. _Tilletia caries_ with conjugating cells. 178 102. _Aspergillus glaucus_ and _Eurotium_. 190 103. _Erysiphe cichoracearum_, receptacle and mycelium. 192 104. Twig with _Tubercularia_ and _Nectria_. 193 105. Section of _Tubercularia_ with conidia. 193 106. D. _Nectria_ with _Tubercularia_, ascus and paraphyses. 195 107. Cells and pseudospores of _Æcidium berberidis_. 201 108. Cells and pseudospores of _Æcidium graveolens_. 201 109. _Torrubia militaris_ on pupa of a moth. 243

FUNGI

THEIR NATURE, USES, INFLUENCES, ETC. 

I. 

NATURE OF FUNGI. 

The most casual observer of Nature recognizes in almost every instancethat comes under his notice in every-day life, without the aid oflogical definition, the broad distinctions between an animal, a plant, and a stone. To him, the old definition that an animal is possessed oflife and locomotion, a plant of life without locomotion, and a mineraldeficient in both, seems to be sufficient, until some day he travelsbeyond the circuit of diurnal routine, and encounters a sponge or azoophyte, which possesses only one of his supposed attributes ofanimal life, but which he is assured is nevertheless a member of theanimal kingdom. Such an encounter usually perplexes the neophyte atfirst, but rather than confess his generalizations to have been toogross, he will tenaciously contend that the sponge must be a plant, until the evidence produced is so strong that he is compelled todesert his position, and seek refuge in the declaration that onekingdom runs into the other so imperceptibly that no line ofdemarcation can be drawn between them. Between these two extremes ofbroad distinction, and no distinction, lies the ground occupied by thescientific student, who, whilst admitting that logical definitionfails in assigning briefly and tersely the bounds of the threekingdoms, contends that such limits exist so positively, that theuniversal scientific mind accepts the recognized limit withoutcontroversy or contradiction. 

In like manner, if one kingdom be made the subject of inquiry, thesame difficulties will arise. A flowering plant, as represented by arose or a lily, will be recognized as distinct from a fern, a seaweed, or a fungus. Yet there are some flowering plants which, at firstsight, and without examination, simulate cryptogams, as, for example, many _Balanophoræ_, which the unscientific would at once class withfungi. It is nevertheless true that even the incipient botanist willaccurately separate the phanerogams from the cryptogams, and by meansof a little more, but still elementary knowledge, distribute thelatter amongst ferns, mosses, fungi, lichens, and algæ, withcomparatively few exceptions. It is true that between fungi andlichens there exists so close an affinity that difficulties arise, anddoubts, and disputations, regarding certain small groups or a fewspecies; but these are the exception, and not the rule. Botanistsgenerally are agreed in recognizing the five principal groups ofCryptogamia, as natural and distinct. In proportion as we advance fromcomparison of members of the three kingdoms, through that of theprimary groups in one kingdom, to a comparison of tribes, alliances, and orders, we shall require closer observation, and more and moreeducation of the eye to see, and the mind to appreciate, relationshipsand distinctions. 

We have already assumed that fungi are duly and universally admitted, as plants, into the vegetable kingdom. But of this fact some have evenventured to doubt. This doubt, however, has been confined to one orderof fungi, except, perhaps, amongst the most illiterate, although nowthe animal nature of the _Myxogastres_ has scarcely a serious advocateleft. In this order the early condition of the plant is pulpy andgelatinous, and consists of a substance more allied to sarcode thancellulose. De Bary insinuated affinities with _Amoeba_, [A] whilstTulasne affirmed that the outer coat in some of these productionscontained so much carbonate of lime that strong effervescence tookplace on the application of sulphuric acid. Dr. Henry Carter is wellknown as an old and experienced worker amongst amoeboid forms ofanimal life, and, when in Bombay, he devoted himself to theexamination of the _Myxogastres_ in their early stage, and the resultof his examinations has been a firm conviction that there is norelationship whatever between the _Myxogastres_ and the lower forms ofanimal life. De Bary has himself very much modified, if not whollyabandoned, the views once propounded by him on this subject. Whenmature, and the dusty spores, mixed with threads, sometimes spiral, are produced, the _Myxogastres_ are so evidently close allies of the_Lycoperdons_, or Puffballs, as to leave no doubt of their affinities. It is scarcely necessary to remark that the presence of zoospores isno proof of animal nature, for not only do they occur in the whiterust (_Cystopus_), and in such moulds as _Peronospora_, [B] but arecommon in algæ, the vegetable nature of which has never beendisputed. 

There is another equally important, but more complicated subject towhich we must allude in this connection. This is the probability ofminute fungi being developed without the intervention of germs, fromcertain solutions. The observations of M. Trécul, in a paper laidbefore the French Academy, have thus been summarized:--1. Yeast cellsmay be formed in the must of beer without spores being previouslysown. 2. Cells of the same form as those of yeast, but with differentcontents, arise spontaneously in simple solution of sugar, or to whicha little tartrate of ammonia has been added, and these cells arecapable of producing fermentation in certain liquids under favourableconditions. 3. The cells thus formed produce _Penicillium_ like thecells of yeast. 4. On the other hand, the spores of _Penicillium_ arecapable of being transformed into yeast. [C] The interpretation of thisis, that the mould _Penicillium_ may be produced from a sugarsolution by "spontaneous generation, " and without spore or germ of anykind. The theory is, that a molecular mass which is developed incertain solutions or infusions, may, under the influence of differentcircumstances, produce either animalcules or fungi. "In all thesecases, no kind of animalcule or fungus is ever seen to originate frompreexisting cells or larger bodies, but always from molecules. "[D] Themolecules are said to form small masses, which soon melt together toconstitute a globular body, from which a process juts out on one side. These are the so-called _Torulæ_, [E] which give off buds which aresoon transformed into jointed tubes of various diameters, terminatingin rows of sporules, _Penicillium_, or capsules containing numerousglobular seeds, _Aspergillus_ (_sic_). 

This is but another mode of stating the same thing as above referredto by M. Trécul, that certain cells, resembling yeast cells (_Torula_), are developed spontaneously, and that these ultimately pass through theform of mould called _Penicillium_ to the more complex _Mucor_ (whichthe writer evidently has confounded with _Aspergillus_, unless healludes to the ascigerous form of _Aspergillus_, long known as_Eurotium_). From what is now known of the polymorphism of fungi, therewould be little difficulty in believing that cells resembling yeastcells would develop into _Penicillium_, as they do in _fact_ in what iscalled the "vinegar plant, " and that the capsuliferous, or highercondition of this mould may be a _Mucor_, in which the sporules areproduced in capsules. The difficulty arises earlier, in the supposedspontaneous origination of yeast cells from molecules, which result fromthe peculiar conditions of light, temperature, &c. , in which certainsolutions are placed. It would be impossible to review all thearguments, or tabulate all the experiments, which have been employedfor and against this theory. It could not be passed over in silence, since it has been one of the stirring questions of the day. The greatproblem how to exclude all germs from the solutions experimentedupon, and to keep them excluded, lies at the foundation of the theory. It must ever, as we think, be matter of doubt that all germs were notexcluded or destroyed, rather than one of belief that forms known to bedeveloped day by day from germs should under other conditionsoriginate spontaneously. 

Fungi are veritably and unmistakably plants, of a low organization, itis true, but still plants, developed from germs, somewhat analogous, but not wholly homologous, to the seeds of higher orders. The processof fertilization is still obscure, but facts are slowly and graduallyaccumulating, so that we may hope at some not very distant period tocomprehend what as yet are little removed from hypotheses. Admittingthat fungi are independent plants, much more complex in theirrelations and development than was formerly supposed, it will beexpected that certain forms should be comparatively permanent, thatis, that they should constitute good species. Here, also, efforts havebeen made to develop a theory that there are no legitimate speciesamongst fungi, accepting the terms as hitherto applied to floweringplants. In this, as in allied instances, too hasty generalizationshave been based on a few isolated facts, without due comprehension ofthe true interpretation of such facts and phenomena. Polymorphism willhereafter receive special illustration, but meantime it may be well tostate that, because some forms of fungi which have been described, andwhich have borne distinct names as autonomous species, are now provedto be only stages or conditions of other species, there is no reasonfor concluding that no forms are autonomous, or that fungi whichappear and are developed in successive stages are not, in theirentirety, good species. Instead, therefore, of insinuating that thereare no good species, modern investigation tends rather to theestablishment of good species, and the elimination of those that arespurious. It is chiefly amongst the microscopic species thatpolymorphism has been determined. In the larger and fleshy funginothing has been discovered which can shake our faith in the speciesdescribed half a century, or more, ago. In the Agarics, for instance, the forms seem to be as permanent and as distinct as in the floweringplants. In fact, there is still no reason to dissent, except to a verylimited extent, from what was written before polymorphism wasaccredited, that, "with a few exceptions only, it may without doubt beasserted that more certain species do not exist in any part of theorganized world than amongst fungi. The same species constantly recurin the same places, and if kinds not hitherto detected presentthemselves, they are either such as are well known in other districts, or species which have been overlooked, and which are found on betterexperience to be widely diffused. There is nothing like chance abouttheir characters or growth. "[F]

The parasitism of numerous minute species on living and growing plantshas its parallel even amongst phanerogams in the mistletoe andbroom-rape and similar species. Amongst fungi a large number are thusparasitic, distorting, and in many cases ultimately destroying, theirhost, burrowing within the tissues, and causing rust and smut in cornand grasses, or even more destructive and injurious in such moulds asthose of the potato disease and its allies. A still larger number offungi are developed from decayed or decaying vegetable matter. Theseare found in winter on dead leaves, twigs, branches, rotten wood, theremains of herbaceous plants, and soil largely charged withdisintegrated vegetables. As soon as a plant begins to decay itbecomes the source of a new vegetation, which hastens its destruction, and a new cycle of life commences. In these instances, whetherparasitic on living plants or developed on dead ones, the source isstill vegetable. But this is not always the case, so that it cannot bepredicated that fungi are wholly epiphytal. Some species are alwaysfound on animal matter, leather, horn, bone, &c. , and same affect suchunpromising substances as minerals, from which it would be supposedthat no nourishment could be obtained, not only hard gravel stones, fragments of rock, but also metals, such as iron and lead, of whichmore may be said when we come to treat of the habitats of fungi. Although in general terms fungi may be described as "hysterophytal orepiphytal mycetals deriving nourishment by means of a mycelium fromthe matrix, "[G] there are exceptions to this rule with which themajority accord. 

Of the fungi found on animal substances, none are more extraordinarythan those species which attack insects. The white mould which inautumn proves so destructive to the common house-fly may for thepresent be omitted, as it is probably a condition of one of the_Saprolegniei_, which some authors include with fungi, and others withalgæ. Wasps, spiders, moths, and butterflies become enveloped in akind of mould named _Isaria_, which constitutes the conidia of_Torrubia_, a genus of club-shaped _Sphæriæ_ afterwards developed. Some species of _Isaria_ and _Torrubia_ also affect the larvæ and pupæof moths and butterflies, converting the whole interior into a mass ofmycelium, and fructifying in a clavate head. It has been subject fordiscussion whether in such instances the fungus commenced itsdevelopment during the life of the insect, and thus hastened itsdeath, or whether it resulted after death, and was subsequent to thecommencement of decay. [H] The position in which certain large mothsare found standing on leaves when infested with _Isaria_ resembles soclosely that of the house-fly when succumbing to _Sporendonema Muscæ_, would lead to the conclusion that certainly in some cases the insectwas attacked by the fungus whilst still living; whilst in the case ofburied caterpillars, such as the New Zealand or British _Hepialus_, itis difficult to decide. Whether in life or death in these instances, it is clear that the silk-worm disease _Muscardine_ attacks the livinginsect, and causes death. In the case of the _Guêpes végétantes_, thewasp is said to fly about with the fungus partially developed. 

In all fungi we may recognize a vegetative and a reproductive system:sometimes the first only becomes developed, and then the fungus isimperfect, and sometimes the latter is far more prominent than theformer. There is usually an agglomeration of delicate threads, either jointed or not, which are somewhat analogous to the roots ofhigher plants. These delicate threads permeate the tissues ofplants attacked by parasitic fungi, or they run over dead leavesforming whitened patches, formerly bearing the name of _Himantia_, but really the mycelium of some species of _Marasmius_. If checkedor disturbed, the process stops here, and only a mycelium ofinterwoven threads is produced. In this condition the mycelium of onespecies so much resembles that of another, that no accuratedetermination can be made. If the process goes on, this mycelium givesrise to the stem and cap of an agaricoid fungus, completing thevegetative system. This in turn gives origin to a spore-bearingsurface, and ultimately the fruit is formed, and then the fungus iscomplete; no fungus can be regarded as perfect or complete withoutits reproductive system being developed. In some this is verysimple, in others it is as complex. In many of the moulds we haveminiature representatives of higher plants in the mycelium orroots, stem, branches, and at length capsules bearing sporidia, whichcorrespond to seeds. It is true that leaves are absent, but these aresometimes compensated by lateral processes or abortive branchlets. A tuft of mould is in miniature a forest of trees. Although such adefinition may be deemed more poetic than accurate, more figurativethan literal, yet few could believe in the marvellous beauty of atuft of mould if they never saw it as exhibited under the microscope. In such a condition no doubt could be entertained of its vegetablecharacter. But there is a lower phase in which these plants aresometimes encountered; they may consist only of single cells, orstrings of cells, or threads of simple structure floating influids. In such conditions only the vegetative system is probablydeveloped, and that imperfectly, yet some have ventured to givenames to isolated cells, or strings of cells, or threads ofmycelium, which really in themselves possess none of the elementsof correct classification--the vegetative system, even, beingimperfect, and consequently the reproductive is absent. As alreadyobserved, no fungus is perfect without fruit of some kind, and thepeculiarities of structure and development of fruit form one of themost important elements in classification. To attempt, therefore, togive names to such imperfect fragments of undeveloped plants isalmost as absurd as to name a flowering plant from a strayfragment of a root-fibril accidentally cast out of the ground--nay, even worse, for identification would probably be easier. It is well toprotest at all times against attempts to push science to the vergeof absurdity; and such must be the verdict upon endeavours todetermine positively such incomplete organisms as floating cells, or hyaline threads which may belong to any one of fifty species ofmoulds, or after all to an alga. This leads us to remark, inpassing, that there are forms and conditions under which fungi maybe found when, fructification being absent--that is, the vegetativesystem alone developed--they approximate so closely to algæ that itis almost impossible to say to which group the organisms belong. 

Finally, it is a great characteristic of fungi in general that theyare very rapid in growth, and rapid in decay. In a night a puffballwill grow prodigiously, and in the same short period a mass of pastemay be covered with mould. In a few hours a gelatinous mass of_Reticularia_ will pass into a bladder of dust, or a _Coprinus_ willbe dripping into decay. Remembering this, mycophagists will take notethat a fleshy fungus which may be good eating at noon may undergo suchchanges in a few hours as to be anything but good eating at night. Many instances have been recorded of the rapidity of growth in fungi;it may also be accepted as an axiom that they are, in many instances, equally as rapid in decay. 

The affinity between lichens and fungi has long been recognized to itsfull and legitimate extent by lichenologists and mycologists. [I] Inthe "Introduction to Cryptogamic Botany, " it was proposed to unitethem in one alliance, under the name of _Mycetales_, in the samemanner as the late Dr. Lindley had united allied orders underalliances in his "Vegetable Kingdom;" but, beyond this, there was nopredisposition towards the theory since propounded, and which, likeall new theories, has collected a small but zealous circle ofadherents. It will be necessary briefly to summarize this theory andthe arguments by which it is supported and opposed, inasmuch as it isintimately connected with our subject. 

As recently as 1868, Professor Schwendener first propounded hisviews, [J] and then briefly and vaguely, that all and every individuallichen was but an algal, which had collected about it a parasiticfungal growth, and that those peculiar bodies which, under the name of_gonidia_, were considered as special organs of lichens, were onlyimprisoned algæ. In language which the Rev. J. M. Crombie[K] describesas "pictorial, " this author gave the general conclusion at which hehad arrived, as follows:--"As the result of my researches, all thesegrowths are not simple plants, not individuals in the usual sense ofthe term; they are rather colonies, which consist of hundreds andthousands of individuals, of which, however, only one acts as master, while the others, in perpetual captivity, provide nourishment forthemselves and their master. This master is a fungus of the order_Ascomycetes_, a parasite which is accustomed to live upon the work ofothers; its slaves are green algæ, which it has sought out, or indeedcaught hold of, and forced into its service. It surrounds them, as aspider does its prey, with a fibrous net of narrow meshes, which isgradually converted into an impenetrable covering. While, however, thespider sucks its prey and leaves it lying dead, the fungus incites thealgæ taken in its net to more rapid activity; nay, to more vigorousincrease. " This hypothesis, ushered upon the world with all theprestige of the Professor's name, was not long in meeting withadherents, and the cardinal points insisted upon were--1st. That thegeneric relationship of the coloured "gonidia" to the colourlessfilaments which compose the lichen thallus, had only been assumed, andnot proved; 2nd. That the membrane of the gonidia was chemicallydifferent from the membrane of the other tissues, inasmuch as thefirst had a reaction corresponding to that of algæ, whilst the secondhad that of fungi; 3rd. That the different forms and varieties ofgonidia corresponded with parallel types of algæ; 4th. That as thegermination of the spore had not been followed further than thedevelopment of a hypothallus, it might be accounted for by the absenceof the essential algal on which the new organism should becomeparasitic; 5th. That there is a striking correspondence between thedevelopment of the fruit in lichens and in some of the sporidiiferousfungi (_Pyrenomycetes_). 

These five points have been combated incessantly by lichenologists, who would really be supposed by ordinary minds to be the mostpractically acquainted with the structure and development of theseplants, in opposition to the theorists. It is a fact which should havesome weight, that no lichenologist of repute has as yet accepted thetheory. In 1873 Dr. E. Bornet[L] came to the aid of Schwendener, andalmost exhausted the subject, but failed to convince either thepractised lichenologist or mycologist. The two great points sought tobe established are these, that what we call lichens are compoundorganisms, not simple, independent vegetable entities; and that thiscompound organism consists of unicellular algæ, with a fungusparasitic upon them. The coloured gonidia which are found in thesubstance, or thallus of lichens, are the supposed algæ; and thecellular structure which surrounds, encloses, and imprisons thegonidia is the parasitic fungus, which is parasitic on somethinginfinitely smaller than itself, and which it entirely and absolutelyisolates from all external influences. 

Dr. Bornet believed himself to have established that every gonidium ofa lichen may be referred to a species of algæ, and that the connectionbetween the hypha and gonidia is of such a nature as to exclude allpossibility of the one organ being produced by the other. This hethinks is the only way in which it can be accounted for that thegonidia of diverse lichens should be almost identical. 

Dr. Nylander, in referring to this hypothesis of an imprisonedalgal, [M] writes: "The absurdity of such an hypothesis is evident fromthe very consideration that it cannot be the case that an organ(gonidia) should at the same time be a parasite on the body of whichit exercises vital functions; for with equal propriety it might becontended that the liver or the spleen constitutes parasites of themammiferæ. Parasite existence is autonomous, living upon a foreignbody, of which nature prohibits it from being at the same time anorgan. This is an elementary axiom of general physiology. Butobservation directly made teaches that the green matter originallyarises within the primary chlorophyll- or phycochrom-bearing cellule, and consequently is not intruded from any external quarter, nor arisesin any way from any parasitism of any kind. The cellule at first isobserved to be empty, and then, by the aid of secretion, green matteris gradually produced in the cavity and assumes a definite form. Itcan, therefore, be very easily and evidently demonstrated that theorigin of green matter in lichens is entirely the same as in otherplants. " On another occasion, and in another place, the same eminentlichenologist remarks, [N] as to the supposed algoid nature ofgonidia--"that such an unnatural existence as they would thus pass, enclosed in a prison and deprived of all autonomous liberty, is notat all consonant with the manner of existence of the other algæ, andthat it has no parallel in nature, for nothing physiologicallyanalogous occurs anywhere else. Krempelhuber has argued that there areno conclusive reasons against the assumption that the lichen-gonidiamay be self-developed organs of the lichen proper rather than algæ, and that these gonidia can continue to vegetate separately, and so bemistaken for unicellular algæ. " In this Th. Fries seems substantiallyto concur. But there is one strong argument, or rather a repetition ofan argument already cited, placed in a much stronger light, which isemployed by Nylander in the following words:--"So far are what arecalled algæ, according to the turbid hypothesis of Schwendener, fromconstituting true algæ, that on the contrary it may be affirmed thatthey have a lichenose nature, whence it follows that these pseudo-algæare in a systematic arrangement to be referred rather to the lichens, and that the class of algæ hitherto so vaguely limited should becircumscribed by new and truer limits. "

As to another phase in this question, there are, as Krempelhuberremarks, species of lichens which in many countries do not fructify, and whose propagation can only be carried on by means of the soredia, and the hyphæ of such could in themselves alone no more serve forpropagation than the hyphæ from the pileus or stalk of an Agaric, while it is highly improbable that they could acquire this faculty byinterposition of a foreign algal. On the other hand he argues: "It ismuch more conformable to nature that the gonidia, as self-developedorgans of the lichens, should, like the spores, enable the hyphæproceeding from them to propagate the individual. "[O]

A case in point has been adduced[P] in which gonidia were produced bythe hypha, and the genus _Emericella_, [Q] which is allied to _Husseia_in the _Trichogastres_, shows a structure in the stem exactlyresembling _Palmella botryoides_ of Greville, and to what occurs in_Synalyssa_. _Emericella_, with one or two other genera, must, however, be considered as connecting _Trichogastres_ with lichens, andthe question cannot be considered as satisfactorily decided till aseries of experiments has been made on the germination of lichenspores and their relation to free algæ considered identical withgonidia. Mr. Thwaites was the first to point out[R] the relation ofthe gonidia in the different sections of lichens to different types ofsupposed algæ. The question cannot be settled by mere _à priori_notions. It is, perhaps, worthy of remark that in _Chionyphe Carteri_the threads grow over the cysts exactly as the hypha of lichens isrepresented as growing over the gonidia. 

Recently, Dr. Thwaites has communicated his views on one phase of thiscontroversy, [S] which will serve to illustrate the question as seenfrom the mycological side. As is well known, this writer has hadconsiderable experience in the study of the anatomy and physiology ofall the lower cryptogamia, and any suggestion of his on such a subjectwill at least commend itself to a patient consideration. 

"According to our experience, " he writes, "I think parasitic fungiinvariably produce a sad effect upon the tissues they fix themselvesupon or in. These tissues become pale in colour, and in every respectsickly in appearance. But who has ever seen the gonidia of lichens theworse for having the 'hypha' growing amongst them? These gonidia arealways in the plumpest state, and with the freshest, healthiest colourpossible. Cannot it enter into the heads of these most patient andexcellent observers, that a cryptogamic plant may have two kinds oftissue growing side by side, without the necessity of one beingparasitic upon the other, just as one of the higher plants may havehalf a dozen kinds of tissue making up its organization? Thebeautifully symmetrical growth of the same lichens has seemed to me asufficient argument against one portion being parasitic upon another, but when we see all harmony and robust health, the idea that oneportion is subsisting parasitically upon another appears to me to be aperfect absurdity. "

It appears to us that a great deal of confusion and a large number oferrors which creep into our modern generalizations and hypotheses, maybe traced to the acceptance of analogies for identities. How manycases of mistaken identity has the improvement of microscopes revealedduring the past quarter of a century. This should at least serve as acaution for the future. 

Apart, however, from the "gonidia, " whatever they may be, is theremainder of the lichen a genuine fungus? Nylander writes, "Theanatomical filamentose elements of lichens are distinguished byvarious characters from the hyphæ of fungi. They are firmer, elastic, and at once present themselves in the texture of lichens. On the otherhand, the hyphæ of fungi are very soft, they possess a thin wall, andare not at all gelatinous, while they are immediately dissolved by theapplication of hydrate of potash, &c. "[T]

Our own experience is somewhat to the effect, that there are some fewlichens which are doubtful as to whether they are fungi or lichens, but, in by far the majority of cases, there is not the slightestdifficulty in determining, from the peculiar firmness and elasticityof the tissues, minute peculiarities which the practised hand candetect rather than describe, and even the general character of thefruit that they differ materially from, though closely allied tofungi. We have only experience to guide us in these matters, but thatis something, and we have no experience in fungi of anything like a_Cladonia_, however much it may resemble a _Torrubia_ or _Clavaria_. We have _Pezizæ_ with a subiculum in the section _Tapesia_, but theveriest tyro would not confound them with species of _Parmelia_. It istrue that a great number of lichens, at first sight, and casually, resemble species of the _Hysteriacei_, but it is no less strange thantrue, that lichenologists and mycologists know their own sufficientlynot to commit depredations on each other. 

Contributions are daily being made to this controversy, and alreadythe principal arguments on both sides have appeared in an Englishdress, [U] hence it will be unnecessary to repeat those which aremodifications only of the views already stated, our own conclusionsbeing capable of a very brief summary: that lichens and fungi areclosely related the one to the other, but that they are not identical;that the "gonidia" of lichens are part of the lichen-organization, andconsequently are not algæ, or any introduced bodies; that there is noparasitism; and that the lichen thallus, exclusive of gonidia, iswholly unknown amongst fungi. 

The Rev. J. M. Crombie has therefore our sympathies in the remark withwhich his summary of the gonidia controversy closes, in which hecharacterizes it as a "sensational romance of lichenology, " of the"unnatural union between a captive algal damsel and a tyrant fungalmaster. "

 [A] De Bary, "Des Myxomycètes, " in "Ann. Des Sci. Nat. " 4 sér. Xi. P. 153; "Bot. Zeit. " xvi. P. 357. De Bary's views are controverted by M. Wigand in "Ann. Des Sci. Nat. " 4 sér. (Bot. ) xvi. P. 255, &c. 

 [B] De Bary, "Recherches sur le Developpement de quelques Champignons Parasites, " in "Ann. Des Sci. Nat. " 4 sér. (Bot. ) xx. P. 5. 

 [C] "Popular Science Review, " vol. Viii. P. 96. 

 [D] Dr. J. H. Bennett "On the Molecular Origin of Infusoria, " p. 56. 

 [E] They have, however, no close relation with real _Torulæ_, such as _T. Monilioides_, &c. --COOKE'S _Handbook_, p. 477. 

 [F] Berkeley's "Outlines of British Fungology, " p. 24. 

 [G] Berkeley's "Introduction to Cryptogamic Botany, " p. 235. 

 [H] Gray, "Notices of Insects which form the Basis of Fungoid Parasites. "

 [I] On the relation or connection between fungi and lichens, H. C. Sorby has some pertinent remarks in his communication to the Royal Society on "Comparative Vegetable Chromatology" (Proceedings Royal Society, vol. Xxi. 1873, p. 479), as one result of his spectroscopic examinations. He says, "Such being the relations between the organs of reproduction and the foliage, it is to some extent possible to understand the connection between parasitic plants like fungi, which do not derive their support from the constructive energy of their fronds, and those which are self-supporting and possess true fronds. In the highest classes of plants the flowers are connected with the leaves, more especially by means of xanthophyll and yellow xanthophyll, whereas in the case of lichens the apothecia contain very little, if any, of those substances, but a large amount of the lichenoxanthines so characteristic of the class. Looking upon fungi from this chromatological point of view, they bear something like the same relation to lichens that the petals of a leafless parasitic plant would bear to the foliage of one of normal character--that is to say, they are, as it were, the coloured organs of reproduction of parasitic plants of a type closely approaching that of lichens, which, of course, is in very close, if not in absolute agreement with the conclusions drawn by botanists from entirely different data. "

 [J] Schwendener, "Untersuchungen über den Flechtenthallus. "

 [K] Crombie (J. M. ) "On the Lichen-Gonidia Question, " in "Popular Science Review" for July, 1874. 

 [L] Bornet, (E. ), "Recherches sur les Gonidies des Lichens, " in "Ann. Des Sci. Nat. " 1873, 5 sér. Vol. Xvii. 

 [M] Nylander, "On the Algo-Lichen Hypothesis, " &c. , in "Grevillea, " vol. Ii. (1874), No. 22, p. 146. 

 [N] In Regensburg "Flora, " 1870, p. 92. 

 [O] Rev. J. M. Crombie, in "Popular Science Review, " July, 1874. 

 [P] Berkeley's "Introduction to Cryptogamic Botany, " p. 373, fig. 78_a. _

 [Q] Berkeley's "Introduction, " p. 341, fig. 76. 

 [R] "Annals and Magazine of Natural History, " April, 1849. 

 [S] In "Gardener's Chronicle" for 1873, p. 1341. 

 [T] "Grevillea, " vol ii. P. 147, in note. 

 [U] W. Archer, in "Quart. Journ. Micr. Sci. " vol. Xiii. P. 217; vol. Xiv. P. 115. Translation of Schwendener's "Nature of the Gonidia of Lichens, " in same journal, vol. Xiii. P. 235. 

II. 

STRUCTURE. 

Without some knowledge of the structure of fungi, it is scarcelypossible to comprehend the principles of classification, or toappreciate the curious phenomena of polymorphism. Yet there is sogreat a variety in the structure of the different groups, that thissubject cannot be compressed within a few paragraphs, neither do wethink that this would be desired if practicable, seeing that theanatomy and physiology of plants is, in itself, sufficiently importantand interesting to warrant a rather extended and explicit survey. Inorder to impart as much practical utility as possible to this chapter, it seems advisable to treat some of the most important and typicalorders and suborders separately, giving prominence to the featureswhich are chiefly characteristic of those sections, following theorder of systematists as much as possible, whilst endeavouring torender each section independent to a considerable extent, and completein itself. Some groups naturally present more noteworthy features thanothers, and will consequently seem to receive more than theirproportional share of attention, but this seeming inequality couldscarcely have been avoided, inasmuch as hitherto some groups have beenmore closely investigated than others, are more intimately associatedwith other questions, or are more readily and satisfactorily examinedunder different aspects of their life-history. 

[Illustration: FIG. 1. --Agaric in Process of Growth. ]

AGARICINI. --For the structure that prevails in the order to which themushroom belongs, an examination of that species will be almostsufficient. Here we shall at once recognize three distinct partsrequiring elucidation, viz. The rooting slender fibres that traversethe soil, and termed the _mycelium_, or spawn, the stem and cap orpileus, which together constitute what is called the _hymenophore_, and the plates or gills on the under surface of the cap, which bearthe _hymenium_. The earliest condition in which the mushroom can berecognized as a vegetable entity is in that of the "spawn" ormycelium, which is essentially an agglomeration of vegetating spores. Its normal form is that of branched, slender, entangled, anastomosing, hyaline threads. At certain privileged points of the mycelium, thethreads seem to be aggregated, and become centres of verticalextension. At first only a small nearly globose budding, like a grainof mustard seed, is visible, but this afterwards increases rapidly, and other similar buddings or swellings appear at the base. [A] Theseare the young hymenophore. As it pushes through the soil, itgradually loses its globose form, becomes more or less elongated, andin this condition a longitudinal section shows the position of thefuture gills in a pair of opposite crescent-shaped darker-colouredspots near the apex. The dermal membrane, or outer skin, seems to becontinuous over the stem and the globose head. At present, there is noexternal evidence of an expanded pileus and gills; a longitudinalsection at this stage shows that the gills are being developed, thatthe pileus is assuming its cap-like form, that the membrane stretchingfrom the stem to the edge of the young pileus is separating from theedge of the gills, and forming a _veil_, which, in course of time, will separate below and leave the gills exposed. When, therefore, themushroom has arrived almost at maturity, the pileus expands, and inthis act the veil is torn away from the margin of the cap, and remainsfor a time like a collar around the stem. Fragments of the veil oftenremain attached to the margin of the pileus, and the collar adherentto the stem falls back, and thenceforth is known as the _annulus_ orring. We have in this stage the fully-developed hymenophore, --the stemwith its ring, supporting an expanded cap or pileus, with gills on theunder surface bearing the hymenium. [B] A longitudinal section cutthrough the pileus and down the stem, gives the best notion of thearrangement of the parts, and their relation to the whole. By thismeans it will be seen that the pileus is continuous with the stem, that the substance of the pileus descends into the gills, and thatrelatively the substance of the stem is more fibrous than that of thepileus. In the common mushroom the ring is very distinct surroundingthe stem, a little above the middle, like a collar. In some Agaricsthe ring is very fugacious, or absent altogether. The form of thegills, their mode of attachment to the stem, their colour, and moreespecially the colour of the spores, are all very important featuresto be attended to in the discrimination of species, since they vary indifferent species. The whole substance of the Agaric is cellular. Alongitudinal slice from the stem will exhibit under the microscopedelicate tubular cells, the general direction of which is lengthwise, with lateral branches, the whole interlacing so intimately that it isdifficult to trace any individual thread very far in its course. Itwill be evident that the structure is less compact as it approachesthe centre of the stem, which in many species is hollow. The_hymenium_ is the spore-bearing surface, which is exposed or naked, and spread over the gills. These plates are covered on all sides witha delicate membrane, upon which the reproductive organs are developed. If it were possible to remove this membrane in one entire piece andspread it out flat, it would cover an immense surface, as comparedwith the size of the pileus, for it is plaited or folded like a lady'sfan over the whole of the gill-plates, or lamellæ, of the fungus. [C]If the stem of a mushroom be cut off close to the gills, and the caplaid upon a sheet of paper, with the gills downwards, and left therefor a few hours, when removed a number of dark radiating lines will bedeposited upon the paper, each line corresponding with the intersticesbetween one pair of gills. These lines are made up of spores whichhave fallen from the hymenium, and, if placed under the microscope, their character will at once be made evident. If a fragment of thehymenium be also submitted to a similar examination, it will be foundthat the whole surface is studded with spores. The first peculiaritywhich will be observed is, that these spores are almost uniformly ingroups of four together. The next feature to be observed is, that eachspore is borne upon a slender stalk or sterigma, and that four ofthese sterigmata proceed from the apex of a thicker projection, fromthe hymenium, called a _basidium_, each basidium being the supporterof four sterigmata, and each sterigma of a spore. [D] A closerexamination of the hymenium will reveal the fact that the basidia areaccompanied by other bodies, often larger, but without sterigmata orspores; these have been termed _cystidia_, and their structure andfunctions have been the subject of much controversy. [E] Both kinds ofbodies are produced on the hymenium of most, if not all, theAgaricini. 

[Illustration: FIG. 2. --Section of Common Mushroom. ]

[Illustration: FIG. 3. --_a. _ Sterile cells. _b. _ Basidia. _c. _ Cystidium. From _Gomphidius_ (de Seynes). ]

The basidia are usually expanded upwards, so as to have more or lessof a clavate form, surmounted by four slender points, or tubularprocesses, each supporting a spore; the contents of these cells aregranular, mixed apparently with oleaginous particles, whichcommunicate through the slender tubes of the spicules with theinterior of the spores. Corda states that, although only one spore isproduced at a time on each sporophore, when this falls away others areproduced in succession for a limited period. As the spores approachmaturity, the connection between their contents and the contents ofthe basidia diminishes and ultimately ceases. When the basidium whichbears mature spores is still well charged with granular matter, it maybe presumed that the production of a second or third series of sporesis quite possible. Basidia exhausted entirely of their contents, andwhich have become quite hyaline, may often be observed. 

The cystidia are usually larger than the basidia, varying in size andform in different species. They present the appearance of largesterile cells, attenuated upwards, sometimes into a slender neck. Corda was of opinion that these were male organs, and gave them thename of _pollinaires_. Hoffmann has also described[F] both theseorgans under the names of _pollinaria_ and _spermatia_, but does notappear to recognize in them the sexual elements which those nameswould indicate; whilst de Seynes suggests that the cystidia are onlyorgans returned to vegetative functions by a sort of hypertrophy ofthe basidia. [G] This view seems to be supported by the fact that, inthe section _Pluteus_ and some others, the cystidia are surmounted byshort horns resembling sterigmata. Hoffmann has also indicated[H] thepassage of cystidia into basidia. The evidence seems to be in favourof regarding the cystidia as barren conditions of basidia. There areto be found upon the hymenium of Agarics a third kind of elongatedcells, called by Corda[I] basilary cells, and by Hoffmann "sterilecells, " which are either equal in size or smaller than the basidia, with which also their structure agrees, excepting in the developmentof spicules. These are the "proper cells of the hymenium" of Léveillé, and are simply the terminal cells of the gill structure--cells which, under vigorous conditions, might be developed into basidia, but whichare commonly arrested in their development. As suggested by de Seynes, the hymenium seems to be reduced to great simplicity, "one sole andself-same organ is the basis of it; according as it experiences anarrest of development, as it grows and fructifies, or as it becomeshypertrophied, it gives us a paraphyse, a basidium, or a cystidium--inother terms, atrophied basidium, normal basidium and hypertrophiedbasidium; these are the three elements which form the hymenium. "[J]

The only reproductive organs hitherto demonstrated in Agarics are thespores, or, as sometimes called, from their method of production, _basidiospores_. [K] These are at first colourless, but afterwardsacquire the colour peculiar to the species. In size and form they are, within certain limits, exceedingly variable, although form and sizeare tolerably constant in the same species. At first all are globose;as they mature, the majority are ovoid or elliptic; some are fusiform, with regularly attenuated extremities. In _Hygrophorus_ they arerather irregular, reniform, or compressed in the middle. Sometimes theexternal surface is rough with more or less projecting warts. Somemycologists are of opinion that the covering of the spore is double, consisting of an _exospore_ and an _endospore_, the latter being veryfine and delicate. In other orders the double coating of the spore hasbeen demonstrated. When the spore is coloured, the external membranealone appears to possess colour, the endospore being constantlyhyaline. It may be added here, that in this order the spore is simpleand unicellular. In _Lactarius_ and _Russula_ the trama, or innersubstance, is vesicular. True latex vessels occur occasionally in_Agaricus_, though not filled with milk as in _Lactarius_. 

[Illustration: FIG. 4. --_Polyporus giganteus_ (reduced). ]

POLYPOREI. --In this order the gill plates are replaced by tubes orpores, the interior of which is lined by the hymenium; indicationsof this structure having already been exhibited in some of thelower _Agaricini. _ In many cases the stem is suppressed. Thesubstance is fleshy in _Boletus_, but in _Polyporus_ the greaternumber of species are leathery or corky, and more persistent. Thebasidia, spicules, and quaternate spores agree with those of_Agaricini_. [L] In fact there are no features of importance whichrelate to the hymenium in any order of _Hymenomycetes_ (the_Tremellini_ excepted) differing from the same organ in _Agaricini_, unless it be the absence of _cystidia_. 

[Illustration: FIG. 5. --_Hydnum repandum. _]

HYDNEI. --Instead of pores, in this order the hymenium is spread overthe surface of spines, prickles, or warts. [M]

AURICULARINI. --The hymenium is more or less even, and in--

CLAVARIEI the whole fungus is club-shaped, or more or less intricatelybranched, with the hymenium covering the outer surface. 

[Illustration: FIG. 6. --_Calocera viscosa. _]

[Illustration: FIG. 7. --_Tremella mesenterica. _]

TREMELLINI. --In this order we have a great departure from thecharacter of the substance, external appearance, and internalstructure of the other orders in this family. Here we have agelatinous substance, and the form is lobed, folded, convolute, oftenresembling the brain of some animal. The internal structure has beenspecially illustrated by M. Tulasne, [N] through the common species, _Tremella mesenterica_. This latter is of a fine golden yellow colour, and rather large size. It is uniformly composed throughout of acolourless mucilage, with no appreciable texture, in which aredistributed very fine, diversely branched and anastomosing filaments. Towards the surface, the ultimate branches of this filamentous networkgive birth, both at their summits and laterally, to globular cells, which acquire a comparatively large size. These cells are filled witha protoplasm, to which the plant owes its orange colour. When theyhave attained their normal dimensions, they elongate at the summitinto two, three, or four distinct, thick, obtuse tubes, into which theprotoplasm gradually passes. The development of these tubes is unequaland not simultaneous, so that one will often attain its fulldimensions, equal, perhaps, to three or four times the diameter of thegenerative cell, whilst the others are only just appearing. Bydegrees, as each tube attains its full size, it is attenuated into afine point, the extremity of which swells into a spheroidal cell, which ultimately becomes a spore. Sometimes these tubes, or spicules, send out one or two lateral branches, each terminated by a spore. These spores (about ·006 to ·008 _mm. _ diameter) are smooth, anddeposit themselves, like a fine white dust, on the surface of the_Tremella_ and on its matrix. M. Léveillé[O] was of opinion that thebasidia of the Tremellini were monosporous, whilst M. Tulasne hasdemonstrated that they are habitually tetrasporous, as in other of theHymenomycetes. Although agreeing in this, they differ in otherfeatures, especially in the globose form of the basidia, mode ofproduction of the spicules, and, finally, the division of the basidiainto two, three, or four cells by septa which cut each other in theiraxis. This division precedes the growth of the spicules. It is notrare to see these cells, formed at the expense of an unilocularbasidium, become partly isolated from each other; in certain casesthey seem to have separated very early, they then become larger thanusual, and are grouped on the same filament so as to represent a kindof buds. This phenomenon usually takes place below the level of thefertile cells, at a certain depth in the mucous tissue of the_Tremella_. 

Besides the reproductive system here described, Tulasne also madeknown the existence of a series of filaments which produce spermatia. These filaments are often scattered and confused with those whichproduce the basidia, and not distinguishable from them in size or anyother apparent characteristic, except the manner in which theirextremities are branched in order to produce the spermatia. At othertimes the spermatia-bearing surface covers exclusively certainportions of the fungus, especially the inferior lobes, impartingthereto a very bright orange colour, which is communicated by thelayer of spermatia, unmixed with spores. These spots retain theirbright colour, while the remainder of the plant becomes pale, orcovered with a white dust. The spermatia are very small, spherical, and smooth, scarcely equalling ·002 _mm. _ They are sessile, sometimessolitary, sometimes three or four together, on the slightly swollenextremities of certain filaments of the weft of the fungus. [P] Tulasnefound it impossible to make these corpuscles germinate, and in allessential particulars they agreed with the spermatia found inascomycetous fungi. 

In the genus _Dacrymyces_, the same observer found the structure tohave great affinity with that of _Tremella_. The spores in the speciesexamined were of a different form, being oblong, very obtuse, slightlycurved (·013 - ·019 × ·004 - ·006 _mm. _), at first unilocular, butafterwards triseptate. The basidia are cylindrical or clavate, filledwith coloured granular matter; each of these bifurcates at the summit, and gradually elongates into two very open branches, which areattenuated above, and ultimately each is crowned by a spore. There areto be found also in the species of this genus globose bodies, designated "sporidioles" by M. Léveillé, which Tulasne tookconsiderable care to trace to their source. He thus accounts forthem:--Each of the cells of the spore emits exteriorly one or severalof these corpuscles, supported on very short and very slenderpedicels, which remain after the corpuscles are detached from them, new corpuscles succeeding the first as long as there remains anyplastic matter within the spore. The pedicels are not all on the sameplane; they are often implanted all on the same, and oftenest on theconvex side of the reproductive body. These corpuscles, though placedunder the most favourable conditions, never gave the least sign ofvegetation, and Tulasne concludes that they are spermatia, analogousto those produced in _Tremella_. The spores which produce spermatiaare not at all apt to germinate, whilst those which did not producespermatia germinated freely. Hence it would appear that, although allspores seem to be perfectly identical, they have not all the samefunction. The same observer detected also amongst specimens of the_Dacrymyces_ some of a darker and reddish tint, always bare of sporesor spermatia on the surface, and these presented a somewhat differentstructure. Where the tissue had turned red it was sterile, theconstituent filaments, ordinarily colourless, and almost empty ofsolid matter, were filled with a highly-coloured protoplasm; they wereof less tenuity, more irregularly thick, and instead of only rarelypresenting partitions, and remaining continuous, as in other parts ofthe plant, were parcelled out into an infinity of straight or curvedpieces, angular and of irregular form, especially towards the surfaceof the fungus, where they compose a sort of pulp, varying in cohesionaccording to the dry or moist condition of the atmosphere. All partsof these reddish individuals seemed more or less infected with thisdisintegration, the basidia divided by transverse diaphragms intoseveral cylindrical or oblong pieces, which finally become free. Transitional conditions were also observed in mixed individuals. Thissterile condition is called by Tulasne "gemmiparous, " and he believesthat it has ere now given origin to one or more spurious species, andmisled mycologists as to the real structure of perfect and fruitful_Dacrymyces_. 

PHALLOIDEI. --In this order the hymenium is at first enclosed within asort of peridium or universal volva, maintaining a somewhat globose oregg-shape. This envelope consists of an outer and inner coat ofsomewhat similar texture, and an intermediate gelatinous layer, oftenof considerable thickness. When a section is made of the fungus, whilst still enclosed in the volva, the hymenium is found to presentnumerous cavities, in which basidia are developed, each surmounted byspicules (four to six) bearing oval or oblong spores. [Q] It is verydifficult to observe the structure of the hymenium in this order, onaccount of its deliquescent nature. As the hymenium approachesmaturity, the volva is ruptured, and the plant rapidly enlarges. In_Phallus_, a long erect cellular stem bears the cap, over which thehymenium is spread, and this expands enormously after escaping therestraint of the volva. Soon after exposure, the hymenium deliquescesinto a dark mucilage, coloured by the minute spores, which drips fromthe pileus, often diffusing a most loathsome odour for a considerabledistance. In _Clathrus_, the receptacle forms a kind of network. In_Aseröe_, the pileus is beautifully stellate. In many the attractiveforms would be considered objects of beauty, were it not for theirdeliquescence, and often foetid odour. [R]

[Illustration: FIG. 8. --Basidia and spores of _Phallus_. ]

PODAXINEI. --This is a small but very curious group of fungi, in whichthe peridium resembles a volva, which is more or less confluent withthe surface of the pileus. They assume hymenomycetal forms, some ofthem looking like Agarics, Boleti, or species of _Hydnum_, withdeformed gills, pores, or spines; in _Montagnites_, in fact, the gillstructure is very distinct. The spores are borne in definite clusterson short pedicels in such of the genera as have been examined. [S]

HYPOGÆI. --These are subterranean puff-balls, in which sometimes adistinct peridium is present; but in most cases it consists entirelyof an external series of cells, continuous with the internalstructure, and cannot be correctly estimated as a peridium. Thehymenium is sinuous and convolute, bearing basidia with sterigmata andspores in the cavities. Sometimes the cavities are traversed bythreads, as in the _Myxogastres_. The spores are in many instancesbeautifully echinulate, sometimes globose, at others elongated, andproduced in such numbers as to lead to the belief that theirdevelopment is successive on the spicules. When fully matured, theperidia are filled with a dusty mass of spores, so that it is scarcelypossible in this condition to gain any notion of the structure. Thisis, indeed, the case with nearly all _Gasteromycetes_. The hypogæousfungi are curiously connected with _Phalloidei_ by the genus_Hysterangium_. 

[Illustration: FIG. 9. --Basidia and spores of _Lycoperdon_. ]

TRICHOGASTRES. [T]--In their early stages the species contained inthis group are not gelatinous, as in the _Myxogastres_, but arerather fleshy and firm. Very little has been added to our knowledgeof structure in this group since 1839 and 1842, when one of uswrote to the following effect:--If a young plant of _Lycoperdoncoelatum_ or _L. Gemmatum_ be cut through and examined with a commonpocket lens, it will be found to consist of a fleshy mass, perforated in every direction with minute elongated, reticulated, anastomosing, labyrinthiform cavities. The resemblance of these to thetubes of _Boleti_ in an early stage of growth, first led me tosuspect that there must be some very close connection between them. If a very thin slice now be taken, while the mass is yet firm, andbefore there is the slightest indication of a change of colour, theouter stratum of the walls of these cavities is found to consist ofpellucid obtuse cells, placed parallel to each other like the pileof velvet, exactly as in the young hymenium of an Agaric orBoletus. Occasionally one or two filaments cross from one wall toanother, and once I have seen these anastomose. At a more advancedstage of growth, four little spicules are developed at the tips ofthe sporophores, all of which, as far as I have been able to observe, are fertile and of equal height, and on each of these spicules aglobose spore is seated. It is clear that we have here a structureidentical with that of the true Hymenomycetes, a circumstance whichaccords well with the fleshy habit and mode of growth. There is somedifficulty in ascertaining the exact structure of the species justnoticed, as the fruit-bearing cells, or sporophores, are verysmall, and when the spicules are developed the substance becomes soflaccid that it is difficult to cut a proper slice, even with thesharpest lancet. I have, however, satisfied myself as to the truestructure by repeated observations. But should any difficulty arisein verifying it in the species in question, there will be none indoing so in _Lycoperdon giganteum_. In this species the fructifyingmass consists of the same sinuous cavities, which are, however, smaller, so that the substance is more compact, and I have not seenthem traversed by any filaments. In an early stage of growth, thesurface of the hymenium, that is of the walls of the cavities, consists of short threads composed of two or three articulations, which are slightly constricted at the joints, from which, especiallyfrom the last, spring short branchlets, often consisting of asingle cell. Sometimes two or more branchlets spring from the samepoint. Occasionally the threads are constricted without anydissepiments, the terminal articulations are obtuse, and soon swellvery much, so as greatly to exceed in diameter those on which theyare seated. When arrived at their full growth, they are somewhatobovate, and produce four spicules, which at length are surmountedeach with a globose spore. When the spores are fully developed, thesporophores wither, and if a solution of iodine be applied, whichchanges the spores to a rich brown, they will be seen still adheringby their spicules to the faded sporophores. The spores soon becomefree, but the spicule often still adheres to them; but they are notattached to the intermingled filaments. In _Bovista plumbea_, thespores have very long peduncles. [U] As in the _Hymenomycetes_, theprevailing type of reproductive organs consisted of quaternaryspores borne on spicules; so in _Gasteromycetes_, the prevailingtype, in so far as it is yet known, is very similar, in some casesnearly identical, consisting of a definite number of minute sporesborne on spicules seated on basidia. In a very large number ofgenera, the minute structure and development of the fructification(beyond the mature spores) is almost unknown, but from analogy itmay be concluded that a method prevails in a large group like the_Myxogastres_ which does not differ in essential particulars from thatwhich is known to exist in other groups. The difficulties in the wayof studying the development of the spores in this are far greaterthan in the previous order. 

[Illustration: FIG. 10. --_a. _ Threads of _Trichia_. _b. _ Portion furthermagnified, with spores. _c. _ Portion of spinulose thread. ]

MYXOGASTRES. --At one time that celebrated mycologist, Professor DeBary, seemed disposed to exclude this group from the vegetable kingdomaltogether, and relegate them to a companionship with amoeboid forms. But in more recent works he seems to have reconsidered, and almost, ifnot entirely, abandoned, that disposition. These fungi, mostly minute, are characterized in their early stages by their gelatinous nature. The substance of which they are then composed bears considerableresemblance to sarcode, and, did they never change from this, theremight be some excuse for doubting as to their vegetable nature; but asthe species proceed towards maturity they lose their mucilaginoustexture, and become a mass of spores, intermixed with threads, surrounded by a cellular peridium. Take, for instance, the genus_Trichia_, and we have in the matured specimens a somewhat globoseperidium, not larger than a mustard seed, and sometimes nearly of thesame colour; this ultimately ruptures and exposes a mass of minuteyellow spherical spores, intermixed with threads of the samecolour. [V] These threads, when highly magnified, exhibit in themselvesa spiral arrangement, which has been the basis of some controversy, and in some species these threads are externally spinulose. The chiefcontroversy on these threads has been whether the spiral markings areexternal or internal, whether caused by twisting of the thread or bythe presence of an external or internal fibre. The spiral appearancehas never been called in question, only the structure from whence itarises, and this, like the striæ of diatoms, is very much an openquestion. Mr. Currey held that the spiral appearance may be accountedfor by supposing the existence of an accurate elevation in the wall ofthe cell, following a spiral direction from one end of the thread tothe other. This supposition would, he thinks, accord well with theoptical appearances, and it would account exactly for the undulationsof outline to which he alludes. He states that he had in hispossession a thread of _Trichia chrysosperma_, in which the spiralappearance was so manifestly caused by an elevation of this nature, inwhich it is so clear that no internal spiral fibre exists, that he didnot think there could be a doubt in the mind of any person carefullyexamining it with a power of 500 diameters that the cause of thespiral appearance was not a spiral fibre. In _Arcyria_, threads of adifferent kind are present; they mostly branch and anastomose, and areexternally furnished with prominent warts or spines, which Mr. Currey[W] holds are also arranged in a spiral manner around thethreads. In other Myxogastres, threads are also present without anyappreciable spiral markings or spines. In the mature condition ofthese fungi, they so clearly resemble, and have such close affinitieswith, the Trichogastres that one is led almost to doubt whether it wasnot on hasty grounds, without due examination or consideration, thatproposals were made to remove them from the society of their kindred. 

[Illustration: FIG. 11. --_Arcyria incarnata_, with portion of threads andspore, magnified. ]

Very little is known of the development of the spores in this group;in the early stages the whole substance is so pulpy, and in the latterso dusty, whilst the transition from one to the other is so rapid, that the relation between the spores and threads, and their mode ofattachment, has never been definitely made out. It has been supposedthat the spinulose projections from the capillitium in some speciesare the remains of pedicels from which, the spores have fallen, butthere is no evidence beyond this supposition in its favour, whilst onthe other hand, in _Stemonitis_, for instance, there is a profuseinterlacing capillitium, and no spines have been detected. In order tostrengthen the supposition, spines should be more commonly present. The threads, or capillitium, form a beautiful reticulated network in_Stemonitis_, _Cribraria_, _Diachæa_, _Dictydium_, &c. In _Spumaria_, _Reticularia_, _Lycogala_, &c. , they are almost obsolete. [X] In nogroup is the examination of the development of structure moredifficult, for the reasons already alleged, than in the Myxogastres. 

[Illustration: FIG. 12. --_Diachæa elegans. _]

[Illustration: FIG. 13. --_Cyathus vernicosus. _]

NIDULARIACEI. --This small group departs in some important particularsfrom the general type of structure present in the rest of theGasteromycetes. [Y] The plants here included may be described underthree parts, the mycelium, the peridium, and the sporangia. Themycelium is often plentiful, stout, rigid, interlacing, and coloured, running over the surface of the soil, or amongst the vegetable débrison which the fungi establish themselves. The peridia are seated uponthis mycelium, and in most instances are at length open above, takingthe form of cups, or beakers. These organs consist of three strata oftissue varying in structure, the external being fibrous, and sometimeshairy, the interior cellular and delicate, the intermediate thick andat length tough, coriaceous, and resistant. When first formed, theperidia are spherical, they then elongate and expand, the mouth beingfor some time closed by a veil, or diaphragm, which ultimatelydisappears. Within the cups lentil-shaped bodies are attached to thebase and sides by elastic cords. These are the sporangia. Each ofthese has a complicated structure; externally there is a filamentoustunic, composed of interlaced fibres, sometimes called the peridiole;beneath this is the cortex, of compact homogenous structure, thenfollows a cellular thicker stratum, bearing, towards the centre of thesporangia, delicate branched threads, or sporophores, on which, attheir extremities, the ovate spores are generated, sometimes in pairs, but normally, it would seem that they are quaternary on spicules, thethreads being true basidia. The whole structure is exceedinglyinteresting and peculiar, and may be studied in detail in Tulasne'smemoir on this group. 

SPHÆRONEMEI. --In this very large and, within certain limits, variableorder, there is but little of interest as regards structure, which isnot better illustrated elsewhere; as, for instance, some sort ofperithecium is always present, but this can be better studied in the_Sphæriacei_. The spores are mostly very minute, borne on delicatesporophores, which originate from the inner surface of the perithecia, but the majority of so-called species are undoubtedly conditions ofsphæriaceous fungi, either spermatogonia or pycnidia, and are of muchmore interest when studied in connection with the higher forms towhich they belong. [Z] Probably the number of complete and autonomousspecies are very few. 

[Illustration: FIG. 14. --_Cyathus. _ _a. _ Sporangium. _b. _ Section. _c. _Sporophore. _d. _ Spores. ]

MELANCONIEI. --Here, again, are associated together a great number ofwhat formerly were considered good species of fungi, but which arenow known to be but conditions of other forms. One great point ofdistinction between these and the preceding is the absence of anytrue perithecium, the spores being produced in a kind of spuriousreceptacle, or from a sort of stroma. The spores are, as a rule, larger and much more attractive than in _Sphæronemei_, and, insome instances, are either very fine, or very curious. Under thishead we may mention the multiseptate spores of _Coryneum_; thetri-radiate spores of _Asterosporium_; the curious crested spores of_Pestalozzia_; the doubly crested spores of _Dilophospora_; and thescarcely less singular gelatinous coated spores of _Cheirospora_. In all cases the fructification is abundant, and the spores frequentlyooze out in tendrils, or form a black mass above the spuriousreceptacle from which they issue. [a]

[Illustration: FIG. 15. --_Asterosporium Hoffmanni. _]

TORULACEI. --In this order there seems at first to be a considerableresemblance to the _Dematiei_, except that the threads are almostobsolete, and the plant is reduced to chains of spores, without traceof perithecium, investing cuticle, or definite stroma. Sometimes thespores are simple, in other cases septate, and in _Sporochisma_ are atfirst produced in an investing cell. In most cases simple threads atlength become septate, and are ultimately differentiated into spores, which separate at the joints when fully mature. 

[Illustration: FIG. 16. --Barren Cysts and Pseudospores of _Lecythea_. ]

[Illustration: FIG. 17. --_Coleosporium Tussilaginis_, Lev. ]

[Illustration: FIG. 18. --_Melampsora salicina. _]

CÆOMACEI. --Of far greater interest are the Coniomycetous parasiteson living plants. The present order includes those in which thespore[b] is reduced to a single cell; and here we may observe that, although many of them are now proved to be imperfect in themselves, and only forms or conditions of other fungals, we shall write of themhere without regard to their duality. These originate, for the mostpart, within the tissues of living plants, and are developed outwardsin pustules, which burst through the cuticle. The mycelium penetratesthe intercellular passages, and may sometimes be found in partsof the plants where the fungus does not develop itself. There is noproper excipulum or peridium, and the spores spring direct from amore compacted portion of the mycelium, or from a cushion-likestroma of small cells. In _Lecythea_, the sub-globose spores are atfirst generated at the tips of short pedicels, from which they areultimately separated; surrounding these spores arise a series ofbarren cells, or cysts, which are considerably larger the true spores, and colourless, while the spores are of some shade of yellow ororange. [c] In _Trichobasis_, the spores are of a similar character, sub-globose, and at first pedicellate; but there are no surroundingcysts, and the colour is more usually brown, although sometimesyellow. In _Uredo_, the spores are at first generated singly, withina mother cell; they are globose, and either yellow or brown, withoutany pedicel. In _Coleosporium_, there are two kinds of spores, those of a pulverulent nature, globose, which are sometimes producedalone at the commencement of the season, and others which originateas an elongated cell; this becomes septate, and ultimately separatesat the joints. During the greater part of the year, both kinds ofspores are to be found in the same pustule. In _Melampsora_, thewinter spores are elongated and wedge-shaped, compacted togetherclosely, and are only matured during winter on dead leaves; the summerspores are pulverulent and globose, being, in fact, what were untilrecently regarded as species of _Lecythea_. In _Cystopus_, the sporesare sub-globose, or somewhat angular, generated in a moniliformmanner, and afterwards separating at the joints. The upper spore isalways the oldest, continuous production of spores going on for sometime at the base of the chain. Under favourable conditions ofmoisture, each of these spores, or conidia, as De Bary terms them, iscapable of producing within itself a number of zoospores;[d] theseultimately burst the vesicle, move about by the aid of vibratilecilia, and at last settle down to germinate. Besides these, otherreproductive bodies are generated upon the mycelium, within thetissues of the plant, in the form of globose oogonia, or restingspores, which, when mature, also enclose great numbers of zoospores. Similar oogonia are produced amongst the _Mucedines_ in the genus_Peronospora_, to which De Bary considers _Cystopus_ to be closelyallied. At all events, this is a peculiarity of structure anddevelopment not as yet met with in any other of the _Cæomacei_. In_Uromyces_ is the nearest approach to the _Pucciniæi_; in fact, it is_Puccinia_ reduced to a single cell. The form of spore is usuallymore angular and irregular than in _Trichobasis_, and the pedicel ispermanent. It may be remarked here, that of the foregoing genera, many of the species are not autonomous that have hitherto beenincluded amongst them. This is especially true of _Lecythea_, _Trichobasis_, and, as it now appears, of _Uromyces_. [e]

[Illustration: FIG. 19. --_Cystopus candidus. _]

[Illustration: FIG. 20. --_Xenodochus carbonarius. _]

[Illustration: FIG. 21. --_Phragmidium bulbosum. _]

PUCCINIÆI. --This group differs from the foregoing chiefly in havingseptate spores. The pustules, or sori, break through the cuticle in asimilar manner, and here also no true peridium is present. In_Xenodochus_, the highest development of joints is reached, eachspore being composed of an indefinite number, from ten to twentycells. With it is associated an unicellular yellow Uredine, of whichit is a condition. Probably, in every species of the _Pucciniæi_, itmay hereafter be proved, as it is now suspected, that an unicellularUredine precedes or is associated with it, forming a condition, orsecondary form of fruit of that species. Many instances of that kindhave already been traced by De Bary, [f] Tulasne, and others, and somehave been a little too rashly surmised by their followers. In_Phragmidium_, the pedicel is much more elongated than in _Xenodochus_, and the spore is shorter, with fewer and a more definite number ofcells for each species; Mr. Currey is of opinion that each cell ofthe spore in _Phragmidium_ has an inner globose cell, which he causedto escape by rupture of the outer cell wall as a sphæroid nucleus, [g]leading to the inference that each cell has its own individual powerof germination and reproduction. In _Triphragmium_, there are threecells for each spore, two being placed side by side, and onesuperimposed. In one species, however, _Triphragmium deglubens_(North American), the cells are arranged as in _Phragmidium_, so thatthis represents really a tricellular _Phragmidium_, linking the presentwith the latter genus. In _Puccinia_ the number of species is by far themost numerous; in this genus the spores are uniseptate, and, as inall the _Pucciniæi_, the peduncles are permanent. There is greatvariability in the compactness of the spores in the sori, or pulvinules. In some species, the sori are so pulverulent that the spores are asreadily dispersed as in the Uredines, in others they are so compact asto be separated from each other with great difficulty. As might beanticipated, this has considerable effect on the contour of the spores, which in pulverulent species are shorter, broader, and more ovate thanin the compact species. If a section of one of the more compact sori bemade, it will be seen that the majority of the spores are side by side, nearly at the same level, their apices forming the external surfaceof the sori, but it will not be unusual to observe smaller andyounger spores pushing up from the hymenial cells, between thepeduncles of the elder spores, leading to the inference that there is asuccession of spores produced in the same pulvinule. In _Podisoma_, arather anomalous genus, the septate spores are immersed in agelatinous stratum, and some authors have imagined that they have anaffinity with the Tremellini, but this affinity is more apparent thanreal. The phenomena of germination, and their relations to _Roestelia_, if substantiated, establish their claim to a position amongst the_Pucciniæi_. [h] It seems to us that _Gymnosporangium_ does not differgenerically from _Podisoma_. In a recently-characterized species, _Podisoma Ellisii_, the spores are bi-triseptate. This is, moreover, peculiar from the great deficiency in the gelatinous element. Inanother North American species, called _Gymnosporangium biseptatum_, Ellis, which is distinctly gelatinous, there are similar biseptatespores, but they are considerably broader and more obtuse. In otherdescribed species they are uniseptate. 

[Illustration: FIG. 22. --Pseudospores of _Puccinia_. ]

USTILAGINEI. --These fungi are now usually treated as distinct from the_Cæomacei_, to which they are closely related. [i] They are alsoparasitic on growing plants, but the spores are usually black orsooty, and never yellow or orange; on an average much smaller than inthe _Cæomacei_. In _Tilletia_, the spores are spherical andreticulated, mixed with delicate threads, from whence they spring. Inthe best known species, _Tilletia caries_, they constitute the "bunt"of wheat. The peculiarities of germination will be alluded tohereafter. In _Ustilago_, the minute sooty spores are developed eitheron delicate threads or in compacted cells, arising first from a sortof semi-gelatinous, grumous stroma. It is very difficult to detect anythreads associated with the spores. The species attack the flowers andanthers of composite and polygonaceous plants, the leaves, culms, andgermen of grasses, &c. , and are popularly known as "smuts. " In_Urocystis_ and _Thecaphora_, the spores are united together intosub-globose bodies, forming a kind of compound spore. In some speciesof _Urocystis_, the union which subsists between them is comparativelyslight. In _Thecaphora_, on the contrary, the complex spore, oragglomeration of spores, is compact, being at first apparentlyenclosed in a delicate cyst. In _Tuburcinia_, the minute cells arecompacted into a hollow sphere, having lacunæ communicating with theinterior, and often exhibiting the remains of a pedicel. 

[Illustration: FIG. 23. --_Thecaphora hyalina. _]

[Illustration: FIG. 24. --_Æcidium Berberidis. _]

ÆCIDIACEI. --This group differs from the foregoing three groupsprominently in the presence of a cellular peridium, which enclosesthe spores; hence some mycologists have not hesitated to proposetheir association with the Gasteromycetes, although every otherfeature in their structure seems to indicate a close affinitywith the _Cæomacei_. The pretty cups in the genus _Æcidium_ aresometimes scattered and sometimes collected in clusters, either withspermogonia in the centre or on the opposite surface. The cupsare usually white, composed of regularly arranged bordered cellsat length bursting at the apex, with the margins turned back andsplit into radiating teeth. The spores are commonly of a brightorange or golden yellow, sometimes white or brownish, and areproduced in chains, or moniliform strings, slightly attached toeach other, [j] and breaking off at the summit at the same time thatthey continue to be produced at the base, so that for some timethere is a successive production of spores. The spermogonia arenot always readily detected, as they are much smaller than theperidia, and sometimes precede them. The spermatia are expelledfrom the lacerated and fringed apices, and are very minute andcolourless. In _Roestelia_ the peridia are large, growing incompany, and splitting longitudinally in many cases, or by alacerated mouth. In most instances, the spores are brownish, butin a splendid species from North America (_Roestelia aurantiaca_, Peck), recently characterized, they are of a bright orange. IfOersted is correct in his observations, which await confirmation, these species are all related to species of _Podisoma_ as asecondary form of fruit. [k] In the _Roestelia_ of the pear-tree, aswell as in that of the mountain ash, the spermogonia will be foundeither in separate tufts on discoloured spots, or associated withthe _Roestelia_, In _Peridermium_ there is very little structuraldifference from _Roestelia_, and the species are all found onconiferous trees. In _Endophyllum_, the peridia are immersed in thesucculent substance of the matrix; whilst in _Graphiola_, there isa tougher and withal double peridium, the inner of which forms atuft of erect threads resembling a small brush. [l]

[Illustration: FIG. 25. --_Helminthosporium molle. _]

HYPHOMYCETES. --The predominant feature in the structure of this orderhas already been intimated to consist in the development of thevegetative system under the form of simple or branched threads, onwhich the fruit is generated. The common name of mould is applied tothem perhaps more generally than to other groups, although the term istoo vague, and has been too vaguely applied to be of much service ingiving an idea of the characteristics of this order. Leaving thesmaller groups, and confining ourselves to the _Dematiei_ and the_Mucedines_, we shall obtain some notion of the prevalent structure. In the former the threads are more or less carbonized, in the latternearly colourless. One of the largest genera in _Dematiei_ is_Helminthosporium_. It appears on decaying herbaceous plants, and onold wood, forming effused black velvety patches. The mycelium, ofcoloured jointed threads, overlays and penetrates the matrix; fromthis arise erect, rigid, and usually jointed threads, of a dark brown, nearly black colour at the base, but paler towards the apex. In mostcases these threads have an externally cortical layer, which impartsrigidity; usually from the apex, but sometimes laterally, the sporesare produced. Although sometimes colourless, these are most commonlyof some shade of brown, more or less elongated, and dividedtransversely by few or many septa. In _Helminthosporium Smithii_, thespores much exceed the dimensions of the threads;[m] in other speciesthey are smaller. In _Dendryphium_, the threads and spores are verysimilar, except that the threads are branched at their apex, and thespores are often produced one at the end of another in a shortchain. [n] In _Septosporium_ again, the threads and spores are similar, but the spores are pedicellate, and attached at or near the base;whilst in _Acrothecium_, with similar threads and spores, the latterare clustered together at the apex of the threads. In _Triposporium_, the threads are similar, but the spores are tri-radiate; and in_Helicoma_, the spores are twisted spirally. Thus, we might passthrough all the genera to illustrate this chief feature of coloured, septate, rather rigid, and mostly erect threads, bearing at some pointspores, which in most instances are elongated, coloured, and septate. 

[Illustration: FIG. 26. --_Acrothecium simplex. _]

[Illustration: FIG. 27. --_Peronospora Arenariæ. _]

MUCEDINES. --Here, on the other hand, the threads, if coloured at all, are still delicate, more flexuous, with much thinner walls, and neverinvested with an external cortical layer. One of the most importantand highly developed genera is _Peronospora_, the members of which areparasitic upon and destructive of living vegetables. It is to thisgenus that the mould of the too famous potato disease belongs. Professor De Bary has done more than any other mycologist in theinvestigation and elucidation of this genus; and his monograph is amasterpiece in its way. [o] He was, however, preceded by Mr. Berkeley, and more especially by Dr. Montagne, by many years in elucidation ofthe structure of the flocci and conidia in a number of species. [p] Inthis genus, there is a delicate mycelium, which penetrates theintercellular passages of living plants, giving rise to erect branchedthreads, which bear at the tips of their ultimate ramuli, sub-globose, ovate, or elliptic spores, or, as De Bary terms them--conidia. Deeplyseated on the mycelium, within the substance of the foster plant, other reproductive bodies, called oogonia, originate. These arespherical, more or less warted and brownish, the contents of whichbecome differentiated into vivacious zoospores, capable, whenexpelled, of moving in water by the aid of vibratile cilia. A similarstructure has already been indicated in _Cystopus_, otherwise it israre in fungi, if the _Saprolegniei_ be excluded. In _Botrytis_ and in_Polyactis_, the flocci and spores are similar, but the branches ofthe threads are shorter and more compact, and the septa are morecommon and numerous; the oogonia also are absent. De Bary has selected_Polyactis cinerea_, as it occurs on dead vine leaves, to illustratehis views of the dualism which he believes himself to have discoveredin this species. "It spreads its mycelium in the tissue which isbecoming brown, " he writes, "and this shows at first essentially thesame construction and growth as that of the mycelium filaments of_Aspergillus_. " On the mycelium soon appear, besides those which arespread over the tissue of the leaves, strong, thick, mostlyfasciculate branches, which stand close to one another, breaking forthfrom the leaf and rising up perpendicularly, the conidia-bearers. Theygrow about 1 _mm. _ long, divide themselves, by successively risingpartitions, into some prominent cylindrical linked cells, and thentheir growth is ended, and the upper cell produces near its pointthree to six branches almost standing rectangularly. Of these theunder ones are the longest, and they again shoot forth from undertheir ends one or more still shorter little branches. The nearer theyare to the top, the shorter are the branches, and less divided; theupper ones are quite branchless, and their length scarcely exceeds thebreadth of the principal stem. Thus a system of branches appears, uponwhich, on a small scale, a bunch of grapes is represented. All thetwigs soon end their growth; they all separate their inner space fromthe principal stem, by means of a cross partition placed close to it. All the ends, and also that of the principal stem, swell about thesame time something like a bladder, and on the upper free half of eachswelling appear again, simultaneously, several fine protuberances, close together, which quickly grow to little oval bladders filled withprotoplasm, and resting on their bearers with a sub-sessile, pedicellate, narrow basis, and which at length separate themselvesthrough a partition as in _Aspergillus_. The detached cells are theconidia of our fungus; only one is formed on each stalk. When theformation is completed in the whole of the panicle, the littlebranches which compose it are deprived of their protoplasm in favourof the conidia; it is the same with the under end of the principalstem, the limits of which are marked by a cross partition. Thedelicate wall of these parts shrinks up until it is unrecognizable;all the conidia of the panicle approach one another to form anirregular grape-like bunch, which rests loosely on the bearer, andfrom which it easily falls away as dust. If they be brought into waterthey fall off immediately; only the empty, shrivelled, delicate skinsare to be found on the branch which bore them, and the places on whichthey are fixed to the principal stem clearly appear as roundcircumscribed hilums, generally rather arched towards the exterior. The development of the main stem is not ended here. It remains solidand filled with protoplasm as far as the portion which forms the endthrough its conidia. Its end, which is to be found among these pieces, becomes pointed after the ripening of the first panicle, pushes theend of the shrivelled member on one side, and grows to the same lengthas the height of one or two panicles, and then remains still, to forma second panicle similar to the first. This is later equallyperfoliated as the first, then a third follows, and thus a largenumber of panicles are produced after and over one another on the samestem. In perfect specimens, every perfoliated panicle hangs loosely toits original place on the surface of the stem, until by shaking or theaccess of water to it, it falls immediately into the single conidia, or the remains of branches, and the already-mentioned oval hilums areleft behind. Naturally, the stem becomes longer by every perfoliation;in luxuriant specimens the length can reach that of some lines. Itspartition is already, by the ripening of the first panicle from thebeginning of its foundation, strong and brown; it is only colourlessat the end which is extending, and in all new formations. During allthese changes the filament remains either unbranched, except asregards the transient panicles, or it sends out here and there, at theperfoliated spots, especially from the lower ones, one or two strongbranches, standing opposite one another and resembling the principalstem. 

[Illustration: FIG. 28. --_Polyactis cinerea. _ _a. _ Apex of hypha. ]

The mycelium, which grows so exuberantly in the leaf, often bringsforth many other productions, which are called _sclerotia_, and are, according to their nature, a thick bulbous tissue of myceliumfilaments. Their formation begins with the profuse ramification of themycelium threads in some place or other; generally, but not always, inthe veins of the leaf; the intertwining twigs form an uninterruptedcavity, in which is often enclosed the shrivelling tissue of the leaf. The whole body swells to a greater thickness than that of the leaf, and protrudes on the surface like a thickened spot. Its form variesfrom circular to fusiform; its size is also very unequal, rangingbetween a few lines and about half a millimetre in its largestdiameter. At first it is colourless, but afterwards its outer layersof cells become round, of a brown or black colour, and it issurrounded by a black rind, consisting of round cells, which separateit from the neighbouring tissue. The tissue within the rind remainscolourless; it is an entangled uninterrupted tissue of fungusfilaments, which gradually obtain very solid, hard, cartilaginouscoats. The sclerotium, which ripens as the rind becomes black, loosensitself easily from the place of its formation, and remains preservedafter the latter is decayed. 

[Illustration: FIG. 29. --_Peziza Fuckeliana. _ _a. _ Natural size. _b. _Section enlarged. _c. _ Ascus and sporidia. ]

The sclerotia are, here as in many other fungi, biennial organs, designed to begin a new vegetation after a state of apparent quietude, and to send forth special fruit-bearers. They may in this respect becompared to the bulbs and perennial roots of under shrubs. The usualtime for the development of the sclerotia is late in the autumn, after the fall of the vine leaves. As long as the frost does not setin, new ones continually spring up, and each one attains to ripenessin a few days. If frost appears, it can lie dry a whole year, withoutlosing its power of development. This latter commences when thesclerotium is brought into contact with damp ground during the usualtemperature of our warmer seasons. If this occur soon, at the latestsome weeks after it is ripe, new vegetation grows very quickly, generally after a few days; in several parts the colourless filamentsof the inner tissue begin to send out clusters of strong branches, which, breaking through the black rind, stretch themselves upperpendicularly towards the surface, separate from one another, andthen take all the characteristics of the conidia-bearers. Many suchclusters can be produced on one sclerotium, so that soon the greaterpart of the surface is covered by filamentous conidia-bearers withtheir panicles. The colourless tissue of the sclerotium disappears inthe same degree as the conidia-bearers grow, and at last the blackrind remains behind empty and shrivelled. If we bring, after manymonths, for the first time, the ripe sclerotium, in damp ground, insummer or autumn, after it has ripened, the further development takesplace more slowly, and in an essentially different form. It is truethat from the inner tissue numerous filamentous branches shoot forthat the cost of this growing fascicle, and break through the blackrind, but its filaments remain strongly bound, in an almost parallelsituation, to a cylindrical cord, which for a time lengthens itselfand spreads out its free end to a flat plate-like disc. This is alwaysformed of strongly united threads, ramifications of the cylindricalcord. On the free upper surface of the disc, the filaments shoot forthinnumerable branches, which, growing to the same height, thick andparallel with one another, cover the before-named disc. Some remainnarrow and cylindrical, are very numerous, and produce fine hairs(paraphyses); others, also very numerous, take the form of club-likeampulla cells, and each one forms in its interior eight free swimmingoval spores. Those ampulla cells are sporidiiferous asci. After thespores have become ripe, the free point of the utricle bursts, and thespores are scattered to a great distance by a mechanism which we willnot here further describe. New ampullas push themselves between thosewhich are ripening and withering; a disc can, under favourablecircumstances, always form new asci for weeks at a time. The number ofthe already described utricle-bearers is different, according to thesize of the sclerotium; smaller specimens usually produce only one, larger two to four. The size is regulated by that of the sclerotia, and ranges, in full-grown specimens, between one and more millimetresfor the length of the stalk, and a half to three (seldom more)millimetres for the breadth of the disc. [q] For some time the conidiaform, belonging to the Mucedines, has been known as _Botrytis cinerea_(or _Polyactis cinerea_). The compact mycelium, or sclerotium, as animperfect fungus, bore the name of _Sclerotium echinatum_, whilst tothe perfect and cup-like form has been given the name of _PezizaFuckeliana_. We have reproduced De Bary's life-history of this mouldhere, as an illustration of structure in the _Mucedines_, buthereafter we shall have to write of similar transformations whentreating of polymorphism. 

The form of the threads, and the form and disposition of the spores, vary according to the genera of which this order is composed. In_Oidium_ the mostly simple threads break up into joints. Many of theformer species are now recognized as conditions of _Erysiphe_. In_Aspergillus_, the threads are simple and erect, with a globose head, around which are clustered chains of simple spores. In _Penicillium_, the lower portion of the threads is simple, but they are shortlybranched at the apex, the branches being terminated by necklaces ofminute spores. In _Dactylium_, the threads are branched, but thespores are collected in clusters usually, and are moreover septate. Inother genera similar distinctions prevail. These two groups of blackmoulds and white moulds are the noblest, and contain the largestnumber of genera and species amongst the _Hyphomycetes_. There is, however, the small group of _Isariacei_, in which the threads arecompacted, and a semblance of such hymenomycetal forms as _Clavaria_and _Pterula_ is the result, but it is doubtful if this group containsmany autonomous species. In another small group, the _Stilbacei_, there is a composite character in the head, or receptacle, [r] and inthe stem when the latter is present. Many of these, again, as_Tubercularia_, _Volutella_, _Fusarium_, &c. , contain doubtfulspecies. In _Sepedoniei_ and _Trichodermacei_, the threads are reducedto a minimum, and the spores are such a distinctive element thatthrough these groups the _Hyphomycetes_ are linked with the_Coniomycetes_. These groups, however, are not of sufficient size orimportance to demand from us, in a work of this character, anythingmore than the passing allusion which we have given to them. 

[Illustration: FIG. 30. --_Penicillium chartarum_, Cooke. ]

We come now to consider the structure in the Sporidiifera, in whichthe fructifying corpuscles or germs, whether called spores orsporidia, are generated within certain privileged cysts, usually indefinite numbers. In systematic works, these are included under twoorders, the _Physomycetes_ and the _Ascomycetes_. The former of theseconsists of cyst-bearing moulds, and from their nearest affinity tothe foregoing will occupy the first place. 

[Illustration: FIG. 31. --_Mucor mucedo_, with three sporangia. _a. _Portion of frill with sporangiola. ]

PHYSOMYCETES include, especially amongst the _Mucorini_, many mostinteresting and instructive species for study, which even very latelyhave occupied the attention of continental mycologists. Most of thesephenomena are associated more or less with reproduction, and as suchwill have to be adverted to again, but there are points in thestructure which can best be alluded to here. Again taking Professor deBary's researches as our guide, [s] we will illustrate this by thecommon _Mucor mucedo_: If we bring quite fresh horse-dung into a dampconfined atmosphere, for example, under a bell-glass, there appears onits surface, after a few days, an immense white mildew. Upright strongfilaments of the breadth of a hair raise themselves over the surface, each of them soon shows at its point a round little head, whichgradually becomes black, and a closer examination shows us that in allprincipal points it perfectly agrees with the sporangia of otherspecies. Each of these white filaments is a sporangia-bearer. Theyspring from a mycelium which is spread in the dung, and appear singlyupon it. Certain peculiarities in the form of the sporangium, and thelittle long cylindrical spores, which, when examined separately, arequite flat and colourless, are characteristic of the species. If thelatter be sown in a suitable medium, for example, in a solution ofsugar, they swell, and shoot forth germinating utricles, which quicklygrow to mycelia, which bear sporangia. This is easily produced on themost various organic bodies, and _Mucor mucedo_ is therefore foundspontaneously on every substratum which is capable of nourishingmildew, but on the above-named the most perfect and exuberantspecimens are generally to be found. The sporangia-bearers are atfirst always branchless and without partitions. After the sporangiumis ripe, cross partitions in irregular order and number often appearin the inner space, and on the upper surface branches of differentnumber and size, each of which forms a sporangium at its point. Thesporangia which are formed later are often very similar, but sometimesvery different, to those which first appeared, because their partitionis very thick and does not fall to pieces when it is ripe, butirregularly breaks off, or remains entire, enclosing the spores, andat last falls to the ground, when the fungus withers. The crosspartition which separates the sporangia from its bearers is in thosewhich are first formed (which are always relatively thicker sporangia)very strongly convex, while those which follow later are oftensmaller, and in little weak specimens much less arched, and sometimesquite straight. After a few days, similar filaments generally showthemselves on the dung between the sporangia-bearers, which appear tothe naked eye to be provided with delicate white frills. Where such anone is to be found, two to four rectangular expanding little branchesspring up to the same height round the filament. Each of these, aftera short and simple process, branch out into a furcated form; thefurcations being made in such a manner that the ends of the branch atlast so stand together that their surface forms a ball. Finally, eachof the ends of a branch swells to a little round sporangium, which islimited by a partition (called sporangiolum, to distinguish it fromthe larger ones), in which some, generally four, spores are formed inthe manner already known. When the sporangiola are alone, they havesuch a peculiar appearance, with their richly-branched bearers, thatthey can be taken for something quite different to the organs of the_Mucor mucedo_, and were formerly not considered to belong to it. Thatthey really belong to the _Mucor_ is shown by the principal filamentwhich it bears, not always, but very often, ending with a largesporangium, which is characteristic of the _Mucor mucedo_; it is stillmore evident if we sow the spores of the sporangiolum, for, as itgerminates, a mycelium is developed, which, near a simple bearer, canform large sporangia, and those form sporangiola, the first alwaysconsiderably preponderating in number, and very often exclusively. Ifwe examine a large number of specimens, we find every possible middleform between the simple or less branched sporangia-bearers and thetypical sporangiola frills; and we arrive at last at the conclusionsimply to place the latter among the varieties of form which thesporangia-bearer of the _Mucor mucedo_ shows, like every other typicalorganic form within certain limits. On the other hand, propagationorgans, differing from those of the sporangia and their products, belong to _Mucor mucedo_, which may be termed conidia. On the dung(they are rare on any other substance) these appear at the same time, or generally somewhat later, than the sporangia-bearers, and are notunlike those to the naked eye. In a more accurate examination, theyappear different; a thicker, partition-less filament rises up anddivides itself, generally three-forked, at the length of onemillimetre, into several series of branchlets. The forked branches ofthe last series bear under their points, which are mostly capillary, short erect little ramuli, and these, with which the ends of theprincipal branches articulate on their somewhat broad tops, severalspores and conidia, near one another; about fifteen to twenty areformed at the end of each little ramulus. The peculiarities andvariations which so often appear in the ramification need not bediscussed here. After the articulation of the conidia, their bearerssink together by degrees, and are quite destroyed. The ripe conidiaare round like a ball, their surface is scarcely coloured, and almostwholly smooth. These conidioid forms were at first described as aseparate species under the name of _Botrytis Jonesii_. How, then, dothey belong to the _Mucor_?[t] That they appear gregariously is aslittle proof of an original relation to one another, here aselsewhere. Attempts to prove that the conidia and sporangia-bearersoriginate on one and the same mycelium filament may possibly hereaftersucceed. Till now this has not been the case, and he who has evertried to disentangle the mass of filaments which exuberantly coversthe substratum of a _Mucor_ vegetation, which has reached so far as toform conidia, will not be surprised that all attempts have hithertoproved abortive. The suspicion of the connection founded on thegregariously springing up, and external resemblance, is fullyjustified, if we sow the conidia in a suitable medium, for example, ina solution of sugar. They here germinate and produce a mycelium whichexactly resembles that of the _Mucor mucedo_, and, above all, theyproduce in profusion the typical sporangia of the same on its bearers. The latter are till now alone reproductions of conidia-bearers, andhave never been observed on mycelia which have grown out of conidia. 

[Illustration: FIG. 32. --Small portion of _Botrytis Jonesii_. ]

These phenomena of development appear in the _Mucor_ when it dwells ona damp substance, which must naturally contain the necessarynourishment for it, and is exposed to the atmospheric air. Itsmycelium represents at first strong branched utricles withoutpartitions; the branches are of the higher order, mostly divided intorich and very fine-pointed ramuli. In old mycelium, and also in thesporangia-bearers, the contents of which are mostly used for theformation of spores, and the substratum of which is exhausted for ourfungus, short stationary pieces, filled with protoplasm, are veryoften formed into cells through partitions in order to produce spores, that is, grow to a new fruitful mycelium. These cells are calledgemmules, brooding cells, and resemble such vegetable buds and sproutsof foliaceous plants which remain capable of development after theorgans of vegetation are dead, in order to grow, under suitablecircumstances, to new vegetating plants, as, for example, the bulbs ofonions, &c. 

If we bring a vegetating mycelium of _Mucor mucedo_ into a mediumwhich contains the necessary nourishment for it, but excluded from thefree air, the formation of sporangia takes place very sparingly or notat all, but that of gemmules is very abundant. Single interstitialpieces of the ramuli, or even whole systems of branches, are quitefilled with a rich greasy protoplasm; the short pieces and ends arebound by partitions which form particular, often tun-like or globularcells; the longer ones are changed, through the formation of crosspartitions, into chains of similar cells; the latter often attain bydegrees strong, thick walls, and their greasy contents often pass intoinnumerable drops of a very regular globular form and of equal size. Similar appearances show themselves after the sowing of spores, whichare capable of germinating in the medium already described, from whichthe air is excluded. Either short germinating utricles shoot forth, which soon form themselves into rows of gemmules, or the spores swellto large round bladders filled with protoplasm, and shoot forth onvarious parts of their surface innumerable protuberances, which, fixing themselves with a narrow basis, soon become round vesiculatecells, and on which the same sprouts which caused their production arerepeated, formations which remind us of the fungus of fermentationcalled globular yeast. Among all the known forms of gemmules we find avariety which are intermediate, all of which show, when brought into anormal condition of development, the same proportion, and the samegermination, as those we first described. 

We have detailed rather at length the structure and development of oneof the most common of the Mucors, which will serve as an illustrationof the order. Other distinctions there may be which are of moreinterest as defining the limits of genera, except such as may benoticed when we come to write more specially of reproduction. 

ASCOMYCETES. --Passing now to the _Ascomycetes_, which are especiallyrich in genera and species, we must first, and but superficially, allude to _Tuberacei_, an order of sporidiiferous fungi of subterraneanhabit, and rather peculiar structure. [u] In this order an externalstratum of cells forms a kind of perithecium, which is more or lessdeveloped in different genera. This encloses the hymenium, which issinuous, contorted, and twisted, often forming lacunæ. The hymenium insome genera consists of elongated, nearly cylindrical asci, enclosing adefinite number of sporidia; in the true truffles and theirimmediate allies, the asci are broad sacs, containing very large andbeautiful, often coloured, sporidia. These latter have either asmooth, warted, spinulose, or lacunose epispore, and, as will be seenfrom the figures in Tulasne's Monograph, [v] or those in the lastvolume of Corda's great work, [w] are attractive microscopical objects. In some cases, it is not difficult to detect paraphyses, but inothers they would seem to be entirely absent. A comparatively largenumber have been discovered and recorded in Great Britain, [x] but ofthose none are more suitable for study of general structure than theordinary truffle of the markets. 

The structure of the remaining Ascomycetes can be studied under twogroups, _i. E. _, the fleshy Ascomycetes, or, as they have been termed, the Discomycetes, and the hard, or carbonaceous Ascomycetes, sometimes called the Pyrenomycetes. Neither of these names gives anaccurate idea of the distinctions between the two groups, in theformer of which the discoid form is not universal, and the lattercontains somewhat fleshy forms. But in the Discomycetes thehymenium soon becomes more or less exposed, and in the latter it isenclosed in a perithecium. The Discomycetes are of two kinds, thepileate and the cup-shaped. Of the pileate such a genus as _Gyromitra_or _Helvella_ is, in a certain sense, analogous to the Agaricsamongst _Hymenomycetes_, with a superior instead of an inferiorhymenium, and enclosed, not naked, spores. Again, _Geoglossum_ issomewhat analogous to _Clavaria_. Amongst the cup-shaped, _Peziza_is an Ascomycetous _Cyphella_. But these are perhaps more fancifulthan real analogies. 

Recently Boudier has examined one group of the cup-shaped Discomycetes, the _Ascobolei_, and, by making a somewhat free use of his Memoir, [y] wemay arrive at a general idea of the structure in the cupulateDiscomycetes. They present themselves at first under the form of asmall rounded globule, and almost entirely cellular. This smallglobule, the commencement of the receptacle, is not long in increasing, preserving its rounded form up to the development of the asci. At thisperiod, under the influence of the rapid growth of these organs, it soonproduces at its summit a fissure of the external membrane, whichbecomes a more marked depression in the marginate species. Thereceptacle thus formed increases rapidly, becomes plane, more convex, or more or less undulated at the margin, if at all of large size. Fixed to the place where it is generated by some more or lessabundant mycelioid filaments, the receptacle becomes somewhatcup-shaped and either stipitate or sessile, composed of thereceptacle proper and the hymenium. 

[Illustration: FIG. 33. --Section of cup of _Ascobolus_. _a. _ Externalcells. _b. _ Secondary layer. _c. _ Subhymenial tissue (Janczenski). ]

The receptacle proper comprehends the subhymenial tissue, theparenchyma, and the external membrane. The subhymenial tissue iscomposed of small compact cells, forming generally a more coloured anddense stratum, the superior cells of which give rise to the asci andparaphyses. The parenchyma is seated beneath this, and is generally ofinterlaced filaments, of a looser consistency than the preceding, united by intermediate cellules. The external membrane, whichenvelopes the parenchyma, and limits the hymenium, differs from thepreceding by the cells often being polyhedric, sometimes transverse, and united together, and sometimes separable. Externally it issometimes smooth, and sometimes granular or hairy. 

The hymenium is, however, the most, important part, consisting of (1)the paraphyses, (2) the asci, and sometimes (3) an investing mucilage. The asci are always present, the paraphyses are sometimes rare, andthe mucilage in many cases seems to be entirely wanting. 

The paraphyses, which are formed at the first commencement of thereceptacle, are at first very short, but soon elongate, and becomewholly developed before the appearance of the asci. They are linear, sometimes branched and sometimes simple, often more or less thickenedat their tips; almost always they contain within them some oleaginousgranules, either coloured or colourless. Their special function seemsstill somewhat obscure, and Boudier suggests that they may beexcitatory organs for the dehiscence of the asci. However this may be, some mycologists are of opinion that, at least in some of theAscomycetes, the paraphyses are abortive asci, or, at any rate, thatabortive asci mixed with the paraphyses cannot be distinguished fromthem. 

The mucilage forms itself almost at the same time as the paraphyses, and previous to the formation of the asci. This substance appears as acolourless or yellowish mucilage, which envelopes the paraphyses andasci, and so covers the hymenium with a shining coat. 

The asci appear first at the base of the paraphyses, under the form ofoblong cells, filled with colourless protoplasm. By rapid growth, theysoon attain a considerable size and fulness, the protoplasm beinggradually absorbed by the sporidia, the first indication of which isalways the central nucleus. The mucilage also partly disappears, andthe asci, attaining their maturity, become quite distinct, eachenclosing its sporidia. But before they take their complete growththey detach themselves from the subhymenial tissue, and beingattenuated towards their base, are forced upwards by pressure of theyounger asci, to, and in some instances beyond, the upper surface ofthe disc. This phenomenon commences during the night, and continuesduring the night and all the morning. It attains its height atmid-day, and it is then that the slightest breath of air, theslightest movement, suffices to cause dehiscence, which is generallyfollowed by a scarcely perceptible contractile motion of thereceptacle. 

[Illustration: FIG. 34. --Asci, sporidia, and paraphyses of _Ascobolus_(Boudier). ]

There is manifestly a succession in formation and maturity of the asciin a receptacle. In the true _Ascobolei_, in which the sporidia arecoloured, this may be more distinctly seen. At first some thinprojecting points appear upon the disc, the next day they are morenumerous, and become more and more so on following days, so as torender the disc almost covered with raised black or crystallinepoints;[z] these afterwards diminish day by day, until they ultimatelycease. The asci, after separation from the subhymenial tissue, continue to lengthen, or it may be that their elasticity permits ofextension, during expulsion. Boudier considers that an amount ofelasticity is certain, because he has seen an ascus arrive atmaturity, eject its spores, and then make a sharp and considerablemovement of retraction, then the ascus returned again, immediatelytowards its previous limits, always with a reduction in the number ofits contained sporidia. 

The dehiscence of the asci takes place in the _Ascobolei_, in somespecies of _Peziza_, _Morchella_, _Helvella_, and _Verpa_, by means ofan apical operculum, and in other _Pezizæ_, _Helotium_, _Geoglossum_, _Leotia_, _Mitrula_, &c. , by a fissure of the ascus. This operculummay be the more readily seen when the ascus is coloured by a drop oftincture of iodine. 

The sporidia are usually four or eight, or some multiple of thatnumber, in each ascus, rarely four, most commonly eight. At a fixedtime the protoplasm, which at first filled the asci, disappears or isabsorbed in a mucilaginous matter, which occupies its place, in themidst of which is a small nucleus, which is the rudiment of the firstspore; other spores are formed consecutively, and then the substanceseparates into as many sections as there are sporidia. From thisperiod each sporidium seems to have a separate existence. All have anucleus, which is scarcely visible, often slightly granular, but whichis quite distinct from the oleaginous sporidioles so frequent amongstthe Discomycetes, and which are sometimes called by the same name. Thesporidia are at first a little smaller than when mature, and aresurrounded by mucilage. After this period the sporidia lose theirnebulous granulations, whilst still preserving their nucleus; theiroutlines are distinct, and, amongst the true _Ascobolei_, commenceacquiring a rosy colour, the first intimation of maturity. This colourmanifests itself rapidly, accumulating exclusively upon the epispore, which becomes of a deep rose, then violet, and finally violet blue, sodeep as sometimes to appear quite black. There are some modificationsin this coloration, since, in some species, it passes from a vinousred to grey, then to black, or from rose-violet to brown. 

The epispore acquires a waxy consistence by this pigmentation, so thatit may be detached in granules. It is to this particular consistencyof the epispore that the cracks so frequent in the coloured sporidiaof _Ascobolus_ are due, through contraction of the epispore. As theyapproach maturity, the sporidia accumulate towards the apex of theasci, and finally escape in the manner already indicated. 

In all essential particulars there is a great similarity in thestructure of the other Discomycetes, especially in their reproductivesystem. In most of them coloured sporidia are rare. In some thereceptacle is pileate, clavate, or inflated, whilst in _Stictis_ it isvery much reduced, and in the lowest form of all, _Ascomyces_, it isentirely absent. In the _Phacidiacei_, the structure is very similarto that of the _Elvellacei_, whilst the _Hysteriacei_, with greateraffinities with the latter, still tend towards the _Pyrenomycetes_ bythe more horny nature of the receptacle, and the greater tendency ofthe hymenium to remain closed, at least when dry. In some species of_Hysterium_, the sporidia are remarkably fine. M. Duby[AA] hassubjected this group to examination, and M. Tulasne partly so. [AB]

SPHÆRIACEI. --In this group there is considerable variation, withincertain limits. It contains an immense number of species, and theseare daily being augmented. The general feature in all is thepresence of a perithecium, which contains and encloses the hymenium, and at length opening by a pore or ostiolum at the apex. In somethe perithecia are simple, in others compound; in some immersed ina stroma, in others free; in some fleshy or waxy, in otherscarbonaceous, and in others membranaceous. But in all there is thisimportant difference from the Ascomycetes we have already had underconsideration, that the hymenium is never exposed. The peritheciumconsists usually of an external layer of cellular structure, whichis either smooth or hairy, usually blackish, and an internalstratum of less compact cells, which give rise to the hymenium. 

[Illustration: FIG. 35. --Perithecium of _Sphæria_ and Section. ]

As in the _Discomycetes_, the hymenium consists of asci, paraphyses, and mucilage, but the whole forms a less compact and more gelatinousmass within the perithecium. The formation and growth of the asci andsporidia differ little from what we have described, and when maturethe asci dehisce, and the sporidia alone are ejected from theostiolum. We are not aware that operculate asci have yet beendetected. It has been shown in some instances, and suspected inothers, that certain moulds, formerly classed with _Mucedines_ and_Dematiei_, especially in the genus _Helminthosporium_, bear theconidia of species of _Sphæria_, so that this may be regarded as oneform of fruit. 

Perithecia, very similar externally to those of _Sphæria_, butcontaining spores borne on slender pedicels and not enclosed in asci, have had their relations to certain species of _Sphæria_ indicated, and these are no longer regarded so much as species of _Hendersonia_or _Diplodia_ as the pycnidia of _Sphæria_. Other and more minuteperithecia, containing minute, slender stylospores in great numbers, formerly classed with _Aposphæria_, _Phoma_, &c. , but are nowrecognized as spermogonia containing the spermatia of _Sphæriæ_. Howthese influence each other, when and under what circumstances thespermatia are instrumental in impregnation of the sporidia, is stillmatter of mystery. It is clear, however, that in all these conidia, macrospores, microspores, and some spermatia, or by whatever namesthey may be called, there exists a power of germination. Tulasne hasindicated in some instances five or six forms of fruit as belonging toone fungus, of which the highest and most perfect condition is aspecies of _Sphæria_. 

[Illustration: FIG. 36. --_Uncinula adunca. _]

PERISPORIACEI. --Except in the perithecia rupturing irregularly, andnot dehiscing by a pore, some of the genera in this group differlittle in structure from the _Sphæriacei_. On the other hand, the_Erysiphei_ present important and very interesting features. Theyoccur chiefly on the green parts of growing plants. At first there isa more or less profuse white mycelium. [AC] This gives rise to chainsof conidia (_Oidium_), and afterwards small sphæroid projectionsappear at certain points on the mycelium. These enlarge, take anorange colour, ultimately passing into brown, and then nearly black. Externally these perithecia are usually furnished with long, spreading, intertwined, or branching appendages, sometimes beautifullybranched or hooked at their tips. In the interior of the receptacles, pear-shaped or ovate asci are formed in clusters, attached together atthe base, and containing two or more hyaline sporidia. Other forms offruit have also been observed on the same mycelium. In an exoticgenus, _Meliola_, the fulcra, or appendages, as well as the mycelium, are black, otherwise it is very analogous to such a genus of_Erysiphei_ as _Microsphæria_. In _Chætomium_, the perithecia bristlewith rigid, dark-coloured hairs, and the sporidia are coloured. Ourlimits, however, will not permit of further elucidation of the complexand varied structure to be found amongst fungi. [AD]

 [A] A curious case occurred some years since at Bury St. Edmunds, which may be mentioned here in connection with the development of these nodules. Two children had died under suspicious circumstances, and an examination of the body of the latter after exhumation was made, a report having arisen that the child died after eating mushrooms. As certain white nodules appeared on the inner surface of the intestines, it was at once hastily concluded that the spores of the mushroom had germinated, and that the nodules were infant mushrooms. This appeared to one of us so strange, that application was made for specimens, which were kindly forwarded, and a cursory glance was enough to convince us that they were not fungoid. An examination under the microscope further confirmed the diagnosis, and the application of nitric acid showed that the nodules were merely due to chalk mixture, which had been given to the child for the diarrhetic symptoms under which he succumbed. 

 [B] Ehrenberg compared the whole structure of an Agaric with that of a mould, the mycelium corresponding with the hyphasma, the stem and pileus with the flocci, and the hymenium with the fructifying branchlets. The comparison is no less ingenious than true, and gives a lively idea of the connection of the more noble with the more humble fungi. --_Ehrb. De Mycetogenesi. _

 [C] In _Paxillus involutus_ the hymenium may be readily torn off and unfolded. 

 [D] This was well delineated in "Flora Danica, " plate 834, as observed in _Coprinus comatus_ as long ago as 1780. 

 [E] A. De Bary, "Morphologie und Physiologie der Pilze, " in "Hofmeister's Handbuch, " vol. Ii. Cap. 5, 1866, translated in "Grevillea, " vol. I. P. 181. 

 [F] "Die Pollinarien und Spermatien von _Agaricus_, " in "Botanische Zeitung, " Feb. 29 and March 7, 1856. 

 [G] "Essai d'une Flore mycologique de la Région de Montpellier. " Paris, 1863. 

 [H] Hoffmann, "Botanische Zeitung, " 1856, p. 139. 

 [I] Corda, "Icones Fungorum hucusque cognitorum, " iii. P. 41. Prague, 1839. 

 [J] Cooke, M. C. , "Anatomy of a Mushroom, " in "Popular Science Review, " vol. Viii. P. 380. 

 [K] An attempt was made to show that, in _Agaricus melleus_, distinct asci were found, in a certain stage, on the gills or lamellæ. We have in vain examined the gills in various conditions, and could never detect anything of the kind. It is probable that the asci belonged to some species of _Hypomyces_, a genus of parasitic Sphæriaceous fungi. 

 [L] It is not intended that the spores are always quaternate in _Agaricini_, though that number is constant in the more typical species. They sometimes exceed four, and are sometimes reduced to one. 

 [M] The species long known as _Hydnum gelatinosum_ was examined by Mr. F. Currey in 1860 (_Journ. Linn. Soc. _), and he came to the conclusion that it was not a good _Hydnum_. Since then it has been made the type of a new genus (Hydnogloea B. And Br. Or, as called by Fries, in the new edition of "Epicrisis, " _Tremellodon_, Pers. Myc. Eur. ), and transferred to the _Tremellini_. Currey says, upon examining the fructification, he was surprised to find that, although in its external characters it was a perfect _Hydnum_, it bore the fruit of a _Tremella_. If one of the teeth be examined with the microscope, it will be seen to consist of threads bearing four-lobed sporophores, and spores exactly similar to _Tremella_. It will thus be seen, he adds, that the plant is exactly intermediate between _Hydnei_ and _Tremellini_, forming, as it were, a stepping-stone from one to the other. 

 [N] Tulasne, L. R. And C. , "Observations on the Organization of the Tremellini, " in "Ann. Des Sci. Nat. " 3^me sér. Xix. (1853), pp. 193, &c. 

 [O] M. Léveillé, in "Ann. Des Sci. Nat. " 2^me sér. Viii. P. 328; 3^me sér. Ix. P. 127; also Bonorden, "Handbuch der Mycologie, " p. 151. 

 [P] Tulasne, in "Ann. Des Sci. Nat. " (loc. Cit. ) xix. Pl. X. Fig. 29. Tulasne, "New Notes upon Tremellinous Fungi, " in "Journ. Linn. Soc. " vol. Xiii. (1871), p. 31. 

 [Q] Berkeley, M. J. , "On the Fructification of Lycoperdon, Phallus, &c. , " in "Ann. Nat. Hist. " 1840, vol. Iv. P. 158, pl. 5. Berkeley, M. J. , "Introduction Crypt. Bot. " p. 346. 

 [R] Tulasne, L. R. And C. , "Fungi Hypogæi. " Paris. Berkeley and Broome, "British Hypogæous Fungi, " in "Ann. Nat. Hist. " 1846, xviii. P. 74. Corda, "Icones Fungorum, " vol. Vi. Pl. Vii. Viii. 

 [S] Tulasne, "Sur le Genre _Secotium_, " in "Ann. Des Sci. Nat. " (1845), 3^me sér. Vol. Iv. P. 169, plate 9. 

 [T] Tulasne, L. R. And C. , "De la Fructification des _Scleroderma_ comparée a celle des _Lycoperdon_ et des _Borista_, " in "Ann. Des Sci. Nat. " 1842, xvii. P. 5. Tulasne, L. R. And C. , "Sur les Genres Polysaccum et Geaster, " in "Ann. Des Sci. Nat. " 1842, xviii. P. 129, pl. 5 and 6. 

 [U] Berkeley, "On the Fructification of Lycoperdon, &c. , " in "Annals of Natural History" (1840), iv. P. 155. 

 [V] Wigand, "Morphologie des Genres Trichia et Arcyria, " in "Ann. Des Sci. Nat. " 4^me sér. Xvi. P. 223. 

 [W] Currey, "On Spiral Threads of Trichia, " in "Quart. Journ. Micr. Science" (1855), iii. P. 17. 

 [X] In some of the genera, as, for instance, in _Badhamia_, _Enerthenema_, and _Reticularia_, the spores are produced within delicate cells or cysts, which are afterwards absorbed. 

 [Y] Tulasne, "Essai d'une Monographie des Nidulariées, " in "Ann. Des Sci. Nat. " (1844), i. 41 and 64. 

 [Z] Berkeley, M. J. , "Introduction, Crypt. Bot. " p. 330. 

 [a] Berkeley, M. J. , "Introduction, Crypt. Bot. " p. 329. 

 [b] In the _Cæomacei_ and _Pucciniæi_ the term "pseudospore" would be much more accurate. 

 [c] Léveillé, "Sur la Disposition Méthodique des Urédinées, " in "Ann. Des Sci. Nat. " (1847), vol. Viii. P. 369. 

 [d] De Bary, "Champignons Parasites, " in "Ann. Des Sci. Nat. " 4^me sér. Vol. Xx. 

 [e] Tulasne, "Mémoire sur les Urédinées, &c. , " in "Ann. Des Sci. Nat. " (1854), vol. Ii. P. 78. 

 [f] De Bary, "Ueber die Brandpilze, " Berlin, 1853. 

 [g] Currey, in "Quart. Journ. Micr. Sci. " (1857), vol. V. P. 119, pl. 8, fig 13. 

 [h] Cooke, "On Podisoma, " in "Journal of Quekett Microscopical Club, " vol. Ii. P. 255. 

 [i] Tulasne, "Mémoire sur les Ustilaginées, " in "Ann. Des Sci. Nat. " (1847), vii. Pp. 12 and 73. 

 [j] Corda, "Icones Fungorum, " vol. Iii. Fig. 45. 

 [k] Cooke, "On Podisoma, " in "Quekett Journal, " vol. Ii. P. 255. 

 [l] It may be a question whether _Graphiola_ is not more nearly allied to _Trichocoma_ (Jungh Fl. Crypt. Javæ, p. 10, f. 7) than to the genera with which it is usually associated. --M. J. B. 

 [m] Cooke, "On Microscopic Moulds, " in "Quekett Journal, " vol. Ii. Plate 7. 

 [n] _See_ "Dendryphium Fumosum, " in "Quekett Journal, " vol. Ii. Plate 8; or, "Corda Prachtflora, " plate 22. 

 [o] De Bary, "Champignons Parasites, " in "Ann. Des Sci. Nat. " 4^me sér. Vol. Xx. 

 [p] Berkeley, "On the Potato Murrain, " in "Journ. Of Hort. Soc. Of London, " vol. I. (1846), p. 9. 

 [q] De Bary, "On Mildew and Fermentation, " p. 25, reprinted from "German Quarterly Magazine, " 1872; De Bary, "Morphologie und Physiologie der Pilze, " (1866), 201. 

 [r] Cooke, "Handbook of British Fungi, " vol. Ii. P. 552. 

 [s] De Bary, "On Mildew and Fermentation, " in "Quarterly German Magazine, " for 1872. 

 [t] We are quite aware that Von Tieghem and Le Monnier, in "Ann. Des Sci. Nat. " 1873, p. 335, dispute that this belongs to _Mucor mucedo_, and assert that _Chætocladium Jonesii_ is itself a true _Mucor_, with monosporous sporangia. 

 [u] Vittadini, "Monographia Tuberacearum, " 1831. 

 [v] Tulasne, "Fungi Hypogæi, " 1851. 

 [w] Corda, "Icones Fungorum, " vol. Vi. 

 [x] Berkeley and Broome, in "Ann. Of Nat. Hist. " 1st ser. Vol. Xviii. (1846), p. 73; Cooke, in "Seem. Journ. Bot. "

 [y] Boudier (E. ), "Mémoire sur les Ascobolés, " in "Ann. Des Sci. Nat. " 5^me sér. Vol. X. (1869). 

 [z] Only in some of the Discomycetes are the asci exserted. 

 [AA] Duby, "Mémoire sur la Tribu des Hysterinées, " 1861. 

 [AB] Tulasne, "Selecta Fungorum Carpologia, " vol. Iii. 

 [AC] Tulasne, "Selecta Fungorum Carpologia, " vol. I. Léveillé, "Organisation, &c. , sur l'Érysiphé, " in "Ann. Des Sci. Nat. " (1851), vol. Xv. P. 109. 

 [AD] Other works besides those already cited, which may be consulted with advantage on structure, are--

 Tulasne, L. R. And C. , various articles in "Annales des Sciences Naturelles, " série iii. And iv. 

 Hoffmann, "Icones Analyticæ Fungorum. "

 De Bary, "Der Ascomyceten. " Leipzic, 1863. 

 Berkeley, M. J. , "Introduction to Cryptogamic Botany. "

 Seynes, J. De, "Recherches, &c. , des Fistulines. " Paris, 1874. 

 Winter, G. , "Die Deutschen Sordarien. " 1874. 

 Corda, J. , "Prachtflora. " Prague, 1840. 

 De Bary, "Über der Brandpilze. " 1853. 

 Brefeld, O. , "Botan. Untersuch. ü Schimmelpilze. "

 Fresenius, G. , "Beiträge zur Mykologie. " 1850. 

 Von Tieghem and Le Monnier, in "Annales des Sciences Naturelles" (1873), p. 335. 

 Cornu, M. , "Sur les Saprolegniées, " in "Ann. Des Sci. Nat. " 5^me sér. Xv. P. 5. 

 Janczenski, "Sur l'Ascobolus furfuraceus, " in "Ann. Des Sci. Nat. " 5^me sér. Xv. P. 200. 

 De Bary and Woronin, "Beiträge zur Morphologie und Physiologie der Pilze. " 1870. 

 Bonorden, H. F. , "Abhandlungen aus dem Gebiete der Mykologie. " 1864. 

 Coemans, E. , "Spicilége Mycologique. " 1862, etc. 

III

CLASSIFICATION

A work of this kind could not be considered complete without someaccount of the systematic arrangement or classification which theseplants receive at the hands of botanists. It would hardly avail toenter too minutely into details, yet sufficient should be attempted toenable the reader to comprehend the value and relations of thedifferent groups into which fungi are divided. The arrangementgenerally adopted is based upon the "Systema Mycologicum" of Fries, asmodified to meet the requirements of more recent microscopicalresearches by Berkeley in his "Introduction, "[A] and adopted inLindley's "Vegetable Kingdom. " Another arrangement was proposed byProfessor de Bary, [B] but it has never met with general acceptance. 

In the arrangement to which we have alluded, all fungi are dividedinto two primary sections, having reference to the mode in which thefructification is produced. In one section, the spores (which occupynearly the same position, and perform similar functions, to the seedsof higher plants) are naked; that is, they are produced on spicules, and are not enclosed in cysts or capsules. This section is calledSPORIFERA, or spore-bearing, because, by general consent, the term_spore_ is limited in fungi to such germ-cells as are not produced incysts. The second section is termed SPORIDIIFERA, or sporidia-bearing, because in like manner the term _sporidia_ is limited to suchgerm-cells as are produced in cells or cysts. These cysts arerespectively known as _sporangia_, and _asci_ or _thecæ_. The truemeaning and value of these divisions will be better comprehended whenwe have detailed the characters of the families composing these twodivisions. 

First, then, the section SPORIFERA contains four families, in two ofwhich a hymenium is present, and in two there is no proper hymenium. The term _hymenium_ is employed to represent a more or less expandedsurface, on which the fructification is produced, and is, in fact, thefruit-bearing surface. When no such surface is present, the fruit isborne on threads, proceeding direct from the root-like filaments ofthe mycelium, or an intermediate kind of cushion or stroma. The twofamilies in which an hymenium is present are called _Hymenomycetes_and _Gasteromycetes_. In the former, the hymenium is exposed; in thelatter, it is at first enclosed. We must examine each of theseseparately. 

The common mushroom may be accepted, by way of illustration, as a typeof the family _Hymenomycetes_, in which the hymenium is exposed, andis, in fact, the most noticeable feature in the family from which itsname is derived. The pileus or cap bears on its under surfaceradiating plates or gills, consisting of the hymenium, over which arethickly scattered the basidia, each surmounted by four spicules, andon each spicule a spore. When mature, these spores fall freely uponthe ground beneath, imparting to it the general colour of the spores. But it must be observed that the hymenium takes the form ofgill-plates in only one order of _Hymenomycetes_, namely, the_Agaricini_; and here, as in _Cantharellus_, the hymenium is sometimesspread over prominent veins rather than gills. Still furtherdivergence is manifest in the _Polyporei_, in which order the hymeniumlines the inner surface of pores or tubes, which are normally on theunder side of the pileus. Both these orders include an immense numberof species, the former more or less fleshy, the latter more or lesstough and leathery. There are still other forms and orders in thisfamily, as the _Hydnei_, in which the hymenium clothes the surface ofprickles or spines, and the _Auricularini_, in which the hymenium isentirely or almost even. In the two remaining orders, there is astill further divergence from the mushroom form. In the one called_Clavariei_, the entire fungus is either simply cylindrical orclub-shaped, or it is very much branched and ramified. Whatever formthe fungus assumes, the hymenium covers the whole exposed surface. Inthe _Tremellini_, a peculiar structure prevails, which at first seemsto agree but little with the preceding. The whole plant is gelatinouswhen fresh, lobed and convolute, often brain-like, and varying insize, according to species, from that of a pin's head to that of aman's head. Threads and sporophores are imbedded in the gelatinoussubstance, [C] so that the fertile threads are in reality not compactedinto a true hymenium. With this introduction we may state that thetechnical characters of the family are thus expressed:--

_Hymenium free, mostly naked, or, if enclosed at first, soonexposed; spores naked, mostly quaternate, on distinct spicules_ =HYMENOMYCETES. 

[Illustration: FIG. 37. --_Agaricus nudus. _]

In this family some mycologists believe that fungi attain the highestform of development of which they are capable, whilst others contendthat the fructification of the _Ascomycetes_ is more perfect, and thatsome of the noblest species, such as the pileate forms, are entitledto the first rank. The morel is a familiar example. Whatever may besaid on this point, it is incontrovertible that the noblest and mostattractive, as well as the largest, forms are classed under the_Hymenomycetes_. 

In _Gasteromycetes_, the second family, a true hymenium is alsopresent, but instead of being exposed it is for a long time enclosedin an outer peridium or sac, until the spores are fully matured, orthe fungus is beginning to decay. The common puff-ball (_Lycoperdon_)is well known, and will illustrate the principal feature of thefamily. Externally there is a tough coat or peridium, which is atfirst pale, but ultimately becomes brown. Internally is at first acream-coloured, then greenish, cellular mass, consisting of thesinuated hymenium and young spores, which at length, and when thespores are fully matured become brownish and dusty, the hymeniumbeing broken up into threads, and the spores become free. In earlierstages, and before the hymenium is ruptured, the spores have beenfound to harmonize with those of _Hymenomycetes_ in their mode ofproduction, since basidia are present surmounted each by fourspicules, and each spicule normally surmounted by a spore. [D] Here is, therefore, a cellular hymenium bearing quaternary spores, but, instead of being exposed, this hymenium is wholly enclosed withinan external sac or peridium, which is not ruptured until thespores are fully matured, and the hymenium is resolved intothreads, together forming a pulverulent mass. It must, however, beborne in mind, that in only some of the orders composing thisfamily is the hymenium thus evanescent, in others being more or lesspermanent, and this has led naturally enough to the recognition oftwo sub-families, in one of which the hymenium is more or lesspermanent, thus following the Hymenomycetous type; and in theother, the hymenium is evanescent, and the dusty mass of spores tendsmore towards the _Coniomycetes_, this being characterized as theconiospermous (or dusty-spored) sub-family. 

The first sub-family includes, first of all, the _Hypogæi_, orsubterranean species. And here again it becomes necessary to remindthe reader that all subterranean fungi are not included in thisorder, inasmuch as some, of which the truffle is an example, aresporidiiferous, developing their sporidia in asci. To these allusionmust hereafter be made. In the _Hypogæi_, the hymenium is permanent andconvoluted, leaving numerous minute irregular cavities, in which thespores are produced on sporophores. When specimens are very old anddecaying, the interior may become pulverulent or deliquescent. Thestructure of subterranean fungi attracted the attention of Messrs. Tulasne, and led to the production of a splendid monograph on thesubject. [E] Another order belonging to this sub-family is the_Phalloidei_, in which the volva or peridium is ruptured whilst theplant is still immature, and the hymenium when mature becomesdeliquescent. Not only are some members of this order most singular inappearance, but they possess an odour so foetid as to be unapproached inthis property by any other vegetable production. [F] In this order, theinner stratum of the investing volva is gelatinous. When still young, and previous to the rupture of the volva, the hymenium presents sinuouscavities in which the spores are produced on spicules, after themanner of _Hymenomycetes_. [G] _Nidulariacei_ is a somewhat aberrantorder, presenting a peculiar structure. The peridium consists of two orthree coats, and bursts at the apex, either irregularly or in astellate manner, or by the separation of a little lid. Within thecavity are contained one or more secondary receptacles, which areeither free or attached by elastic threads to the common receptacle. Ultimately the secondary receptacles are hollow, and spores areproduced in the interior, borne on spicules. [H] The appearance in somegenera as of a little bird's-nest containing eggs has furnished thename to the order. 

The second sub-family contains the coniospermous puff-balls, andincludes two orders, in which the most readily distinguishablefeature is the cellular condition of the entire plant, in its earlierstages, in the _Trichogastres_, and the gelatinous condition ofthe early state of the _Myxogastres_. Both are ultimately resolvedinternally into a dusty mass of threads and spores. In the former, the peridium is either single or double, occasionally borne on astem, but usually sessile. In _Geaster_, the "starry puff-balls, " theouter peridium divides into several lobes, which fall back in astellate manner, and expose the inner peridium, like a ball in thecentre. In _Polysaccum_, the interior is divided into numerouscells, filled with secondary peridia. The mode of spore-productionhas already been alluded to in our remarks on _Lycoperdon_. Allthe species are large, as compared with those of the followingsub-family, and one species of _Lycoperdon_ attains an enormoussize. One specimen recorded in the "Gardener's Chronicle" wasthree feet four inches in circumference, and weighed nearly tenpounds. In the _Myxogastres_, the early stage has been the subject ofmuch controversy. The gelatinous condition presents phenomena sounlike anything previously recorded in plants, that one learnedprofessor[I] did not hesitate to propose their exclusion from thevegetable, and recognition in the animal, kingdom as associates ofthe Gregarines. When mature, the spores and threads so much resemblethose of the _Trichogastres_, and the little plants themselves areso veritably miniature puff-balls, that the theory of their animalnature did not meet with a ready acceptance, and is now virtuallyabandoned. The characters of the family we have thus briefly reviewedare tersely stated, as--

_Hymenium more or less permanently concealed, consisting in most casesof closely-packed cells, of which the fertile ones bear naked sporeson distinct spicules, exposed only by the rupture or decay of theinvesting coat or peridium_ = GASTEROMYCETES. 

[Illustration: FIG. 38. --_Scleroderma vulgare_, Fr. ]

[Illustration: FIG. 39. --_Ceuthospora phacidioides_ (Greville). ]

We come now to the second section of the _Sporifera_, in which nodefinite hymenium is present. And here we find also two families, inone of which the dusty spores are the prominent feature, and hencetermed _Coniomycetes_; the other, in which the threads are mostnoticeable, is _Hyphomycetes_. In the former of these, the reproductivesystem seems to preponderate so much over the vegetative, that thefungus appears to be all spores. The mycelium is often nearlyobsolete, and the short pedicels so evanescent, that a rusty or sootypowder represents the mature fungus, infesting the green parts ofliving plants. This is more especially true of one or two orders. Itwill be most convenient to recognize two artificial sub-families forthe purpose of illustration, in one of which the species are developedon living, and in the other on dead, plants. We will commence with thelatter, recognizing first those which are developed beneath thecuticle, and then those which are superficial. Of the sub-cuticular, two orders may be named as the representatives of this group inBritain, these are the _Sphæronemei_, in which the spores are containedin a more or less perfect perithecium, and the _Melanconiei_, in whichthere is manifestly none. The first of these is analogous to the_Sphæriacei_ of _Ascomycetous_ fungi, and probably consists largely ofspermogonia of known species of _Sphæria_, the relations of which havenot hitherto been traced. The spores are produced on slender threadsspringing from the inner wall of the perithecium, and, when mature, areexpelled from an orifice at the apex. This is the normal condition, towhich there are some exceptions. In the _Melanconiei_, there is notrue perithecium, but the spores are produced in like manner upon a kindof stroma or cushion formed from the mycelium, and, when mature, areexpelled through a rupture of the cuticle beneath which they aregenerated, often issuing in long gelatinous tendrils. Here, again, the majority of what were formerly regarded as distinct species havebeen found, or suspected, to be forms of higher fungi. The _Torulacei_represent the superficial fungi of this family, and these consist of amore or less developed mycelium, which gives rise to fertile threads, which, by constriction and division, mature into moniliform chainsof spores. The species mostly appear as blackish velvety patches orstains on the stems of herbaceous plants and on old weathered wood. 

Much interest attaches to the other sub-family of _Coniomycetes_, in whichthe species are produced for the most part on living plants. So muchhas been discovered during recent years of the polymorphism whichsubsists amongst the species in this section, that any detailedclassification can only be regarded as provisional. Hence we shallproceed here upon the supposition that we are dealing with autonomousspecies. In the first place, we must recognize a small section in whicha kind of cellular peridium is present. This is the _Æcidiacei_, or orderof "cluster cups. " The majority of species are very beautiful objectsunder the microscope; the peridia are distinctly cellular, and white orpallid, produced beneath the cuticle, through which they burst, and, rupturing at the apex, in one genus in a stellate manner, so that theteeth, becoming reflexed, resemble delicate fringed cups, with theorange, golden, brown, or whitish spores or pseudospores nestling in theinterior. [J] These pseudospores are at first produced in chains, butultimately separate. In many cases these cups are either accompanied orpreceded by spermogonia. In two other orders there is no peridium. In the_Cæomacei_, the pseudospores are more or less globose or ovate, sometimeslaterally compressed and simple; and in _Pucciniæi_, they are elongated, often subfusiform and septate. In both, the pseudospores are producedin tufts or clusters _direct from the mycelium. The Cæomacei_ mightagain be subdivided into _Ustilagines_[K] and _Uredines_. [L] In theformer, the pseudospores are mostly dingy brown or blackish, and in thelatter more brightly coloured, often yellowish. The _Ustilagines_include the smuts and bunt of corn-plants, the _Uredines_ include thered rusts of wheat and grasses. In some of the species included in thelatter, two forms of fruit are found. In _Melampsora_, the summerpseudospores are yellow, globose, and were formerly classed as a speciesof _Lecythea_, whilst the winter pseudospores are brownish, elongated, wedge-shaped by compression, and compact. The _Pucciniæi_[M] differprimarily in the septate pseudospores, which in one genus (_Puccinia_) areuniseptate; in _Triphragmium_, they are biseptate; in _Phragmidium_, multiseptate; and in _Xenodochus_, moniliform, breaking up intodistinct articulations. It is probable that, in all of these, as isknown to be the case in most, the septate pseudospores are preceded oraccompanied by simple pseudospores, to which they are mysteriouslyrelated. There is still another, somewhat singular, group usuallyassociated with the _Pucciniæi_, in which the septate pseudospores areimmersed in gelatin, so that in many features the species seem toapproach the _Tremellini_. This group includes two or three genera, thetype of which will be found in _Podisoma_. [N] These fungi are parasitic onliving junipers in Britain and North America, appearing year after yearupon the same gouty swellings of the branches, in clavate or horn-shapedgelatinous processes of a yellowish or orange colour. Anomalous as itmay at first sight appear to include these tremelloid forms with thedust-like fungi, their relations will on closer examination be more fullyappreciated, when the form of pseudospores, mode of germination, andother features are taken into consideration, especially when compared with_Podisoma Ellisii_, already alluded to. This family is technicallycharacterized as, --

_Distinct hymenium none. Pseudospores either solitary or concatenate, produced on the tips of generally short threads, which are eithernaked or contained in a perithecium, rarely compacted into agelatinous mass, at length producing minute spores_ = CONIOMYCETES. 

The last family of the sporifera is _Hyphomycetes_, in which thethreads are conspicuously developed. These are what are morecommonly called "moulds, " including some of the most elegant anddelicate of microscopic forms. It is true of many of these, as wellas of the _Coniomycetes_, that they are only conidial forms ofhigher fungi; but there will remain a very large number of specieswhich, as far as present knowledge extends, must be accepted asautonomous. In this family, we may again recognize three subdivisions, in one of which the threads are more or less compacted into a commonstem, in another the threads are free, and in the third the threadscan scarcely be distinguished from the mycelium. It is this lattergroup which unites the _Hyphomycetes_ with the _Coniomycetes_, theaffinities being increased by the great profusion with which thespores are developed. The first group, in which the fertile threadsare united so as to form a compound stem, consists of two smallorders, the _Isariacei_ and the _Stilbacei_, in the former of whichthe spores are dry, and in the latter somewhat gelatinous. Many ofthe species closely imitate forms met with in the _Hymenomycetes_, such as _Clavaria_; and, in the genus _Isaria_, it is almost beyonddoubt that the species found on dead insects, moths, spiders, flies, ants, &c. , are merely the conidiophores of species of_Torrubia_. [O]

The second group is by far the largest, most typical, and attractivein this family. It contains the black moulds and white moulds, technically known as the _Dematiei_ and the _Mucedines_. In the first, the threads are more or less corticated, that is, the stem has adistinct investing membrane, which peels off like a bark; and thethreads, often also the spores, are dark-coloured, as if charred orscorched. In many cases, the spores are highly developed, large, multiseptate, and nucleate, and seldom are spores and threadscolourless or of bright tints. In the _Mucedines_, on the contrary, the threads are never coated, seldom dingy, mostly white or of purecolours, and the spores have less a tendency to extra development ormultiplex septation. In some genera, as in _Peronospora_ forinstance, [P] a secondary fruit is produced in the form of restingspores from the mycelium; and these generate zoospores as well as theprimary spores, similar to those common in _Algæ_. This latter genusis very destructive to growing plants, one species being the chiefagent in the potato disease, and another no less destructive to cropsof onions. The vine disease is produced by a species of _Oidium_, which is also classed with _Mucedines_, but which is really theconidiiferous form of _Erysiphe_. In other genera, the majority ofspecies are developed on decaying plants, so that, with the exceptionof the two genera mentioned, the _Hyphomycetes_ exert a much lessbaneful influence on vegetation than the _Coniomycetes_. The lastsection, including the _Sepedoniei_, has been already cited asremarkable for the suppression of the threads, which are scarcely tobe distinguished from the mycelium; the spores are profuse, nestlingon the floccose mycelium; whilst in the _Trichodermacei_, the sporesare invested by the threads, as if enclosed in a sort of falseperidium. A summary of the characters of the family may therefore bethus briefly expressed:--

_Filamentous; fertile threads naked, for the most part free or looselycompacted, simple or branched, bearing the spores at their apices, rarely more closely packed, so as to form a distinct common stem_ =HYPHOMYCETES. 

[Illustration: FIG. 40. --_Rhopalomyces candidus. _]

Having thus disposed of the _Sporifera_, we must advert to the twofamilies of _Sporidiifera_. As more closely related to the _Hyphomycetes_, the first of these to be noticed is the _Physomycetes_, in which thereis no proper hymenium, and the threads proceeding from the mycelium bearvesicles containing an indefinite number of sporidia. The fertile threadsare either free or only slightly felted. In the order _Antennariei_, thethreads are black and moniliform, more or less felted, bearing irregularsporangia. A common fungus named _Zasmidium cellare_, found in cellars, and incrusting old wine bottles, as with a blackened felt, belongs tothis order. The larger and more highly-developed order, _Mucorini_, differs in the threads, which are simple or branched, being free, erect, and bearing the sporangia at the tips of the thread, or branches. Some ofthe species bear great external resemblance to _Mucedines_ until thefruit is examined, when the fructifying heads, commonly globose or ovate, are found to be delicate transparent vesicles, enclosing a large numberof minute sporidia; when mature, the sporangia burst and the sporidiaare set free. In some species, it has long been known that a sort ofconjugation takes place between opposite threads, which results in theformation of a sporangium. [Q] None of these species are destructive tovegetation, appearing only upon decaying, and not upon living, plants. A state approaching putrescence seems to be essential to their vigorousdevelopment. The following characters may be compared with those ofthe family preceding it:--

_Filamentous, threads free or only slightly felted, bearing vesicles, which contain indefinite sporidia_ = PHYSOMYCETES. 

[Illustration: FIG. 41. --_Mucor caninus. _]

In the last family, the _Ascomycetes_, we shall meet with a very greatvariety of forms, all agreeing in producing sporidia contained incertain cells called asci, which are produced from the hymenium. Insome of these, the asci are evanescent, but in the greater number arepermanent. In _Onygenei_, the receptacle is either club-shaped orsomewhat globose, and the peridium is filled with branched threads, which produce asci of a very evanescent character, leaving thepulverulent sporidia to fill the central cavity. The species are allsmall, and singular for their habit of affecting animal substances, otherwise they are of little importance. The _Perisporiacei_, on theother hand, are very destructive of vegetation, being produced, in themajority of cases, on the green parts of growing plants. To this orderthe hop mildew, rose mildew, and pea mildew belong. The mycelium isoften very much developed, and in the case of the maple, pea, hop, andsome others, it covers the parts attacked with a thick white coating, so that from a distance the leaves appear to have been whitewashed. Seated on the mycelium, at the first as little orange points, are theperithecia, which enlarge and become nearly black. In some species, very elegant whitish appendages radiate from the sides of theperithecia, the variations in which aid in the discrimination ofspecies. The perithecia contain pear-shaped asci, which spring fromthe base and enclose a definite number of sporidia. [R] The ascithemselves are soon dissolved. Simultaneously with the development ofsporidia, other reproductive bodies are produced direct from themycelium, and in some species as many as five different kinds ofreproductive bodies have been traced. The features to be remembered in_Perisporiacei_, as forming the basis of their classification, are, that the asci are saccate, springing from the base of the perithecia, and are soon absorbed. Also that the perithecia themselves are notperforated at the apex. 

The four remaining orders, though large, can be easily characterized. In _Tuberacei_, all the species are subterranean, and the hymenium ismostly sinuated. In _Elvellacei_, the substance is more or lessfleshy, and the hymenium is exposed. In _Phacidiacei_, the substanceis hard or leathery, and the hymenium is soon exposed. And in_Sphæriacei_, although the substance is variable, the hymenium isnever exposed, being enclosed in perithecia with a distinct opening atthe apex, through which the mature spores escape. Each of these fourorders must be examined more in detail. The _Tuberacei_, orsubterranean _Ascomycetes_, are analogous to the _Hypogæi_ of the_Gasteromycetes_. The truffle is a familiar and highly prized example. There is a kind of outer peridium, and the interior consists of afleshy hymenium, more or less convoluted, sometimes sinuous andconfluent, so as to leave only minute elongated and irregularcavities, and sometimes none at all, the two opposing faces of thehymenium meeting and coalescing. [S] Certain privileged cells of thehymenium swell, and ultimately become asci, enclosing a definitenumber of sporidia. The sporidia in many cases are large, reticulated, echinulate or verrucose, and mostly somewhat globose. In the genus_Elaphomyces_, the asci are more than commonly diffluent. 

The _Elvellacei_ are fleshy in substance, or somewhat waxy, sometimestremelloid. There is no peridium, but the hymenium is always exposed. There is a great variety of forms, some being pileate, and otherscup-shaped, as there is also a great variation in size, from theminute _Peziza_, small as a grain of sand, to the large _Helvellagigas_, which equals in dimensions the head of a child. In the pileateforms, the stroma is fleshy and highly developed; in the cup-shaped, it is reduced to the external cells of the cup which enclose thehymenium. The hymenium itself consists of elongated fertile cells, orasci, mixed with linear thread-like barren cells, called paraphyses, which are regarded by some authors as barren asci. These are placedside by side in juxtaposition with the apex outwards. Each ascuscontains a definite number of sporidia, which are sometimes coloured. When mature, the asci explode above, and the sporidia may be seenescaping like a miniature cloud of smoke in the light of the mid-daysun. The disc or surface of the hymenium is often brightly coloured inthe genus _Peziza_; tints of orange, red, and brown having thepredominance. 

In _Phacidiacei_, the substance is hard and leathery, intermediatebetween the fleshy _Elvellacei_ and the more horny of the _Sphæriacei_. The perithecia are either orbicular or elongated, and the hymenium soonbecomes exposed. In some instances, there is a close affinity withthe _Elvellacei_, the exposed hymenium being similar in structure, but in all the disc is at first closed. In orbicular forms, thefissure takes place in a stellate manner from the centre, and theteeth are reflexed. In the _Hysteriacei_, where the perithecia areelongated, the fissure takes place throughout their length. As arule, the sporidia are more elongated, more commonly septate, and moreusually coloured, than in _Elvellacei_. Only a few solitary instancesoccur of individual species that are parasitic on living plants. 

[Illustration: FIG. 42. --_Sphæria aquila. _]

In the _Sphæriacei_, the substance of the stroma (when present) and ofthe perithecia is variable, being between fleshy and waxy in_Nectriei_, and tough, horny, sometimes brittle, in _Hypoxylon_. Aperithecium, or cell excavated in the stroma which fulfils thefunctions of a perithecium, is always present. The hymenium lines theinner walls of the perithecium, and forms a gelatinous nucleus, consisting of asci and paraphyses. When fully mature, the asci areruptured and the sporidia escape by a pore which occupies the apex ofthe perithecium. Sometimes the perithecia are solitary or scattered, and sometimes gregarious, whilst in other instances they are closelyaggregated and immersed in a stroma of variable size and form. Conidia, spermatia, pycnidia, &c. , have been traced to and associatedwith some species, but the history of others is still obscure. Many ofthe coniomycetous forms grouped under the _Sphæronemei_ are probablyconditions of the _Sphæriacei_, as are also the _Melanconiei_, andsome of the _Hyphomycetes_. A very common fungus, for instance, whichis abundant on sticks and twigs, forming rosy or reddish pustules thesize of a millet seed, formerly named _Tubercularia vulgaris_, isknown to be the conidia-bearing stroma of the sphæriaceous fungus, _Nectria cinnabarina_;[T] and so with many others. The following arethe technical characters of the family:--

_Fruit consisting of sporidia, mostly definite, contained in asci, springing from a naked or enclosed stratum of fructifying cells andforming a hymenium or nucleus_ = ASCOMYCETES. 

If the characters of the different families are borne in mind, therewill be but little difficulty in assigning any fungus to the order towhich it belongs by means of the foregoing remarks. For more minuteinformation, and for analytical tables of the families, orders, andgenera, we must refer the student to some special systematic work, which will present fewer difficulties, if he keeps in mind thedistinctive features of the families. [U]

To assist in this we have given on the following page an analyticalarrangement of the families and orders, according to the systemrecognized and adopted in the present volume. It is, in all essentialparticulars, the method adopted in our "Handbook, " based on that ofBerkeley's "Introduction" and "Outlines. "

 [A] Rev. M. J. Berkeley, "Introduction to Cryptogamic Botany" (1857), London, pp. 235 to 372. 

 [B] De Bary, in "Streinz Nomenclator Fungorum, " p. 722. 

 [C] Tulasne, L. And C. R. , "Observations sur l'Organisation des Trémellinées, " "Ann. Des Sci. Nat. " 1853, xix. P. 193. 

 [D] Berkeley, M. J. , "On the Fructification of _Lycoperdon_, _Phallus_, and their Allied Genera, " in "Ann. Of Nat. Hist. " (1840), vol. Iv. P. 155; "Ann. Des Sci. Nat. " (1839), xii. P. 163. Tulasne, L. R. And C. , "De la Fructification des _Scléroderma_ comparée à celle des _Lycoperdon_ et des _Bovista_, " in "Ann. Des Sci. Nat. " 2^me sér. Xvii. P. 5. 

 [E] Tulasne, L. R. And C. , "Fungi Hypogæi, " Paris, 1851; "Observations sur le Genre Elaphomyces, " in "Ann. Des Sci. Nat. " 1841, xvi. 5. 

 [F] _Stapeliæ_ in this respect approach most closely to the _Phalloidei_. 

 [G] Berkeley, in "Ann. Nat. Hist. " vol. Iv. P. 155. 

 [H] Tulasne, L. R. And C. , "Recherches sur l'Organisation et le Mode de Fructification des Nidulariées, " "Ann. Des Sci. Nat. " (1844), i. P. 41. 

 [I] De Bary, A. , "Des Myxomycètes, " in "Ann. Des Sci. Nat. " 4^me sér. Xi. P. 153; "Bot. Zeit. " xvi. P. 357. 

 [J] Corda, "Icones Fungorum, " vol. Iii. Fig. 45. 

 [K] Tulasne, "Mémoire sur les Ustilaginées, " "Ann. Des Sci. Nat. " (1847), vii. 12-73. 

 [L] Tulasne, "Mémoire sur les Urédinées, " "Ann. Des Sci. Nat. " (1854), ii. 78. 

 [M] Tulasne, "Sur les Urédinées, " "Ann. Des Sci. Nat. " 1854, ii. Pl. 9. 

 [N] Cooke, M. C. , "Notes on _Podisoma_, " in "Journ. Quek. Micr. Club, " No. 17 (1871), p. 255. 

 [O] Tulasne, L. R. And C. , "Selecta Fungorum Carpologia, " vol. Iii. Pp. 4-19. 

 [P] De Bary, A. , "Recherches sur les Champignons Parasites, " in "Ann. Des Sci. Nat. " 4^me sér. Xx. P. 5; "Grevillea, " vol. I. P. 150. 

 [Q] A. De Bary, translated in "Grevillea, " vol. I. P. 167; Tulasne, "Ann. Des Sci. Nat. " 5^me sér. (1866), p. 211. 

 [R] Léveillé, J. H. , "Organisation, &c. , de l'Érysiphé, " in "Ann. Des Sci. Nat. " (1851), xv. P. 109. 

 [S] Tulasne, L. R. And C. , "Fungi Hypogæi, " Paris; Vittadini, C. , "Monographia Tuberacearum, " Milan, 1831. 

 [T] "A Currant Twig and Something on it, " in "Gardener's Chronicle" for January 28, 1871. 

 [U] Berkeley, M. J. , "Introduction to Cryptogamic Botany, " London, 1857; Cooke, M. C. , "Handbook of British Fungi, " London, 1871 ; Corda, A. C. J. , "Anleitung zum Studium der Mycologie, " Prag, 1842; Kickx, J. , "Flore Cryptogamique des Flanders, " Gand, 1867; Fries, E. , "Systema Mycologicum, " Lund, 1830; Fries, E. , "Summa Vegetabilium Scandinaviæ, " 1846; Secretan, L. , "Mycographie Suisse, " Geneva, 1833; Berkeley, M. J. , "Outlines of British Fungology, " London, 1860. 

 TABULAR ARRANGEMENT OF FAMILIES AND ORDERS. 

 DIVISION I. SPORIFERA. _Spores naked. _

I. Hymenium free, mostly naked, or soon exposed HYMENOMYCETES. Hymenium normally inferior-- Fruit-bearing surface lamellose _Agaricini. _ Fruit-bearing surface porous or tubular _Polyporei. _ Fruit-bearing surface clothed with prickles _Hydnei. _ Fruit-bearing surface even or rugose _Auricularini. _ Hymenium superior or encircling-- Clavate, or branched, rarely lobed _Clavariei. _ Lobed, convolute, or disc-like, gelatinous _Tremellini. _

II. Hymenium enclosed in a peridium, ruptured when mature GASTEROMYCETES. Hymenomycetous-- Subterranean, naked or enclosed _Hypogæi. _ Terrestrial, hymenium deliquescent _Phalloidei. _ Peridium enclosing sporangia, containing spores _Nidulariacei. _ Coniospermous-- Stipitate, hymenium convolute, drying into a dusty mass, enclosed in a volva _Podaxinei. _ Cellular at first, hymenium drying up into a dusty mass of threads and spores _Trichogastres. _ Gelatinous at first, peridium containing at length a dusty mass of threads and spores _Myxogastres. _

III. Spores naked, mostly terminal, on inconspicuous threads, free or enclosed in a perithecium CONIOMYCETES. Growing on dead or dying plants-- Subcutaneous-- Perithecium more or less distinct _Sphæronemei. _ Perithecium obsolete or wanting _Melanconiei. _ Superficial-- Fructifying surface naked. Spores compound or tomiparous _Torulacei. _ Parasitic on living plants-- Peridium distinctly cellular _Æcidiacei. _ Peridium none-- Spores sub-globose, simple or deciduous _Cæomacei. _ Spores mostly oblong, usually septate _Pucciniæi. _

IV. Spores naked, on conspicuous threads, rarely compacted, small HYPHOMYCETES. Fertile threads compacted, sometimes cellular-- Stem or stroma compound-- Spores dry, volatile _Isariacei. _ Mass of spores moist, diffluent _Stilbacei. _ Fertile threads, free or anastomosing-- Fertile threads dark, carbonized-- Spores mostly compound _Dematiei. _ Fertile threads not carbonized-- Very distinct-- Spores mostly simple _Mucedines. _ Scarcely distinct from mycelium-- Spores profuse _Sepedoniei. _

 DIVISION II. SPORIDIIFERA. _Sporidia in Asci. _

V. Fertile cells seated on threads, not compacted into a hymenium PHYSOMYCETES. Threads felted, moniliform-- Sporangia irregular _Antennariei. _ Threads free-- Sporangia terminal or lateral _Mucorini. _ Aquatic _Saprolegniei. _

VI. Asci formed from the fertile cells of a hymenium ASCOMYCETES. Asci often evanescent-- Receptacle clavæform-- Asci springing from threads _Onygenei. _ Perithecia free-- Asci springing from the base _Perisporiacei. _ Asci persistent-- Perithecia opening by a distinct ostiolum _Sphæriacei. _ Hard or coriaceous, hymenium at length exposed _Phacidiacei. _ Hypogæous; hymenium complicated _Tuberacei. _ Fleshy, waxy, or tremelloid; hymenium mostly exposed _Elvellacei. _

IV. 

USES. 

The rigid utilitarian will hardly be satisfied with the shortcatalogue which can be furnished of the uses of fungi. Excepting thosewhich are employed more or less for human food, very few are of anypractical value in arts or medicine. It is true that imperfectconditions of fungi exert a very important influence on fermentation, and thus become useful; but, unfortunately, fungi have the reputationof being more destructive and offensive than valuable or useful. Notwithstanding that a large number of species have from time to timebeen enumerated as edible, yet those commonly employed and recognizedare very few in number, prejudice in many cases, and fear in others, militating strongly against additions to the number. In Great Britainthis is especially the case, and however advisable it may be toexercise great care and caution in experimenting on untried ordoubtful species, it can only be regarded as prejudice which preventsgood, in fact, excellent, esculent species being more extensivelyused, instead of allowing them to rot by thousands on the spots wherethey have grown. Poisonous species are also plentiful, and no goldenrule can be established by means of which any one may detect at aglance good from bad, without that kind of knowledge which is appliedto the discrimination of species. Yet, after all, the characters ofhalf a dozen good esculent fungi are acquired as easily as thedistinctions between half a dozen birds such as any ploughboy candiscriminate. 

The common mushroom (_Agaricus campestris_) is the best knownesculent, whether in its uncultivated or in a cultivated state. InBritain many thousands of people, notably the lower classes, will notrecognize any other as fit for food, whilst in Italy the same classeshave a strong prejudice against this very species. [A] In Vienna, wefound by personal experience that, although many others are eaten, itis this which has the most universal preference, yet it appears butsparingly in the markets as compared with others. In Hungary it doesnot enjoy by any means so good a reputation. In France and in Germanyit is a common article of consumption. The different varieties found, as the results of cultivation, present some variation in colour, scaliness of pileus, and other minor features, whilst remaining trueto the constituent characters of the species. Although it is not ourintention to enumerate here the botanical distinctions of the speciesto which we may call attention, yet, as mistakes (sometimes fatal) areoften being recorded, in which other fungi are confounded with this, we may be permitted a hint or two which should be remembered. Thespores are purple, the gills are at first delicate pink, afterwardspurple; there is a permanent ring or collar round the stem, and itmust _not_ be sought in woods. Many accidents might have been sparedhad these facts been remembered. 

The meadow mushroom (_Agaricus arvensis_) is common in meadows andlowland pastures, and is usually of a larger size than the preceding, with which it agrees in many particulars, and is sent in enormousquantities to Covent Garden, where it frequently predominates over_Agaricus campestris_. Some persons prefer this, which has a strongerflavour, to the ordinary mushroom, and it is the species most commonlysold in the autumn in the streets of London and provincial towns. According to Persoon, it is preferred in France; and, in Hungary, itis considered as a special gift from St. George. It has acquired inEngland the name of horse mushroom, from the enormous size itsometimes attains. Withering mentions a specimen that weighed fourteenpounds. [B]

One of the commonest (in our experience the _most_ common) of alledible fungi in the public markets of Vienna is the Hallimasche(_Agaricus melleus_), which in England enjoys no good reputation forflavour or quality; indeed, Dr. Badham calls it "nauseous anddisagreeable, " and adds that "not to be poisonous is its onlyrecommendation. " In Vienna it is employed chiefly for making sauce;but we must confess that even in this way, and with a prejudice infavour of Viennese cookery, our experience of it was not satisfactory. It is at best a sorry substitute for the mushroom. In the summer andautumn this is a very common species in large tufts on old stumps. Insimilar localities, and also in tufts, but neither so large, nor socommon, _Agaricus fusipes_ is found. It is preferable to the foregoingas an esculent, and is easily recognized by the spindle-shaped stem. 

_Agaricus rubescens_, P. , belongs to a very suspicious group offungi, in which the cap or pileus is commonly studded or sprinkledwith paler warts, the remains of an investing volva. To this groupthe poisonous but splendid fly-agaric (_Agaricus muscarius_)belongs. Notwithstanding its bad company, this agaric has a goodreputation, especially for making ketchup; and Cordier reports itas one of the most delicate mushrooms of the Lorraine. [C] Its nameis derived from its tendency to become red when bruised. 

The white variety of an allied species (_Agaricus vaginatus_) has beencommended, and Dr. Badham says that it will be found inferior to butfew agarics in flavour. 

A scaly-capped fungus (_Agaricus procerus_), with a slender stem, called sometimes the parasol mushroom, from its habit, is an esteemedesculent. In Italy and France it is in high request, and is includedin the majority of continental works on the edible fungi. [D] InAustria, Germany, and Spain, it has special "vulgar" names, and iseaten in all these countries. It is much more collected in Englandthan formerly, but deserves to be still better known. When once seenit can scarcely be confounded with any other British species, save oneof its nearest allies, which partakes of its own good qualities(_Agaricus rachodes_), though not quite so good. 

_Agaricus prunulus_, Scop. , and _Agaricus orcella_, Badh. , if they benot forms of the same species (which Dr. Bull contends that they arenot[E]), have also a good reputation as esculents. They are both neat, white agarics, with a mealy odour, growing respectively in woods andopen glades. _Agaricus nebularis_, Batsch, is a much larger species, found in woods, often in large gregarious patches amongst dead leaves, with a smoky mouse-coloured pileus, and profuse white spores. It issometimes as much as five or six inches in diameter, with rather afaint odour and mild taste. On the continent, as well as in Britain, this is included amongst edible fungi. Still larger and more imposingis the magnificent white species, _Agaricus maximus_, Fr. , [F] which isfigured by Sowerby, [G] under the name of _Agaricus giganteus_. It willattain a diameter of fourteen inches, with a stem, two inches thick, and rather a strong odour. 

A spring fungus, the true St. George's mushroom, _Agaricus gambosus_, Fr. , makes its appearance in pastures, usually growing in rings, inMay and June, and is welcome to mycophagists from its early growth, when esculent species are rare. It is highly esteemed in France andItaly, so that when dried it will realize as much as from twelve tofifteen shillings per pound. Guillarmod includes it amongst Swissesculents. [H] Professor Buckman says that it is one of the earliestand best of English mushrooms, and others have endorsed his opinions, and Dr. Badham in writing of it observes, that small baskets of them, when they first appear in the spring in Italy, are sent as "presentsto lawyers and fees to medical men. "

The closely allied species, _Agaricus albellus_, [I] D. C. , has also thereputation of being edible, but it is so rare in England that thisquality cannot be put to the test. The curious short-stemmed _Agaricusbrevipes_, Bull, [J] has a similar reputation. 

Two singularly fragrant species are also included amongst theesculent. These are _Agaricus fragrans_, Sow. , and _Agaricus odorus_, Bull. Both have a sweet anise-like odour, which is persistent for along time. The former is pale tawny-coloured, nearly white, the latterof a dirty pale green. Both are white-spored, and although somewhatlocal, sufficient specimens of _Ag. Odorus_ may be collected in theautumn for domestic use. We have the assurance of one who has oftenproved them that they constitute an exquisite dish. 

A clear ivory-white fungus, _Agaricus dealbatus_, of which a crispedvariety is occasionally found in great numbers, springing up on oldmushroom beds in dense clusters, is very good eating, but ratherdeficient in the delicate aroma of some other species. The typicalform is not uncommon on the ground in fir plantations. A more robustand larger species, _Agaricus geotrupes_, Bull, found on the bordersof woods, often forming rings, both in this country and in the UnitedStates, as well as on the continent of Europe, is recognized asesculent. 

We may add to these three or four other species, in which the stem islateral, and sometimes nearly obsolete. The largest and most common isthe oyster mushroom (_Agaricus ostreatus_, Jacq. [K]), so universallyeaten, that it is included in almost every list and book on ediblefungi; it is the most common species in Transylvania, tons of itsometimes appearing in the markets. It does not possess that delicateflavour which is found in many species, and although extolled by somebeyond its merits, it is nevertheless perfectly wholesome, and, whenyoung and carefully cooked, not to be despised. It must not beconfounded with a very similar species (_Agaricus euosmus_, B. ), withrosy spores, which is unpleasant. _Agaricus tessellatus_, Bull, _Agaricus pometi_, Fr. , _Agaricus glandulosus_, Bull, are all alliesof the foregoing, and recorded as edible in the United States, although not one of the three has hitherto been recorded as occurringin Great Britain. To these may also be added the following:--_Agaricussalignus_, [L] Fr. , which is rare in England, but not uncommon abroadand in the United States. In Austria it is commonly eaten. _Agaricusulmarius_, [M] Bull, is common on elm trunks, not only in Britain butalso in North America, and is by some preferred to the oystermushroom. An allied species, _Agaricus fossulatus_, Cooke, [N] is foundon the Cabul Hills, where it is collected, dried, and forms an articleof commerce with the plains. Another, but smaller species, is dried inthe air on strings passed through a hole in the short stem (_Agaricussubocreatus_, Cooke), and sent, it is believed, from China toSingapore. 

The smallest species with which we have any acquaintance, that isedible, is the "nail fungus" (_Agaricus esculentus_, [O] Jacq. ), scarcely exceeding one inch in diameter of the pileus, with a thinrooting stem. The taste in British specimens when raw is bitter andunpleasant, but it is clearly eaten in Austria, as its name testifies, and elsewhere in Europe. It is found in fir plantations in the spring, at which season it is collected from the fir woods around and sent toVienna, where it is only used for flavouring sauces under the name of"Nagelschwämme. "

Before quitting the group of true agarics, to which all hithertoenumerated belong, we must mention a few others of less importance, but which are included amongst those good for food. Foremost of theseis a really splendid orange species (_Agaricus cæsarius_, Scop. [P]), which belongs to the same subgenus as the very deleterious fly-agaric, and the scarcely less fatal _Agaricus vernus_, Bull. It is universallyeaten on the continent, but has hitherto never been found in GreatBritain. In the same subgenus, _Agaricus strobiliformis_, [Q] Fr. , which is rare in this country, and probably also _Agaricus Ceciliæ_, B. & Br. [R] Besides these, _Agaricus excoriatus_, Schæff. , _Agaricusmastoideus_, Fr. , _Agaricus gracilentus_, Kromb. , and _Agaricusholosericeus_, Fr. , [S] all belonging to the same subgenus as theparasol mushroom, more or less uncommon in England. 

Although the larger number of esculent agarics are white-spored, somefew, worthy of note, will be found in the other sections, and notablyamongst these the common mushroom and its congener the meadow, orhorse mushroom. In addition to those already enumerated, might beincluded also the _Agaricus pudicus_, Bull, which is certainlywholesome, as well as its ally, _Agaricus leochromus_, Cooke, [T] bothof which have rusty spores. 

The late Dr. Curtis, [U] in a letter to the Rev. M. J. Berkeley, enumerates several of the fungi which are edible amongst those foundin the United States. Of these, he says, _Agaricus amygdalinus_, Curt. , can scarcely be distinguished when cooked from the commonmushroom. _Agaricus frumentaceus_, Bull, and three allied new species, peculiar to the United States, are commended. _Agaricus cæspitosus_, Curt. , he says, is found in enormous quantities, a single clustercontaining from fifty to one hundred stems, and might well be deemed avaluable species in times of scarcity. It would not be highly esteemedwhere other and better species can be had, but it is generallypreferred to _Agaricus melleus_, Fr. It is suitable for drying forwinter use. In the same communication, he observes that the imperial(_Agaricus cæsarius_, Scop. ), grows in great quantities in oakforests, and may be obtained by the cart-load in its season; but tohis taste, and that of his family, it is the most unpalatable offungi, nor could he find any of the most passionate mycophagists whowould avow that they liked it. There is a disagreeable saline flavourthat they could not remove nor overlay. In addition to these, the sameauthority enumerates _Agaricus russula_, Schæff. , _Agaricushypopithyus_, Curt. , and _Agaricus consociatus_, Curt. , the latter twobeing confined to the United States; _Agaricus columbetta_, Fr. , foundin Britain, but not eaten, as well as _Agaricus radicatus_, Bull. _Agaricus bombycinus_, Schæff. , and _Agaricus speciosus_, Fr. , arefound in Britain, but by no means common; _Agaricus squarrosus_, Mull. , has always been regarded with great suspicion in this country, where it is by no means uncommon; _Agaricus cretaceus_, Fr. , and_Agaricus sylvaticus_, Schæff. , are close allies of the commonmushroom. 

Dr. Curtis says that hill and plain, mountain and valley, woods, fields, and pastures, swarm with a profusion of good nutritious fungi, which are allowed to decay where they spring up, because people do notknow how, or are afraid, to use them. By those of us who know theiruse, their value was appreciated, as never before, during the latewar, when other food, especially meat, was scarce and dear. Then suchpersons as I have heard express a preference for mushrooms over meathad generally no need to lack grateful food, as it was easily had forthe gathering, and within easy distance of their homes if living inthe country. Such was not always the case, however. I remember once, during the gloomy period when there had been a protracted drought, andfleshy fungi were to be found only in damp shaded woods, and but feweven there, I was unable to find enough of any one species for a meal, so, gathering of every kind, I brought home thirteen different kinds, had them all cooked together in one grand _pot pourri_, and made anexcellent supper. 

One important use to which several species of fungi can be applied, isthe manufacture of ketchup. For this purpose, not only is themushroom, _Agaricus campestris_, and the horse mushroom, _Agaricusarvensis_, available, but also _Agaricus rubescens_ is declared to beexcellent for the purpose, and a delicious, but pale, extract is to beobtained from _Marasmius oreades_. Other species, as _Coprinuscomatus_, and _Coprinus atramentarius_, are also available, togetherwith _Fistulina hepatica_, and _Morchella esculenta_. In somedistricts, when mushrooms are scarce, it is stated that almost anyspecies that will yield a dark juice is without scruple mixed with thecommon mushroom, and it should seem without any bad consequence exceptthe deterioration of the ketchup. [V] There is an extensive manufactureof ketchup conducted at Lubbenham, near Market Harborough, but thegreat difficulty appears to be the prevention of decomposition. Messrs. Perkins receive tons of mushrooms from every part of thekingdom, and they find, even in the same species, an immensedifference in the quality and quantity of the produce. The price ofmushrooms varies greatly with the season, ranging between one pennyand sixpence per pound. Messrs. Perkins are very careful in theirselection, but little discrimination is used by country manufacturerson a small scale, who use such doubtful species as _Agaricuslacrymabundus_, with _Agaricus spadiceus_, and a host of alliedspecies, which they characterize as nonpareils and champignons. In theeastern counties _Agaricus arvensis_ has the preference for ketchup. 

The generic distinctions between the genuine Agarics and some of theallied genera can hardly be appreciated by the non-botanical reader, but we have nevertheless preferred grouping the edible speciestogether in a somewhat botanical order; and, pursuing this plan, thenext species will be those of _Coprinus_, in which the gills aredeliquescent after the plant has arrived at maturity. The manedmushroom (_Coprinus comatus_, Fr. )[W] is the best of edible species inthis group. It is very common here by roadsides and other places, andwhilst still young and cylindrical, and the gills still whitish orwith a roseate tint, it is highly to be commended. Similar, butperhaps somewhat inferior, is _Coprinus atramentarius_, Fr. , [X]equally common about old stumps and on the naked soil. Both speciesare also found and eaten in the United States. 

In _Cortinarius_, the veil is composed of arachnoid threads, and thespores are rusty. The number of edible species are few. Foremost isthe really handsome _Cortinarius violaeus_, Fr. , [Y] often nearly fourinches in diameter, and of a beautiful violet colour; and the smaller_Cortinarius castaneus_, Fr. , [Z] scarcely exceeding an inch indiameter, both being found in woods, and common alike to Britain andthe United States. _Cortinarius cinnamomeus_, Fr. , is also a lover ofwoods, and in northern latitudes is found inhabiting them everywhere. It has a cinnamon-coloured pileus, with yellowish flesh, and its odourand flavour is said to partake of the same spice. In Germany it isheld in high esteem. _Cortinarius emodensis_, B. , is eaten in NorthernIndia. 

The small genus _Lepista_ of Smith, (which, however, is not adopted byFries in his now edition of the "Epicrisis") includes one esculentspecies in _Lepista personata_, the _Agaricus personatus_ of Fries. [a]It is by no means uncommon in Northern Europe or America, frequentlygrowing in large rings; the pileus is pallid, and the stem stainedwith lilac. Formerly it was said to be sold in Covent Garden Marketunder the name of "blewits, " but we have failed to see or hear of itduring many years in London. 

Small fungi of ivory-whiteness are very common amongst grass on lawnsin autumn. These are chiefly _Hygrophorus virgineus_, Fr. , [b] andalthough not much exceeding an inch in diameter, with a short stem, and wide decurrent gills, they are so plentiful in season thatquantity soon compensates for the small size. Except that it isoccasionally eaten in France, it does not enjoy much reputationabroad. A larger species, varying from buff to orange, _Hygrophoruspratensis_, Fr. , [c] is scarcely less common in open pastures. This isvery gregarious in habit, often growing in tufts, or portions ofrings. The pileus is fleshy in the centre, and the gills thick anddecurrent. In France, Germany, Bohemia, and Denmark, it is includedwith esculent species. In addition may be mentioned _Hygrophoruseburneus_, Fr. , another white species, as also _Hygrophorus niveus_, Fr. , which grows in mossy pastures. _Paxillus involutus_, Fr. , [d]though very common in Europe, is not eaten, yet it is included by Dr. Curtis with the esculent species of the United States. 

The milky agarics, belonging to the genus _Lactarius_, are distinguishedby the milky juice which is exuded when they are wounded. The sporesare more or less globose, and rough or echinulate, at least in manyspecies. The most notable esculent is _Lactarius deliciosus_, Fr. , [e] inwhich the milk is at first saffron-red, and afterwards greenish, theplant assuming a lurid greenish hue wherever bruised or broken. Universal commendation seems to fall upon this species, writersvying with each other to say the best in its praise, and mycophagistseverywhere endorsing the assumption of its name, declaring it to bedelicious. It is found in the markets of Paris, Berlin, Prague, andVienna, as we are informed, and in Sweden, Denmark, Switzerland, Russia, Belgium; in fact, in nearly all countries in Europe it isesteemed. 

Another esculent species, _Lactarius volemum_, Fr. , [f] has white milk, which is mild to the taste, whilst in deleterious species with whitemilk it is pungent and acrid. This species has been celebrated fromearly times, and is said to resemble lamb's kidney. 

_Lactarius piperatus_, Fr. , is classed in England with dangerous, sometimes poisonous species, whereas the late Dr. Curtis, of NorthCarolina, has distinctly informed us that it is cooked and eatenin the United States, and that he has partaken of it. He includes_Lactarius insulsus_, Fr. , and _Lactarius subdulcis_, Fr. , [g]amongst esculent species; both are also found in this country, butnot reputed as edible; and _Lactarius angustissimus_, Lasch, whichis not British. Species of _Lactarius_ seem to be eaten almostindiscriminately in Russia when preserved in vinegar and salt, inwhich condition they form an important item in the kinds of foodallowed in their long fasts, some _Boleti_ in the dried stateentering into the same category. 

The species of _Russula_ in many respects resemble _Lactarii_ withoutmilk. Some of them are dangerous, and others esculent. Amongst thelatter may be enumerated _Russula heterophylla_, Fr. , which is verycommon in woods. Vittadini pronounces it unsurpassed for fineness offlavour by even the notable _Amanita cæsarea_. [h] Roques gives also anaccount in its favour as consumed in France. Both these authors givefavourable accounts of _Russula virescens_, P. , [i] which the peasantsabout Milan are in the habit of putting over wood embers to toast, andeating afterwards with a little salt. Unfortunately it is by no meanscommon in England. A third species of _Russula_, with buff-yellowgills, is _Russula alutacea_, Fr. , which is by no means to bedespised, notwithstanding that Dr. Badham has placed it amongstspecies to be avoided. Three or four others have also the merit ofbeing harmless, and these recorded as esculent by some one or moremycological authors: _Russula lactea_, Fr. , a white species, foundalso in the United States; _Russula lepida_, Fr. , a roseate species, found also in lower Carolina, U. S. ; and another reddish species, _Russula vesca_, Fr. , as well as _Russula decolorans_, Fr. Whilstwriting of this genus, we may observe, by way of caution, that itincludes also one very noxious red species, _Russula emetica_, Fr. , with white gills, with which some of the foregoing might be confoundedby inexperienced persons. 

The chantarelle _Cantharellus cibarius_, Fr. , has a most charming andenticing appearance and odour. In colour, it is of a bright goldenyellow, and its smell has been compared to that of ripe apricots. Itis almost universally eaten in all countries where it is found, England excepted, where it is only to be met with at the "Freemason'sTavern" on state occasions, and at the tables of pertinaciousmycophagists. [j] Trattinnick says: "Not only this same fungus neverdid any one harm, but might even restore the dead. "[k]

The fairy-ring champignon _Marasmius oreades_, Fr. , though small, isplentiful, and one of the most delicious of edible fungi. It grows inexposed pastures, forming rings, or parts of rings. This champignonpossesses the advantage of drying readily, and preserving its aromafor a long time. We have often regretted that no persistent attemptsand experiments have been made with the view of cultivating thisexcellent and useful species. _Marasmius scorodonius_, Fr. , [l] asmall, strong-scented, and in all respects inferior species, found onheaths and dry pastures, extending even to the United States, isconsumed in Germany, Austria, and other continental countries, where, perhaps its garlic odour has been one of its recommendations as aningredient in sauces. In this enumeration we have not exhausted allthe gill-bearing species which might be eaten, having included onlythose which have some reputation as esculents, and of these moreparticularly those found in Great Britain and the United States. 

Amongst the _Polyporei_, in which the gill plates are represented bypores or tubes, fewer esculent species are to be met with than in the_Agaricini_, and the majority of these belong to the genus _Boletus_. Whilst in Vienna and Hanover, we were rather surprised to find_Boletus edulis_, Fr. , cut into thin slices and dried, exposed forsale in almost every shop where meal, peas, and other farinaceousedibles were sold. This species is common enough in England, but as arule it does not seem to please the English palate, whereas on thecontinent no fungus is more commonly eaten. This is believed to be thesuillus eaten by the ancient Romans, [m] who obtained it from Bithynia. The modern Italians dry them on strings for winter use, and inHungary a soup is made from them when fresh. A more excellent species, according to our judgment, is _Boletus æstivalis_, Fr. , [n] whichappears in early summer, and has a peculiar nutty flavour when raw, reminding one more of a fresh mushroom. _Boletus scaber_, Fr. , [o] isalso common in Britain, as well as the continent, but does not enjoyso good a reputation as _B. Edulis_. Krombholz says that _Boletusbovinus_, Fr. , a gregarious species, found on heaths and in fir woods, is much sought after abroad as a dish, and is good when dried. _Boletus castaneus_, Fr. , [p] is a small species with a mild, pleasanttaste when raw, and very good when properly cooked. It is notuncommonly eaten on the continent. _Boletus chrysenteron_, Fr. , [q] and_Boletus subtomentosus_, Fr. , are said to be very poor eating, andsome authors have considered them injurious; but Mr. W. G. Smithstates that he has on more than one occasion eaten the former, andTrattinnick states that the latter is eaten in Germany. The late Mr. Salter informed us that, when employed on the geological staff, he atone time lived almost entirely on different species of Boleti, withoutusing much discrimination. Sir W. C. Trevelyan also informs us that hehas eaten _Boletus luridus_ without any unpleasant consequences, butwe confess that we should be sorry to repeat the experiment. Dr. Badham remarks that he has eaten _Boletus Grevillei_, B. , _Boletusflavus_, With. , and _Boletus granulatus_, L. , the latter beingrecognized also as edible abroad. Dr. Curtis experimented, in theUnited States, on _Boletus collinitus_, and although he professes notto be particularly fond of the Boleti, he recognizes it as esculent, and adds that it had been pronounced delicious by some to whom he hadsent it. He also enumerates as edible _Boletus luteus_, Fr. , _Boletuselegans_, Fr. , _Boletus flavidus_, Fr. , _Boletus versipellis_, Fr. , _Boletus leucomelas_, Tr. , and _Boletus ovinus_, Sch. Two Italianspecies of _Polyporus_ must not be forgotten. These are _Polyporustuberaster_, Pers. , which is procured by watering the _pietrafunghaia_, or fungus stone, a kind of tufa, in which the mycelium isembedded. It is confined to Naples. The other species is _Polyporuscorylinus_, Mauri. , procured artificially in Rome from charred stumpsof the cob-nut tree. [r]

Of true _Polyporus_, only two or three species have been regardedfavourably as esculents. These are--_Polyporus intybaceus_, Fr. , whichis of very large size, sometimes attaining as much as forty pounds;_Polyporus giganteus_, Fr. , also very large, and leathery when old. Both these species are natives of Britain. Only young and juicyspecimens must be selected for cooking. _Polyporus umbellatus_, Fr. , is stated by Fries to be esculent, but it is not found in Britain. _Polyporus squamosus_, Fr. , has been also included; but Mrs. Husseythinks that one might as well think of eating saddle-flaps. None ofthese receive very much commendation. Dr. Curtis enumerates, amongstNorth American species, the _Polyporus cristatus_, Fr. , _Polyporusporipes_, Fr. , which, when raw, tastes like the best chestnuts orfilberts, but is rather too dry when cooked. _Polyporus Berkeleii_, Fr. , is intensely pungent when raw, but when young, and before thepores are visible, it may be eaten with impunity, all its pungencybeing dissipated by cooking. _Polyporus confluens_, Fr. , he considerssuperior, and, in fact, quite a favourite. _Polyporus sulfureus_, Fr. , which is not eaten in Europe, he considers just tolerably safe, butnot to be coveted. It is by no means to be recommended to persons withweak stomachs. In his catalogue, Dr. Curtis enumerates one hundred andeleven species of edible fungi found in Carolina. [s]

With _Fistulina hepatica_, Fr. , it is different; for here we encountera fleshy, juicy fungus, resembling beefsteak a little in appearance, and so much more in its uses, that the name of "beefsteak fungus" hasbeen given to it. Some authors are rapturous in their praise of_Fistulina_. It sometimes attains a very large size, Dr. Badhamquoting[t] one found by himself nearly five feet in circumference, and weighing eight pounds; whilst another found by Mr. Graves weighednearly thirty pounds. In Vienna it is sliced and eaten with salad, like beetroot, which it then much resembles. On the continent it iseverywhere included amongst the best of edible species. 

The _Hydnei_, instead of pores or tubes, are characterized by spinesor warts, over which the fructifying surface is expanded. The mostcommon is _Hydnum repandum_, Fr. , found in woods and woody places inEngland, and on the continent, extending into the United States. Whenraw, it is peppery to the taste, but when cooked is much esteemed. From its drier nature, it can readily be dried for winter use. Lesscommon in England is _Hydnum imbricatum_, Fr. , although not souncommon on the continent. It is eaten in Germany, Austria, Switzerland, France, and elsewhere. _Hydnum lævigatum_, Swartz, iseaten in Alpine districts. [u] Of the branched species, _Hydnumcoralloides_, Scop. , [v] and _Hydnum Caput Medusæ_, Bull, [w] areesculent, but very rare in England. The latter is not uncommon inAustria and Italy, the former in Germany, Switzerland, and France. _Hydnum erinaceum_, Bull, is eaten in Germany[x] and France. 

The Clavarioid fungi are mostly small, but of these the majority ofthe white-spored are edible. _Clavaria rugosa_, Bull, is a commonBritish species, as also is _Clavaria coralloides_, L. , the formerbeing found also in the United States. _Clavaria fastigiata_, D. C. , is not uncommon; but _Clavaria amethystina_, Bull, a beautiful violetspecies, is rare. In France and Italy, _Clavaria cinerea_, Bull, isclassed with esculents; and it is not uncommon in Britain. _Clavariabotrytis_, P. , and _Clavaria aurea_, Schæff. , are large and beautifulspecies, but rare with us; they extend also into the United States. Others might be named (Dr. Curtis enumerates thirteen species eaten inCarolina), which are certainly wholesome, but they are of littleimportance as edible species. _Sparassis crispa_, Fr. , is, on thecontrary, very large, resembling in size, [y] and somewhat inappearance, a cauliflower; it has of late years been found severaltimes in this country. In Austria it is fricasseed with butter andherbs. 

Of the true Tremellæ, none merit insertion here. The curious Jew's ear(_Hirneola auricula-Judæ_, Fr. ), with one or two other species of_Hirneola_, are collected in great quantities in Tahiti, and shippedin a dried state to China, where they are used for soup. Some of thesefind their way to Singapore. 

The false truffles (_Hypogæi_) are of doubtful value, one species(_Melanogaster variegatus_, Tul. ) having formerly been sold in themarkets of Bath as a substitute for the genuine truffle. [z] Neitheramongst the _Phalloidei_ do we meet with species of any economicvalue. The gelatinous volva of a species of _Ileodictyon_ is eaten bythe New Zealanders, to whom it is known as thunder dirt; whilst thatof _Phallus Mokusin_ is applied to a like purpose in China;[AA] butthese examples would not lead us to recommend a similar use for_Phallus impudicus_, Fr. , in Britain, or induce us to prove theassertion of a Scotch friend that the porous stem is very goodeating. 

One species of puff-ball, _Lycoperdon giganteum_, Fr, [AB] has manystaunch advocates, and whilst young and cream-like, it is, when wellmanipulated, an excellent addition to the breakfast-table. A decidedadvantage is possessed by this species, since one specimen is oftenfound large enough to satisfy the appetites of ten or twelve persons. Other species of _Lycoperdon_ have been eaten when young, and we havebeen assured by those who have made the experiment, that they arescarcely inferior to their larger congener. _Bovista nigrescens_, Fr. , and _Bovista plumbea_, Fr. , are also eaten in the United States. Morethan one species of _Lycoperdon_ and _Bovista_ appear in the bazaarsof India, as at Secunderabad and Rangoon; while the white ant-hills, together with an excellent Agaric, produce one or more species of_Podaxon_ which are esculent when young. A species of _Scleroderma_which grows abundantly in sandy districts, is substituted for trufflesin Perigord pies, of which, however, it does not possess any of thearoma. 

[Illustration: FIG. 43. --_Morchella gigaspora_, from Kashmir. ]

Passing over the rest of the sporiferous fungi, we find amongst the_Ascomycetous_ group several that are highly esteemed. Amongst thesemay first be named the species of morel, which are regarded asdelicacies wherever they are found. _Morchella esculenta_, Pers. , isthe most common species, but we have also _Morchella semilibera_, D. C. , and the much larger _Morchella crassipes_, Pers. Probably all thespecies of _Morchella_ are esculent, and we know that many besides theabove are eaten in Europe and other places; _Morchella deliciosa_, Fr. , in Java; _Morchella bohemica_, Kromb. , in Bohemia; _Morchellagigaspora_, Cooke, and _Morchella deliciosa_, Fr. , in Kashmere. [AC]_Morchella rimosipes_, D. C. , occurs in France and Bohemia;_Morchella Caroliniana_, Bosc. , in the Southern United States ofAmerica. W. G. Smith records the occurrence in Britain of specimens of_Morchella crassipes_, P. , ten inches in height, and one specimen waseleven inches high, with a diameter of seven and a half inches. [AD]

Similar in uses, though differing in appearance, are the species of_Helvella_, of which several are edible. In both these genera, theindividuals can be dried so readily that they are the more valuable onthat account, as they can be used for flavouring in winter when freshspecimens of any kind of fungus are difficult to procure. The mostcommon English species is _Helvella crispa_, Fr. , but _Helvellalacunosa_, Fr. , is declared to be equally good, though not so largeand somewhat rare. _Helvella infula_, Fr. , is also a large species, but is not British, although it extends to North America, as also does_Helvella sulcata_, Afz. Intermediate between the morel and _Helvella_is the species which was formerly included with the latter, but nowknown as _Gyromitra esculenta_, Fr. [AE] It is rarely found in GreatBritain, but is more common on the continent, where it is held inesteem. A curious stipitate fungus, with a pileus like a hood, called_Verpa digitaliformis_, Pers. , [AF] is uncommon in England, butVittadini states that it is sold in the Italian markets, although onlyto be recommended when no other esculent fungus offers, which issometimes the case in spring. [AG]

Two or three species of _Peziza_ have the reputation of beingesculent, but they are of very little value; one of these is _Pezizaacetabulum_, L. , another is _Peziza cochleata_, Huds. , and a third is_Peziza venosa_, Pers. [AH] The latter has the most decided nitrousodour, and also fungoid flavour, whilst the former seem to have butlittle to recommend them; we have seen whole baskets full of _Pezizacochleata_ gathered in Northamptonshire as a substitute for morels. 

A very interesting genus of edible fungi, growing on evergreenbeech trees in South America, has been named _Cyttaria_. One ofthese, _Cyttaria Darwinii_, B. , occurs in Terra del Fuego, where itwas found by Mr. C. Darwin[AI] growing in vast numbers, andforming a very essential article of food for the natives. Another is_Cyttaria Berteroi_, B. , also seen by Mr. Darwin in Chili, and eatenoccasionally, but apparently not so good as the preceding. [AJ] Anotherspecies is _Cyttaria Gunnii_, B. , which abounds in Tasmania, and isheld in repute amongst the settlers for its esculent properties. [AK]

[Illustration: FIG. 44. --_Cyttaria Gunnii_, B. ]

It remains for us only to note the subterranean fungi, of which thetruffle is the type, to complete our enumeration of esculent species. The truffle which is consumed in England is _Tuber æstivum_, Vitt. ;but in France the more highly-flavoured _Tuber melanospermum_, Vitt. , [AL] and also _Tuber magnatum_, Pico, with some other species. In Italy they are very common, whilst some are found in Algeria. Onespecies at least is recorded in the North-west of India, but inNorthern Europe and North America they appear to be rare, and_Terfezia Leonis_ is used as an esculent in Damascus. A large speciesof _Mylitta_, sometimes several inches in diameter, occurs plentifullyin some parts of Australia. Although often included with fungi, thecurious production known under the name of _Pachyma cocos_, Fr. , isnot a fungus, as proved by the examinations made by the Rev. M. J. Berkeley. It is eaten under the name of "Tuckahoe" in the UnitedStates, and as it consists almost entirely of pectic acid, it issometimes used in the manufacture of jelly. 

In the Neilgherries (S. India), a substance is occasionally foundwhich is allied to the native bread of southern latitudes. It is foundat an elevation of 5, 000 feet. The natives call it "a little man'sbread, " in allusion to the tradition that the Neilgherries were oncepeopled by a race of dwarfs. [AM] At first it was supposed that thesewere the bulbs of some orchid, but later another view was held oftheir character. Mr. Scott, who examined the specimens sent down tohim, remarks that, instead of being the product of orchids, it is thatof an underground fungus of the genus _Mylitta_. It indeed seems, hesays, very closely allied to, if really distinct from, the so-callednative bread of Tasmania. [AN]

Of the fungi employed in medicine, the first place must be assigned toergot, which is the sclerotioid condition of a species of _Claviceps_. It occurs not only on rye but on wheat, and many of the wild grasses. On account of its active principle, this fungus still holds its placein the Materia Medica. Others which formerly had a reputation are nowdiscarded, as, for instance, the species of _Elaphomyces_; and_Polyporus officinalis_, Fr. , which has been partly superseded as astyptic by other substances, was formerly employed as a purgative. Theripe spongy capillitium of the great puff-ball _Lycoperdon giganteum_, Fr. , has been used for similar purposes, and also recommended as ananodyne; indeed formidable surgical operations have been performedunder its influence, and it is frequently used as a narcotic in thetaking of honey. Langsdorf gives a curious account of its employmentas a narcotic; and in a recent work on Kamtschatka it is said toobtain a very high price in that country. Dr. Porter Smith writes ofits employment medicinally by the Chinese, but from his own specimensit is clearly a species of _Polysaccum_, which he has mistaken for_Lycoperdon_. In China several species are supposed to possess greatvirtue, notably the _Torrubia sinensis_, Tul. , [AO] which is developedon dead caterpillars; as it is, however, recommended to administer itas a stuffing to roast duck, we may be sceptical as to its ownsanitary qualities. _Geaster hygrometricus_, Fr. , we have alsodetected amongst Chinese drugs, as also a species of _Polysaccum_, andthe small hard _Mylitta lapidescens_, Horn. In India, a large butimperfect fungus, named provisionally _Sclerotium stipitatum_, Curr. , found in nests of the white ant, is supposed to possess greatmedicinal virtues. [AP] A species of _Polyporus_ (_P. Anthelminticus_, B. ), which grows at the root of old bamboos, is employed in Burmah asan anthelmintic. [AQ] In former times the Jew's ear (_Hirneola auriculaJudæ_, Fr. ) was supposed to possess great virtues, which are nowdiscredited. Yeast is still included amongst pharmaceuticalsubstances, but could doubtless be very well dispensed with. Trufflesare no longer regarded as aphrodisiacs. 

For other uses, we can only allude to amadou, or German tinder, whichis prepared in Northern Europe from _Polyporus fomentarius_, Fr. , cutin slices, dried, and beaten until it is soft. This substance, besidesbeing used as tinder, is made into warm caps, chest protectors, andother articles. This same, or an allied species of _Polyporus_, probably _P. Igniarius_, Fr. , is dried and pounded as an ingredient insnuff by the Ostyacks on the Obi. In Bohemia some of the largePolyporei, such as _P. Igniarius_ and _P. Fomentarius_, have the poresand part of the inner substance removed, and then the pileus isfastened in an inverted position to the wall, by the part whereoriginally it adhered to the wood. The cavity is then filled withmould, and the fungus is used, with good effect, instead offlower-pots, for the cultivation of such creeping plants as requirebut little moisture. [AR]

The barren mycelioid condition of _Penicillium crustaceum_, Fr. , isemployed in country districts for the domestic manufacture of vinegarfrom saccharine liquor, under the name of the "vinegar plant. " It isstated that _Polysaccum crassipes_, D. C. , [AS] is employed in theSouth of Europe to produce a yellow dye; whilst recently _Polyporussulfureus_, Fr. , has been recommended for a similar purpose. _Agaricusmuscarius_, Fr. , the fly-agaric, known to be an active poison, is usedin decoction in some parts of Europe for the destruction of flies andbugs. Probably _Helotium æruginosum_, Fr. , [AT] deserves mention here, because it stains the wood on which it grows, by means of its diffusemycelium, of a beautiful green tint, and the wood thus stained isemployed for its colour in the manufacture of Tonbridge ware. 

This completes the list, certainly of the most important, of the fungiwhich are of any direct use to humanity as food, medicine, or in thearts. As compared with lichens, the advantage is certainly in favourof fungi; and even when compared with algæ, the balance appears intheir favour. In fact, it may be questioned whether, after all, fungido not present a larger proportion of really useful species than anyother of the cryptogams; and without any desire to disparage theelegance of ferns, the delicacy of mosses, the brilliancy of somealgæ, or the interest which attaches to lichens, it may be claimed forfungi that in real utility (not uncombined with injuries as real) theystand at the head of the cryptogams, and in closest alliance with theflowering plants. 

 [A] Badham, Dr. C. D. , "A Treatise on the Esculent Funguses of England, " 1st edition (1847), p. 81, pl. 4; 2nd edition, edited by F. Currey, M. A. (1863), p. 94, pl. 4; Cooke, M. C. , "A Plain and Easy Account of British Fungi, " 1st edition (1862), p. 44. 

 [B] Mr. Worthington Smith has published, on two sheets, coloured figures of the most common esculent and poisonous fungi (London, Hardwicke), which will be found more useful than mere description in the discrimination of the species. 

 [C] Roques, J. , "Hist. Des Champignons Comestibles et Vénéneux, " Paris (1832), p. 130. 

 [D] Lenz, Dr. H. 0. , "Die Nützlichen und Schädlichen Schwämme, " Gotha (1831), p. 32, pl. 2. 

 [E] Bull, H. G. , in "Transactions of Woolhope Club" (1869). Fries admits them as distinct species in the new edition of his "Epicrisis. "

 [F] Hussey's "Illustrations of Mycology, " ser. I. Pl. 79. 

 [G] Sowerby's "British Fungi, " pl. 244. 

 [H] Favre-Guillarmod, "Les Champignons Comestibles du Canton de Neuchatel" (1861), p. 27. 

 [I] Sowerby, "English Fungi, " pl. 122; Smith, in "Seemann's Journ. Bot. " (1866), t. 46, f. 45. 

 [J] Klotsch, "Flora Borussica, " t. 374; Smith, in "Seem. Journ. Bot. " (1869), t. 95, f. 1-4. 

 [K] Krombholz, "Abbildungen der Schwämme, " pl. 41, f. 1-7. 

 [L] Tratinnick, L. , "Fungi Austriaci, " p. 47, pl. 4, f. 8. 

 [M] Vittadini, "Fungi Mangerecci, " pl. 23. 

 [N] Cooke, in "Journal of Botany, " vol. Viii. P. 352. 

 [O] Cooke, M. C. , "A Plain and Easy Guide, " &c. , p. 38, pl. 6, fig. 1. 

 [P] Krombholz, "Schwämme, " t. 8. Vittadini, "Mang. " t. 1. 

 [Q] Vittadini, "Mangerecci, " t. 9. 

 [R] Berkeley, "Outlines, " pl. 3, fig. 5. 

 [S] Saunders and Smith, "Mycological Illustr. " pl. 23. 

 [T] Cooke, M. C. , "Handbook of British Fungi, " vol. I. Pl. 1, fig. 2. 

 [U] "Gardener's Chronicle" (1869), p. 1066. 

 [V] Berkeley, "Outlines of British Fungology, " p. 64. 

 [W] Cooke, "Easy Guide to British Fungi, " pl. 11. 

 [X] Ibid. , pl. 12. 

 [Y] Hussey, "Mycol. Illust. " pl. 12. 

 [Z] Bulliard, "Champ. " t. 268. 

 [a] Cooke, "Easy Guide, " pl. 4, fig. 1; Hussey, "Illust. " vol. Ii. Pl. 40. 

 [b] Greville, "Scot. Crypt. Flora, " t. 166. 

 [c] Ibid. , t. 91. 

 [d] Sowerby, "Fungi, " pl. 56; Schæffer, "Icones Bav. " t. 72. 

 [e] Trattinnick, L. , "Die Essbaren Schwämme" (1809), p. 82, pl. M; Barla, J. B. , "Champignons de la Nice" (1859), p. 34, pl. 19. 

 [f] Smith, "Edible Mushrooms, " fig. 26. 

 [g] Barla, "Champ. Nice, " t. 20, f. 4-10. 

 [h] Vittadini, C. , "Funghi Mangerecci" (1835), p. 209; Barla, "Champ. Nice, " pl. I. 

 [i] Vittadini, C. , "Funghi Mangerecci, " p. 245; Roques, "Champ. Comest. " p. 86. 

 [j] Badham, Dr. , "Esculent Funguses of Britain, " 2nd ed. P. 110; Hussey, "Illust. Brit. Mycol. " 1st ser. Pl. 4; Barla, "Champ. " pl. 28, f. 7-15. 

 [k] Trattinnick, L. , "Essbaren Schwämme, " p. 98. 

 [l] Lenz, "Die Nützlichen und Schädlichen Schwämme, " p. 49. 

 [m] Badham, "Esculent Funguses of Great Britain, " 2 ed. P. 91. 

 [n] Hussey, "Myc. Illus. " ii. Pl. 25; Paulet, "Champ. " t. 170. 

 [o] Barla, J. B. , "Champ. De la Nice, " p. 71, pl. 35, f. 1-5. 

 [p] Hussey, "Illustr. " ii. T. 17; Barla, "Champ. Nice, " t. 32, f. 11-15. 

 [q] Hussey, "Illustr. " i. T. 5; Krombholz, "Schwämme, " t. 76. 

 [r] Badham's "Esculent Funguses, " 1st ed. Pp. 116 and 120. 

 [s] Catalogue of Plants of Carolina, U. S. 

 [t] Badham, Dr. , "Esculent Funguses, " 2nd ed. P. 128; Hussey, "Illustrations, " 1st ser. Pl. 65; Berkeley, in "Gard. Chron. " (1861), p. 121; Bull, in "Trans. Woolhope Club" (1869). 

 [u] Barla, "Champ. Nice, " p. 79, pl. 38, f. 5, 6. 

 [v] Roques, I. C. P. 48. 

 [w] Lenz, p. 93; Roques, I. C. P. 47, pl. 2, fig. 5. 

 [x] Lenz, H. O. , "Die Nützlichen und Schädlichen Schwämme, " p. 93. 

 [y] Berkeley, M. J. , in "Intellectual Observer, " No. 25, pl. 1. 

 [z] Berkeley, M. J. , "Outlines of British Fungology, " p. 293. 

 [AA] Berkeley, M. J. , "Introduction to Crypt. Bot. " p. 347. 

 [AB] Cooke, M. C. , "A Plain and Easy Guide, " &c. , p. 96. 

 [AC] Cooke, M. C. , "On Kashmir Morels, " in "Trans. Bot. Soc. Edin. " vol. X. P. 439, with figs. 

 [AD] Smith, "Journ. Bot. " vol. Ix. P. 214. 

 [AE] Cooke, "Handbook, " fig. 322. 

 [AF] Cooke, "Handbook, " fig. 324. 

 [AG] Vittadini, C. , "Funghi Mangerecci, " p. 117. 

 [AH] Greville, "Sc. Crypt. Fl. " pl. 156. 

 [AI] Berkeley, in "Linn Trans. " xix. P. 37; Cooke, in "Technologist" (1864), p. 387. 

 [AJ] Berkeley, M. J. , in "Linn. Trans. " xix. P. 37. 

 [AK] Berkeley, M. J. , in "Hooker, Flora Antarctica, " p. 147; in "Hooker's Journ. Bot. " (1848), 576, t. 20, 21. 

 [AL] Vittadini, C. , "Monographia Tuberacearum" (1831), pp. 36, &c. 

 [AM] "Proceedings Agri. Hort. Soc. India" (Dec. 1871), p. Lxxix. 

 [AN] _Ibid. _ (June, 1872), p. Xxiii. 

 [AO] Lindley, "Vegetable Kingdom, " fig. Xxiv. 

 [AP] Currey, F. , in "Linn. Trans. " vol. Xxiii. P. 93. 

 [AQ] "Pharmacopoeia of India, " p. 258. 

 [AR] "Gard. Chron. " (1862), p. 21. 

 [AS] Barla, "Champ. De la Nice, " p. 126, pl. 47, fig. 11. 

 [AT] Greville, "Scott. Crypt. Flora, " pl. 241. 

V. 

NOTABLE PHENOMENA. 

There are no phenomena associated with fungi that are of greaterinterest than those which relate to luminosity. The fact that fungiunder some conditions are luminous has long been known, sinceschoolboys in our juvenile days were in the habit of secretingfragments of rotten wood penetrated by mycelium, in order to exhibittheir luminous properties in the dark, and thus astonish their moreignorant or incredulous fellows Rumphius noted its appearance inAmboyna, and Fries, in his Observations, gives the name of _Thelephoraphosphorea_ to a species of _Corticium_ now known as _Corticiumcæruleum_, on account of its phosphorescence under certain conditions. The same species is the _Auricularia phosphorea_ of Sowerby, but hemakes no note of its phosphorescence. Luminosity in fungi "has beenobserved in various parts of the world, and where the species has beenfully developed it has been generally a species of _Agaricus_ whichhas yielded the phenomenon. "[A] One of the best-known species is the_Agaricus olearius_ of the South of Europe, which was examined byTulasne with especial view to its luminosity. [B] In his introductoryremarks, he says that four species only of Agaricus that are luminousappear at present to be known. One of them, _A. Olearius_, D. C. , isindigenous to Central Europe; another, _A. Igneus_, Rumph. , comes fromAmboyna; the third, _A. Noctileucus_, Lév. , has been discovered atManilla by Gaudichaud, in 1836; the last, _A. Gardneri_, Berk. , isproduced in the Brazilian province of Goyaz, upon dead leaves. As tothe _Dematium violaceum_, Pers. , the _Himantia candida_, Pers. , citedonce by Link, and the _Thelephora cærulea_, D. C. _(Corticiumcæruleum_, Fr. ), Tulasne is of opinion that their phosphorescentproperties are still problematical; at least no recent observationconfirms them. 

The phosphorescence of _A. Olearius_, D. C. , appears to have beenfirst made known by De Candolle, but it seems that he was in error instating that these phosphorescent properties manifest themselves onlyat the time of its decomposition. Fries, describing the _Cladosporiumumbrinum_, which lives upon the Agaric of the olive-tree, expressedthe opinion that the Agaric only owes its phosphorescence to thepresence of the mould. This, however, Tulasne denies, for he writes, "I have had the opportunity of observing that the Agaric of the oliveis really phosphorescent of itself, and that it is not indebted to anyforeign production for the light it emits. " Like Delile, he considersthat the fungus is only phosphorescent up to the time when it ceasesto grow; thus the light which it projects, one might say, is amanifestation of its vegetation. 

"It is an important fact, " writes Tulasne, "which I can confirm, andwhich it is important to insist upon, that the phosphorescence is notexclusively confined to the hymenial surface. Numerous observationsmade by me prove that the whole of the substance of the fungusparticipates very frequently, if not always, in the faculty of shiningin the dark. Among the first Agarics which I examined, I found many, the stipe of which shed here and there a light as brilliant as thehymenium, and led me to think that it was due to the spores which hadfallen on the surface of the stipe. Therefore, being in the dark, Iscraped with my scalpel the luminous parts of the stipe, but it didnot sensibly diminish their brightness; then I split the stipe, bruised it, divided it into small fragments, and I found that thewhole of this mass, even in its deepest parts, enjoyed, in a similardegree to its superficies, the property of light. I found, besides, aphosphorescence quite as brilliant in all the cap, for, having splitit vertically in the form of plates, I found that the trama, whenbruised, threw out a light equal to that of their fructiferoussurfaces, and there is really only the superior surface of the pileus, or its cuticle, which I have never seen luminous. 

"As I have said, the Agaric of the olive-tree, which is itselfvery yellow, reflects a strong brilliant light, and remainsendowed with this remarkable faculty whilst it grows, or, atleast, while it appears to preserve an active life, and remains fresh. The phosphorescence is at first, and more ordinarily, recognizableat the surface of the hymenium. I have seen a great number of youngfungi which were very phosphorescent in the gills, but not in anyother part. In another case, and amongst more aged fungi, thehymenium of which had ceased to give light, the stipe, on thecontrary, threw out a brilliant glare. Habitually, the phosphorescenceis distributed in an unequal manner upon the stipe, and the sameupon the gills. Although the stipe is luminous at its surface, it isnot always necessarily so in its interior substance, if one bruisesit, but this substance frequently becomes phosphorescent aftercontact with the air. Thus, I had irregularly split and slit a largestipe in its length, and I found the whole flesh obscure, whilston the exterior were some luminous places. I roughly joined thelacerated parts, and the following evening, on observing themanew, I found them all flashing a bright light. At another time, Ihad with a scalpel split vertically many fungi in order to hastentheir dessication; the evening of the same day, the surface of allthese cuts was phosphorescent, but in many of these pieces of fungithe luminosity was limited to the cut surface which remainedexposed to the air; the flesh beneath was unchanged. 

"I have seen a stipe opened and lacerated irregularly, the whole ofthe flesh of which remained phosphorescent during three consecutiveevenings, but the brightness diminished in intensity from the exteriorto the interior, so that on the third day it did not issue from theinner part of the stipe. The phosphorescence of the gills is in no waymodified at first by immersing the fungus in water; when they havebeen immersed they are as bright as in the air, but the fungi which Ileft immersed until the next evening lost all their phosphorescence, and communicated to the water an already sensible yellow tint; alcoholput upon the phosphorescent gills did not at once completelyobliterate the light, but visibly enfeebled it. As to the spores, which are white, I have found many times very dense coats of themthrown down on porcelain plates, but I have never seen themphosphorescent. 

"As to the observation made by Delile that the Agaric of the olivedoes not shine during the day when placed in total darkness, I thinkthat it could not have been repeated. From what I have said of thephosphorescence of _A. Olearius_, one naturally concludes that theredoes not exist any necessary relation between this phenomenon and thefructification of the fungus; the luminous brightness of the hymeniumshows, says Delile, 'the greater activity of the reproductive organs, 'but it is not in consequence of its reproductive functions, which maybe judged only as an accessory phenomenon, the cause of which isindependent of, and more general than these functions, since all theparts of the fungus, its entire substance, throws forth at one time, or at successive times, light. From these experiments Tulasne infersthat the same agents, oxygen, water, and warmth, are perfectlynecessary to the production of phosphorescence as much in livingorganized beings as in those which have ceased to live. In eithercase, the luminous phenomena accompany a chemical reaction whichconsists principally in a combination of the organized matter with theoxygen of the air; that is to say, in its combustion, and in thedischarge of carbonic acid which thus shows itself. "

We have quoted at considerable length from these observations ofTulasne on the Agaric of the olive, as they serve very much toillustrate similar manifestations in other species, which doubtlessresemble each other in their main features. 

Mr. Gardner has graphically described his first acquaintance in Brazilwith the phosphorescent species which now bears his name. It wasencountered on a dark night of December, while passing through thestreets of Villa de Natividate. Some boys were amusing themselveswith some luminous object, which at first he supposed to be a kind oflarge fire-fly, but on making inquiry he found it to be a beautifulphosphorescent Agaric, which he was told grew abundantly in theneighbourhood on the decaying fronds of a dwarf palm. The whole plantgives out at night a bright light somewhat similar to that emitted bythe larger fire-flies, having a pale greenish hue. From thiscircumstance, and from growing on a palm, it was called by theinhabitants "flor de coco. "[C]

The number of recognized phosphorescent species of _Agaricus_ is notlarge, although two or three others may be enumerated in addition tothose cited by Tulasne. Of these, _Agaricus lampas_, and some others, are found in Australia. [D] In addition to the _Agaricus noctileucus_, discovered by Gaudichaud, and the _Agaricus igneus_ of Rumphius, foundin Amboyna, Dr. Hooker speaks of the phenomenon as common in Sikkim, but he seems never to have been able to ascertain with what species itwas associated. 

Dr. Cuthbert Collingwood has communicated some further informationrelative to the luminosity of a species of _Agaricus_ in Borneo(supposed to be _A. Gardneri_), in which he says, "The night beingdark, the fungi could be very distinctly seen, though not at any greatdistance, shining with a soft pale greenish light. Here and therespots of much more intense light were visible, and these proved to bevery young and minute specimens. The older specimens may more properlybe described as possessing a greenish luminous glow, like the glow ofthe electric discharge, which, however, was quite sufficient to defineits shape, and, when closely examined, the chief details of its formand appearance. The luminosity did not impart itself to the hand, anddid not appear to be affected by the separation from the root on whichit grew, at least not for some hours. I think it probable that themycelium of this fungus is also luminous, for, upon turning up theground in search of small luminous worms, minute spots of light wereobserved, which could not be referred to any particular object or bodywhen brought to the light and examined, and were probably due to someminute portions of its mycelium. "[E] The same writer also adds, "Mr. Hugh Low has assured me that he saw the jungle all in a blaze of light(by which he could see to read) as, some years ago, he was ridingacross the island by the jungle road; and that this luminosity wasproduced by an Agaric. "

Similar experiences were detailed by Mr. James Drummond in a letterfrom Swan River, in which two species of Agaric are concerned. Theygrew on the stumps of trees, and had nothing remarkable in theirappearance by day, but by night emitted a most curious light, such asthe writer never saw described in any book. One species was foundgrowing on the stump of a _Banksia_ in Western Australia. The stumpwas at the time surrounded by water. It was on a dark night, whenpassing, that the curious light was first observed. When the funguswas laid on a newspaper, it emitted by night a phosphorescent light, enabling persons to read the words around it, and it continued to doso for several nights with gradually decreasing intensity as the plantdried up. In the other instance, which occurred some years after, theauthor, during one of his botanical trips, was struck by theappearance of a large Agaric, measuring sixteen inches in diameter, and weighing about five pounds. This specimen was hung up to dry inthe sitting-room, and on passing through the apartment in the dark itwas observed to give out the same remarkable light. The luminousproperty continued, though gradually diminishing, for four or fivenights, when it ceased on the plant becoming dry. "We called some ofthe natives, " he adds, "and showed them this fungus when emittinglight, and the poor creatures cried out 'chinga, ' their name for aspirit, and seemed much afraid of it. "[F]

Although the examples already cited are those of species of Agaric, luminosity is not by any means wholly confined to that genus. Mr. Worthington Smith has recorded his experiences of some specimens ofthe common _Polyporus annosus_ which were found on some timbers in theCardiff coal mines. He remarks that the colliers are well acquaintedwith phosphorescent fungi, and the men state that sufficient light isgiven "to see their hands by. " The specimens of _Polyporus_ were soluminous that they could be seen in the dark at a distance of twentyyards. He observes further, that he has met with specimens of_Polyporus sulfureus_ which were phosphorescent. Some of the fungifound in mines, which emit light familiar to the miners, belong to theincomplete genus _Rhizomorpha_, of which Humboldt amongst others givesa glowing account. Tulasne has also investigated this phenomenon inconnection with the common _Rhizomorpha subterranea_, Pers. Thisspecies extends underneath the soil in long strings, in theneighbourhood of old tree stumps, those of the oak especially, whichare becoming rotten, and upon these it is fixed by one of itsbranches. These are cylindrical, very flexible, branching, and clothedwith a hard bark, encrusting and fragile, at first smooth and brown, becoming later very rough and black. The interior tissue, at firstwhitish, afterwards of a more or less deep brown colour, is formed ofextremely long parallel filaments from . 0035 to . 015 _mm. _ indiameter. 

On the evening of the day when I received the specimens, [G] he writes, the temperature being about 22° Cent. , all the young branchesbrightened with an uniform phosphoric light the whole of their length;it was the same with the surface of some of the older branches, thegreater number of which were still brilliant in some parts, and onlyon their surface. I split and lacerated many of these twigs, but theirinternal substance remained dull. The next evening, on the contrary, this substance, having been exposed to contact with the air, exhibitedat its surface the same brightness as the bark of the branches. I madethis observation upon the old stalks as well as upon the young ones. Prolonged friction of the luminous surfaces reduced the brightnessand dried them to a certain degree, but did not leave on the fingersany phosphorescent matter. These parts continued with the sameluminous intensity after holding them in the mouth so as to moistenthem with saliva; plunged into water, held to the flame of a candle sothat the heat they acquired was very appreciable to the touch, theystill emitted in the dark a feeble light; it was the same after beingheld in water heated to 30° C. ; but putting them in water bearing atemperature of 55° C. Extinguished them entirely. They are equallyextinguished if held in the mouth until they catch the temperature;perhaps, still, it might be attributed less to the heat which iscommunicated to them than to the deficiency of sufficient oxygen, because I have seen some stalks, having become dull in the mouth, recover after a few instants a little of their phosphorescence. Ayoung stalk which had been split lengthwise, and the internalsubstance of which was very phosphorescent, could imbibe olive oilmany times and yet continue for a long time to give a feeble light. Bypreserving these _Rhizomorphæ_ in an adequate state of humidity, Ihave been able for many evenings to renew the examination of theirphosphorescence; the commencement of dessication, long before theyreally perish, deprives them of the faculty of giving light. Thosewhich had been dried for more than a month, when plunged into water, commenced to vegetate anew and send forth numerous branches in a fewdays; but I could only discover phosphorescence at the surface ofthese new formations, or very rarely in their immediate neighbourhood, the mother stalks appearing to have lost by dessication their luminousproperties, and did not recover them on being recalled to life. Theseobservations prove that what Schmitz has written was not true, thatall parts of these fungi were seldom phosphorescent. 

The luminous phenomenon in question is without doubt more complicatedthan it appears, and the causes to which we attribute it are certainlypowerfully modified by the general character of the objects in whichthey reside. Most of the German botanists give this explanation, others suppose that it forms at first or during its continuance aspecial matter, in which the luminous property resides; this matter, which is said to be mucilaginous in the luminous wood, appears to bein the _Rhizomorpha_ only a kind of chemical combination between themembrane and some gummy substance which they contain. Notwithstandingthis opinion, I am assured that all external mucous matter wascompletely absent from the _Agaricus olearius_, and I neitherdiscovered it upon the branches of _Rhizomorpha subterranea_ nor uponthe dead leaves which I have seen phosphorescent; in all these objectsthe luminous surfaces were nothing else than their proper tissue. 

It may be remarked here that the so-called species of _Rhizomorpha_are imperfect fungi, being entirely devoid of fructification, consisting in fact only of a vegetative system--a sort of compactmycelium--(probably of species of _Xylaria_) with some affinity to_Sclerotium_. 

Recently an extraordinary instance of luminosity was recorded asoccurring in our own country. [H] "A quantity of wood had beenpurchased in a neighbouring parish, which was dragged up a very steephill to its destination. Amongst them was a log of larch or spruce, itis not quite certain which, 24 feet long and a foot in diameter. Someyoung friends happened to pass up the hill at night, and weresurprised to find the road scattered with luminous patches, which, when more closely examined, proved to be portions of bark or littlefragments of wood. Following the track, they came to a blaze of whitelight which was perfectly surprising. On examination, it appeared thatthe whole of the inside of the bark of the log was covered with awhite byssoid mycelium of a peculiarly strong smell, but unfortunatelyin such a state that the perfect form could not be ascertained. Thiswas luminous, but the light was by no means so bright as in thoseparts of the wood where the spawn had penetrated more deeply, andwhere it was so intense that the roughest treatment scarcely seemed tocheck it. If any attempt was made to rub off the luminous matter itonly shone the more brightly, and when wrapped up in five folds ofpaper the light penetrated through all the folds on either side asbrightly as if the specimen was exposed; when, again, the specimenswere placed in the pocket, the pocket when opened was a mass of light. The luminosity had now been going on for three days. Unfortunately wedid not see it ourselves till the third day, when it had, possiblyfrom a change in the state of electricity, been somewhat impaired; butit was still most interesting, and we have merely recorded what weobserved ourselves. It was almost possible to read the time on theface of a watch even in its less luminous condition. We do not for amoment suppose that the mycelium is essentially luminous, but arerather inclined to believe that a peculiar concurrence of climaticconditions is necessary for the production of the phenomenon, which iscertainly one of great rarity. Observers as we have been of fungi intheir native haunts for fifty years, it has never fallen to our lot towitness a similar case before, though Prof. Churchill Babington oncesent us specimens of luminous wood, which had, however, lost theirluminosity before they arrived. It should be observed that the partsof the wood which were most luminous were not only deeply penetratedby the more delicate parts of the mycelium, but were those which weremost decomposed. It is probable, therefore, that this fact is anelement in the case as well as the presence of fungoid matter. "

In all cases of phosphorescence recorded, the light emitted isdescribed as of the same character, varying only in intensity. Itanswers well to the name applied to it, as it seems remarkably similarto the light emitted by some living insects and other animalorganisms, as well as to that evolved, under favourable conditions, bydead animal matter--a pale bluish light, resembling that emitted byphosphorus as seen in a dark room. 

Another phenomenon worthy of note is the change of colour which thebruised or cut surface of some fungi undergo. Most prominent amongstthese are certain poisonous species of _Boletus_, such, for instance, as _Boletus luridus_, and some others, which, on being bruised, cut, or divided, exhibit an intense, and in some cases vivid, blue. Attimes this change is so instantaneous that before the two freshly-cutportions of a _Boletus_ can be separated, it has already commenced, and proceeds rapidly till the depth of intensity has been gained. This blue colour is so universally confined to dangerous species thatit is given as a caution that all species which exhibit a blue colourwhen cut or bruised, should on no account be eaten. The degree ofintensity varies considerably according to the condition of thespecies. For example, _Boletus cærulescens_ is sometimes only veryslightly, if at all, tinged with blue when cut, though, as the nameimplies, the peculiar phenomenon is generally highly developed. Itcannot be said that this change of colour has as yet been fullyinvestigated. One writer some time since suggested, if he did notaffirm, that the colour was due to the presence of aniline, othershave contented themselves with the affirmation that it was a rapidoxidization and chemical change, consequent upon exposure of thesurfaces to the air. Archdeacon Robinson examined this phenomenon indifferent gases, and arrived at the conclusion that the change dependson an alteration of molecular arrangement. [I]

One of the best of the edible species of _Lactarius_, known as_Lactarius deliciosus_, changes, wherever cut or bruised, to a dulllivid green. This fungus is filled with an orange milky fluid, whichbecomes green on exposure to the air, and it is consequently the juicewhich oxidizes on exposure. Some varieties more than others of thecultivated mushroom become brownish on being cut, and a similar changewe have observed, though not recorded, in other species. 

The presence of a milky juice in certain fungi has been alluded to. This is by no means confined to the genus _Lactarius_, in which suchjuice is universal, sometimes white, sometimes yellow, and sometimescolourless. In Agarics, especially in the subgenus _Mycena_, the gillsand stem are replete with a milky juice. Also in some species of_Peziza_, as for instance in _Peziza succosa_, B. , sometimes foundgrowing on the ground in gardens, and in _Peziza saniosa_, Schrad. , also a terrestrial species, the same phenomenon occurs. To this mightbe added such species as _Stereum spadiceum_, Fr. , and _Stereumsanguinolentum_, Fr. , both of which become discoloured and bleedingwhen bruised, while _Corticium lactescens_ distils a watery milk. 

Fungi in general have not a good repute for pleasant odours, and yetit must be conceded that they are not by any means devoid of odour, sometimes peculiar, often strong, and occasionally very offensive. There is a peculiar odour common to a great many forms, which has cometo be called a fungoid odour; it is the faint smell of a long-closeddamp cellar, an odour of mouldiness and decay, which often arises froma process of eremocausis. But there are other, stronger, and equallydistinct odours, which, when once inhaled, are never to be forgotten. Amongst these is the fetid odour of the common stinkhorn, which isintensified in the more beautiful and curious _Clathrus_. It is veryprobable that, after all, the odour of the _Phallus_ would not be sounpleasant if it were not so strong. It is not difficult to imagine, when one encounters a slight sniff borne on a passing breeze, thatthere is the element of something not by any means unpleasant aboutthe odour when so diluted; yet it must be confessed that when carriedin a vasculum, in a close carriage, or railway car, or exposed in aclose room, there is no scruple about pronouncing the odour intenselyfetid. The experience of more than one artist, who has attempted thedelineation of _Clathrus_ from the life, is to the effect that theodour is unbearable even by an enthusiastic artist determined onmaking a sketch. 

Perhaps one of the most fetid of fungi is _Thelephora palmata_. Somespecimens were on one occasion taken by Mr. Berkeley into his bedroomat Aboyne, when, after an hour or two, he was horrified at finding thescent far worse than that of any dissecting room. He was anxious tosave the specimens, but the scent was so powerful that it was quiteintolerable till he had wrapped them in twelve thick folds of thestrongest brown paper. The scent of _Thelephora fastidiosa_ is badenough, but, like that of _Coprinus picaceus_, it is probably derivedfrom the imbibition of the ordure on which it is developed. Thereneeds no stronger evidence that the scent must not only be powerful, but unpleasant, when an artist is compelled, before a rough sketch ismore than half finished, to throw it away, and seek relief in the openair. A great number of edible Agarics have the peculiar odour offresh meal, but two species, _Agaricus odorus_ and _Agaricusfragrans_, have a pleasant anise-like odour. In two or three speciesof tough _Hydnum_, there is a strong persistent odour somewhat likemelilot or woodruffe, which does not pass away after the specimen hasbeen dried for years. In some species of _Marasmius_, there is adecidedly strong odour of garlic, and in one species of _Hygrophorus_, such a resemblance to that of the larva of the goat moth, that itbears the name of _Hygrophorus cossus_. Most of the fleshy formsexhale a strong nitrous odour during decay, but the most powerful weremember to have experienced was developed by a very large specimen of_Choiromyces meandriformis_, a gigantic subterranean species of thetruffle kind, and this specimen was four inches in diameter whenfound, and then partially decayed. It was a most peculiar, but strongand unpleasantly pungent nitrous odour, such as we never remember tohave met with in any other substance. _Peziza venosa_ is remarkablewhen fresh for a strong scent like that of aquafortis. 

Of colour, fungi exhibit an almost endless variety, from white, through ochraceous, to all tints of brown until nearly black, orthrough sulphury yellow to reds of all shades, deepening into crimson, or passing by vinous tints into purplish black. These are thepredominating gradations, but there are occasional blues and mineralgreens, passing into olive, but no pure or chlorophyllous green. Thenearest approach to the latter is found in the hymenium of some_Boleti_. Some of the Agarics exhibit bright colours, but the largernumber of bright-coloured species occur in the genus _Peziza_. Nothingcan be more elegant than the orange cups of _Peziza aurantia_, theglowing crimson of _Peziza coccinea_, the bright scarlet of _Pezizarutilans_, the snowy whiteness of _Peziza nivea_, the delicate yellowof _Peziza theleboloides_, or the velvety brown of _Peziza repanda_. Amongst Agarics, the most noble _Agaricus muscarius_, with its wartycrimson pileus, is scarcely eclipsed by the continental orange_Agaricus cæsarius_. The amethystine variety of _Agaricus laccatus_ isso common and yet so attractive; whilst some forms and species_Russula_ are gems of brilliant colouring. The golden tufts of morethan one species of _Clavaria_ are exceedingly attractive, and thedelicate pink of immature _Lycogala epidendrum_ is sure to commandadmiration. The minute forms which require the microscope, as much toexhibit their colour as their structure, are not wanting in rich anddelicate tints, so that the colour-student would find much to charmhim, and good practice for his pencil in these much despised examplesof low life. 

Amongst phenomena might be cursorily mentioned the peculiar sarcodioidmycelium of _Myxogastres_, the development of amoeboid forms fromtheir spores, and the extraordinary rapidity of growth, as thewell-known instance of the _Reticularia_ which Schweinitz observedrunning over iron a few hours after it had been red hot. Mr. Berkeleyhas observed that the creamy mycelium of _Lycogala_ will not reviveafter it has become dry for a few hours, though so active before. 

 [A] M. J. Berkeley, "Introduction to Cryptogamic Botany, " p. 265. 

 [B] Tulasne, "Sur la Phosphorescence des Champignons, " in "Ann. Des Sci. Nat. " (1848), vol. Ix, p. 338. 

 [C] In "Hooker's Journal of Botany" (1840), vol. Ii. P. 426. 

 [D] Berkeley, "Introduction to Crypt. Bot. " t. 265. 

 [E] Dr. Collingwood, in "Journal of Linnæan Society (Botany), " vol. X. P. 469. 

 [F] In "Hooker's Journal of Botany" for April, 1842. 

 [G] Tulasne, "Sur la Phosphorescence, " in "Ann. Des Sci. Nat. " (1848), vol ix. P. 340, &c. 

 [H] Rev. M. J. Berkeley, in "Gardener's Chronicle" for 1872, p. 1258. 

 [I] Berkeley, "Introduction to Crypt. Bot. " p. 266. 

VI. 

THE SPORE AND ITS DISSEMINATION. 

A work of this character would hardly be deemed complete without somereference to the above subject, which has moreover a relation to someof the questions discussed, and particularly of spore diffusion in theatmosphere. The largest spore is microscopic, and the smallest knownscarcely visible under a magnifying power of 360 diameters. Takinginto account the large number of species of fungi, probably scarcelyless numerous than all the flowering plants, and the immense number ofspores which some of the individuals produce, they must be exceedinglyplentiful and widely diffused, though from their minuteness not easyto be discerned. It has been attempted to estimate the number ofspores which might be produced by one single plant of _Lycoperdon_, but the number so far exceeds that which the mind is accustomed tocontemplate that it seems scarcely possible to realize theirprofusion. Recent microscopic examinations of the common atmosphere[A]show the large quantity of spores that are continually suspended. Inthese investigations it was found that spores and similar cells wereof constant occurrence, and were generally present in considerablenumbers. That the majority of the cells were living, and ready toundergo development on meeting with suitable conditions, was verymanifest, as in those cases in which preparations were retained underobservation for any length of time, germination rapidly took place inmany of the cells. In few instances did any development take place, beyond the formation of networks of mycelium, or masses of toruloidcells, but, in one or two, distinct sporules were developed on thefilaments arising from some of the larger septate spores; and in a fewothers, _Penicillium_ and _Aspergillus_ produced their characteristicheads of fructification. With regard to the precise nature of thespores, and other cells present in various instances, little can besaid, as, unless their development were to be carefully followed outthrough all its stages, it is impossible to refer them to theircorrect species or even genera. The greater number of them areapparently referable to the old orders of fungi, _Sphæronemei_, _Melanconei_, _Torulacei_, _Dematiei_ and _Mucedines_, while someprobably belonged to the _Pucciniæi_ and _Cæomacei_. 

Hence it is demonstrated that a large number of the spores of fungiare constantly present in the atmosphere, which is confirmed bythe fact that whenever a suitable pabulum is exposed it is takenpossession of by floating spores, and soon converted into a forestof fungoid vegetation. It is admitted that the spores of suchcommon moulds as _Aspergillus_ and _Penicillium_ are so widelydiffused, that it is almost impossible to exclude them from closedvessels, or the most carefully guarded preparations. Specialcontrivances for the dispersion of the spores in the different groupsfollow a few general types, and it is only rarely that we meet withany method that is confined only to a species or genus. Some ofthe more significant forms of spores may be illustrated, with theirmodes of dissemination. 

BASIDIOSPORES is a term which we may employ here to designate allspores borne at the tips of such supports as are found in the_Hymenomycetes_ and _Gasteromycetes_, to which the name of basidia hasbeen given. In fact, under this section we may include all the sporesof those two orders, although we may be ignorant of the precise modein which the fruit of most of the _Myxogastres_ is developed. Guardingourselves at the outset against any misinterpretation as to the use ofthis term, which, in fact, we employ simply to designate the fruit of_Hymenomycetes_, we may have excuse in our desire to limit specialterms as much as possible. In the _Agaricini_ the spores areplentiful, and are distributed over the hymenium or gill plates, thesurface of which is studded with basidia, each of which normallyterminates with four short, erect, delicate, thread-like processes, each of which is surmounted by a spore. These spores are colourless orcoloured, and it is upon this fact that primary divisions in the genus_Agaricus_ are based, inasmuch as colour in the spores appears to be apermanent feature. In white-spored species the spores are white in allthe individuals, not mutable as the colour of the pileus, or thecorolla in phanerogamic plants. So also with the pink spored, rustyspored, black spored, and others. This may serve to explain whycolour, which is so little relied upon in classification amongst thehigher plants, should be introduced as an element of classification inone of the largest genera of fungi. 

[Illustration: FIG. 45. --Spores of (_a_) _Agaricus mucidus_; (_b_)_Agaricus vaginatus_; (_c_) _Agaricus pascuus_; (_d_) _Agaricusnidorosus_; (_e_) _Agaricus campestris_. (Smith. )]

[Illustration: FIG. 46. --Spores of (_a_) _Lactarius blennius_; (_b_)_Lactarius fuliginosus_; (_c_) _Lactarius quietus_. (Smith. )]

There are considerable differences in size and form amongst the sporesof the _Agaricini_, although at first globose; when mature they areglobose, oval, oblong, elliptic, fusiform, and either smooth ortuberculated, often maintaining in the different genera or subgeneraone particular characteristic, or typical form. It is unnecessary hereto particularize all the modifications which the form and colour ofthe spores undergo in different species, as this has already beenalluded to. The spores in the _Polyporei_, _Hydnei_, &c. , are lessvariable, of a similar character, as in all the _Hymenomycetes_, except perhaps the _Tremellini_. 

[Illustration: FIG. 46a. --(_a_) Spore of _Gomphidius viscidus;_ (_b_)spore of _Coprinus micaceus_. ]

[Illustration: FIG. 47. --Spores of (_a_) _Polyporus cæsius_; (_b_)_Boletus parasiticus_; (_c_) _Hydnum_. ]

When an Agaric is mature, if the stem is cut off close to the gills, and the pileus inverted, with the gills downwards on a sheet of blackpaper (one of the pale-spored species is best for this purpose), andleft for a few hours, or all night, in that position, the paper willbe found imprinted in the morning with a likeness of the under side ofthe pileus with its radiating gills, the spores having been throwndown upon the paper in such profusion, from the hymenium, and ingreater numbers from the opposed surfaces of the gills. This littleexperiment will be instructive in two or three points. It willillustrate the facility with which the spores are disseminated, theimmense number in which they are produced, and the adaptability of thegill structure to the economy of space, and the development of thelargest number of basidiospores from a given surface. The tubes orpores in _Polyporei_, the spines in _Hydnei_, are modifications of thesame principles, producing a like result. 

In the _Gasteromycetes_ the spores are produced in many cases, probablyin most, if not all, at the tips of sporophores; but the hymenium, instead of being exposed, as in the _Hymenomycetes_, is enclosed withinan outer peridium or sac, which is sometimes double. The majority ofthese spores are globose in form, some of them extremely minute, variously coloured, often dark, nearly black, and either externallysmooth or echinulate. In some genera, as _Enerthenema_, _Badhamia_, &c. , a definite number of spores are at first enclosed in delicatecysts, but these are exceptions to the general rule: this also is thecase in at least one species of _Hymenogaster_. As the spores approachmaturity, it may be observed in such genera as _Stemonitis_, _Arcyria_, _Diachea_, _Dictydium_, _Cribraria_, _Trichia_, &c. , that they areaccompanied by a sort of reticulated skeleton of threads, whichremain permanent, and served in earlier stages, doubtless, assupports for the spores; being, in fact, the skeleton of the hymenium. It has been suggested that the spiral character of the threads in_Trichia_ calls to mind the elaters in the _Hepaticæ_, and like themmay, by elasticity, aid in the dispersion of the spores. There isnothing known, however, which will warrant this view. When the sporesare mature, the peridium ruptures either by an external orifice, asin _Geaster_, _Lycoperdon_, &c. , or by an irregular opening, and thelight, minute, delicate, spores are disseminated by the slightestbreath of air. Specimens of _Geaster_ and _Bovista_ are easilyseparated from the spot on which they grew; when rolling from placeto place, the spores are deposited over a large surface. In the_Phalloidei_ the spores are involved in a slimy mucus which wouldprevent their diffusion in such a manner. This gelatinous substance hasnevertheless a peculiar attraction for insects, and it is not altogetherromantic to believe that in sucking up the fetid slime, they alsoimbibe the spores and transfer them from place to place, so that evenamongst fungi insects aid in the dissemination of species. Whether ornot the _Myxogastres_ should be included here is matter of opinion, since the mode in which the spores are developed is but little known;analogy with the _Trichogastres_ in other points alone leading to theconclusion that they may produce basidiospores. The slender, elasticstems which support the peridia in many species are undoubted aids tothe dissemination of the spores. [B]

[Illustration: FIG. 48. --_Diachea elegans. _]

Under the name of STYLOSPORES may be classed those spores which in someorders of _Coniomycetes_ are produced at the apex of short threads, either enclosed in a perithecium, or seated upon a kind of stroma. These are exceedingly variable, sometimes large, and multiseptate, atother times minute, resembling spermatia. In such genera as arechiefly epiphytal, in _Septoria_, _Phyllosticta_, and their allies, the minute spores are enclosed within membranaceous perithecia, andwhen mature these are ejected from the orifice at the apex, or areexposed by the breaking off of the upper portion of the perithecia. In_Diplodia_ and _Hendersonia_ the spores are larger, mostly coloured, often very fine in the latter genus, and multiseptate, escaping fromthe perithecia by a terminal pore. Probably the species are onlypycnidia of _Sphæriacei_, but that is of no consequence in relationto our present inquiry. Of stylospores which deserve mention on accountof their singularity of form, we may note those of _Dilophosporagraminis_, which are straight, and have two or three hair-likeappendages at each extremity. In _Discosia_ there is a single obliquebristle at each end, or at the side of the septate spores, whilst in_Neottiospora_ a tuft of delicate hairs is found at one extremityonly. The appendages in _Dinemasporium_ are similar to those of_Discosia_. The spores in _Prosthemium_ may be said in some sort toresemble compound _Hendersonia_, being fusiform and multiseptate, oftenunited at the base in a stellate manner. In this genus, as in_Darluca_, _Cytispora_, and the most of those belonging to the_Melanconiei_, the spores when mature are expelled from the orifice ofthe perithecium or spurious perithecium, either in the form oftendrils, or in a pasty mass. In these instances the spores are moreor less involved in gelatine, and when expelled lie spread over thematrix, around the orifice; their ultimate diffusion being due tomoisture washing them over other parts of the same tree, since it isprobable that their natural area of dissemination is not large, thehigher plants, of which they are mostly conditions, being developed onthe same branches. More must be known of the relations between_Melanconium_ and Tulasne's sphæriaceous genus _Melanconis_ beforewe can appreciate entirely the advantage to _Melanconium_ and someother genera, that the wide diffusion of their spores should bechecked by involving them in mucus, or their being agglutinated to thesurface of the matrix, only to be softened and diffused by rain. Thespores in many species amongst the _Melanconiei_ are remarkably fine;those of _Stegonosporium_ have the endochrome partite and cellular. In _Stilbospora_ and _Coryneum_ the spores are multiseptate, large, and mostly coloured. In _Asterosporium_ the spores are stellate, whilst in _Pestalozzia_ they are septate, with a permanent peduncle, and crested above with two or three hyaline appendages. 

[Illustration: FIG. 49. --Spore of _Hendersonia polycystis_. ]

[Illustration: FIG. 50. --Spores of _Dilophospora graminis_. ]

[Illustration: FIG. 51. --Spores of _Discosia_. ]

[Illustration: FIG. 52. --Spore of _Prosthemium betulinum_. ]

[Illustration: FIG. 53. --Spore of _Stegonosporium cellulosum_. ]

[Illustration: FIG. 54. --Stylospores of _Coryneum disciforme_. ]

[Illustration: FIG. 55. --Spores of _Asterosporium Hoffmanni_. ]

[Illustration: FIG. 56. --Spores of _Pestalozzia_. ]

[Illustration: FIG. 57. --_Bispora monilioides_. ]

The _Torulacei_ externally, and to the naked eye, are very similar tothe black moulds, and the mode of dissemination will be alike in both. The spores are chiefly compound, at first resembling septate threads, and at length breaking up into joints, each joint of which possessesthe function of a spore. In some instances the threads are connate, side by side, as in _Torula hysterioides_, and in _Speira_, beingconcentrically arranged in laminæ in the latter genus. The structurein _Sporochisma_ is very peculiar, the joints breaking up within anexternal tube or membrane. The spores in _Sporidesmium_ appear toconsist of irregular masses of cells, agglomerated into a kind ofcompound spore. Most of the species become pulverulent, and the sporesare easily diffused through the air like an impalpable dust. They forma sort of link between the stylospores of one section of the_Coniomycetes_, and the pseudospores of the parasitical section. 

PSEUDOSPORE is, perhaps, the most fitting name which can be applied tothe so-called spores of the parasitical _Coniomycetes_. Their peculiargermination, and the production of reproductive bodies on the germtubes, prove their analogy to some extent with the prothallus of othercryptogams, and necessitate the use of some term to distinguish themfrom such spores as are reproductive without the intervention of apromycelium. The differences between these pseudospores in theseveral genera are confined in some instances to their septation, inothers to their mode of development. In the _Æcidiacei_ thepseudospores are more or less globose, produced in chains within anexternal cellular peridium. In the _Cæomacei_ they are simple, sometimes produced in chains, and sometimes free, with or without acaduceous peduncle. In the _Ustilaginei_ they are simple, darkcoloured, and occasionally attached in subglobose masses, as in_Urocystis_ and _Thecaphora_, which, are more or less compact. In the_Pucciniæi_ the distinctive features of the genera are based upon themore or less complex nature of the pseudospores, which are bilocularin _Puccinia_, trilocular in _Triphragmium_, multilocular in_Phragmidium_, &c. In the curious genus _Podisoma_ the septatepseudospores are involved in a gelatinous element. The diffusion ofthese fruits is more or less complete according to their compact orpulverulent nature. In some species of _Puccinia_ the sori are socompact that they remain attached to the leaves long after they aredead and fallen. In the genus _Melampsora_, the wedge-shapedwinter-pseudospores are not perfected until after the dead leaves havefor a long time remained and almost rotted on the ground. It isprobable that their ultimate diffusion is only accomplished by therotting and disintegration of the matrix. In the _Cæomacei_, _Ustilaginei_, and _Æcidiacei_ the pseudospores are pulverulent, as insome species of _Puccinia_, and are easily diffused by the motion ofthe leaves in the wind, or the contact of passing bodies. Theirdiffusion in the atmosphere seems to be much less than in the case ofthe _Hyphomycetes_. By what means such a species as _Pucciniamalvacearum_, which has very compact sori, has become within so shorta period diffused over such a wide area, is a problem which in thepresent state of our knowledge must remain unsolved. It may be throughminute and plentiful secondary spores. 

[Illustration: FIG. 58. --Pseudospores of _Thecaphora hyalina_. ]

[Illustration: FIG. 59. --Pseudospores of _Puccinia_. ]

[Illustration: FIG. 60. --Pseudospores of _Triphragmium_. ]

[Illustration: FIG. 61. --Pseudospores of _Phragmidium bulbosum_. ]

[Illustration: FIG. 62. --_Melampsora salicina. _ (Winter fruit. )]

SPERMATIA are very minute delicate bodies found associated with manyof the epiphyllous _Coniomycetes_, and it has been supposed areproduced in conjunction with some of the _Sphæriacei_, but their realfunction is at present obscure, and the name is applied rather uponconjecture than knowledge. It is by no means improbable that spermatiado exist extensively amongst fungi, but we must wait in patience forthe history of their relationship. 

TRICHOSPORES might be applied better, perhaps, than _conidia_ to thespores which are produced on the threads of the _Hyphomycetes_. Some ofthem are known to be the conidia of higher plants; but as this is by nomeans the case with all, it would be assuming too much to give thename of conidia to the whole. By whatever name they may be called, thespores of the _Hyphomycetes_ are of quite a different type from any yetmentioned, approximating, perhaps, most closely to the basidiosporesof the _Hymenomycetes_ in some, and _Gasteromycetes_ in others; as, for instance, in the _Sepedoniei_ and the _Trichodermacei_. Theform of the spores and their size differ materially, as well as themanner in which they are produced on the threads. In many they arevery minute and profuse, but larger and less plentiful in the_Dematiei_ than in the _Mucedines_. The spores of some species of_Helminthosporium_ are large and multiseptate, calling to mind thespores of the _Melanconiei_. Others are very curious, being stellate in_Triposporium_, circinate in _Helicoma_ and _Helicocoryne_, angular in_Gonatosporium_, and ciliate in _Menispora ciliata_. Some are producedsingly and some in chains, and in some the threads are nearlyobsolete. In _Peronospora_, it has been demonstrated that certainspecies produce minute zoospores from the so-called spores. Thedissemination of the minute spores of the _Mucedines_ through theair is undoubted; rain also certainly assists not only in thedispersion of the spores in this as in other groups, but also in theproduction of zoospores which require moisture for that purpose. Theform of the threads, and the mode of attachment of the spores, is farmore variable amongst the _Mucedines_ than the form of the spores, butthe latter are in all instances so slightly attached to their supportsas to be dissevered by the least motion. This aids also in thediffusion of the spores through the atmosphere. 

[Illustration: FIG. 63. --Spores of _Helicocoryne_. ]

SPORANGIA are produced in the _Physomycetes_ usually on the tips orbranches of delicate threads, and these when mature dehisce and setfree the minute sporidia. These are so small and uniform in theircharacter that they require but a passing mention. The method ofdiffusion agrees much with that of the _Mucedines_, the walls of thesporangia being usually so thin and delicate as to be easily ruptured. Other modes of fructification prevail in some species by theproduction of cysts, which are the result of conjugation of thethreads. These bodies are for the most part furnished with thicker andmore resistant walls, and the diffusion of their contents will beregulated by other circumstances than those which influence thedispersion of the minute sporidia from the terminal cysts. Probablythey are more perennial in their character, and are assimilated moreto the oogonia of _Cystopus_ and _Peronospora_, being rather of thenature of resting spores, inasmuch as the same threads usually bearthe terminal fruits. 

[Illustration: FIG. 64. --Sporidium of _Genea verrucosa_. ]

[Illustration: FIG. 65. --Alveolate sporidium of _Tuber_. ]

THECASPORES is a term which may be applied generally to all sporidiaproduced in asci, but these are in turn so innumerable and variablethat it will be necessary to treat of some of the groups individually. The _Thecaspores_, for instance, of the _Tuberacei_ offer severalfeatures whereby they may be distinguished from other thecaspores. Theasci in which these sporidia are generated mostly partake of a broadlysaccate, ovate form. The number of sporidia contained in an individualascus is usually less than in the majority of the _Ascomycetes_, andthe sporidia approximate more nearly to the globose form. Usually, also, they are comparatively large. Many have been figured by Corda[C]and Tulasne. [D] Three types of spores may be said to prevail in the_Tuberacei_: the smooth spored, the warted or spinulose, and theareolate. The first of these may be represented by the _Stephensiabombycina_, in which the globose sporidia are quite smooth andcolourless. The warted sporidia may be observed in _Genea verrucosa_, the spinulose in _Tuber nitidum_, and the areolate are present in_Tuber æstivum_ and _Tuber excavatum_, in which the epispore isdivided into polygonal alveoli, bounded by thin, membranaceous, prominent partitions. This form of sporidium is very beautiful. In allno special provision is made for the dissemination of the sporidia, as, from their subterranean habit, none would be available save theultimate dissolution of the external integuments. As they are greedilydevoured by several animals, it is possible that they may be dispersedthrough the excrements. 

In the _Perisporiacei_ the perithecium has no proper orifice, orostiolum, for the discharge of the mature sporidia, which are usuallysmall, and are disseminated by the irregular rupture of the somewhatfragile conceptacles. The asci are usually more or less saccate, andthe sporidia approximate to a globose form. The asci are often verydiffluent. In _Perisporium vulgare_ the ovate brown sporidia are atfirst, and for some time, attached together in fours in a concatenateor beaded manner. In some species of _Erysiphei_ the conceptacleencloses but a single sporangium, in others several, which areattached together at the base. In some species the sporangia containtwo, in others four, in others eight, and in others numerous sporidia. In _Chætomium_ the asci are cylindrical, and in most cases thecoloured sporidia are lemon-shaped. When the conceptacles are fullymatured, it is commonly the case that the asci are absorbed and thesporidia are free in the interior of the conceptacles. 

[Illustration: FIG. 66. --Asci, sporidia, and paraphyses of _Ascobolus_(Boudier). ]

Of the fleshy _Discomycetes_ the genus _Peziza_ may be taken asthe type. If the structure which prevails in this genus be broughtto mind, it will be remembered that the hymenium lines an expandedcup, and that the asci are packed together, side by side, with theirapices outwards, and their bases attached to a substratum of cellswhich form the inner layer of the receptacle. The sporidia areusually eight in each ascus, either arranged in single or doublerows, or irregularly grouped together. The asci are produced insuccession; the later, pressing themselves upwards between thosepreviously developed, cause the rupture of the mature asci at theapex and the ejection of the sporidia with considerable force. Whena large _Peziza_ is observed for a time a whitish cloud will be seento rise suddenly from the surface of the disc, which is repeated againand again whenever the specimen is moved. This cloud consists ofsporidia ejected simultaneously from several asci. Sometimes theejected sporidia lie like frost on the surface of the disc. Theories have been devised to account for this sudden extrusion of thesporidia, in _Ascobolus_, and a few species of _Peziza_, of the ascialso, the most feasible one being the successive growth of theasci; contraction of the cup may also assist, as well as some otherless potent causes. It may be remarked here that the sporidia in_Peziza_ and _Helotium_ are mostly colourless, whilst in _Ascobolus_they pass through pink to violet, or dark brown, and the epispore, which is of a waxy nature, becomes fissured in a more or lessreticulated manner. 

[Illustration: FIG. 67. --Sporidium of _Ostreichnion Americanum_. ]

The sporidia in _Hysterium_ proper are usually coloured, oftenmultiseptate, sometimes fenestrate, and occasionally of considerablesize. There is no evidence that the sporidia are ever excluded in thesame manner as in _Peziza_, the lips closing over the disc so much asto prevent this. The diffusion of the sporidia probably depends on thedissolution of the asci, and hence they will not be widely dispersed, unless, perhaps, by the action of rain. 

In _Tympanis_, asci of two kinds have been observed in some species;one kind containing an indefinite number of very minute bodiesresembling spermatia, and the other octosporous, containing sporidiaof the usual type. 

The _Sphæriacei_ include an almost infinite variety in the form andcharacter of the sporidia. Some of these are indefinite in the numbercontained in an ascus, although the majority are eight, and a fewless. In the genera _Torrubia_ and _Hypocrea_ the structure differssomewhat from other groups, inasmuch as in the former the longthread-like sporidia break up into short joints, and in the latter theascus contains sixteen subglobose or subquadrate sporidia. Otherspecies contain linear sporidia, which are often the length of theascus, and may either be simple or septate. In _Sphæria ulnaspora_ thesporidia are abruptly bent at the second joint. Shorter fusiformsporidia are by no means uncommon, varying in the number of septa, andin constriction at the joints in different species. Elliptic or ovatesporidia are common, as are those of the peculiar form which may betermed sausage-shaped. These are either hyaline or coloured of someshade of brown. Coloured sporidia of this kind are common in _Xylaria_and _Hypoxylon_, as well as in certain species of the section_Superficiales_. Coloured sporidia are often large and beautiful: theyare mostly of an elongated, elliptical form, or fusiform. Asnoteworthy may be mentioned the sporidia of _Melanconis lanciformis_, those of _Valsa profusa_, and some species of _Massaria_, the latterbeing at first invested with a hyaline coat. Some coloured sporidiahave hyaline appendages at each extremity, as in _MelanconisBerkeleii_, and an allied species, _Melanconis bicornis_, from theUnited States, also some dung _Sphæriæ_, as _S. Fimiseda_, includedunder the proposed genus _Sordaria_. [E] Hyaline sporidia occasionallyexhibit a delicate bristle-like appendage at each extremity, as in the_Valsa thelebola_, or with two additional cilia at the centralconstriction, as in _Valsa taleola_. A peculiar form of sporidium ispresent in certain species of _Sphæria_ found on dung, for which thegeneric name of _Sporormia_ has been proposed, in which the sporidium(as in _Perisporium vulgare_) consists of four coloured ovate joints, which ultimately separate. Multiseptate fenestrate sporidia are notuncommon in _Cucurbitaria_ and _Pleospora_, as well as in _Valsafenestrata_ and some other species. In the North American _Sphæriaputaminum_ the sporidia are extraordinarily large. 

[Illustration: FIG. 68. --Ascus and sporidia of _Hypocrea_. ]

[Illustration: FIG. 69. --Sporidium of _Sphæria ulnaspora_. ]

[Illustration: FIG. 70. --Sporidia of _Valsa profusa_ (Currey). ]

[Illustration: FIG. 71. --Sporidia of _Massaria foedans_. × 400. ]

[Illustration: FIG. 72. --Sporidium of _Melanconis bicornis_, Cooke. ]

[Illustration: FIG. 73. --Caudate sporidia of _Sphæria fimiseda_. ]

[Illustration: FIG. 74. --Sporidia of _Valsa thelebola_. ]

[Illustration: FIG. 75. --Sporidia of _Valsa taleola_. × 400. ]

[Illustration: FIG. 76. --Sporidium of _Sporormia intermedia_. ]

[Illustration: FIG. 77. --Asci and sporidia of _Sphæria_ (_Pleospora_)_herbarum_. ]

[Illustration: FIG. 78. --Sporidium of _Sphæria putaminum_. × 400. ]

The dissemination of the sporidia may, from identity of structure inthe perithecium, be deemed to follow a like method in all. Whenmature, they are in a great measure expelled from the mouth of theperithecia, as is evident in species with large dark sporidia, such asexist in the genera _Hypoxylon_, _Melanconis_, and _Massaria_. Inthese genera the sporidia, on maturity, may be observed blackening thematrix round the mouths of the perithecia. As moisture has an evidenteffect in producing an expulsion of sporidia by swelling thegelatinous nucleus, it may be assumed that this is one of the causesof expulsion, and therefore of aids to dissemination. When _Sphæriæ_are submitted to extra moisture, either by placing the twig whichbears them on damp sand, or dipping one end in a vessel of water, thesporidia will exude and form a gelatinous bead at the orifice. Theremay be other methods, and possibly the successive production of newasci may also be one, and the increase in bulk by growth of thesporidia another; but of this the evidence is scanty. 

Finally, OOGONIA may be mentioned as occurring in such genera as_Peronospora_ amongst moulds, _Cystopus_ amongst Uredines, and the_Saprolegniaceæ_ amongst the _Physomycetes_. The zoospores beingfurnished with vibratile cilia, are for some time active, and needonly water in which to disseminate themselves, and this is furnishedby rain. 

We have briefly indicated the characteristics of some of the moreimportant types of spores to be found in fungi, and some of themodes by which it is known, or presumed, that their disseminationtakes place. In this summary we have been compelled to rest contentwith suggestions, since an exhaustive essay would have occupiedconsiderable space. The variability in the fruit of fungi, in so faras we have failed to demonstrate, will be found exhibited in theillustrated works devoted more especially to the minute species. [F]

 [A] Cunningham, in "Ninth Annual Report of the Sanitary Commissioner with the Government of India. " Calcutta, 1872. 

 [B] See "Corda Icones, " tab. 2. 

 [C] Corda, "Icones Fungorum, " vol. Vi. Prague. 

 [D] Tulasne, "Fungi Hypogæi. " Paris. 

 [E] Winter, "Die Deutschen Sordarien" (1873). 

 [F] Corda, "Icones Fungorum, " 6 vols. (1837-1842); Sturm, "Deutschlands Flora, " Pilze (1841); Tulasne, "Selecta Fungorum Carpologia;" Bischoff, "Kryptogamenkunde" (1860); Corda, "Anleitung zum Studium der Mykologie" (1842); Fresenius, "Beiträge zur Mykologie" (1850); Nees Ton Esenbeck, "Das System der Pilze" (1816); Bonorden, "Handbuch der Allgemeinen Mykologie" (1851). 

VII. 

GERMINATION AND GROWTH. 

In describing the structure of these organisms in a previouschapter, the modes of germination and growth from the spores havebeen purposely excluded and reserved for the present. It may beassumed that the reader, having followed us to this point, isprepared for our observations by some knowledge of the chief featuresof structure in the principal groups, and of the main distinctionsin the classification, or at least sufficient to obviate anyrepetition here. In very many species it is by no means difficult toinduce germination of the spores, whilst in others success is by nomeans certain. 

M. De Seynes made the _Hymenomycetes_ an especial object of study, [A]but he can give us no information on the germination and growth of thespore. Hitherto almost nothing is positively known. As to the form ofthe spore, it is always at first spherical, which it retains for along time, while attached to the basidia, and in some species, butrarely, this form is final, as in _Ag. Terreus_, &c. The most usualform is either ovoid or regularly elliptic. All the _Coprini_ have thespores oval, ovoid, more or less elongated or attenuated from thehilum, which is more translucent than the rest of the spore. This lastform is rather general amongst the Leucospores, in _Amanita_, _Lepiota_, &c. At other times the spores are fusiform, with regularlyattenuated extremities, as in _Ag. Ermineus_, Fr. , or with obtuseextremities, as in _Ag. Rutilans_, Sch. In _Hygrophorus_ they arerather irregular, reniform, or compressed in the centre all round. Hoffmann[B] has given a figure taken from _Ag. Chlorophanus_, andSeynes verified it upon _Ag. Ceraceus_, Sow. (See figures on page121. )

The exospore is sometimes roughened, with more or less projectingwarts, as may be seen in _Russula_, which much resembles _Lactarius_in this as in some other particulars. The spores of the _Dermini_ andthe _Hyporhodii_ often differ much from the sphærical form. In _Ag. Pluteus_, Fr. , and _Ag. Phaiocephalus_, Bull, there is already acommencement of the polygonal form, but the angles are much rounded. It is in _Ag. Sericeus_, _Ag. Rubellus_, &c. , that the polygonal formbecomes most distinct. In _Dermini_ the angles are more or lesspronounced, and become rather acute in _Ag. Murinus_, Sow. , and _Ag. Ramosus_, Bull. The passage from one to the other may be seen in thestellate form of the conidia of _Nyctalis_. 

It is almost always the external membrane that is coloured, which issubject to as much variation as the form. The more fine and more delicateshades are of rose, yellow-dun or yellow, violet, ashy-grey, clearfawn colour, yellow-orange, olive-green, brick-red, cinnamon-brown, reddish-brown, up to sepia-black and other combinations. It is only bythe microscope and transparency that one can make sure of these tints;upon a sufficient quantity of agglomerated spores the colour may bedistinguished by the naked eye. Colour, which has only a slightimportance when considered in connection with other organs, acquiresmuch in the spores, as a basis of classification. 

With the growth of Agarics from the mycelium, or spawn, we are notdeficient in information, but what are the conditions necessary tocause the spores themselves to germinate before our eyes and producethis mycelium is but too obscure. In the cultivated species we proceedon the assumption that the spores have passed a period of probation inthe intestines of the horse, and by this process have acquired agerminating power, so that when expelled we have only to collect them, and the excrement in which they are concealed, and we shall secure acrop. [C] As to other species, we know that hitherto all attempts tosolve the mystery of germination and cultivation has failed. There areseveral species which it would be most desirable to cultivate if theconditions could be discovered which are essential to germination. [D]In the same manner the _Boleti_ and _Hydnei_--in fact, all otherhymenomycetal fungi, with the exception of the _Tremellini_--stillrequire to be interrogated by persevering experiment and close inquiryas to their mode of germination, but more especially as to theessential conditions under which alone a fruitful mycelium isproduced. 

[Illustration: FIG. 79. --(_a_) Basidia and spores of _Exidia spiculosa_;(_b_) Germinating spore. ]

The germination of the spore has been observed in some of the_Tremellini_. Tulasne described it in _Tremella violacea_. [E] Thesespores are white, unilocular, and filled with a plastic matter ofhomogeneous appearance. From some portion of their surface anelongated germ filament is produced, into which the contents of thereproductive cell pass until quite exhausted. Other spores, perhapsmore abundant, have a very different kind of vegetation. From theirconvex side, more rarely from the outer edge, these particular sporesemit a conical process, generally shorter than themselves, anddirected perpendicularly to the axis of their figure. This appendagebecomes filled with protoplasm at the expense of the spore, and itsfree and pointed extremity finally dilated into a sac, at firstglobose and empty. This afterwards admits into its cavity the plasticmatter contained in its support, and, increasing, takes exactly theform of a new spore, without, however, quite equalling in size theprimary or mother spore. The spore of the new formation long retainsits pedicel, and the mother spore which produced it, but these latterorgans are then entirely empty and extremely transparent. Sometimestwo secondary spores are thus engendered from the same spore, andtheir pedicels may be implanted on the same or on different sides, soas to be parallel in the former case, and growing in oppositedirections in the latter. The fate of these secondary spores was notdetermined. 

[Illustration: FIG. 80. --Germinating spore and (_a_) corpuscles of_Dacrymyces deliquescens_. ]

In _Dacrymyces deliquescens_ are found mingled amongst the sporesimmense numbers of small round or ovoid unilocular bodies, withoutappendages of any kind, which long puzzled mycologists. Tulasneascertained that they are derived from the spores of this fungus whenthey have become free, and rest on the surface of the hymenium. Eachof the cells of the spore emits exteriorly one or several of thesecorpuscles, supported on very short slender pedicels, which remainafter the corpuscles are detached from them. This latter circumstanceevidences that new corpuscles succeed the firstborn one on eachpedicel as long as there remains any plastic matter within the spore. The latter, in fact, in consequence of this labour of production, becomes gradually emptied, and yet preserves the generative pedicelsof the corpuscles, even when it no longer contains any solid orcoloured matter. These pedicels are not all in the same plane, as maybe ascertained by turning the spore on its longitudinal axis; but itoften seems to be so when they are looked at in profile, on account ofthe very slight distance which then separates them one from another. It will also be remarked that they are in this case often implantedall on the same side of the reproductive body, and most often on itsconvex side. Their fecundity is exhausted with the plastic contents ofthe spore. The corpuscles, when placed in the most favourableconditions, have never given the least sign of vegetation; they havealso remained for a long time in water without experiencing anyappreciable alteration. 

All the individuals of _Dacrymyces deliquescens_ do not produce thesecorpuscles in the same abundance; those which bear the most arerecognizable by the pale tint of the reproductive dust with which theyare covered; in others, where this dust preserves its goldenappearance, only a few corpuscles are found. The spores which producecorpuscles do not appear at all apt to germinate. On the other hand, multitudes of spores will germinate which had not produced anycorpuscles. Tulasne remarks on this, that these observations wouldauthorize us to think that all spores, though perfectly identical toour eyes, have not, without distinction, the same fate, nor doubtlessthe same nature; and, in the second place, that these two kinds ofbodies, if they are not always isolated, yet are most frequently metwith on distinct individuals. This author claims for the corpuscles inquestion that they are spermatia, and thinks that their origin is onlyso far unusual in that they proceed from veritable spores. 

The whole of the _Gasteromycetes_ have as yet to be challenged as tothe mode and conditions of germination and development. It is probablethat these will not materially differ from those which prevail in_Hymenomycetes_. 

The germination in _Æcidium_ has been followed out by Tulasne, [F]either by placing the pseudospores in a drop of water, or confiningthem in a moist atmosphere, or by placing the leaves on which the_Æcidium_ flourishes upon water. The pseudospores plunged in watergerminated more readily than the others. If the conditions werefavourable, germination would take place in a few hours. _ÆcidiumRanunculacearum_, D. C. , on leaves of figwort, gives rarely more thanone germinating filament, which soon attains three times the length ofthe diameter of the pseudospore. This filament generally remainssimple, sometimes torulose, and distorted in a long spire. Sometimesit has been seen divided into two branches, nearly equal to eachother. The spore in germinating empties itself of its plasticcontents, contracts, and diminishes in size. The pseudospores of_Æcidium crassum_, P. , emit three long filaments, which describespirals, imitating the twistings of the stem of a bean or bindweed. In_Æcidium Violæ_, Schum, one filament is produced, which frequentlyrolls up its anterior extremity into a spire, but more often this sameextremity rises in a large ovoid, irregular vesicle, which continuesthe axis of the filament, or makes with it a more or less decidedangle. In whatever manner placed, this vesicle attracts to it all theorange protoplasm, and hardly does this become settled and completebefore the vesicle becomes the starting point of a new development, for it begins to produce at its apex a filament, more slender than theprevious one, stiff, and unbranched. 

[Illustration: FIG. 81. --Germination of _Æcidium Euphorbia (sylvaticæ)_, Tulasne. ]

According to M. Tulasne, the germination of the pseudospores of_Æcidium Euphorbiæ_ on _Euphorbia sylvatica_ differ in some respectsfrom the preceding. When dropped upon water these spores very soonemit a short tube, which ordinarily curves in an arch or circle, almost from its origin, attaining a length of from three to six timesthe diameter of the spore; then this tube gives rise to four spicules, each of which produces a small obovate or reniform sporule; thegeneration of these sporules absorbs all the plastic matter containedin the germ-tube, which permits of the observation that it was dividedinto four cells corresponding with the number of spicules. Thesesporules germinate very rapidly from an indefinite point of theirsurface, emitting a filiform process, which is flexuous and verydelicate, not extending more in length than three times that of thelong axis of the sporule, often less, reproducing at its summit a newsporule, differing in form and size from that which preceded it. Thissporule of the second formation becomes at its apex a vital centre, and sprouts one or more linear buds, of which the elongation isoccasionally interrupted by the formation of vesicular swellings. AsTulasne observes, the pseudospores of the _Æcidium_ and the greaternumber of Uredines are easily wetted with water before arriving atmaturity; but when they are ripe, on the contrary, they appear to beclothed with a greasy matter which protects them from the liquid, forcing them almost all to rest on the surface. 

The pseudospores of _Roestelia_ are produced in strings or chaplets, as in _Æcidium_, with this difference, that instead of beingcontiguous they are separated by narrow isthmuses. The ripepseudospores are enveloped in a thick tegument, of a dark browncolour. They germinate readily on water, producing a filament fifteentimes as long as the diameter of the spore. This filament is sometimesrolled or curved. Towards its extremity it exhibits protuberanceswhich resemble the rudiments of ramuli, or they terminate in a vesiclewhich gives rise to a slender filament. The tegument of thesepseudospores, above all in those which have germinated, and haveconsequently become more transparent, it is easy to see has manypores, or round ostioles. 

In _Peridermium_ the pseudospores, when dropped upon water, germinateat any point of their surface. Sometimes two unequal filaments issuefrom the same spore. After forty-eight hours of vegetation in the air, the greater part had already emitted a multitude of thick littlebranches, themselves either simple or branched, giving to thefilaments a peculiar aspect. Tulasne did not on any occasion observethe formation of secondary spores. 

In the Uredines proper the germination seems to be somewhat similar, or at least not offering sufficient differences to warrant specialreference in _Uredo_, _Trichobasis_, _Lecythea_, &c. In _Coleosporium_there are two kinds of spores, one kind consisting of pulverulentsingle cells, and the other of elongated septate cells, which break upinto obovate joints. Soon after the maturity of the pulverulentspores, each begins to emit a long tube, which is habitually simple, and produces at its summit a reproductive cellule, or reniformsporule. The orange protoplasm passes along the colourless tubes tothe terminal sporule at the end of its vegetation. The two forms ofspores in this genus are constantly found on the same leaf, and in thesame pulvinule, but generally the pulverulent spores abound at thecommencement of the summer. The reniform sporules begin to germinatein a great number as soon as they are free; some few extend a filamentwhich remains simple and uniform, but more commonly it forms at itsextremity a second sporule. If this does not become isolated, to playan independent life, the filament is continued, and new vesicles arerepeated many times. 

[Illustration: FIG. 82. --Germinating pseudospores of (_b_) _ColeosporiumSonchi_; (_s s_) secondary spores, or sporules (Tulasne). ]

[Illustration: FIG. 83. --Germinating pseudospore (_b_) of _Melampsorabetulina_ (Tulasne). ]

In _Melampsora_ the summer spores are of the _Lecythea_ type, and wereincluded in that genus till their relation with _Melampsora_ wasclearly made out. The winter spores are in solid pulvinules, and theirfructification takes place towards the end of winter or in the spring. This phenomenon consists in the production of cylindrical tubes, which start from the upper extremity of the wedge-shaped spores, ormore rarely from the base. These tubes are straight or twisted, simpleor bifurcated, and each of them very soon emits four monosporousspicules, at the same time that they become septate. The sporules arein this instance globose. 

[Illustration: FIG. 84. --Germinating pseudospore of _Uromyceappendiculatus_. (Tulasne. )]

In _Uromyces_ germination follows precisely the same type as that ofthe upper cell of _Puccinia_; in fact, Tulasne states that it is verydifficult to say in what they differ from the _Pucciniæ_ which areaccidentally unilocular. 

In _Cystopus_ a more complex method prevails, which will be examinedmore closely hereafter. 

In _Puccinia_, as already observed when describing their structure, the pseudospores are two-celled. From the pores of each cell, whichare near the central septum, springs a clavate tube, which attains twoor three times the total length of the fruit, and of which the veryobtuse extremity curves more or less in the manner of a crozier. [G]This tube, making a perfectly uncoloured transparent membrane, isfilled with a granular and very pale plastic matter at the expenseof the generative cell, which is soon rendered vacant; then itgives rise to four spicules, usually on the same side, and at thesummit of these produces a reniform cellule. The four sporules soengendered exhaust all the protoplasm at first contained in thegenerative cell, so that their united capacity proves to be evidentlymuch insufficient to contain it, the more so as it leads to thebelief that this matter undergoes as it condenses an elaborationwhich diminishes its size. In all cases the spicule originatesbefore the sporule which it carries, and also attains its full lengthwhen the sporule appears. The form of the latter is at firstglobular, then ellipsoid, and more or less curved. All these phasesof vegetation are accomplished in less than twelve hours, and ifthe spore is mature and ready for germination, it is sufficient toprovoke it by keeping the pseudospores in a humid atmosphere. During this process the two cells do not separate, nor does onecommence germination before the other, but both simultaneously. When the sporules are produced, the protospore, somewhat analogousto a prothallus, has performed its functions and decays. Towardsthe time of the falling of the sporules they are nearly all dividedinto four unequal cells by transverse and parallel septa. Thesesporules in time produce, from any point on their surface, afilament, which reproduces a new sporule, resembling the first, butgenerally smaller. This sporule of the second generation ordinarilydetaches itself from its support before germinating. 

[Illustration: FIG. 85. --Germinating pseudospore of _Puccinia Moliniæ_. (Tulasne. )]

[Illustration: FIG. 86. --Germinating pseudospore of _Triphragmiumulmariæ_ (Tulasne. )]

The pseudospores of _Triphragmium ulmariæ_ have been seen in Aprilgerminating on old leaves of the meadowsweet which survived thewinter, whilst at the same time new tufts of the spores were beingdeveloped on the leaves of the year. These fruits of the springvegetation would not germinate the same year. Each cell in germinationemits a long cylindrical filament, containing a brownish protoplasm, on which four spicules, bearing as many sporules, are generated. 

[Illustration: FIG. 87. --Germinating pseudospore of _Phragmidiumbulbosum_. (Tulasne. )]

The germination of the black fruits of _Phragmidium_ only appears totake place in the spring. It greatly resembles that in _Puccinia_, except that the filament is shorter, and the sporules are sphericaland orange-coloured, instead of being kidney-shaped and pale. In thespecies found on the leaves of the common bramble, the filamentemitted by each cell attains three or four times the length of thefruit. The granular orange protoplasm which fills it passes ere longinto the sporules, which are engendered at the extremity of pointedspicules. After the long warty fruits are emptied of their contentsthey still seem as dark as before, but the pores which are pierced inthe sides, through which the germinating filaments have proceeded, aremore distinctly visible. 

It will be observed that throughout all these allied genera of_Uromyces_, _Puccinia_, _Triphragmium_, and _Phragmidium_ the sametype of germination prevails, which confirms the accuracy of theirclassification together, and renders still less probable the supposedaffinity of _Phragmidium_ with _Sporidesmium_, which was at one timeheld by very astute mycologists, but which is now abandoned. Thisstudy of germination leads also to a very definite conclusion withregard to the genus _Uromyces_--that it is much more closely relatedto _Puccinia_ and its immediate allies than to other unicellularUredines. 

The germination of the pseudospores of the gelatinous Uredines of thegenus _Podisoma_ was studied by Tulasne. [H] These pretended spores, he writes, are formed of two large conical cells, opposed by theirbase and easily separating. They vary in length. The membrane of whichthey are formed is thin and completely colourless in most of them, though much thicker and coloured brown in others. It is principallythe spores with thin membranes that emit from near the middle veryobtuse tubes, into which by degrees, as they elongate, the contents ofthe parent utricles pass. Each of the two cells of the supposed sporemay originate near its base four of these tubes, opposed to each otherat their point of origin, and their subsequent direction; but it israther rare for eight tubes, two by two, to decussate from the samespore or basidium. Usually there are only two or three which arecompletely developed, and these tend together towards the surface ofthe fungus, which they pass, and expand at liberty in the air. Thetubes generally become thicker by degrees as they elongate, some onlyslightly exceeding the length of the protospores. Others attain threeor four times that length, according to the greater or less distancebetween the protospore and the surface of the plant. In the longesttubes it is easy to observe how the colouring matter passes to theirouter extremity, leaving the portion nearest to the parent cellcolourless and lifeless. When nearly attaining their ultimatedimensions, all the tubes are divided towards their outer extremity bytransverse septa into unequal cells; then simple and solitaryprocesses, of variable length and form, but attenuated upwards, proceed from each segment of the initial tube, and produce at theirextremity an oval spore (teleutospore, Tul. ), which is slightly curvedand unilocular. These spores absorb all the orange endochrome from theoriginal tubes. They appear in immense numbers on the surface of thefungus, and when detached from their spicules fall upon the ground oron any object which may be beneath them. So freely are they depositedthat they may be collected on paper, or a slip of glass, like a finegold-coloured powder. Again, these secondary spores (teleutospores)are capable of germination, and many of them will be found to havegerminated on the surface of the _Podisoma_ whence they originated. The germ filament which they produce springs habitually from the side, at a short distance from the hilum, which indicates the point ofattachment to the original spicule. These filaments will attain tofrom fifteen to twenty times the diameter of the spore in lengthbefore branching, and are in themselves exceedingly delicate. Thetubes which issue from the primary spores (protospores, Tul. ) are notalways simple, but sometimes forked; and the cells which areultimately formed at their extremities, though producing filiformprocesses, do not always generate secondary spores (teleutospores) attheir apices. This mode of germination, it will be seen, resemblesgreatly that which takes place in _Puccinia_. 

[Illustration: FIG. 88. --Germinating pseudospores of _Podisoma Juniperi_. (Tulasne)]

The germination of the Ustilagines was in part examined by Tulasne, but since has received accessions through the labours of Dr. A. Fischer von Waldheim. [I] Nothing, however, of any importance is addedto our knowledge of the germination of _Tilletia_, which was madeknown as early as 1847. [J] After some days a little obtuse tube isprotruded through the epispore, bearing at its apex long fusiformbodies, which are the sporules of the first generation. Theseconjugate by means of short transverse tubes, after the manner of thethreads of _Zygnema_. Afterwards long elliptical sporules of thesecond generation are produced on short pedicels by the conjugatedfusiform bodies of the first generation. (Fig. 89, _ss. _) Ultimatelythese sporules of the second generation germinate, and generate, onshort spicules, similar sporules of a third generation. (Fig. 89, _st. _)

[Illustration: FIG. 89. --Germinating pseudospore (_g_) of _Tilletiacaries_ with secondary spores in conjugation. (Tul. )]

In _Ustilago (flosculorum)_ germination takes place readily in warmweather. The germ tube is rather smaller at its base than further on. In from fifteen to eighteen hours the contents become coarselygranular; at the same time little projections appear on the tube whichare narrowed at the base, into which some of the protoplasm passes. These ultimately mature into sporules. At the same time a terminalsporule generally appears on the threads. Secondary sporulesfrequently grow from the primary, which are rather smaller, and theseoccasionally give rise to a third generation. 

In _Urocystis (pompholygodes)_ the germinating tubes springexclusively from the darker central cells of the clusters. From theseare developed at their extremity three or four linear bodies, as in_Tilletia_, but after this no further development has as yet beentraced. It may be remarked here that Waldheim observed similarconjugation of the sporules in some species of _Ustilago_ as havebeen remarked in the sporules of the first generation in _Tilletia_. 

[Illustration: FIG. 90. --Pseudospore of _Ustilago receptaculorum_ ingermination, and secondary spores in conjugation. (Tul. )]

[Illustration: FIG. 91. --Conidia and zoospores of _Cystopus candidus_;_a. _ conidium with the plasma divided; _b. _ zoospores escaping; _c. _zoospores escaped from the conidium; _d. _ active zoospores; _e. _zoospores, having lost their cilia, commencing to germinate. ]

Returning to _Cystopus_, as the last of the Uredines, we must brieflyrecapitulate the observations made by Professor de Bary, [K] who, bythe bye, claims for them an affinity with _Peronospora_ (Mucedines buttoo well known in connection with the potato disease), and _not_ withthe Uredines and their allies. In this genus there are two kinds ofreproductive organs, those produced on the surface of the plantbursting through the cuticle in white pustules, and which De Baryterms _conidia_, which are generated in chains, and certain globosebodies termed _oogonia_, which are developed on the mycelium in theinternal tissues of the foster plant. When the conidia are sown onwater they rapidly absorb the moisture, and swell; the centre of oneof the extremities soon becomes a large obtuse papilla resembling theneck of a bottle. This is filled with a granular protoplasm, in whichvacuoles are formed. Soon, however, these vacuoles disappear, and veryfine lines of demarcation separate the protoplasm into from five toeight polyhedric portions, each presenting a little faintly-colouredvacuole in the centre (_a_). Soon after this division the papilla atthe extremity swells, opens itself, and at the same time the five toeight bodies which had formed in the interior are expelled one by one(_b_). These are zoospores, which at first take a lenticular form, and group themselves before the mouth of the parent cell in a globosemass (_c. _) Very soon, however, they begin to move, and then vibratilecilia show themselves (_d_), and by means of these appendages theentire globule moves in an oscillating manner as one by one thezoospores disengage themselves, each becoming isolated and swimmingfreely in the surrounding fluid. The movement is precisely that of thezoospores of Algæ. 

[Illustration: FIG. 92. --Resting spore of _Cystopus candidus_ withzoospores escaped. ]

The generation of the zoospores commences within from an hour and ahalf to three hours after the sowing of the conidia on water. From theoogonia, or resting spores, similar zoospores, but in greater number, are generated in the same manner, and their conduct after becomingfree is identical. Their movements in the water usually last from twoto three hours, then they abate, the cilia disappear, and the sporebecomes immovable, takes a globose form, and covers itself with amembrane of cellulose. Afterwards the spore emits, from any pointwhatever of its surface, a thin, straight or flexuous tube, whichattains a length of from two to ten times the diameter of the spore. The extremity becomes clavate or swollen, after the manner of avesicle, which receives by degrees the whole of the protoplasm. 

De Bary then proceeds to describe experiments which he had performedby watering growing plants with these zoospores, the result being thatthe germinating tubes did not penetrate the epidermis, but entered bythe stomates, and there put forth an abundant mycelium which traversedthe intercellular passages. Altogether the germination of theseconidia or zoospores offers so many differences from the ordinarygermination of the Uredines, and is so like that which prevails in_Peronospora_, in addition to the fact of both genera producing winterspores or oogonia, that we cannot feel surprised that the learnedmycologist who made these observations should claim for _Cystopus_ anaffinity with _Peronospora_ rather than with the plants so longassociated with it amongst the _Coniomycetes_. 

In passing from these to the _Mucedines_, therefore, we cannot do somore naturally than by means of that genus of white moulds to which wehave just alluded. The erect branched threads bear at the tip of theirbranchlets spores, or conidia, which conduct themselves in a likemanner to the organs so named in _Cystopus_, and oogonia or restingspores developed on the mycelium within the tissues of the fosterplant also give origin to similar zoospores. 

The conidia are borne upon erect, elongated filaments, originatingfrom the creeping mycelium. These threads are hollow, and rarelyseptate; the upper portion divided into numerous branches, and theseagain are subdivided, the ultimate ramuli each terminated by a singleconidium. This body when mature is oval or elliptical, filled withprotoplasm, but there is a diversity in their mode of germination. Inthe greater part, of which _P. Effusa_ may be taken as an example, theconidia have the function of simple spores. Placed in favourableconditions, each of them puts forth a germ-tube, the formation ofwhich does not differ in any essential point from what is known of thespores of the greater part of fungi. 

The short oval conidia of _P. Gangliformis_ have little obtuse papillæat their apex, and it is at this point that germination commences. 

The conidia of _P. Densa_ are similar, but the germination isdifferent. When placed in a drop of water, under favourablecircumstances, the following changes may be observed in from four tosix hours. The protoplasm, at first uniformly distributed in all theconidia, appears strewn with semi-lenticular, and nearly equidistantvacuoles, of which the plane face is immediately in contact with theperiphery of the protoplasm. These vacuoles number from sixteen toeighteen in _P. Macrocarpa_, but are less numerous in _P. Densa_. Ashort time after the appearance of the vacuoles the entire conidiumextends itself so that the papilla disappears. Suddenly it reappears, elongates itself, its attenuated membrane vanishes, and the protoplasmis expelled by the narrow opening that remains in place of thepapilla. In normal cases the protoplasm remains united in a singlemass that shows a clear but very delicate outline. When it has reachedthe front of the opening in the conidium, which is thus emptied, themass remains immovable. In _P. Densa_ it is at first of a veryirregular form, but assumes by degrees a regular globose shape. Thisis deprived of a distinct membrane, the vacuoles that disappeared inthe expulsion again become visible, but soon disappear for a secondtime. The globule becomes surrounded with a membrane of cellulose, andsoon puts out from the point opposite to the opening of the conidium athick tube which grows in the same manner as the germ-tube of theconidia in other species. Sometimes the expulsion of the protoplasm isnot completely accomplished; a portion of it remaining in the membraneof the conidium detaches itself from the expelled portion, and whilethis is undergoing changes takes the form of a vesicle, which isdestroyed with the membrane. It is very rare that the protoplasm isnot evacuated, and that the conidia give out terminal or lateral tubesin the manner that is normal to other species without papillæ. Thegermination just described does not take place unless the conidia areentirely surrounded by water; it is not sufficient that they reposeupon its surface. Besides, there is another condition which, withoutbeing indispensable, has a sensible influence on the germination of_P. Macrocarpa_, and that is the exclusion of light. To ascertain ifthe light or the darkness had any influence, two equal sowings wereplaced side by side, the one under a clear glass bell, the other undera blackened glass bell. Repeated many times, these experiments alwaysgave the same result--germination in from four to six hours in theconidia under the blackened glass; no change in those under the clearglass up to the evening. In the morning germination was completed. 

The conidia of _P. Umbelliferarum_ and _P. Infestans_[L] show ananalogous structure. These bodies, if their development be normal, become zoosporangia. When they are sown upon water, one sees at theend of some hours the protoplasm divided by very fine lines, and eachof the parts furnished with a small central vacuole. Then the papillaof the conidium disappears. In its place appears a rounded opening, bywhich the parts of the protoplasm are expelled rapidly, one after theother. Each of these, when free, immediately takes the form of aperfect zoospore, and commences to agitate itself. In a few momentsthe sporangium is empty and the spores disappear from the field of themicroscope. 

The zoospores are oval or semi-oval, and in _P. Infestans_ the twocilia spring from the same point on the inferior border of thevacuole. Their number in a sporangium are from six to sixteen in _P. Infestans_, and from six to fourteen in _P. Umbelliferarum_. Themovement of the zoospores ceases at the end of from fifteen to thirtyminutes. They become motionless, cover themselves with a membrane ofcellulose, and push out slender bent germ-tubes which are rarelybranched. It is but seldom that two tubes proceed from the same spore. The same development of the zoospores in _P. Infestans_ is favoured bythe exclusion of the light. Placed in a position moderately lighted orprotected by a blackened bell, the conidia very readily producedzoospores. 

A second form of germination of the conidia in _P. Infestans_, whensown upon a humid body or on the surface of a drop of water, consistsin the conidium emitting from its summit a simple tube, the extremityof which swells itself into the form of an oval vesicle, drawing toitself, little by little, all the protoplasm contained in theconidium. Then it isolates itself from the germ-tube by a septum, andtakes all the essential characteristics of the parent conidium. Thissecondary conidium can sometimes engender a third cellule by a similarprocess. These secondary and tertiary productions have equally thecharacter of sporangia. When they are plunged into water, the ordinaryproduction of zoospores takes place. 

Lastly, there is a third mode of germination which the conidia of _P. Infestans_ manifest, and which consists in the conidium emitting fromits summit a simple or branched germ-tube. This grows in a similarmanner to the conidia first named as of such species as _P. Effusa_. The conditions which control this form of germination cannot beindicated, since some conidia which germinate after this manner willsometimes be found mixed with others, the majority of which furnishzoospores. It may be that the conidia themselves are in some sort ofabnormal condition. 

In all the species examined the conidia possess the power ofgermination from the moment of their maturity. The younger they arethe more freely they germinate. They can retain this power for somedays or weeks, provided they are not entirely dried. Dessication in anordinary temperature seemed sufficient to destroy the faculty ofgerminating in twenty-four hours, when the conidia had been removedfrom the leaves on which they were produced. They none of themretained the faculty during a few months, hence they cannot preserveit during the winter. 

The germs of _Peronospora_ enter the foster plant if the spores aresown upon a part suitable for the development of the parasite. It iseasy to convince one's self that the mycelium, springing from thepenetrating germs, soon takes all the characters that are found in theadult state. Besides, when cultivated for some time, conidiiphorousbranches can be seen growing, identical with those to which it owesits origin. Such cultivation is so readily accomplished that it can bemade upon cut leaves preserved fresh in a moist atmosphere. 

In the species of _Peronospora_ that inhabit perennial plants, orannual plants that last through the winter, the mycelium hidden in thetissues of the foster-plant lasts with it. In the spring itrecommences vegetation, and emits its branches into the newly-formedorgans of its host, there to fructify. The _Peronospora_ of the potatois thus perennial by means of its mycelium contained in the brownedtissue of the diseased tubers. When in the spring a diseased potatobegins to grow, the mycelium rises in the stalk, and soon betraysitself by blackish spots. The parasites can fructify abundantly onthese little stalks, and in consequence propagate themselves in thenew season by the conidia coming from the vivacious mycelium. 

The diseased tubers of the potato always contain the mycelium of _P. Infestans_, which never fructifies there as long as the skin of thetuber is intact. But when, in cutting the tuber, the parenchymaoccupied by the mycelium is exposed to the contact of the air, itcovers itself with conidia-bearing branches at the end of fromtwenty-four to forty-eight hours. Analogous results are obtained withthe stalks of the potato. It is evident that in these experimentsnothing is changed except the contact of the air; the specificconditions particularly remain the same. It appears, therefore, thatit is this contact alone which determines generally the production ofthe conidiiferous branches. [M]

The mode of germination and development in the Mucors has been studiedby several observers, but most recently by Van Tieghem and LeMonnier. [N] In one of the common forms, the _Mucor phycomyces_ of someauthors, and the _Phycomyces nitens_ of others, the process is givenin detail. In this species germination will not take place in ordinarywater, but it readily takes place in orange juice and other media. Thespore loses colour, swells, and absorbs fluid around it until doubleits original size and ovoid. Then a thick thread is emitted from oneor both extremities, which elongates and becomes branched in a pinnatemanner. Sometimes the exospore is ruptured and detached loosely fromthe germinating spore. After about forty-eight hours from the firstsowing, the mycelium will send branches into the air, which againbecome abundantly branched; other short submerged branches will alsoremain simple, or have tuft-like ramifications, each terminating in apoint, so as to bristle with spiny hairs. In two or three daysabruptly swollen branches, of a club shape, will make their appearanceon the threads both in the air and in the fluid. Sometimes thesebranches are prolonged into an equal number of sporangia-bearingthreads, but most frequently they divide first at their swollensummits into numerous branches, of which usually one, sometimes twoor three, develop into sporangia-bearing threads, while the rest areshort, pointed, and form a tuft of rootlets. Sometimes these rootletsreduce themselves to one or more rounded protuberances towards thebase of the sporangia-bearing threads. 

[Illustration: FIG. 93. --Zygospores of _Mucor phycomyces_. (Van Tieghem. )]

There are often also a certain number of the branches which hadacquired a clavate shape, and do not erect themselves above thesurface, instead of producing a fertile thread, which would seem tohave been their first intention, become abruptly attenuated, and aremerely prolonged into a mycelial filament. Although in other specieschlamydospores are formed in such places on the mycelium, nothing ofthe kind has been traced in this species, more than here indicated. Occasionally, when germination is arrested prematurely, certainportions of the hyphæ, in which the protoplasm maintains its vitality, become partitioned off. This may be interpreted as a tendency towardsthe formation of chlamydospores, but there is no condensation ofprotoplasm, or investiture with a special membrane. Later on thisisolated protoplasm is gradually altered, separating into somewhatregular ovoid or fusiform granules, which have, to a certain extent, the appearance of spores in an ascus, but they seem to be incapable ofgermination. 

Another method of reproduction, not uncommon in _Mucorini_, isdescribed by Van Tieghem in this species. Conjugating threads on thesubstratum by degrees elaborate zygospores, but these, contrary tothe mode in other species, are surrounded by curious branchedprocesses which emanate from the arcuate cells on either side of thenewly-developed zygospore. This system of reproduction is againnoticed more in detail in the chapter on polymorphism. 

M. De Seynes has given the details of his examination of the sporidiaof _Morchella esculenta_ during germination. [O] A number of thesesporidia, placed in water in the morning, presented, at nine o'clockof the same evening, a sprout from one of the extremities, measuringhalf the length of the spore. In the morning of the next day thissprout had augmented, and become a filament three or four times aslong. The next day these elongated filaments exhibited some transversedivisions and some ramifications. On the third day, the germinationbeing more advanced, many more of the sporidia were as completelychanged, and presented, in consequence of the elongation, theappearance of a cylindrical ruffle, the cellular prolongations arisingfrom the germination having a tendency towards one of the extremitiesof the longer axis of the sporidium, and more often to the two opposedextremities, either simultaneously or successively. Out of manyhundreds of sporidia examined during germination, he had only seen avery few exceptions to this rule, among which he had encountered thecentrifugal tendency to vegetate by two opposed filaments, provingthat if it bears a second by the side of the primal filament situatedat one of the poles, a second would also be seen from the side of thefilament coming from the opposite pole. 

Before being submitted to the action of water, the contents of thesporidia seemed formed of two distinct parts, one big drop of yellowoil of the same form as the sporidium, with the space between it andthe cell wall occupied by a clear liquid, more fluid and lessrefractive, nearly colourless, or at times slightly roseate. As themembrane absorbed the water by which it was surrounded, the quantityof this clear liquid was augmented, and the rosy tint could be moreeasily distinguished. All the contents of the spore, which up to thistime remained divided into two parts, presented altogether one aspect, only containing numerous granulations, nearly of equal size, completely filling it, and reaching the inner face of the sporicmembrane. 

After this time the sporidium augments in size very rapidly, becomingat times irregular, and sometimes even as much as from two to threetimes its original dimensions, then there appears at the surface, usually at one of the poles of the ellipse, a small prominence, withan extremely fine membrane, which does not appear to separate itselffrom that which surrounds the sporidium, and it is difficult to saywhether it is a prolongation of the internal membrane going across theoutside, or simply a prolongation caused by a continuation of tissueof an unique membrane. Sometimes there may be seen at the point wherethe primal filament issues from the sporidium a circular mark, whichappears to indicate the rupture of the external membrane. From thistime another change comes over the contents. We again find the yellowoily liquid, now occupying the external position, with some drops ofcolourless or roseate liquid in the centre, so that the oily liquidand the more limpid fluid interchange the positions which theyoccupied previous to the commencement of germination. Whether thesetwo fluids have undergone any change in their constitution isdifficult to determine, at all events the oily liquid appears to beless refractive and more granular, and it may be that it is a productof new formation, containing some of the elements of the primitiveoily drop. Having regard to the delicate character of the membrane ofthe germinating filaments, De Seynes supposed that it might offergreater facility for the entrance of water by endosmose, and accountfor the rapid enlargement of the sporidia. By a series of experimentshe became satisfied that this was the case to a considerable extent, but he adds:--"I cannot help supposing that a greater absorption ofgreasy matter in the cell which is the first product of germinationraises an objection to an aqueous endosmose. One can also see in thisexperience a proof of the existence of two special membranes, and sosuppose that the germinative cell is the continuation of the internalmembrane, the external membrane alone being susceptible of absorbingthe liquids, at least with a certain rapidity. "

[Illustration: FIG. 94. --Sporidium of _Ascobolus_ germinating. ]

In other _Discomycetes_ germination takes place in a similar manner. Boudier[P] narrates that in _Ascobolus_, when once the spore reaches afavourable place, if the circumstances are good, _i. E. _, if thetemperature is sufficiently high and the moisture sufficient, it willgerminate. The time necessary for this purpose is variable, some hourssufficing for some species; those of _A. Viridis_, for example, germinate in eight or ten hours, doubtless because, being terrestrial, it has in consequence less heat. The spore slightly augments in size, then opens, generally at one or other extremity, sometimes at two, orat any point on its surface, in order to pass the mycelium tubes. Atfirst simple, without septa, and granular in the interior, above allat the extremity, these tubes, the rudiment of the mycelium, are notlong in elongating, in branching, and later in having partitions. These filaments are always colourless, only the spore may be coloured, or not. Coemans has described them as giving rise to two kinds ofconidia, [Q] the one having the form of _Torula_, when they give riseto continuous filaments, the other in the form of _Penicillium_, whenthey give birth to partitioned filaments. De Seynes could never obtainthis result. Many times he had seen the _Penicillium glaucum_ invadehis sowings, but he feels confident that it had nothing to do with the_Ascobolus_. M. Woronin[R] has detailed some observations on thesexual phenomena which he has observed in _Ascobolus_ and _Peziza_, and so far as the scolecite is concerned these have been confirmed byM. Boudier. 

There is no reason for doubt that in other of the _Discomycetes_ thegermination of the sporidia is very similar to that already seen anddescribed, whilst in the _Pyrenomycetes_, as far as we are aware, although the production of germinating tubes is by no means difficult, development has not been traced beyond this stage. [S]

 [A] Seynes, J. De, "Essai d'une Flore Mycologique de la Montpellier, " &c. (1863), p. 30. 

 [B] Hoffman, "Icones Analyticæ Fungorum. "

 [C] The spores of Agarics which are devoured by flies, however, though returned in their dung in an apparently perfect state, are quite effete. It is, we believe, principally by the _Syrphidæ_, which devour pollen, that fungus spores are consumed. 

 [D] All attempts at Chiswick failed with some of the more esculent species, and Mr. Ingram at Belvoir, and the late Mr. Henderson at Milton, were unsuccessful with native and imported spawn. 

 [E] Tulasne, "On the Organization of the Tremellini, " "Ann. Des. Sci. Nat. " 3^me sér. Xix. (1853), p. 193. 

 [F] Tulasne, "Mémoire sur les Urédinées. "

 [G] Tulasne, in his "Memoirs on the Uredines. "

 [H] Mr. Berkeley has lately published a species under the name of _P. Ellisii_, in which the gelatinous element is scarcely discernible till the plant is moistened. There are two septa in this species, and another species or form has lately been received from Mr. Ellis which has much shorter pedicels, and resembles more closely _Puccinia_, from which it is chiefly distinguished by its revivescent character. 

 [I] Von Waldheim, on the "Development of the Ustilagineæ, " in "Pringsheim's Jahrbucher, " vol. Vii. (1869); translated in "Transactions of N. Y. State Agricultural Society for 1870. "

 [J] Berkeley, on the "Propagation of Bunt, " in "Trans. Hort. Soc. London, " ii. (1847), p. 113; Tulasne, second memoir, in "Ann. Des. Sci. Nat. " ii. (4^me sér. ), p. 77; Cooke, in "Journ. Quekett Micro. Club, " i. P. 170. 

 [K] De Bary, "Recherches, " &c. In "Annales des Sciences Naturelles" (4^me sér. ), xx. P. 5; Cooke in "Pop. Sci. Rev. " iii. (1864), p. 459. 

 [L] This is the mould which produces the potato murrain. 

 [M] De Bary, "Champignons parasitiques, " in "Annales des Sci. Nat. " (4^me sér. ), xx. P. 5; Cooke, "Microscopic Fungi, " cap. Xi. P. 138; "Popular Science Review, " iii. 193 (1864). 

 [N] Van Tieghem and Le Monnier, "Researches on Mucorini, " in "Ann. Des Sci. Nat. " (1873), xvii. P. 261; Summary in "Quart. Journ. Micro. Science" (2nd ser. ), xiv. P. 49. 

 [O] Seynes, "Essai d'une Flore Mycologique. "

 [P] Boudier, "Mémoire sur l'Ascoboles, " pt. I. Iv. F. 13-15. 

 [Q] Coemans, "Spicilége Mycologique, " i. P. 6. 

 [R] Woronin, "Abhandlungen der Senchenbergischen Naturfor. Gesellschaft" (1865), p. 333. 

 [S] In the very important observations made by Dr. Cunningham at Calcutta, on substances floating in the atmosphere, it appeared that the sporidia of many _Sphæriæ_ actually germinated after being taken up by the air. The multitude of fungus spores which were observed in every case was quite extraordinary. 

VIII. 

SEXUAL REPRODUCTION. 

The existence of some sort of sexual reproduction in Fungi has long beensuspected, although in earlier instances upon insufficient grounds; butof late years observations have multiplied and facts accumulated whichleave no doubt of its existence. If the _Saprolegniæ_ are left out of thequestion as disputed Fungi, there still remain a number of wellauthenticated instances of the phenomena of copulation, and many otherfacts which indicate some sort of sexual relationship. The precisemanner in which those minute bodies, so common amongst the _Sphæronemei_, which we prefer to call stylospores, perform their functions is still to agreat extent a mystery; yet it is no longer doubted that certain speciesof _Aposphæria_, _Phoma_, _Septoria_, &c. , are only conditions of somespecies of _Sphæria_, often developed and matured in close proximity tothem on the same host. In _Æcidium_, _Roestelia_, &c. , spermogonia areproduced plentifully on or near the same spots on which thefructification appears, either simultaneously or at a later period. [A] Therelation of _Cytispora_ to _Valsa_ was suspected by Fries very manyyears ago, and, as since demonstrated, with very good reason. Allattempts, however, to establish anything like sexual reproduction inthe higher forms of _Hymenomycetes_ have at present been unsuccessful; andthe same may be said of the _Gasteromycetes_; but in _Ascomycetes_ and_Physomycetes_ instances abound. 

We know not whether any importance is to be attached to the views ofM. A. S. Oersted, [B] which have not since been confirmed, but whichhave been cited with some approval by Professor de Bary, as to a traceof sexual organs in _Hymenomycetes_. He is supposed to have seen in_Agaricus variabilis_, P. , oocysts or elongated reniform cells, whichspring up like rudimentary branches of the filaments of the mycelium, and enclose an abundant protoplasm, if not even a nucleus. At the baseof these oocysts appear the presumed antheridia, that is to say, oneor two slender filaments, which generally turn their extremitiestowards the oocysts, and which more rarely are applied to them. Then, without ulteriorily undergoing any appreciable modifications, thefertile cell or oocyst becomes enveloped in a network of filaments ofmycelium which proceed from the one which bears it, and this tissueforms the rudiments of the cap. The reality of some kind offecundation in this circumstance, and the mode of the phenomena, ifthere is one, are for the present equally uncertain. If M. Oersted'sopinion is confirmed, naturally the whole of the cap will be theproduct of fecundation. Probably Karsten (Bonplandia, 1862, p. 62) sawsomething similar in _Agaricus campestris_, but his account isobscure. 

[Illustration: FIG. 95. --Zygospore of _Mucor phycomyces_. ]

In _Phycomyces_ the organs of reproduction have been subjected toclose examination by Van Tieghem, [C] and although he failed todiscover chlamydospores in this, he describes them in other Mucors. Inthis species, besides the regular sexual development, by means ofsporangia, there is a so-called sexual reproduction by means ofzygospores, which takes place in this wise. The threads whichconjugate to form the zygospores are slender and erect on the surfaceof the substratum. Two of these threads come into close contactthrough a considerable length, and clasp each other by alternateprotuberances and depressions. Some of the protuberances are prolongedinto slender tubes. At the same time the free extremities of thethreads dilate, and arch over one towards the other until their topstouch like a vice, each limb of which rapidly increases in size. Eachof these arcuate, clavate cells has now a portion of its extremityisolated by a partition, by means of which a new hemispherical cell isformed at the end of each thread at its point of junction with theopposed thread. These cells become afterwards cylindrical by pressure, the protoplasm is aggregated into a mass, the double membrane at thepoint of first contact is absorbed, and the two confluent masses ofprotoplasm form a zygospore invested with a tubercular coat andenveloped by the primary wall of the two conjugating cells. Duringthis formation of the zygospore, the two arched cells whence thezygospore originated develop a series of dichotomous processes inclose proximity to the walls which separate them from the zygospore. These processes appear at first on one of the arcuate cells insuccessive order. The first makes its appearance above upon the convexside; the succeeding ones to the right and left in descending order;the last is in the concavity beneath. It is only after the developmentof this that the first process appears on the opposite cell, which isfollowed by others in the same order. These dichotomous processes arenothing more than branches developed from the arcuate, or mothercells. During all these changes, while the zygospore enlarges, thewall of the arcuate cells becomes coloured brown. This colouring ismore marked on the convex side, and it shows itself first in the cellon which the dichotomous branches are first produced, and whichretains the darker tint longer than the other. The zone from whencethe processes issue, and also the processes themselves, have theirwalls blackened deeply, while the walls of the conjugated cells, whichcontinue to clothe the zygospore during the whole of its development, are bluish-black. By pressure, the thin brittle coat which envelopesthe zygospore is ruptured, and the coat of the zygospore exposed, formed of a thick cartilaginous membrane, studded with large irregularwarts. 

The germination of the zygospores in this species has not as yet beenobserved, but it is probably the same or very similar to that observedin other species of _Mucor_. In these the rough tuberculate episporesplits on one side, and its internal coat elongates itself andprotrudes as a tube filled with protoplasm and oil globules, terminating in an ordinary sporangium. Usually the amount of nutrimentcontained in the zygospore is exhausted by the formation of theterminal sporangium, according to Brefeld;[D] but Van Tieghem and LeMonnier remark that in their examinations they have often seen apartition formed at about a third of the length of the principalfilament from the base, below which a strong branch is given off, andthis is also terminated by a large sporangium. 

[Illustration: FIG. 96. --Zygospore of _Rhizopus_ in different stages. (DeBary. )]

De Bary has given a precise account of the formation of the zygosporein another of the Mucors, _Rhizopus nigricans_, in which he says thatthe filaments which conjugate are solid rampant tubes, which arebranched without order and confusedly intermingled. Where two of thesefilaments meet each of them pushes towards the other an appendagewhich is at first cylindrical and of the same diameter. From the firstthese two processes are applied firmly one to the other by theirextremities; they increase in size, become clavate, and constitutetogether a fusiform body placed across the two conjugated filaments. Between the two halves of this body there exists no constantdifference of size; often they are both perfectly equal. In eachthere is collected an abundance of protoplasm, and when they haveattained a certain development the largest extremity of each isisolated by a septum from the clavule, which thus becomes the supportor suspender of the copulative cell. The two conjugated cells of thefusiform body are generally unequal; the one is a cylinder as long asit is broad, the other is disciform, and its length is only equal tohalf its breadth. The primitive membrane of the clavule forms betweenthe copulative cells a solid partition of two membranes, but soonafter the cells have become defined the medial partition becomespierced in the centre, and then soon entirely disappears, so that thetwo twin cells are confounded in one single zygospore, which is due tothe union of two more or less similar utricles. After its formationthe zygospore still increases considerably in size, and acquires adiameter of more than one-fifth of a millimetre. Its form is generallyspherical, and flattened on the faces which are united to thesuspenders, or it resembles a slightly elongated cask. The membranethickens considerably, and consists at the time of maturity of twosuperposed integuments; the exterior or epispore is solid, of a darkblackish-blue colour, smooth on the plane faces in contact with thesuspenders, but covered everywhere else with thick warts, which arehollow beneath. The endospore is thick and composed of several layers, colourless, and covered with warts, which correspond and fit intothose of the epispore. The contents of the zygospore are a coarselygranular protoplasm, in which float large oleaginous drops. While thezygospore is increasing in size, the suspender of the smallercopulative cell becomes a rounded and stipitate utricle, often dividedat the base by a septum, and which attains almost to the size of thezygospore. The suspender of the larger copulative cell preserves itsprimitive form and becomes scarcely any larger. It is rare that thereis not a considerable difference of size between the two conjugatedcells and the suspenders. [E]

Similar conjugation with like results also takes place in _Syzygitesmegalocarpus_. In this species the germination of the zygospores hasbeen observed. If, after a certain time of repose, these bodies areplaced on a moist substratum, they emit a germ-like tube, which, without originating a proper mycelium, develops at the expense of thenutritive material stored in the zygospore into a carpophore or fruitbearer, which is many times dichotomously branched, bearing terminalsporangia characteristic of the species. 

It has already been remarked by us that the _Saprolegnei_ are claimedby some authors as Algæ, whilst we are more disposed to regard them asclosely allied to the Mucors, and as they exhibit in themselves strongevidence in support of the existence of sexual reproduction, we cannotforbear giving a summary of what has been observed by De Bary andothers in this very interesting and singular group of plants, to whichM. Cornu has recently dedicated an exhaustive monograph. [F]

In _Saprolegnia monoica_, and others, the female organs consist ofoogonia--that is to say, of cells which are at first globose and richin plastic matter, which most generally terminate short branches ofthe mycelium, and which are rarely seen in an interstitial position. The constitutive membrane of the adult oogonia is reabsorbed in agreat many points, and is there pierced with rounded holes. At thesame time the plasma is divided into a larger or smaller number ofdistinct portions, which are rounded into little spheres, and separatefrom the walls of the conceptacle in order to group themselves at thecentre, where they float in a watery fluid. These gonospheres are thensmooth and bare, with no membrane on their surface of the nature ofcellulose. 

[Illustration: FIG. 97. --Conjugation in _Achlya racemosa_. (Cornu. )]

During the formation of the oogonia there arise from its pedicelor from neighbouring filaments slight cylindrical curved branches, sometimes turned round the support of the oogonia, and which all tendtowards this organ. Their superior extremity is intimately appliedto its wall, then ceases to be elongated, becomes slightly inflated, and is limited below by a partition; it is then an oblong cell, slightly curved, filled with protoplasm, and intimately applied tothe oogonia--in fact, an antheridium or organ of the male sex. Each oogonium possesses one or several antheridia. Towards the timewhen the gonospheres are formed it may be observed that eachantheridium sends to the interior of the oogonia one or severaltubular processes, which have crossed its side wall, and which openat their extremity in order to discharge their contents. These, while they are flowing out, present some very agile corpuscles, andwhich, considering their resemblance to those in _Vaucheria_, towhich the name of spermatozoids are applied, ought to be consideredas the fecundating corpuscles. After the evacuation of the antheridiathe gonospheres are found to be covered with cellulose; they thenconstitute so many oospores, with solid walls. De Bary considersthat, bearing in mind analogous phenomena observed in _Vaucheria_, andthe direct observations of Pringsheim, [G] the cellulose membrane onthe surface of the gonospheres is only the consequence of a sexualfecundation. 

In _Achlya dioica_ the antheridium is cylindrical, the plasma which itencloses is divided into particles, which attain nearly the size ofthe zoospores of the same plant. These particles become globosecells, grouped in the centre of the antheridium. Afterwards thecontents of these latter cells become divided into numerous bacillaryspermatozoids, which first break the wall of their mother cell, andthen issue from the antheridium. These rod-like corpuscles, whichresemble the spermatozoids in _Vaucheria_, have their movementsassisted by a long cilium. It is presumable that here, as in theAlgæ, the spermatozoids introduce themselves into the cavity ofthe oogonium, and unite with the gonospheres. 

Amongst obscure and doubtful bodies are those described by Pringsheim, which have their origin in thick filaments or tubes, similar to thosewhich form the zoosporangia, and represent so many distinct littlemasses of plasma within an homogeneous parietal ganglion. The contourof these plastic masses is soon delineated in a more precise manner. We see in their interior some homogeneous granules, which are at firstglobose, then oval, and finally travel to the enlarged and ampullæformextremity of the generating tube. There they become rounded or ovalcells covered with cellulose, and emit from their surface one orseveral cylindrical processes, which elongate towards the wall of theconceptacle, and pierce it, without, however, ever projecting very farbeyond it. At the same time the lacunose protoplasm of each cellbecomes divided into a number of corpuscles, which escape by the openextremity of the cylindrical neck. They resemble in their organizationand agility the spermatozoids of _Achlya dioica_. They soon becomemotionless in water, and do not germinate. During the development ofthese organs, the protoplasm of the utricle which contains them offersat first completely normal characteristics, and disappears entirely bydegrees as they increase. De Bary and Pringsheim believe that theseorgans constitute the antheridia of the species of _Saprolegnia_ towhich they belong. 

The oospores of the _Saprolegniæ_, when arrived at maturity, possess atolerably thick double integument, consisting of an epispore and anendospore. After a considerable time of repose they give rise totubular or vesicular germs, which, without being much elongated, produce zoospores. [H]

De Bary has claimed for the oogonia in _Cystopus_ and _Peronospora_ akind of fecundation which deserves mention here. [I] These same fruits, he says, which owe their origin to sexual organs, should bear thenames of _oogonia_ and _antheridia_, according to the terminologyproposed by Pringsheim for analogous organs in the Algæ. The formationof the oogonia, or female organs, commences by the terminal orinterstitial swelling of the tubes of the mycelium, which increase andtake the form of large spherical or oboval cells, and which separatethemselves by septa from the tube which carries them. Their membraneencloses granules of opaque protoplasm, mingled with numerous bulkygranules of colourless fatty matter. 

[Illustration: FIG. 98. --Conjugation in _Peronospora; a. Antheridium_. (De Bary. )]

The branches of the mycelium which do not bear oogonia apply theirobtuse extremities against the growing oogonia; this extremity swells, and, by a transverse partition, separates itself from the supportingtube. It is the antheridium, or male organ, which is formed by thisprocess; it takes the form of an obliquely clavate or obovate cellule, which is always considerably smaller than the oogonium, and adheres toits walls by a plane or convex area. The slightly thickened membraneof the antheridia encloses protoplasm which is finely granular. It isseldom that more than one antheridium applies itself to an oogonium. 

The two organs having together achieved their development, the largegranules contained in the oogonium accumulate at its centre to groupthemselves under the form of an irregular globule deprived of a propermembrane, and surrounded by a bed of almost homogeneous protoplasm. This globule is the _gonosphere_, or reproductive sphere, which, through the means of fecundation, should become the reproductivebody, vegetable egg, or oospore. The gonosphere having been formed, the antheridium shoots out from the centre of its face, close againstthe oogonium, a straight tube, which perforates the walls of thefemale cell, and traversing the protoplasm of its periphery, directsitself to the gonosphere. It ceases to elongate itself as soon as ittouches it, and the gonosphere becomes clothed with a membrane ofcellulose, and takes a regular spheroidal form. 

[Illustration: FIG. 99. --Antheridia and oogonium of _Peronospora_. (DeBary. )]

Considering the great resemblance of these organs with the sexualorgans of the Saprolegniæ, which are closely allied to the Algæ, andof which the sexuality has been proved, De Bary adds, we have no doubtwhatever that the phenomena just described represent an act offecundation, and that the tube pushed out by the antheridium should beregarded as a fecundating tube. It is remarkable that amongst thesefungi the tube projected by the antheridium effects fecundation onlyby contact. Its extremity never opens, and we never find antherozoids;on the contrary, the antheridium presents, up to the maturity of theoospore, the appearance which it presented at the moment offecundation. 

The primitive membrane of the oospore, at first very thin, soonacquires a more sensible thickness, and becomes surrounded by anexternal layer (epospore), which is formed at the expense of theprotoplasm of the periphery. This disappears in proportion as theepispore attains maturity, and finally there only remains a quantityof granules, suspended in a transparent watery fluid. At the period ofmaturity, the epispore is a slightly thickened, resistant membrane, ofa yellowish-brown colour, and finely punctate. The surface is almostalways provided with brownish warts, which are large and obtuse, sometimes isolated, and sometimes confluent, forming irregular crests. These warts are composed of cellulose, which reagents colour of a deepblue, whilst the membrane which bears them preserves its primitivecolour. One of the warts, larger than the rest, and recognizable byits cylindrical form, always forms a kind of thick sheath around thefecundating tube. The ripe endospore is a thick, smooth, colourlessmembrane, composed of cellulose containing a bed of finely granulatedprotoplasm, which surrounds a great central vacuole. This oospore, orresting spore, may remain dormant in this state within the tissues ofthe foster plant for some months. Its ultimate development byproduction of zoospores is similar to the production of zoospores fromconidia, which it is unnecessary to repeat here. The oospore becomesan oosporangium, and from it at least a hundred germinating bodies areat length expelled. 

Amongst the principal observers of certain phenomena of copulation incells formed in the earliest stages of the _Discomycetes_ areProfessor de Bary, [J] Dr. Woronin, [K] and Messrs. Tulasne. [L] In the_Ascobolus pulcherrimus_ of Crouan, Woronin ascertained that the cupderives its origin from a short and flexible tube, thicker than theother branches of the mycelium, and which is soon divided bytransverse septa into a series of cells, the successive increase ofwhich finally gives to the whole a torulose and unequal appearance. The body thus formed he calls a "vermiform body. " The same observeralso seems to have convinced himself that there exists always inproximity to this body certain filaments, the short arched orinflected branches of which, like so many antheridia, rest theiranterior extremities on the utriform cells. This contact seems tocommunicate to the vermiform body a special vital energy, which isimmediately directed towards the production of a somewhat filamentoustissue, on which the hymenium is at a later period developed. This"vermiform body" of M. Woronin has since come to be recognized underthe name of "scolecite. "

Tulasne observes that this "scolecite" or ringed body can be readilyisolated in _Ascobolus furfuraceus_. When the young receptacles arestill spherical and white, and have not attained a diameter exceedingthe one-twentieth of a millimetre, it is sufficient to compress themslightly in order to rupture them at the summit and expel the"scolecite. " This occupies the centre of the little sphere, and isformed of from six to eight cells, curved in the shape of a comma. 

In _Peziza melanoloma_, A. And S. , the same observer succeeded stillbetter in his searches after the scolecite, which he remarks is inthis species most certainly a lateral branch of the filaments of themycelium. This branch is isolated, simple, or forked at a shortdistance from its base, and in diameter generally exceeding that ofthe filament which bears it. This branch is soon arcuate or bent, andoften elongated in describing a spiral, the irregular turns of whichare lax or compressed. At the same time its interior, at firstcontinuous, becomes divided by transverse septa into eight or ten ormore cells. Sometimes this special branch terminates in a croziershape, which is involved in the bent part of another crozier whichterminates a neighbouring filament. In other cases the growing branchis connected, by its extremity, with that of a hooked branch. Thesecontacts, however, did not appear to Tulasne to be so much normal asaccidental. But of the importance of the ringed body, or "scolecite, "there was no room for doubt, as being the certain and habitualrudiment of the fertile cup. In fact, inferior cells are produced fromthe flexuous filaments which creep about its surface, cover andsurround it on all sides, while joining themselves to each other. Atfirst continuous, then septate, these cells by their union constitutea cellular tissue, which increases little by little until thescolecite is so closely enveloped that only its superior extremity canbe seen. These cellular masses attain a considerable volume before thehymenium begins to show itself in a depression of their summit. Solong as their smallness permits of their being seen in the field ofthe microscope, it can be determined that they adhere to a singlefilament of the mycelium by the base of the scolecite which remainsnaked. 

Although Tulasne could not satisfy himself of the presence of any actof copulation in _Ascobolus furfuraceus_, or _Peziza melanoloma_, hewas more successful with _Peziza omphalodes_. As early as 1860 herecognized the large globose, sessile, and grouped vesicles whichoriginate the fertile tissue, but did not comprehend the part whichthese macrocysts were to perform. Each of these emits from its summita cylindrical tube, generally flexuous, but always more or less bentin a crozier shape, sometimes attenuated at the extremity. Thusprovided, these utricles resemble so many tun-shaped, narrow-neckedretorts, filled with a granular thick roseate protoplasm. In themiddle of these, and from the same filaments, are generated elongatedclavate cells, with paler contents, more vacuoles, which Tulasne names_paracysts_. These, though produced after the _macrocysts_, finallyexceed them in height, and seem to carry their summit so as to meetthe crozier-like prolongations. It would be difficult to determine towhich of these two orders of cells belongs the initiative ofconjugation. Sometimes the advance seems to be on one side, andsometimes on the other. However this may be, the meeting of theextremity of the connecting tube with the summit of the neighbouringparacyst is a constant fact, observed over and over again a hundredtimes. There is no real junction between the dissimilar cells abovedescribed, except at the very limited point where they meet, and therea circular perforation may be discerned at the end, defined by a roundswelling, which is either barely visible or sometimes very decided. Everywhere else the two organs may be contiguous, or more or less neartogether, but they are free from any adherence whatever. If theplastic matters contained in the conjugated cells influence oneanother reciprocally, no notable modification in their appearanceresults at first. The large appendiculate cell seems, however, toyield to its consort a portion of the plasma it contains. One thingonly can be affirmed from these phenomena, that the conjugated cells, especially the larger, wither and empty themselves, while the uprightcompressed filaments, which will ultimately constitute the asci, increase and multiply. [M]

[Illustration: FIG. 100. --Conjugation in _Peziza omphalodes_. (Tulasne. )]

[Illustration: FIG. 100a. --Formation of conceptacle in _Erysiphe_. ]

Certain phenomena concerned in the development of the _Erysiphei_ belongalso to this connection. The mycelium of _Erysiphe cichoracearum_, likethat of other species, consists of branched filaments, crossed in alldirections, which adhere as they climb to the epidermis of the plant onwhich the fungus lives as a parasite. The perithecia are engenderedwhere two filaments cross each other. These swell slightly at thispoint, and each emits a process which imitates a nascent branch, andremains upright on the surface of the epidermis. The processoriginating from the inferior filament soon acquires an oval form anda diameter double that of the filament; then it becomes isolated fromit by a septum, and constitutes a distinct cell, which De Bary[N]terms an oocyst. The appendage which proceeds from the inferior filamentalways adheres intimately to this cell, and elongates into a slendercylindrical tube, which terminates in an obtuse manner at the summitof the same cell. At its base it is also limited by a septum, and soonafter another appears a little below its extremity at a pointindicated beforehand by a constriction. This new septum defines aterminal short obtuse cell, the antheridium, which is thus borne on anarrow tube like a sort of pedicel. Immediately after the formation ofthe antheridia new productions show themselves, both around the oocystand within it. Underneath this cell eight or ten tubes are seen tospring from the filament which bears it; these join themselves by thesides to each other and to the pedicel of the antheridium, while theyapply their inner face to the oocyst, above which their extremities soonmeet. Each of the tubes is then divided by transverse septa into twoor three distinct cells, and in this manner the cellular walls of theperithecia come into existence. 

During this time the oocyst enlarges and divides, without its beingpossible precisely to determine the way in which it happens, into acentral cell and an outer layer, ordinarily simple, of smallercells, contiguous to the general enveloping wall. The central cellbecomes the single ascus, which is characteristic of the species, and the layer which surrounds it constitutes the inner wall of itsperithecium. The only changes afterwards observed are the increasein size of the perithecium, the production of the root-like filamentswhich proceed from its outer wall, the brown tint which it assumes, and finally the formation of the sporidia in the ascus. Theantheridium remains for a long time recognizable without undergoingany essential modification, but the dark colour of the peritheciumsoon hides it from the observer's eye. De Bary thinks that he isauthorized in assuming the probability that the conceptacles andorgans of fructification of others of the _Ascomycetes_, includingthe _Discomycetes_ and the _Tuberacei_, are the results of sexualgeneration. 

Certain phenomena which have been observed amongst the _Coniomycetes_are cited as examples of sexual association. Amongst these may benamed the conjugation of the slender spores of the first generation, produced on the germinating threads of _Tilletia_, [O] and similaracts of conjugation, as observed in some species of _Ustilago_. Whether this interpretation should be placed on those phenomena in thepresent condition of our knowledge is perhaps an open question. 

[Illustration: FIG. 101. --_Tilletia caries_ with conjugating cells. ]

Finally, the spermogonia must be regarded as in some occult manner, which as yet has baffled detection, influencing the perfection ofsporidia[P] In _Rhytisma_, found on the leaves of maple and willow, black pitchy spots at first appear, which contain within them a goldenpulp, in which very slender corpuscles are mixed with an abundantmucilage. These corpuscles are the spermatia, which in _Rhytismaacerinum_ are linear and short, in _Rhytisma salicinum_ globose. Whenthe spermatia are expelled, the stroma thickens for the production ofasci and sporidia, which are afterwards developed during the autumnand winter. 

Several of the species of _Hysterium_ also possess spermogonia, notably _H. Fraxini_, which may be distinguished from the ascigerousperithecia with which they are associated by their smaller size andflask-like shape. From these the spermatia are expelled long beforethe maturity of the spores. In _Hypoderma virgultorum_, _H. Commune_, and _H. Scirpinum_, the spermogonia are small depressedblack capsules, which contain an abundance of minute spermatia. These were formerly regarded as distinct species, under the name of_Leptostroma_. In _Stictis ocellata_ a great number of the tuberclesdo not pass into the perfect state until after they have producedeither linear, very short spermatia, or stylospores, the latterbeing reproductive bodies of an oblong shape, equal in size to theperfect sporidia. Some of the tubercles never pass beyond this stage. 

Again, there is a very common fungus which forms black discoid spotson dead holly leaves, called _Ceuthospora phacidioides_, figured byGreville in his "Scottish Cryptogamic Flora, " which expels a profusionof minute stylospores; but later in the season, instead of these, wefind the asci and sporidia of _Phacidium ilicis_, so that the two areforms and conditions the one of the other. 

In _Tympanis conspersa_ the spermogonia are much more commonly metwith than the complete fruit. There is a great external resemblance inthem to the ascigerous cups, but there is no evidence that they areever transformed into such. The perfect sporidia are also very minuteand numerous, being contained in asci borne in cups, which usuallysurround the spermogonia. 

In several species of _Dermatea_ the stylospores and spermatiaco-exist, but they are disseminated before the appearance of theascigerous receptacles, yet they are produced upon a common stroma notunlike that of _Tubercularia_. 

In its early stage the common and well-known _Bulgaria inquinans_, which when mature looks like a black _Peziza_, is a little tubercle, the whole mass of which is divided into ramified lobes, theextremities of which become, towards the surface of the tubercle, receptacles from whence escape waves of spermatia which arecolourless, or stylospores mixed with them which are larger and nearlyblack. 

Amongst the _Sphæriacei_ numerous instances might be cited of minutestylosporous bodies in consort with, or preceding, the ascigerousreceptacles. A very familiar example may be found at the base of oldnettle stems in what has been named _Aposphæria acuta_, but whichtruly are only the stylospores of the _Sphæria coniformis_, theperithecia of which flourish in company or in close proximity to them. Most of these bodies are so minute, delicate, and hyaline that thedifficulties in the way of tracing them in their relations to thebodies with which they are associated are very great. Neverthelessthere is strong presumption in favour of regarding some of them asperforming the functions which the name applied to them indicates. 

Professor de Bary cautiously refrains from accepting spermatia otherthan as doubtful or at least uncertain sexual bodies. [Q] He says thatthe Messrs. Tulasne have supposed that the spermogonia represented themale sex, and that the spermatia were analogous to spermatozoids. Their opinion depends on two plausible reasons, --the spermatia, infact, do not germinate, and the development of the spermogoniagenerally precedes the appearance of the sporophorous organs, a doublecircumstance which reminds us of what is known of the spermatozoidsand antheridia of other vegetables. It remained to discover which werethe female organs which underwent fecundation from the spermatia. 

Many organs placed at first amongst spermatia have been recognized byM. Tulasne as being themselves susceptible of germination, andconsequently ought to take their place among legitimate spores. Thenit must be considered that very many spores can only germinate undercertain conditions. It is, therefore, for the present a doubtfulquestion whether there exist really any spermatia incapable ofgermination, or if the default of germination of these corpuscles doesnot rather depend on the experiments hitherto attempted not havingincluded the conditions required by the phenomena. Moreover, as yet notrace has been discovered of the female organs which are speciallyfecundated by the spermatia. 

Finally, there exist in the _Ascomycetes_ certain organs ofreproduction, diverse spore-bearing apparatus, pycnidia, and others, which, like the spermogonia, usually precede ascophorous fruits. Thereal nature of the spermogonia and spermatia should therefore beregarded as, at present, very uncertain; as regards, however, thespermatia which have never been seen to germinate, perhaps it is aswell not to absolutely reject the first opinion formed concerningthem, or perhaps they might be thought to perform the part ofandrospores, attributing to that expression the meaning whichPringsheim gives it in the _Conferoæ_. The experiments performed withthe spermatia which do not germinate, and with the spermogonia of theUredines, do not, at any rate, appear to justify the reputed masculineor fecundative nature of these organs. The spermogonia constantlyaccompany or precede fruits of _Æcidium_, whence naturally follows thepresumption that the first are in a sexual relation to the second. Still, when Tulasne cultivated _Endophyllum sempervivum_, he obtainedon some perfectly isolated rosettes of _Sempervivum_ some _Æcidium_richly provided with normal and fertile spores, without any trace ofspermogonia or of spermatia. 

 [A] M. Tulasne has devoted a chapter to the spermogonia of the Uredines in his memoir, to which we have already alluded. 

 [B] Oeersted, in "Verhandl der König. Dän. Gesell. Der Wissensch, " 1st January, 1865; De Bary, "Handbuch der Physiol. Botanik" (1866), p. 172; "Annales des Sci. Nat. " (5^me sér. ), vol. V. (1866), p. 366. 

 [C] Van Tieghem and Le Monnier, in "Annales des Sci. Nat. " (1873), vol. Xvii. P. 261. 

 [D] Brefeld, "Bot. Unt. Uber Schimmelpilze, " p. 31. 

 [E] De Bary, "Morphologie und Physiologie der Pilze, " cap. 5, p. 160; "Ann. Des Sci. Nat. " (1866), p. 343. 

 [F] Cornu, in "Ann. Des Sci. Nat. " (5^me sér. ), vol. Xv. P. 1 (1872). 

 [G] Pringsheim's "Jahrbucher, " vol. Ii. P. 169. 

 [H] De Bary, in "Annales des Sciences Naturelles" (5^me sér. ), vol. V. (1866), p. 343; Hoffmeister's "Handbook" (Fungi), cap. V. P. 155. 

 [I] De Bary, in "Annales des Sci. Nat. " (4^me sér. ), vol. Xx. P. 129. 

 [J] De Bary, in "Annales des Sciences Naturelles" (5^me sér. ), p. 343. 

 [K] Woronin, in De Bary's "Beitr. Zur. Morph. Und Physiol. Der Pilze, " ii. (1866), pp. 1-11. 

 [L] Tulasne, "Ann. Des Sci. Nat. " (5^me sér. ), October, 1866, p. 211. 

 [M] Tulasne, "On the Phenomena of Copulation in certain Fungi, " in "Ann. Des Sci. Nat. " (1866), p. 211. 

 [N] De Bary, "Morphologie und Phys. Der Pilze, " cap. V. , p. 162. 

 [O] Berkeley, in "Journ. Hort. Soc. " vol ii. P. 107; Tulasne, "Ann. D. Sc. Nat. " (4^me sér. ), vol. Ii. Tab. 12. 

 [P] Tulasne, "New Researches on the Reproductive Apparatus of Fungi;" "Comptes Rendus, " vol. Xxxv. (1852), p. 841. 

 [Q] De Bary, "Morphologie und Physiologie der Pilze, " cap. V. P. 168. 

IX. 

POLYMORPHISM. 

A great number of very interesting facts have during late years beenbrought to light of the different forms which fungi assume in thecourse of their development. At the same time, we fear that a greatmany assumptions have been accepted for fact, and supposed connectionsand relations between two or three or more so-called species, belonging to different genera, have upon insufficient data beenregarded as so many states or conditions of one and the same plant. Had the very pertinent suggestions of Professor de Bary been moregenerally acted upon, these suspicions would have been baseless. Hisobservations are so valuable as a caution, that we cannot forbearprefacing our own remarks on this subject by quoting them. [A] In orderto determine, he says, whether an organic form, an organ, or anorganism, belongs to the same series of development as another, orthat which is the same is developed from it, or _vice versâ_, there isonly one way, viz. , to observe how the second grows out of the first. We see the commencement of the second begin as a part of the first, perfect itself in connection with it, and at last it often becomesindependent; but be it through spontaneous dismembering from thefirst, or that the latter be destroyed and the second remains, boththeir disunited bodies are always connected together in organiccontinuity, as parts of a whole (single one) that can cease earlier orlater. 

By observing the organic continuity, we know that the apple is theproduct of development of an apple-tree, and not hung on it bychance, that the pip of an apple is a product of the development ofthe apple, and that from the pip an apple-tree can at last bedeveloped, that therewith all these bodies are members of a sphere ofdevelopment or form. It is the same with every similar experience ofour daily life, that where an apple-tree stands, many apples lie onthe ground, or that in the place where apple-pips are sown seedlings, little apple-trees, grow out of the ground, is not important to ourview of the course of development. Every one recognizes that in hisdaily life, because he laughs at a person who thinks a plum whichlies under an apple-tree has grown on it, or that the weeds whichappear among the apple seedlings come from apple-pips. If theapple-tree with its fruit and seed were microscopically small, itwould not make the difference of a hair's breadth in the form of thequestion or the method of answering it, as the size of the objectcan be of no importance to the latter, and the questions whichapply to microscopical fungi are to be treated in the same manner. 

If it then be asserted that two or several forms belong to a series ofdevelopment of one kind, it can only be based on the fact of theirorganic continuity. The proof is more difficult than in large plants, partly because of the delicacy, minuteness, and fragility of thesingle parts, particularly the greater part of the mycelia, partlybecause of the resemblance of the latter in different species, andtherefore follows the danger of confusing them with different kinds, and finally, partly in consequence of the presence of different kindsin the same substratum, and therefore the mixture not only ofdifferent sorts of mycelia, but also that different kinds of sporesare sown. With some care and patience, these difficulties are in noway insurmountable, and they must at any rate be overcome; the organiccontinuity or non-continuity must be cleared up, unless the questionrespecting the course of development, and the series of forms ofspecial kinds, be laid on one side as insolvable. 

Simple and intelligible as these principles are, they have not alwaysbeen acted upon, but partly neglected, partly expressly rejected, notbecause they were considered false, but because the difficulties oftheir application were looked upon as insurmountable. Thereforeanother method of examination was adopted; the spores of a certainform were sown, and sooner or later they were looked after to see whatthe seed had produced--not every single spore--but the seed _enmasse_, that is, in other words, what had grown on that place wherethe seed had been sown. As far as it relates to those forms which areso widely spread, and above all grow in conjunction with oneanother--and that is always the case in the specimens of which wespeak--we can never be sure that the spores of the form which we meanto test are not mingled with those of another species. He who has madean attentive and minute examination of this kind knows that we may besure to find such a mixture, and that such an one was there can beafterwards decidedly proved. From the seed which is sown, thesespores, for which the substratum was most suitable, will more easilygerminate, and their development will follow the more quickly. Thefavoured germs will suppress the less favoured, and grow up at theirexpense. The same relation exists between them as between the seeds, germs, and seedlings of a sown summer plant, and the seeds which havebeen undesignedly sown with it, only in a still more striking manner, in consequence of the relatively quick development of the mildewfungus. 

Therefore, that from the latter a decided form, or a mixture ofseveral forms, is to be found sown on one spot, is no proof oftheir generic connection with one which has been sown for thepurpose of experiments; and the matter will only be more confusedif we call imagination to our aid, and place the forms which arefound near one another, according to a real or fancied resemblance, in a certain series of development. All those statements on thesphere of form and connection, which have for their basis such asuperficial work, and are not based on the clear exposition of thecontinuity of development, as by the origin of the connection ofthe _Mucor_ with _Penicillium_, _Oidium lactis_ and _Mucor_, _Oidium_and _Penicillium_, are rejected as unfounded. 

A source of error, which can also interfere in the last-namedsuperficial method of cultivation for experiments, is, viz. , thatheterogeneous unwished-for spores intrude themselves from without, among the seed which is sown, but that has been until now quitedisregarded. It is of great importance in practice, but in truth, forour present purpose, synonymous with what we have already written. Those learned in the science of this kind of culture lay great stresson its importance, and many apparatuses have been constructed, called"purely cultivating machines, " for the purpose of destroying thespores which are contained in the substratum, and preventing theintrusion of those from without. The mixture in the seed which is sownhas of course not been obviated. These machines may, perhaps, in everyother respect, fulfil their purpose, but they cannot change the formof the question, and the most ingeniously constructed apparatus cannotreplace the attention and intellect of the observer. [B]

Two distinct kinds of phenomena have been grouped under the term"polymorphy. " In one series two or more forms of fruit occurconsecutively or simultaneously on the same individual, and in theother two or more forms appear on a different mycelium, on a differentpart of the same plant, or on a matrix wholly distinct and different;in the latter case the connection being attested or suspectedcircumstantially, in the former proved by the method suggested by DeBary. It will at once be conceded that in cases where actual growthand development substantiate the facts the polymorphy is undoubted, whilst in the other series it can at best be little more thansuspected. We will endeavour to illustrate both these series byexamples. 

One of the first and earliest suspected cases of dualism, which longpuzzled the older mycologists, was observed amongst the Uredines, andmany years ago it was held that there must be some mysteriousassociation between the "red rust" (_Trichobasis ruligo vera_) ofwheat and grasses and the "corn mildew" (_Puccinia graminis_) whichsucceeded it. The simple spored rust first makes its appearance, andlater the bilocular "mildew. " It is by no means uncommon to find thetwo forms in the same pustule. Some have held, without good reason, that the simple cells became afterwards divided and converted into_Puccinia_, but this is not the case; the uredo-spores are alwayssimple, and remain so except in _Uredo linearis_, where everyintermediate stage has been observed. Both are also perfect in theirkind, and capable of germination. 

What the precise relations between the two forms may be has as yetnever been revealed to observers, but that the two forms belong to onespecies is not now doubted. Very many species of _Puccinia_ havealready been found associated with a corresponding _Trichobasis_, andof _Phragmidium_ with a relative _Lecythea_, but it may be open tograve doubt whether some of the very many species associated byauthors are not so classed upon suspicion rather than observation. Weare ready to admit that the evidence is strong in favour of thedimorphism of a large number of species--it _may_ be in all, but thisawaits proof, or substantial presumption on good grounds. Up to thepresent we know that there are species of _Trichobasis_ which havenever been traced to association with a _Puccinia_, and doubtlessthere will be species of _Puccinia_ for which no corresponding _Uredo_or _Trichobasis_ can be found. 

Tulasne remarks, in reference to _Puccinia sonchi_, in one of hismemoirs, that this curious species exhibits, in effect, that a_Puccinia_ may unite three sorts of reproductive bodies, which, takingpart, constitute for the mycologists of the day three entirelydifferent plants--a _Trichobasis_, a _Uromyces_, and a _Puccinia_. TheUredines are not less rich, he adds, in reproductive bodies of diverssorts than the _Pyrenomycetes_ and the _Discomycetes_; and we shouldnot be surprised at this, since it seems to be a law, almost constantin the general harmony of nature, that the smaller the organizedbeings are, the more their races are prolific. 

In _Puccinia variabilis_, Grev. , it is common to find a unicellularform, species of _Trichobasis_, in the same pustules. A likecircumstance occurs with _Puccinia violarum_, Link. , and _Trichobasisviolarum_, B. ; with _Puccinia fallens_, C. , and _Trichobasis fallens_, Desm. ; also with _Puccinia menthæ_, P. , and _Trichobasis Labiatarum_, D. C. In _Melampsora_, again, the prismatic pseudospores of_Melampsora salicina_, Lev. , are the winter fruits of _Lecytheacaprearum_, Lev. , as those of _Melampsora populina_, Lev. , are of_Lecythea populina_, Lev. In the species of _Lecythea_ themselves willbe found, as De Bary[C] has shown, hyaline cysts of a larger size, which surround the pseudospores in the pustules in which they aredeveloped. 

A good illustration of dimorphism in one of the commonest of moulds isgiven by De Bary in a paper from which we have already quoted. [D] Hewrites thus:--In every household there is a frequent unbidden guest, which appears particularly on preserved fruits, viz. , the _mould_which is called _Aspergillus glaucus_. It shows itself to the nakedeye as a woolly floccy crust over the substance, first purely white, then gradually covered with little fine glaucous, or dark green dustyheads. More minute microscopical examination shows that the fungusconsists of richly ramified fine filaments, which are partlydisseminated in the substratum, and partly raised obliquely over it. They have a cylindrical form with rounded ends, and are divided intolong outstretched members, each of which possesses the property whichlegitimatizes it as a vesicle in the ordinary sense of the word; itcontains, enclosed within a delicate structureless wall, those bodieswhich bear the appearance of a finely granulated mucous substance, which is designated by the name of protoplasm, and which eitherequally fills the cells, or the older the cell the more it is filledwith watery cavities called vacuoles. 

All parts are at first colourless. The increase in the length of thefilaments takes place through the preponderating growth near theirpoints; these continually push forward, and, at a short distance fromthem, successive new partitions rise up, but at a greater distance, the growth in the length ceases. This kind of growth is called pointgrowth. The twigs and branches spring up as lateral dilatations ofthe principal filament, which, once designed, enlarges according tothe point growth. This point growth of every branch is, to a certainextent, unlimited. The filaments in and on the substratum are thefirst existing members of the fungus; they continue so long as itvegetates. As the parts which absorb nourishment from and consume thesubstance, they are called the _mycelium_. Nearly every funguspossesses a mycelium, which, without regard to the specific differenceof form and size, especially shows the described nature in itsconstruction and growth. 

The superficial threads of the mycelium produce other filaments besidethose numerous branches which have been described, and which are thefruit thread (carpophore) or conidia thread. These are on an averagethicker than the mycelium threads, and only exceptionally ramified orfurnished with partitions; they rise almost perpendicularly into theair, and attain a length of, on an average, half a millimetre, orone-fiftieth of an inch, but they seldom become longer, and then theirgrowth is at an end. Their free upper end swells in a rounded manner, and from this is produced, on the whole of its upper part, rayeddivergent protuberances, which attain an oval form, and a lengthalmost equal to their radius, or, in weaker specimens, the diameter ofthe rounded head. The rayed divergent protuberances are the directproducers and bearers of the propagating cells, spores, or conidia, and are called sterigmata. Every sterigma at first produces at itspoint a little round protuberance, which, with a strong narrow basis, rests upon the sterigma. These are filled with protoplasm, swell moreand more, and, after some time, separate themselves by a partitionfrom the sterigma into independent cells, spores, or conidia. 

The formation of the first spore takes place at the same end of thesterigma, and in the same manner a second follows, then a third, andso on; every one which springs up later pushes its predecessor in thedirection of the axis of the sterigma in the same degree in which itgrows itself; every successive spore formed from a sterigma remainsfor a time in a row with one another. Consequently every sterigmabears on its apex a chain of spores, which are so much the older, thefarther they stand from the sterigma. The number of the links in achain of spores reaches in normal specimens to ten or more. Allsterigmata spring up at the same time, and keep pace with one anotherin the formation of the spores. Every spore grows for a time, according to its construction, and at last separates itself from itsneighbours. The mass of dismembered spores forms that fine glaucoushue which is mentioned above. The spores, therefore, are articulatedin rows, one after the other, from the ends of the sterigmata. Theripe spore, or conidium, is a cell of a round or broadly oval form, filled with a colourless protoplasm, and, if observed separately, isfound to be provided with a brownish, finely verruculose, dottedwall. 

[Illustration: FIG. 102. --_a. _ _Aspergillus glaucus_; _b. _ conidia; _c. _germinating conidium; _d. _ conceptacle of _Eurotium_; _e. _ ascus. ]

The same mycelium which forms the pedicel for the conidia when it isnear the end of its development, forms by normal vegetation a secondkind of fructification. It begins as delicate thin little branches, which are not to be distinguished by the naked eye, and which mostlyin four or six turns, after a quickly terminated growth, wind theirends like a corkscrew. (Fig. 102. ) The sinuations decrease in widthmore and more, till they at last reach close to one another, and thewhole end changes from the form of a corkscrew into that of a hollowscrew. In and on that screw-like body, a change of a complicated kindtakes place, which is a productive process. In consequence of this, from the screw body a globose receptacle is formed, consisting of athin wall of delicate cells, and a closely entwined row of cellssurrounded by this dense mass (_d_). By the enlargement of all theseparts the round body grows so much, that by the time it is ripe it isvisible to the naked eye. The outer surface of the wall assumes acompactness and a bright yellow colour; the greater part of the cellsof the inner mass become asci for the formation of sporidia, whilethey free themselves from the reciprocal union, take a broad ovalform, and each one produces within its inner space eight sporidia(_e_). These soon entirely fill the ascus. When they are quite ripe, the wall of the conceptacle becomes brittle, and from irregularfissures, arising easily from contact, the colourless round sporidiaare liberated. 

The pedicels of both kinds of fruit are formed from the same myceliumin the order just described. If we examine attentively, we can oftensee both springing up close to one another from the same filament of amycelium. This is not very easy in the close interlacing of the stalksof a mass of fungi in consequence of their delicacy and fragility. Before their connection was known, the conceptacles and the conidiapedicels were considered as organs of two very different species offungi. The conceptacles were called _Eurotium herbariorum_, and theconidia bearers were called _Aspergillus glaucus_. 

Allied to _Eurotium_ is the group of _Erysiphei_, in whichwell-authenticated polymorphy prevails. These fungi are developedon the green parts of growing plants, and at first consist of awhite mouldy stratum, composed of delicate mycelium, on which erectthreads are produced, which break up into subglobose joints orconidia. The species on grass was named _Oidium monilioides_before its relationship was known, but undoubtedly this is only theconidia of _Erysiphe graminis_. In like manner the vine disease(_Oidium Tuckeri_) is most probably only the conidia of a species of_Erysiphe_, of which the perfect condition has not yet beendiscovered. On roses the old _Oidium leucoconium_ is but the conidiaof _Sphærotheca pannosa_, and so of other species. The _Erysiphe_which ultimately appears on the same mycelium consists of globoseperithecia, externally furnished with thread-like appendages, andinternally with asci containing sporidia. In this genus there areno less than five different forms of fruit, [E] the multiformthreads on the mycelium, already alluded to as forms of _Oidium_, theasci contained in the sporangia, which is the proper fruit of the_Erysiphe_, larger stylospores which are produced in othersporangia, the smaller stylospores which are generated in thepycnidia, and separate sporules which are sometimes formed in thejoints of the necklaces of the conidia. These forms are figured in the"Introduction to Cryptogamic Botany" from _Sphærotheca Castagnei_, which is the hop mildew. [F] The vine disease, hop mildew, and rosemildew, are the most destructive species of this group, and theconstant annoyance of cultivators. 

[Illustration: FIG. 103. --_Erysiphe cichoracearum. _ _a. _ Receptacle; _o. _mycelium. (De Bary. )]

When first describing an allied fungus found on old paper, and named_Ascotricha chartarum_, the Rev. M. J. Berkeley called attention tothe presence of globose conidia attached to the threads which surroundthe conceptacles, [G] and this occurred as long since as 1838. In arecent species of _Chætomium_ found on old sacking, _Chætomiumgriseum_, Cooke, [H] we have found tufts in all respects similarexternally to the _Chætomium_, but no perithecium was formed, nakedconidia being developed apparently at the base of the colouredthreads. In _Chætomium funicolum_, Cooke, a black mould was also foundwhich may possibly prove to be its conidia, but at present there is nodirect evidence. 

The brothers Tulasne have made us acquainted with a greaternumber of instances amongst the _Sphæriacei_ in which multipleorgans of reproduction prevail. Very often old and decayingindividuals belonging to species of _Boletus_ will be foundfilled, and their entire substance internally replaced, by thethreads and multitudinous spores of a golden yellow parasite, towhich the name of _Sepedonium chrysospermum_ has been given. According to Tulasne, this is merely a condition of a sphæriaceousfungus belonging to his genus _Hypomyces_. [I]

The same observers also first demonstrated that _Trichoderma viride_, P. , was but the conidia-bearing stage of _Hypocrea rufa_, P. , anothersphæriaceous fungus. The ascigerous stroma of the latter is indeedfrequently associated in a very close manner with the cushions of thepretended _Trichoderma_, or in other cases the same stroma will giverise to a different apparatus of conidia, of which the principalelements are acicular filaments, which are short, upright, and almostsimple, and which give rise to small oval conidia which are solitaryon the tips of the threads. Therefore this _Hypocrea_ will possess twodifferent kinds of conidia, as is the case in many species of_Hypomyces_. 

A most familiar instance of dualism will be found in _Nectriacinnabarina_, of which the conidia form is one of the most common offungi, forming little reddish nodules on all kinds of dead twigs. [J]

[Illustration: FIG. 104. --Twig with _Tubercularia_ on the upper portion, _Nectria_ on the lower. ]

Almost any small currant twig which has been lying on the ground in adamp situation will afford an opportunity of studying this phenomenon. The whole surface of the twig will be covered from end to end withlittle bright pink prominences, bursting through the bark at regulardistances, scarcely a quarter of an inch apart. Towards one end of thetwig probably the prominences will be of a deeper, richer colour, likepowdered cinnabar. The naked eye is sufficient to detect somedifference between the two kinds of pustules, and where the two mergeinto each other specks of cinnabar will be visible on the pinkprojections. By removing the bark it will be seen that the pink bodieshave a sort of paler stem, which spreads above into a somewhat globosehead, covered with a delicate mealy bloom. At the base it penetratesto the inner bark, and from it the threads of mycelium branch in alldirections, confined, however, to the bark, and not entering the woodytissues beneath. The head, placed under examination, will be found toconsist of delicate parallel threads compacted together to form thestem and head. Some of these threads are simple, others are branched, bearing here and there upon them delicate little bodies, which arereadily detached, and which form the mealy bloom which covers thesurface. These are the conidia, little slender cylindrical bodies, rounded at the ends. 

[Illustration: FIG. 105. --Section of _Tubercularia_. _c. _ Threads withconidia. [K]]

Passing to the other bodies, which are of a deeper colour, it willsoon be discovered that, instead of being simple rounded heads, eachtubercle is composed of numerous smaller, nearly globose bodies, closely packed together, often compressed, all united to a baseclosely resembling the base of the other tubercles. If for a moment welook at one of the tubercles near the spot where the crimsontubercles seem to merge into the pink, we shall not only find themparticoloured, but that the red points are the identical globoselittle heads just observed in clusters. This will lead to thesuspicion, which can afterwards be verified, that the red headsare really produced on the stem or stroma of the pink tubercles. 

A section of one of the red tubercles will show us how much theinternal structure differs. The little subglobose bodies which springfrom a common stroma or stem are hollow shells or capsules, externallygranular, internally filled with a gelatinous nucleus. They are, indeed, the perithecia of a sphæriaceous fungus of the genus_Nectria_, and the gelatinous nucleus contains the fructification. Still further examination will show that this fructification consistsof cylindrical asci, each enclosing eight elliptical sporidia, closelypacked together, and mixed with slender threads called paraphyses. 

Here, then, we have undoubted evidence of _Nectria cinnabarina_, withits fruit, produced in asci growing from the stroma or stem, and inintimate relationship with what was formerly named _Tuberculariavulgaris_. A fungus with two forms of fruit, one proper to the pink, or _Tubercularia_ form, with naked slender conidia, the other properto the mature fungus, enclosed in asci, and generated within the wallsof a perithecium. Instances of this kind are now known to be far fromuncommon, although they cannot always, or often, be so clearly anddistinctly traced as in the illustration which we have selected. 

[Illustration: FIG. 106. --D. _Nectria_ surrounding _Tubercularia_; E. Tuft of _Nectria cinnabarina_; F. Section of stroma; G. Ascus andparaphyses. ]

It is not uncommon for the conidia of the _Sphæria_ to partake of thecharacteristics of a mould, and then the perithecia are developedamongst the conidial threads. A recently recorded instance of thisrelates to _Sphæria Epochnii_, B. And Br. , [L] the conidia form ofwhich was long known before the _Sphæria_ related to it wasdiscovered, under the name of _Epochnium fungorum_. The _Epochnium_forms a thin stratum, which overruns various species of _Corticium_. The conidia are at first uniseptate. The perithecia of the _Sphæria_are at first pale bottle-green, crowded in the centre of the_Epochnium_, then black green granulated, sometimes depressed at thesummit, with a minute pore. The sporidia are strongly constricted inthe centre, at first uniseptate, with two nuclei in each division. 

Another _Sphæria_ in which the association is undoubted is the_Sphæria aquila_, Fr. , [M] which is almost always found nestling in awoolly brown subiculum, for the most part composed of barren brownjointed threads. These threads, however, produce, under favourableconditions, mostly before the perfection of the perithecia, minutesubglobose conidia, and in this state constitute what formerly borethe name of _Sporotrichum fuscum_, Link. , but now recognized as theconidia of _Sphæria aquila_. 

In _Sphæria nidulans_, Schw. , a North American species, we have morethan once found the dark brown subiculum bearing large triseptateconidia, having all the characters of the genus _Helminthosporium_. In_Sphæria pilosa_, P. , Messrs. Berkeley and Broome have observed oblongconidia, rather irregular in outline, terminating the hairs of theperithecium. [N] The same authors have also figured the curiouspentagonal conidia springing from flexuous threads accompanying_Sphæria felina_, Fckl. , [O] and also the threads resembling those of a_Cladotrichum_ with the angular conidia of _Sphæria cupulifera_, B. And Br. [P] A most remarkable example is also given by the BrothersTulasne in _Pleospora polytricha_, in which the conidia-bearingthreads not only surround, but grow upon the perithecia, and arecrowned by fascicles of septate conidia. [Q]

Instances of this kind have now become so numerous that only a few canbe cited as examples of the rest. It is not at all improbable that themajority of what are now classed together as species under the genusof black moulds, _Helminthosporium_, will at some not very distantperiod be traced as the conidia of different species of ascomycetousfungi. The same fate may also await other allied genera, but untilthis association is established, they must keep the rank and positionwhich has been assigned to them. 

Another form of dualism, differing somewhat in character from theforegoing, finds illustration in the sphæriaceous genus _Melanconis_, of Tulasne, in which the free spores are still called conidia, thoughin most instances produced in a sort of spurious conceptaculum, orborne on short threads from a kind of cushion-shaped stroma. In the_Melanconis stilbostoma_, [R] there are three forms, one of slenderminute bodies, oozing out in the form of yellow tendrils, which may bespermatia, formerly called _Nemaspora crocea_. Then there are the ovalbrown or olive brown conidia, which are at first covered, then oozingout in a black pasty mass, formerly _Melanconium bicolor_, and finallythe sporidia in asci of _Sphæria stilbostoma_, Fries. In _MelanconisBerkeleii_, Tul. , the conidia are quadrilocular, previously known as_Stilbospora macrosperma_, B. And Br. In a closely-allied species fromNorth America, _Melanconis bicornis_, Cooke, the appendiculatesporidia are similar, and the conidia would also appear to partake ofthe character of _Stilbospora_. We may remark here that we have seen abrown mould, probably an undescribed species of _Dematiei_, growing indefinite patches around the openings in birch bark caused by thecrumpent ostiola of the perithecia of _Melanconis stilbostoma_, fromthe United States. 

In _Melanconis lanciformis_, [S] Tul. , there are, it would appear, four forms of fruit. One of these consists of conidia, characterizedby Corda as _Coryneum disciforme_. [T] Stylospores, which are alsofigured by Corda under the name of _Coniothecium betulinum_;pycnidia, [U] first discovered by Berkeley and Broome, and named bythem _Hendersonia polycystis_;[V] and the ascophorous fruits whichconstituted the _Sphæria lanciformis_ of Fries. Mr. Currey indicated_Hendersonia polycystis_, B. And Br. , as a form of fruit of thisspecies in a communication to the Royal Society in 1857. [W] He saysthis plant grows upon birch, and is in perfection in very moistweather, when it may be recognized by the large black softgelatinous protuberances on the bark, formed by spores escaping anddepositing themselves upon and about the apex of the perithecium. This I suspect to be an abnormal state of a well-known Sphæria (_S. Lanciformis_), which grows upon birch, and upon birch only. 

We might multiply, almost indefinitely, instances amongst the_Sphæriacei_, but have already given sufficient for illustration, andwill therefore proceed briefly to notice some instances amongst the_Discomycetes_, which also bear their complete or perfect fruit inasci. 

The beautiful purple stipitate cups of _Bulgaria sarcoides_, which maybe seen flourishing in the autumn on old rotten wood, are oftenaccompanied by club-shaped bodies of the same colour; or earlier inthe season these clavate bodies may be found alone, and at one timebore the name of _Tremella sarcoides_. The upper part of these clubsdisseminate a great abundance of straight and very slender spermatia. Earlier than this they are covered with globose conidia. Thefully-matured _Bulgaria_ develops on its hymenium clavate delicateasci, each enclosing eight elongated hyaline sporidia, so that we havethree forms of fruit belonging to the same fungus, viz. Conidia andspermatia in the _Tremella_ stage, and sporidia contained in asci inthe mature condition. [X] The same phenomena occur with _Bulgariapurpurea_, a larger species with different fruit, long confounded with_Bulgaria sarcoides_. 

On the dead stems of nettles it is very common to meet with smallorange tubercles, not much larger than a pin's head, which yield atthis stage a profusion of slender linear bodies, produced on delicatebranched threads, and at one time bore the name of _DacrymycesUrticæ_, but which are now acknowledged to be only a condition of alittle tremelloid _Peziza_ of the same size and colour, which might bemistaken for it, if not examined with the microscope, but in whichthere are distinct asci and sporidia. Both forms together are nowregarded as the same fungus, under the name of _Peziza fusarioides_, B. 

The other series of phenomena grouped together under the name ofpolymorphism relate to forms which are removed from each other, sothat the mycelium is not identical, or, more usually, produced ondifferent plants. The first instance of this kind to which we shallmake reference is one of particular interest, as illustrative of theold popular creed, that berberry bushes near corn-fields producedmildewed corn. There is a village in Norfolk, not far from GreatYarmouth, called "Mildew Rollesby, " because of its unenviablenotoriety in days past for mildewed corn, produced, it was said, bythe berberry bushes, which were cut down, and then mildew disappearedfrom the corn-fields, so that Rollesby no longer merited its_sobriquet_. It has already been shown that the corn-mildew (_Pucciniagraminis_) is dimorphous, having a one-celled fruit (_Trichobasis_), as well as a two-celled fruit (_Puccinia_). The fungus which attacksthe berberry is a species of cluster-cup (_Æcidium berberidis_), inwhich little cup-like peridia, containing bright orange pseudospores, are produced in tufts or clusters on the green leaves, together withtheir spermogonia. 

De Bary's observations on this association of forms were published in1865. [Y] In view of the popular belief, he determined to sow thespores of _Puccinia graminis_ on the leaves of the berberry. For thispurpose he selected the septate resting spores from _Poa pratensis_and _Triticum repens_. Having caused the spores to germinate in amoist atmosphere, he placed fragments of the leaves on which they haddeveloped their secondary spores on young but full-grown berberryleaves, under the same atmospheric conditions. In from twenty-four toforty-eight hours a quantity of the germinating threads had boredthrough the walls and penetrated amongst the subjacent cells. Thistook place both on the upper and under surface of the leaves. Since, in former experiments, it appeared that the spores would penetrateonly in those cases where the plant was adapted to develop theparasite, the connection between _P. Graminis_ and _Æcid. Berberidis_seemed more than ever probable. In about ten days the spermogoniaappeared. After a time the cut leaves began to decay, so that thefungus never got beyond the spermogonoid stage. Some three-year-oldseedlings were then taken, and the germinating resting spores appliedas before. The plants were kept under a bell-glass from twenty-four toforty-eight hours, and then exposed to the air like other plants. Fromthe sixth to the tenth day, yellow spots appeared, with singlespermogonia; from the ninth to the twelfth, spermogonia appeared innumbers on either surface; and, a few days later, on the under surfaceof the leaves, the cylindrical sporangia of the _Æcidium_ made theirappearance, exactly as in the normally developed parasite, except thatthey were longer, from being protected from external agents. Theyounger the leaves, the more rapid was the development of theparasite, and sometimes, in the younger leaves, the luxuriance was fargreater than in free nature. Similar plants, to the number of twohundred, were observed in the nursery, and though some of them had_Æcidium_ pustules, not one fresh pustule was produced; while twoplaced under similar circumstances, but without the application of anyresting spores, remained all the summer free from _Æcidium_. It seems, then, indubitable so far that _Æcidium berberidis_ does spring fromthe spores of _Puccinia graminis_. 

It has, however, to be remarked that De Bary was not equallysuccessful in producing the _Puccinia_ from the spores of the_Æcidium_. In many cases the spores do not germinate when placed onglass, and they do not preserve their power of germinating very long. He reverts then to the evidence of experiments instituted byagriculturists. Bönninghausen remarked, in 1818, that wheat, rye, andbarley which were sown in the neighbourhood of a berberry bush coveredwith _Æcidium_ contracted rust immediately after the maturation of thespores of the _Æcidia_. The rust was most abundant where the windcarried the spores. The following year the same observations wererepeated; the spores of the _Æcidium_ were collected, and applied tosome healthy plants of rye. After five or six days these plants wereaffected with rust, while the remainder of the crop was sound. In1863 some winter rye was sown round a berberry bush, which in thefollowing year was infested with _Æcidium_, which was mature in themiddle of May, when the rye was completely covered with rust. Of thewild grasses near the bush, _Triticum repens_ was most affected. Thedistant plants of rye were free from rust. 

[Illustration: FIG. 107. --Cells and pseudospores of _Æcidium berberidis_. ]

The spores of the _Æcidium_ would not germinate on berberry leaves;the berberry _Æcidium_ could not therefore spring from the previous_Æcidium_. The uredospores of _Puccinia graminis_ on germinatingpenetrate into the parenchym of the grass on which they are sown; buton berberry leaves, if the tips of the threads enter for a shortdistance into the stomates their growth at once ceases, and the leavesremain free from parasites. 

[Illustration: FIG. 108. --Cells and pseudospores of _Æcidium graveolens_. ]

Montagne has, however, described a _Puccinia berberidis_ on leaves of_Berberis glauca_ from Chili, which grows in company with _Æcidiumberberidis_. This at first sight seems to contradict the aboveconclusions; but the _Æcidium_ which from the same disc produces thepuccinoid resting spores, appears to be different from the Europeanspecies, inasmuch as the cells of the wall of the sporangium are twiceas large, and the spores decidedly of greater diameter. [Z] The restingspores, moreover, differ not only from those of _Puccinia graminis_, but from those of all other European species. 

From this account, then, it is extremely probable that the _Æcidium_of the berberry enters into the cycle of existence of _Pucciniagraminis_, and, if this be true, wherefore should not other speciesof _Puccinia_ be related in like manner to other _Æcidia_? This is theconclusion to which many have arrived, and, taking advantage ofcertain presumptions, have, we fear, rashly associated many suchforms together without substantial evidence. On the leaves of theprimrose we have commonly a species of _Æcidium_, _Puccinia_, and_Uromyces_ nearly at the same time; we may imagine that all thesebelong to one cycle, but it has not yet been proved. Again, _Uromycescacaliæ_, Unger, _Uredo cacaliæ_, Unger, and _Æcidium cacaliæ_, Thumen, are considered by Heufler[a] to form one cycle. Numerousothers are given by Fuckel, [b] and De Bary, in the same memoir fromwhich we have already cited, notes _Uromyces appendiculatus_, Link. , _U. Phaseolorum_, Tul. , and _Puccinia tragopogonis_, Ca. , aspossessing five kinds of reproductive organs. Towards the end of theyear, shortly stipitate spores appear on their stroma, which do notfall off. These spores, which do not germinate till after a shorteror longer winter rest, may conveniently be called resting spores, or, as De Bary calls them, _teleutospores_, being the last which areproduced. These at length germinate, become articulated, and produceovate or kidney-shaped spores, which in their turn germinate, penetrating the cuticle of the mother plant, avoiding the stomates orapertures by which it breathes. After about two or three weeks, the mycelium, which has ramified among the tissues, produces an_Æcidium_, with its constant companion, spermogonia--distinct cysts, that is, from which a quantity of minute bodies ooze out, often inthe form of a tendril, the function of which is imperfectly known atpresent, but which from analogy we regard as a form of fruit, though it is just possible that they may be rather of the nature ofspermatozoids. The _Æcidia_ contain, within a cellular membranoussac, a fructifying disc, which produces necklaces of spores, whichultimately separate from each other in the form of a granular powder. The grains of which it is composed germinate in their turn, nolonger avoiding the stomates as before, but penetrating throughtheir aperture into the parenchym. The new resultant myceliumreproduces the _Uredo_, or fifth form of fructification, and the_Uredo_ spores fall off like those of the _Æcidium_, and in respect ofgermination, and mode of penetration, present precisely the samephenomena. The disc which has produced the _Uredo_ spores now givesrise to the resting spores, and so the cycle is complete. [c]

The late Professor Oersted, of Copenhagen, was of opinion that he haddemonstrated the polymorphy of the Tremelloid Uredines, and satisfiedhimself that the one condition known as _Podisoma_ was but anotherstage of _Roestelia_. [d] Some freshly gathered specimens of_Gymnosporangium_ were damped with water, and during the nightfollowing the spores germinated profusely, so that the teleutosporesformed an orange-coloured powder. A little of this powder wasplaced on the leaves of five small sorbs, which were damped andplaced under bell-glasses. In five days yellow spots were seen onthe leaves, and in two days more indications of spermogonia. Thespermatia were discharged, and in two months from the firstsowing, the peridia of _Roestelia_ appeared, and were developed. "This trial of spores, " says Oersted, "has conduced to the resultexpected, and proves that the teleutospores of _Gymnosporangium_, when transported upon the sorb, give rise to a totally differentfungus, the _Roestelia cornuta_, that is to say, that an alternategeneration comes between these fungi. They appertain in consequenceto a single species, and the _Gymnosporangium_ ceased to be anindependent species, and must be considered as synonymous with thefirst generation of _Roestelia_. The spores have been transportedupon young shoots of the juniper-tree, and have now commenced toproduce some mycelium in the bark. There is no doubt that in nextspring it will result in _Gymnosporangium_. "

Subsequently the same learned professor instituted similar experimentsupon other hosts, with the spores of _Podisoma_, and from thence heconcluded that _Roestelia_ and _Podisoma_, in all their known species, were but forms the one of the other. Hitherto we are not aware thatthese results have been confirmed, or that the sowing of the spores of_Roestelia_ on juniper resulted in _Podisoma_. Such experiments shouldbe received always with care, and not too hastily accepted in theirapparent results as proven facts. Who shall say that _Roestelia_ wouldnot have appeared on _Sorbus_ within two months without the sowing of_Podisoma_ spores?--because it is not by any means uncommon for thatfungus to appear upon that plant. It is true many mycologists writeand speak of _Roestelia_ and _Podisoma_ (or _Gymnosporangium_) asidentical; but, as we think, without the evidence being so complete asto be beyond suspicion. It is, nevertheless, a curious fact that inEurope the number of species of _Roestelia_ and _Podisoma_ are equal, if one species be excluded, which is certainly not a good _Podisoma_, for the reception of which a new genus has been proposed. [e]

Amongst the ascigerous fungi will be found a curious but interestinggenus formerly called _Cordyceps_, but for which Tulasne, inconsequence of the discovery of secondary forms of fruit, hassubstituted that of _Torrubia_. [f] These curious fungi partake moreor less of a clavate form, and are parasitic on insects. The pupæof moths are sometimes seen bearing upon them the white branchedmould, something like a _Clavaria_ in appearance, to which the name of_Isaria farinosa_ has been given. According to Tulasne, this is theconidia form of the bright scarlet, club-shaped body which is alsofound on dead pupæ, called _Torrubia militaris_. An American mould ofthe same genus, _Isaria sphingum_, found on mature moths, [g] is inlike manner declared to be the conidia of _Torrubia sphingum_;whereas a similar mould, found on dead spiders, called _Isariaarachnophila_, [h] is probably of a similar nature. An allied kindof compact mould, which is parasitic on _Cocci_, on the bark oftrees, recently found in England by Mr. C. E. Broome, and named_Microcera coccophila_, [i] is said by Tulasne to be a condition of_Sphærostilbe_, and it is intimated that other productions of asimilar character bear like relations to other sphæriaceous fungi. For many species of _Torrubia_ no corresponding conidia are yetknown. 

Some instances might be noted, not without interest, in which thefacts of dimorphism or polymorphism have not been satisfactorilyproved, but final judgment is held in suspense until suspicion isreplaced by conviction. Some years since, a quantity of dead boxleaves were collected, on which flourished at the time a mould named_Penicillium roseum_. This mould has a roseate tint, and occurs inpatches on the dead leaves lying upon the ground; the threads areerect and branched above, bearing chains of oblong, somewhatspindle-shaped spores, or, perhaps more accurately, conidia. Whencollected, these leaves were examined, and nothing was observed ornoted upon them except this _Penicillium_. After some time, certainlybetween two and three years, during which period the box remainedundisturbed, circumstances led to the examination again of one or twoof the leaves, and afterwards of the greater number of them, when thepatches of _Penicillium_ were found to be intermixed with anothermould of a higher development, and far different character. Thismould, or rather _Mucor_, consists of erect branching threads, many ofthe branches terminating in a delicate globose, glassy head, orsporangium, containing numerous very minute subglobose sporidia. Thisspecies was named _Mucor hyalinus_. [j] The habit is very much likethat of the _Penicillium_, but without any roseate tint. It is almostcertain that the _Mucor_ could not have been present when the_Penicillium_ was examined, and the leaves on which it had grown wereenclosed in the tin box, but that the _Mucor_ afterwards appeared onthe same leaves, sometimes from the same patches, and, as it wouldappear, from the same mycelium. The great difference in the twospecies lies in the fructification. In the _Penicillium_, the sporesare naked, and in moniliform threads; whilst in _Mucor_ the spores areenclosed within globose membraneous heads or sporangia. Scarcely canwe doubt that the _Mucor_ alluded to above, found thus intermixed, under peculiar circumstances, with _Penicillium roseum_, is no otherthan the higher and more complete form of that species, and that the_Penicillium_ is only its conidiiferous state. The presumption in thiscase is strong, and not so open to suspicion as it would be did notanalogy render it so extremely probable that such is the case, apartfrom the fact of both forms springing from the same mass of mycelium. In such minute and delicate structures it is very difficult tomanipulate the specimens so as to arrive at positive evidence. If afilament of mycelium could be isolated successfully, and a fertilethread, bearing the fruit of each form, could be traced from the sameindividual mycelium thread, the evidence would be conclusive. Indefault of such conclusive evidence, we are compelled to rest withassumption until further researches enable us to record the assumptionas fact. [k]

Apropos of this very connection of _Penicillium_ with _Mucor_, asimilar suspicion attaches to an instance noted by a whollydisinterested observer to this effect. "On a preparation preserved ina moist chamber, on the third day a white speck was seen on thesurface, consisting of innumerable 'yeast' cells, with some filaments, branching in all directions. On the fourth day tufts of _Penicillium_, had developed two varieties--_P. Glaucum_ and _P. Viride_. Thiscontinued until the ninth day, when a few of the filaments springingup in the midst of the _Penicillium_ were tipped with a dewdrop-likedilatation, excessively delicate--a mere distended pellicle. In somecases they seemed to be derived from the same filament as othersbearing the ordinary branching spores of _Penicillium_, but of this Icould not be positive. This kind of fructification increased rapidly, and on the fourteenth day spores had undoubtedly developed within thepellicle, just as had been observed in a previous cultivation, precisely similar revolving movements being also manifested. "[l]Although we have here another instance of _Mucor_ and _Penicillium_growing in contact, the evidence is insufficient to warrant more thana suspicion of their identity, inasmuch as the equally minute sporesof _Mucor_ and _Penicillium_ might have mingled, and each producingits kind, no relationship whatever have existed between them, excepttheir development from the same matrix. 

Another case of association--for the evidence does not proceedfurther--was recorded by us, in which a dark-coloured species of_Penicillium_ was closely associated with what we now believe to be aspecies of _Macrosporium_--but then designated a _Sporidesmium_--and aminute _Sphæria_ growing in succession on damp wall-paper. Associationis all that the _facts_ warrant us in calling it. 

We cannot forbear alluding to one of the species of _Sphæria_ to whichTulasne[m] attributes a variety of forms of fruit, and we do so herebecause we think that a circumstance so extraordinary should beconfirmed before it is accepted as absolutely true. This refers to thecommon _Sphæria_ found on herbaceous plants, known as _Sphæria_(_Pleospora_) _herbarum_. First of all the very common mould called_Cladosporium herbarum_ is constituted as conidia, and of this again_Macrosporium sarcinula_, Berk. , is considered to be anothercondition. In the next place, _Cytispora orbicularis_, Berk. , and_Phoma herbarum_, West. , are regarded as pycnidia, enclosingstylospores. Then _Alternaria tenuis_, Pr. , [n] which is said to beparasitic on _Cladosporium herbarum_, is held to be only a form ofthat species, so that here we have (including the _perithecia_) noless than six forms or phases for the same fungus. As _MacrosporiumCheiranthi_, Pr. , often is found in company with _Cladosporiumherbarum_, that is also open to suspicion. 

We have adduced in the foregoing pages a few instances which willserve to illustrate the polymorphism of fungi. Some of these it willbe observed are accepted as beyond doubt, occurring as they do inintimate relationship with each other. Others are considered asscarcely so well established, but probable, although developedsometimes on different species of plants. Finally, some are regardedas hitherto not satisfactorily proved, or, it may be, only suspicious. In this latter group, however much probability may be in their favour, it can hardly be deemed philosophical to accept them on such slenderevidence as in some cases alone is afforded. It would not have beendifficult to have extended the latter group considerably by theaddition of instances enumerated by various mycologists in their workswithout any explanation of the data upon which their conclusions havebeen founded. In fact, altogether this chapter must be accepted asillustrative and suggestive, but by no means as exhaustive. 

 [A] De Bary, in "Quarterly German Magazine" (1872), p. 197. 

 [B] The method pursued by Messrs. Berkeley and Hoffmann of surrounding the drop of fluid, in which a definite number of spores or yeast globules had been placed, with a pellicle of air, into which the germinating threads might pass and fructify, is perhaps the most satisfactory that has been adopted, though it requires nice manipulation. If carefully managed, the result is irrefragable, though doubts have been cast, without any reason, on their observations. 

 [C] De Bary, "Uber die Brandpilze" (Berlin, 1853), pl. Iv. Figs. 3, 4, 5. 

 [D] A. De Bary, on Mildew and Fermentation, in "Quarterly German Magazine, " vol. Ii. 1872. 

 [E] Berkeley, "Introd. Crypt. Bot. " p. 78, fig. 20. 

 [F] See also Berkeley, in "Trans. Hort. Soc. London, " vol. Ix. P. 68. 

 [G] Berkeley, in "Ann. Nat. Hist. " (June, 1838), No. 116. 

 [H] "Grevillea, " vol. I. P. 176. 

 [I] Tulasne, "On Certain Fungicolous Sphæriæ, " in "Ann. Des Sci. Nat. " 4^me sér. Xiii. (1860), p. 5. 

 [J] "A Currant Twig, and Something on it, " in "Gardener's Chronicle, " January 28, 1871. 

 [K] Figs. 104 to 106 by permission from the "Gardener's Chronicle. "

 [L] Berkeley and Broome, in "Annals of Natural History" (1866), No. 1177, pl. V. Fig. 36; Cooke, "Handbook, " ii. P. 866. 

 [M] Cooke, "Handbook, " ii. P. 853, No. 2549; specimens in Cooke's "Fungi Britannici Exsiccati, " No. 270. 

 [N] Berk. And Br. "Ann. Nat. Hist. " (1865), No. 1096. 

 [O] "Ann. Nat. Hist. " (1871), No. 1332, pl. Xx. Fig. 23. 

 [P] Ibid. No. 1333, pl. Xxi. Fig. 24. 

 [Q] Tulasne, "Selecta Fungorum Carpologia, " ii. P. 269, pl. 29. 

 [R] Cooke, "Handbook, " ii. P. 878; Tulasne, "Carpologia, " ii. P. 120, plate 14. 

 [S] Tulasne, "Selecta Fung. Carp. , " ii. Plate 16. 

 [T] Corda, "Icones Fungorum, " vol. Iii. Fig. 91. 

 [U] Corda, "Icones, " vol. I. Fig. 25. 

 [V] Berk. And Br. "Ann. Nat. Hist. " No. 415. 

 [W] Currey, in "Philosoph. Trans. Roy. Soc. " (1857), pl. 25. 

 [X] Tulasne, "On the Reproductive Apparatus of Fungi, " in "Comptes Rendus" (1852), p. 841; and Tulasne, "Selecta Fungorum Carpologia, " vol. Iii. 

 [Y] "Monatsbericht der Koniglichen Preuss, Acad. Der Wissenschaften au Berlin, " Jan. 1865; Summary, in "Journ. Roy. Hort. Soc. , London, " vol. I. N. S. P. 107. 

 [Z] We have before us an _Æcidium_ on leaves of _Berberis vulgaris_, collected at Berne by Shuttleworth in 1833. It is named by him _Æcidium graveolens_, and differs in the following particulars from _Æcidium berberidis_. The peridia are scattered as in _Æ. Epilobii_, and not collected in clusters. They are not so much elongated. The cells are larger, and the orange spores nearly twice the diameter. There is a decided, strong, but unpleasant odour in the fresh plant; hence the name. The above figures (figs. 107, 108) of the cells and spores of both species are drawn by camera lucida to the same scale--380 diameters. 

 [a] Freiherrn von Hohenbühel-Heufler, in "Oesterr. Botan. Zeitschrift, " No. 3, 1870. 

 [b] Fuckel, "Symbolæ Mycologicæ" (1869), p. 49. 

 [c] Almost simultaneously with De Bary, the late Professor Oersted instituted experiments, from which the same results ensued, as to _Æcidium berberidis_ and _Puccinia graminis_. See "Journ. Hort. Soc. Lond. " new ser. I. , p. 85. 

 [d] "Oversigt over det Kon. Danske Videns. Selskabs" (1866), p. 185, t. 3, 4; (1867, ) p. 208, t. 3, 4; "Résumé du Bulletin de la Soc. Roy. Danoise des Sciences" (1866), p. 15; (1867), p. 38; "Botanische Zeitung" (1867), p. 104; "Quekett Microscopical Club Journal, " vol. Ii. P. 260. 

 [e] This is _Podisoma foliicola_, B. And Br. , or, as proposed in "Journ. Quekett Club, " ii. P. 267, _Sarcostroma Berkeleyi_, C. 

 [f] Tulasne, "Selecta Fungorum Carpologia, " iii. P. 6, pl. I. Figs. 19-31. 

 [g] Cramer's "Papilio Exotic" (1782), fig. 267. 

 [h] Cooke, "Handbook, " p. 548, No. 1639. 

 [i] Ibid. P. 556, No. 1666. 

 [j] Specimens were published under this name in Cooke's "Fungi Britannici Exsiccati, " No. 359. 

 [k] Cooke, "On Polymorphism in Fungi, " in "Popular Science Review. "

 [l] Lewis's "Report on Microscopic Objects found in Cholera Evacuations, " Calcutta, 1870. 

 [m] Tulasne, "Selecta Fungorum Carpologia, " ii. P. 261. 

 [n] Corda, "Prachtflora, " plate vii. 

X. 

INFLUENCES AND EFFECTS. 

It is no longer doubted that fungi exercise a large and very importantinfluence in the economy of nature. It may be that in some directionsthese influences are exaggerated; but it is certain that on the wholetheir influence is far more important for evil and for good than thatof any other of the Cryptogamia. In our endeavour to estimate thecharacter and extent of these influences it will prove advantageous toexamine them under three sections. 1. Their influence on man. 2. Theirinfluence on lower animals. 3. Their influence on vegetation. Underthese sections the chief facts may be grouped, and some approximateidea obtained of the very great importance of this family of inferiorplants, and consequently the advisability of pursuing their study morethoroughly and nationally than has hitherto been done. 

I. In estimating the influence of fungi upon man, we naturally enoughseek in the first instance to know what baneful effects they arecapable of producing on food. Although in the case of "poisonousfungi, " popularly understood, fungi may be the passive agents, yetthey cannot be ignored in an inquiry of this nature. Writing of theUses of Fungi, we have already shown that a large number are availablefor food, and some of these real delicacies; so, on the other hand, itbecomes imperative, even with stronger emphasis, to declare that manyare poisonous, and some of them virulently so. It is not sufficient tosay that they are perfectly harmless until voluntarily introduced intothe human system, whilst it is well known that accidents are alwayspossible, and probably would be if every baneful fungus had the wordPOISON inscribed in capitals on its pileus. 

The inquiry is constantly being made as to what plain rules can begiven for distinguishing poisonous from edible fungi, and we cananswer only that there are none other than those which apply toflowering plants. How can aconite, henbane, oenanthe, stramonium, and such plants, be distinguished from parsley, sorrel, watercress, or spinach? Manifestly not by any general characters, but byspecific differences. And so it is with the fungi. We must learn todiscriminate _Agaricus muscarius_ from _Agaricus rubescens_, in thesame manner as we would discriminate parsley from _Æthusa cynapium_. Indeed, fungi have an advantage in this respect, since one or twogeneral cautions can be given, when none such are applicable forhigher plants. For instance, it may be said truly that all fungithat exhibit a rapid change to blue when bruised or broken shouldbe avoided; that all Agarics are open to suspicion which possess anacrid taste; that fungi found growing on wood should not be eatenunless the species is well known; that no species of edible fungushas a strong, unpleasant odour, and similar cautions, which, afterall, are insufficient. The only safe guide lies in mastering, one byone, the specific distinctions, and increasing the number of one'sown esculents gradually, by dint of knowledge and experience, even asa child learns to distinguish a filbert from an acorn, or withwider experience will thrust in his mouth a leaf of _Oxalis_ andreject that of the white clover. 

One of the most deleterious of fungi that we possess is at the sametime one of the most beautiful. This is the _Agaricus muscarius_, orFly Agaric, which is sometimes used as a fly poison. [A] It has abright crimson pileus studded with pale whitish (sometimes yellowish)warts, and a stem and gills of ivory whiteness. Many instances havebeen recorded of poisoning by this fungus, and amongst them someBritish soldiers abroad, and yet it cannot be doubted that this fungusis eaten in Russia. Two instances have come under our notice ofpersons with some botanical knowledge, and one a gardener, who hadresided in Russia and eaten of this fungus. In one case the Fly Agaricwas collected and shown to us, and in the other the figure wasindicated, so that we might be under no doubt as to the species. Onlyone hypothesis can be advanced in explanation. It is known that alarge number of fungi are eaten in Russia, and that they enter muchinto the domestic cookery of the peasantry, but it is also known thatthey pay considerable attention to the mode of cooking, and add alarge amount of salt and vinegar, both of which, with long boiling, must be powerful agents in counteracting the poison (probably somewhatvolatile) of such fungi as the Fly Agaric. In this place we may give arecipe published by a French author of a process for renderingpoisonous fungi edible. It must be taken on his authority, and not ourown, as we have never made the experiment, notwithstanding it seemssomewhat feasible:--For each pound of mushrooms, cut into moderatelysmall pieces, take a quart of water acidulated with two or threespoonfuls of vinegar, or two spoonfuls of bay salt. Leave themushrooms to macerate in the liquid for two hours, then wash them withplenty of water; this done, put them in cold water and make them boil. After a quarter or half hour's boiling take them off and wash them, then drain, and prepare them either as a special dish, or use them forseasoning in the same manner as other species. [B]

This method is said to have been tried successfully with some of themost dangerous kinds. Of these may be mentioned the emetic mushroom, _Russula emetica_, with a bright red pileus and white gills, whichhas a clear, waxy, tempting appearance, but which is so virulent thata small portion is sufficient to produce disagreeable consequences. Itwould be safer to eschew all fungi with a red or crimson pileus thanto run the risk of indulging in this. A white species, which, however, is not very common, with a bulbous base enclosed in a volva, called_Agaricus vernus_, should also be avoided. The pink spored speciesshould also be regarded with suspicion. Of the _Boleti_ several turnblue when cut or broken, and these again require to be discarded. Thisis especially the case with _Boletus luridus_[C] and _BoletusSatanas_, [D] two species which have the under surface or orifice ofthe pores of a vermilion or blood-red colour. 

Not only are species which are known to be poisonous to be avoided, but discretion should be used in eating recognized good species. Fungiundergo chemical changes so rapidly that even the cultivated mushroommay cause inconvenience if kept so long after being gathered as toundergo chemical change. It is not enough that they should be of agood kind, but also fresh. The employment of plenty of salt in theirpreparation is calculated very much to neutralize any deleteriousproperty. Salt, pepper, and vinegar are much more freely employedabroad in preparing fungi than with us, and with manifest advantage. 

It is undoubtedly true that fungi exert an important influence inskin diseases. This seems to be admitted on all hands by medicalmen, [E] however much they may differ on the question of the extent towhich they are the cause or consequence of disease. Facts generallyseem to bear out the opinion that a great number of skin diseasesare aggravated, and even produced, by fungi. Robin[F] insists that apeculiar soil is necessary, and Dr. Fox says it is usually taughtthat tuberculous, scrofulous, and dirty people furnish the bestnidus. It is scarcely necessary to enumerate all these diseases, with which medical men are familiar, but simply to indicate a few. There is favus or scall-head, called also "porrigo, " which has itsprimary seat in the hair follicles. Plica polonica, which isendemic in Russia, is almost cosmopolitan. Then there is Tineatonsurans, Alopecia, Sycosis, &c. , and in India a more deeply-seateddisease, the Madura Foot, has been traced to the ravages of a fungusdescribed under the name of _Chionyphe Carteri_. [G] It is probablethat the application of different names to the very often imperfectforms of fungi which are associated with different diseases is notscientifically tenable. Perhaps one or two common moulds, such as_Aspergillus_ or _Penicillium_, lie at the base of the majority, butthis is of little importance here, and does not affect the generalprinciple that some skin diseases are due to fungi. 

Whilst admitting that there are such diseases, it must be understoodthat diseases have been attributed to fungi as a primary cause, whenthe evidence does not warrant such a conclusion. Diphtheria and thrushhave been referred to the devastations of fungi, whereas diphtheriacertainly may and does occur without any trace of fungi. Fevers maysometimes be accompanied by fungoid bodies in the evacuations, but itis very difficult to determine them. The whole question of epidemicdiseases being caused by the presence of fungi seems based on mostincomplete evidence. Dr. Salisbury was of opinion that camp measleswas produced by _Puccinia graminis_, the pseudospores of whichgerminated in the damp straw, disseminated the resultant secondarybodies in the air, and caused the disease. This has never beenverified. Measles, too, has been attributed freely, as well asscarlatina, [H] to fungal influences, and the endeavours to implicatefungi in being the cause of cholera have been pertinaciouslypersevered in with no conviction. The presence of certain cysts, saidto be those of _Urocystis_, derived from rice, was announced by Dr. Hallier, but when it was shown that no such fungus was found on rice, this phase of the theory collapsed. Special and competent experts weresent from this country to examine the preparations and hear theexplanations of Dr. Hallier on his theory of cholera contagion, butthey were neither convinced nor satisfied. 

As long ago as 1853, Dr. Lauder Lindsay examined and reported oncholera evacuations, and in 1856 he declared--"It will be evident thatI can see no satisfactory groundwork for the fungus theory of cholera, which I am not a little surprised to find still possesses powerfuladvocates. "[I] And of the examinations undertaken by him hewrites:--"The mycelium and sporules of various species of fungi, constituting various forms of vegetable mould, were found in the scumof the vomit, as well as of the stools, but only at some stage ofdecomposition. They are found, however, under similar circumstances, in the vomit and stools of other diseases, and, indeed, in alldecomposing animal fluids, and they are therefore far from peculiar tocholera. "

Some writers have held that the atmosphere is often highly chargedwith fungi spores, others have denied the presence of organic bodiesto any extent in the air. The experiments conducted in India by Dr. Cunningham[J] have been convincing enough on this point. This reportstates that spores and similar cells were of constant occurrence, andwere generally present in considerable numbers. That the majority ofthe cells were living and ready to undergo development on meeting withsuitable conditions was very manifest, as in those cases in whichpreparations were retained under observation for any length of time, germination rapidly took place in many of the cells; indeed, manyspores already germinating were deposited on the slides. In fewinstances did any development take place beyond the formation ofmycelium or masses of toruloid cells, but in one or two distinctsporules were developed on the filaments arising from some of thelarger septate spores, and in a few others _Penicillium_ and_Aspergillus_ produced their characteristic heads of fructification. 

With regard to the precise nature of the spores and other cellspresent in various instances little can be said, as, unless theirdevelopment were to be carefully followed out through all its stages, it is impossible to refer them to their correct species or evengenera. The greater number of them are apparently referable to the oldorders of fungi--_Sphæronemei_, _Melanconei_, _Torulacei_, _Dematiei_, and _Mucedines_, while some probably belonged to the _Pucciniei_ and_Coæmacei_. Amongst those belonging to the _Torulacei_, the mostinteresting was a representative of the rare genus _Tetraploa_. Distinct green algoid cells occurred in some specimens. Then follow inthe report details of observations made on the rise and fall ofdiseases, of which diarrhoea, dysentery, cholera, ague, and denguewere selected and compared with the increase or diminution ofatmospheric cells. The conclusions arrived at are:--

"Spores and other vegetable cells are constantly present inatmospheric dust, and usually occur in considerable numbers; themajority of them are living, and capable of growth and development. The amount of them present in the air appears to be independent ofconditions of velocity and direction of the wind, and their number isnot diminished by moisture. 

"No connection can be traced between the numbers of bacteria, spores, &c. , present in the air, and the occurrence of diarrhoea, dysentery, cholera, ague, or dengue, nor between the presence or abundance of anyspecial form or forms of cells, and the prevalence of any of thesediseases. 

"The amount of inorganic and amorphous particles and other débrissuspended in the atmosphere is directly dependent on conditions ofmoisture and velocity of wind. "

This report is accompanied by fourteen large and well-executed plates, each containing hundreds of figures of organic bodies collected fromthe air between February and September. It is valuable both for itsevidence as to the number and character of the spores in the air, andalso for the tables showing the relation between five forms ofdisease, and their fluctuations, as compared with the amount of sporesfloating in the atmosphere. 

We are fain to believe that we have represented the influence of fungion man as far as evidence seems to warrant. The presence of forms ofmould in some of their incipient conditions in different diseasedparts of the human body, externally and internally, may be admittedwithout the assumption that they are in any manner the cause of thediseased tissues, except in such cases as we have indicated. Hospitalgangrene may be alluded to in this connection, and it is possible thatit may be due to some fungus allied to the crimson spots (blood rain)which occur on decayed vegetation and meat in an incipient stage ofdecomposition. This fungus was at one time regarded as an algal, atanother as animal; but it is much more probable that it is a lowcondition of some common mould. The readiness with which the spores offungi floating in the atmosphere adhere to and establish themselves onall putrid or corrupt substances is manifest in the experience of allwho have had to do with the dressing of wounds, and in this case it isa matter of the greatest importance that, as much as possible, atmospherical contact should be avoided. 

Recently a case occurred at the Botanic Gardens at Edinburgh which wassomewhat novel. The assistant to the botanical professor was preparingfor demonstration some dried specimens of a large puff-ball, filledwith the dust-like spores, which he accidentally inhaled, and was forsome time confined to his room under medical attendance from theirritation they caused. This would seem to prove that the spores ofsome fungi are liable, when inhaled in large quantities, to derangethe system and become dangerous; but under usual and naturalconditions such spores are not likely to be present in the atmospherein sufficient quantity to cause inconvenience. In the autumn a verylarge number of basidiospores must be present in the atmosphere ofwoods, and yet there is no reason to believe that it is more unhealthyto breathe the atmosphere of a wood in September or October than inJanuary or May. Dreadful effects are said to be produced by a speciesof black rust which attacks the large South of Europe reed, _Arundodonax_. This is in all probability the same species with that whichattacks _Arundo phragmitis_ in this country, the spores of whichproduce violent headaches and other disorders amongst the labourerswho cut the reeds for thatching. M. Michel states that the spores fromthe parasite on _Arundo donax_, either inhaled or injected, produceviolent papular eruption on the face, attended with great swelling, and a variety of alarming symptoms which it is unnecessary toparticularize, in various parts of the body. [K] Perhaps if _Sarcina_should ultimately prove to be a fungus, it may be added to the list ofthose which aggravate, if they are not the primary cause of, diseasein the human subject. 

II. What influences can be attributed to fungi upon animals other thanman? Clearly instinct preserves animals from many dangers. It may bepresumed that under ordinary circumstances there is not much fear of acow or a sheep poisoning itself in a pasture or a wood. But underextraordinary circumstances it is not only possible, but veryprobable, that injuries may occur. For instance, it is well known thatnot only rye and wheat, but also many of the grasses, are liable toinfection from a peculiar form of fungus called "ergot. " In certainseasons this ergot is much more common than others, and the belief isstrong in those who ought to know something of the subject fromexperience, viz. , farmers and graziers, that in such seasons it is notuncommon for cattle to slip their young through feeding on ergotizedgrass. Then, again, it is fairly open to inquiry whether, in yearswhen "red rust" and "mildew" are more than usually plentiful ongrasses, these may not be to a certain extent injurious. Withoutattempting to associate the cattle plague in any way with fungi ongrass, it is nevertheless a most remarkable coincidence that the yearin which the cattle disease was most prevalent in this country was onein which there was--at least in some districts--more "red rust" ongrasses than we ever remember to have seen before or since; theclothes of a person walking through the rusty field soon becameorange-coloured from the abundance of spores. Graziers on this pointagain seem to be generally agreed, that they do not think "red rust"has been proved to be injurious to cattle. The direct influence offungi on quadrupeds, birds, reptilia, &c. , seems to be infinitesimallysmall. 

Insects of various orders have been observed from time to time tobecome the prey of fungi. [L] That known at Guadaloupe under the nameof _La Guêpe Végétale_, or vegetable wasp, has been often cited asevidence that, in some instances at least, the fungus attacks theinsect whilst still living. Dr. Madianna states that he has noticedthe wasp still living with its incumbrance attached to it, thoughapparently in the last stage of existence, and seeming about to perishfrom the influence of its destructive parasite. [M] This fungus iscalled by Tulasne _Torrubia sphecocephala_. [N] About twenty-fivespecies of this genus of sphæriaceous fungi have been described asparasitic on insects. Five species are recorded in South Carolina, onein Pennsylvania, found on the larvæ of the May-bug, and one otherNorth American species on Nocturnal Lepidoptera, one in Cayenne, onein Brazil, on the larva of a _Cicada_, and one on a species of ant, two in the West Indies, one in New Guinea on a species of _Coccus_, and one on a species of _Vespa_ in Senegal. In Australia two specieshave been recorded, and two are natives of New Zealand. Dr. Hookerfound two in the Khassya mountains of India, and one American specieshas also been found at Darjeeling. It has long been known that onespecies, which has a medicinal repute there, is found in China, whilstthree have been recorded in Great Britain. Opinions are divided as towhether in these instances the fungus causes or is subsequent to thedeath of the insect. It is generally the belief of entomologists thatthe death of the insect is caused by the fungus. In the case of_Isaria sphingum_, which is the conidia form of a species of_Torrubia_, the moth has been found standing on a leaf, as duringlife, with the fungus sprouting from its body. 

Other and less perfect forms of fungi also attack insects. During thesummer of 1826, Professor Sebert collected a great many caterpillarsof _Arctia villica_, for the purpose of watching their growth. Theseinsects on arriving at their full size became quite soft, and thensuddenly died. Soon after they became hard, and, if bent, would easilybreak into two pieces. Their bodies were covered with a beautifulshining white mould. If some of the caterpillars affected with theparasitic mould were placed on the same tree with those apparentlyfree from its attack, the latter soon exhibited signs that they alsowere attacked in the same manner, in consequence of coming intocontact with each other. [O]

During the spring of 1851, some twelve or twenty specimens were foundfrom amongst myriads of _Cicada septemdecim_, which, though living, had the posterior third of the abdominal contents converted into adry, powdery, ochreous-yellow compact mass of sporuloid bodies. Theouter coverings of that portion of the insect were loose and easilydetached, leaving the fungoid matter in the form of a cone affixed byits base to the unaffected part of the abdomen of the insect. Thefungus may commence, says Dr. Leidy, its attacks upon the larva, develop its mycelium, and produce a sporular mass within the activepupa, when many are probably destroyed; but should some be onlyaffected so far as not to destroy the organs immediately essential tolife, they might undergo their metamorphosis into the imago, in whichcase they would be affected in the manner previously described. [P]

The common house-fly in autumn is very usually subject to the attacksof a mouldy fungus called _Sporendonema muscæ_, or _Empusa muscæ_ informer times, which is now regarded as the terrestrial condition ofone of the _Saprolegniei_. [Q] The flies become sluggish, and at lastfix themselves to some object on which they die, with their legsextended and head depressed, the body and wings soon becoming coveredwith a minute white mould, the joints of which fall on the surroundingobject. Examples are readily distinguished when they settle on windowsand thus succumb to their foe. Mr. Gray says that a similar mould hasbeen observed on individuals of the wasp family. 

A _Gryllotalpa_ was found in a wood near Newark, Delaware, U. S. , uponturning over a log. The insect was seen standing very quietly at themouth of its oval cell, which is formed in the earth, having a shortcurved tube to the surface. Upon taking it up it exhibited no signs ofmovement, though perfectly fresh and lifelike in appearance. Onexamining it next morning it still presented no signs of life. Everypart of the insect was perfect, not even the antennæ being broken. Upon feeling it, it was very hard and resistant, and on making anincision through the thorax it exhaled a fungoid odour. The insect hadbeen invaded by a parasitic fungus which everywhere filled the animal, occupying the position of all the soft tissue, and extending even intothe tarsal joints. It formed a yellowish or cream-coloured compactmass. [R]

The destructive silk-worm disease, _Botrytis Bassiana_, is also afungus which attacks and destroys the living insect, concerning whichan immense deal has been written, but which has not yet beeneradicated. It has also been supposed that a low form or imperfectcondition of a mould has much to do with the disease of bees known as"foul brood. "[S]

_Penicillium Fieberi_, figured by Corda on a beetle, was doubtlessdeveloped entirely after death, with which event it had probablynothing whatever to do. [T] Sufficient, however, has been written toshow that fungi have an influence on insect life, and this mightbe extended to other animal forms, as to spiders, on which one or twospecies of _Isaria_ are developed, whilst Dr. Leidy has recordedobservations on _Julus_[U] which may be perused with advantage. Fish are subject to a mouldy-looking parasite belonging to the_Saprolegniei_, and a similar form attacks the ova of toads andfrogs. Gold fish in globes and aquaria are very subject to attackfrom this mouldy enemy, and although we have seen them recoverunder a constant change of water, this is by no means always thecase, for in a few weeks the parasite will usually prevail. 

The influence of fungi upon animals in countries other thanEuropean is very little known, except in the case of the species of_Torrubia_ found on insects, and the diseases to which silkworms aresubject. Instances have been recorded of the occurrence of fungoidmycelium--for in most it is nothing more--in the tissues ofanimals, in the hard structure of bone and shell, in the intestines, lungs, and other fleshy parts, and in various organs of birds. [V] Insome of the latter cases it has been described as a Mucor, in most itis merely cells without sufficient character for determination. It isby no means improbable that fungi may be found in such situations;the only question with regard to them is whether they are notaccidental, and not the producers of unhealthy or diseased tissues, even when found in proximity thereto. 

There is one phase of the influences of fungi on the lower animalswhich must not be wholly passed over, and that is the relation whichthey bear to some of the insect tribes in furnishing them with food. It is especially the case with the _Coleoptera_ that many species seemto be entirely dependent on fungi for existence, since they are foundin no other situations. Beetle-hunters tell us that old _Polyporei_, and similar fungi of a corky or woody nature, are always sought afterfor certain species which they seek in vain elsewhere, [W] and thosewho possess herbaria know how destructive certain minute members ofthe animal kingdom are to their choicest specimens, against whosedepredations even poison is sometimes unavailing. 

Some of the Uredines, as _Trichobasis suaveolens_ and _Coleosporiumsonchi_, are generally accompanied by a little orange larva whichpreys upon the fungus; and in the United States Dr. Bolles informs usthat some species of _Æcidium_ are so constantly infested with thisred larva that it is scarcely possible to get a good specimen, or tokeep it from its sworn enemy. Minute _Anguillidæ_ revel in tufts ofmould, and fleshy Agarics, as they pass into decay, become colonies ofinsect life. Small _Lepidoptera_, belonging to the _Tineina_, appearto have a liking for such _Polyporei_ as _P. Sulfureus_ when itbecomes dry and hard, or _P. Squamosus_ when it has attained a similarcondition. _Acari_ and _Psocidæ_ attack dried fungi of all kinds, andspeedily reduce them to an unrecognizable powder. 

III. What are the influences exerted by fungi on other plants? This isa broad subject, but withal an important one, since these influencesact indirectly on man as well as on the lower animals. On man, inasmuch as it interferes with the vegetable portion of his food, either by checking its production or depreciating its quality. On thelower animals, since by this means not only is their natural fooddeteriorated or diminished, but through it injurious effects areliable to be produced by the introduction of minute fungi into thesystem. These remarks apply mainly to fungi which are parasitic onliving plants. On the other hand, the influence of fungi must not belost sight of as the scavengers of nature when dealing with dead anddecaying vegetable matter. Therefore, as in other instances, we havehere also good and bad influences intermingled, so that it cannot besaid that they are wholly evil, or unmixed good. 

Wherever we encounter decaying vegetable matter we meet withfungi, living upon and at the expense of decay, appropriating thechanged elements of previous vegetable life to the support of a newgeneration, and hastening disintegration and assimilation with thesoil. No one can have observed the mycelium of fungi at work on oldstumps, twigs, and decayed wood, without being struck with therapidity and certainty with which disintegration is being carried on. The gardener casts on one side, in a pile as rubbish, twigs andcuttings from his trees, which are useless to him, but which haveall derived much from the soil on which they flourished. Shortlyfungi make their appearance in species almost innumerable, sendingtheir subtle threads of mycelium deep into the tissues of thewoody substance, and the whole mass teems with new life. In thismetamorphosis as the fungi flourish so the twigs decay, for the newlife is supported at the expense of the old, and together thedestroyers and their victims return as useful constituents to thesoil from whence they were derived, and form fresh pabulum for asucceeding season of green leaves and sweet flowers. In woods andforests we can even more readily appreciate the good offices offungi in accelerating the decay of fallen leaves and twigs whichsurround the base of the parent trees. In such places Nature is leftabsolutely to her own resources, and what man would accomplish inhis carefully attended gardens and shrubberies must here be donewithout his aid. What we call decay is merely change; change ofform, change of relationship, change of composition; and all thesechanges are effected by various combined agencies--water, air, light, heat, these furnishing new and suitable conditions for thedevelopment of a new race of vegetables. These, by their vigorousgrowth, continue what water and oxygen, stimulated by light andheat, had begun, and as they flourish for a brief season on the fallenglories of the past summer, make preparation for the coming spring. 

Unfortunately this destructive power of fungi over vegetable tissuesis too often exemplified in a manner which man does not approve. Thedry rot is a name which has been given to the ravages of more than onespecies of fungus which flourishes at the expense of the timber itdestroys. One of these forms of dry rot fungus is _Meruliuslacrymans_, which is sometimes spoken of as if it were the only one, though perhaps the most destructive in houses. Another is _Polyporushybridus_, which attacks oak-built vessels;[X] and these are not theonly ones which are capable of mischief. It appears that the dry rotfungus acts indirectly on the wood, whose cells are saturated with itsjuice, and in consequence lose their lignine and cellulose, thoughtheir walls suffer no corrosion. The different forms of decay in woodare accompanied by fungi, which either completely destroy the tissue, or alter its nature so much by the abstraction of the cellulose andlignine, that it becomes loose and friable. Thus fungi induce therapid destruction of decaying wood. These are the conclusionsdetermined by Schacht, in his memoir on the subject. [Y]

We may allude, in passing, to another phase of destructiveness in themycelium of fungi, which traverse the soil and interfere mostinjuriously with the growth of shrubs and trees. The reader ofjournals devoted to horticulture will not fail to notice the constantappeals for advice to stop the work of fungi in the soil, whichsometimes threatens vines, at others conifers, and at othersrhododendrons. Dead leaves, and other vegetable substances, notthoroughly and completely decayed, are almost sure to introduce thisunwelcome element. 

Living plants suffer considerably from the predations of parasiticspecies, and foremost amongst these in importance are those whichattack the cereals. The corn mildew and its accompanying rust arecosmopolitan, as far as we know, wherever corn is cultivated, whetherin Australia or on the slopes of the Himalayas. The same may also besaid of smut, for _Ustilago_ is as common in Asia and America as inEurope. We have seen it on numerous grasses as well as on barley fromthe Punjab, and a species different from _Ustilago maydis_ on the maleflorets of maize from the same locality. In addition to this, we learnthat in 1870 one form made its appearance on rice. It was described asconstituting in some of the infested grains a whitish, gummy, interlaced, ill-defined, thread-like mycelium, growing at the expenseof the tissues of the affected organs, and at last becoming convertedinto a more or less coherent mass of spores, of a dirty green colour, on the exterior of the deformed grains. Beneath the outer coating theaggregated spores are of a bright orange red; the central portion hasa vesicular appearance, and is white in colour. [Z] It is difficult todetermine from the description what this so-called _Ustilago_ may be, which was said to have affected a considerable portion of the standingrice crop in the vicinity of Diamond Harbour. 

Bunt is another pest (_Tilletia caries_) which occupies the wholefarinaceous portion of the grains of wheat. Since dressing the seedwheat has been so widely adopted in this country, this pest has beenof comparatively little trouble. Sorghum and the small millets, incountries where these are cultivated for food, are liable to attacksfrom allied parasites. Ergot attacks wheat and rice as well as rye, but not to such an extent as to have any important influence upon thecrop. Two or three other species of fungi are sometimes locallytroublesome, as _Dilophospora graminis_, and _Septoria nodorum_ onwheat, but not to any considerable extent. In countries where maize isextensively grown it has not only its own species of mildew(_Puccinia_), but also one of the most enormous and destructivespecies of _Ustilago_. 

A singular parasite on grasses was found by Cesati in Italy, in 1850, infesting the glumes of _Andropogon_. [a] It received the name of_Cerebella Andropogonis_, but it never appears to have increased andspread to such an extent as was at first feared. 

Even more destructive than any of these is the potato disease[b](_Peronospora infestans_), which is, unfortunately, too well known toneed description. This disease was at one time attributed to variouscauses, but long since its ascertained source has been acknowledged tobe a species of white mould, which also attacks tomatoes, but lessvigorously. De Bary has given considerable attention to this disease, and his opinions are clearly detailed in his memoir on _Peronospora_, as well as in his special pamphlet on the potato disease. [c] One seesthe cause of the epidemic, he says, in the diseased state of thepotato itself, produced either accidentally by unfavourable conditionsof soil and atmosphere, or by a depravation that the plant hasexperienced in its culture. According to these opinions, thevegetation of the parasite would be purely accidental, the diseasewould be independent of it, the parasite would be able frequently evento spare the diseased organs. Others see in the vegetation of the_Peronospora_ the immediate or indirect cause of the various symptomsof the disease; either that the parasite invades the stalks of thepotato, and in destroying them, or, so to speak, in poisoning them, determines a diseased state of the tubercles, or that it introducesitself into all the organs of the plant, and that its vegetation isthe immediate cause of all the symptoms of the disease that one meetswith in any organ whatever. His observations rigorously proved thatthe opinions of the latter were those only which were well founded. All the alterations seen on examining spontaneous individuals arefound when the _Peronospora_ is sown in a nourishing plant. The mostscrupulous examination demonstrates the most perfect identity betweenthe cultivated and spontaneous individuals as much in the organizationof the parasite as in the alteration of the plant that nourishes it. In the experiments that he had made he affirms that he never observedan individual or unhealthy predisposition of the nourishing plant. Itappeared to him, on the contrary, that the more the plant was healthy, the more the mould prospered. 

We cannot follow him through all the details of the growth anddevelopment of the disease, or of his experiments on this and alliedspecies, which resulted in the affirmation that the mould immediatelydetermines the disease of the tubercles as well as that of the leaves, and that the vegetation of the _Peronospora_ alone determines theredoubtable epidemic to which the potato is exposed. [d] We believethat this same observer is still engaged in a series of observations, with the view, if possible, of suggesting some remedy or mitigation ofthe disease. 

Dr. Hassall pointed out, many years since, the action of fungousmycelium, when coming in contact with cellular tissue, of inducingdecomposition, a fact which has been fully confirmed by Berkeley. 

Unfortunately there are other species of the same genus of moulds whichare very destructive to garden produce. _Peronospora gangliformis_, B. , attacks lettuces, and is but too common and injurious. _Peronosporaeffusa_, Grev. , is found on spinach and allied plants. _PeronosporaSchleideniana_, D. By. , is in some years very common and destructiveto young onions, and field crops of lucerne are very liable to attackfrom _Peronospora trifoliorum_, D. By. 

The vine crops are liable to be seriously affected by a species ofmould, which is but the conidia form of a species of _Erysiphe_. Thismould, known under the name of _Oidium Tuckeri_, B. , attacks the vinesin hothouses in this country, but on the Continent the vineyards oftensuffer severely[e] from its depredations; unfortunately, not the onlypest to which the vine is subject, for an insect threatens to be evenmore destructive. 

Hop gardens suffer severely, in some years, from a similar disease; inthis instance the mature or ultimate form is perfected. The hop mildewis _Sphærotheca Castagnei_, Lév. , which first appears as whitishmouldy blotches on the leaves, soon becoming discoloured, anddeveloping the black receptacles on either surface of the leaf. Thesemay be regarded as the cardinal diseases of fungoid origin to whichuseful plants are subject in this country. 

Amongst those of less importance, but still troublesome enough tosecure the anathemas of cultivators, may be mentioned _Puccinia Apii_, Ca. , often successful in spoiling beds of celery by attacking theleaves; _Cystopus candidus_, Lév. , and _Glæosporium concentricum_, Grev. , destructive to cabbages and other cruciferous plants;_Trichobasis Fabæ_, Lév. , unsparing when once established on beans;_Erysiphe Martii_, Lév. , in some seasons a great nuisance to the cropof peas. 

Fruit trees do not wholly escape, for _Roestelia cancellata_, Tul. , attacks the leaves of the pear. _Puccinia prunorum_ affects the leavesof almost all the varieties of plum. Blisters caused by _Ascomycesdeformans_, B. , contort the leaves of peaches, as _Ascomycesbullatus_, B. , does those of the pear, and _Ascomyces juglandis_, B. , those of the walnut. Happily we do not at present suffer from_Ascomyces pruni_, Fchl. , which, on the Continent, attacks youngplum-fruits, causing them to shrivel and fall. During the past yearpear-blossoms have suffered from what seems to be a form of_Helminthosporium pyrorum_, and the branches are sometimes infectedwith _Capnodium elongatum_; but orchards in the United States have aworse foe in the "black knot, "[f] which causes gouty swellings in thebranches, and is caused by the _Sphæria morbosa_ of Schweinitz. 

Cotton plants in India[g] were described by Dr. Shortt as subject tothe attacks of a kind of mildew, which from the description appearedto be a species of _Erysiphe_, but on receiving specimens from Indiafor examination, we found it to be one of those diseased conditions oftissue formerly classed with fungi under the name of _Erineum_; and aspecies of Torula attacks cotton pods after they are ripe. Tea leavesin plantations in Cachar have been said to suffer from some sort ofblight, but in all that we have seen insects appear to be thedepredators, although on the decaying leaves _Hendersonia theicola_, Cooke, establishes itself. [h] The coffee plantations of Ceylon sufferfrom the depredations of _Hemiliea vastatrix_, as well as frominsects. [i] Other useful plants have also their enemies in parasiticfungi. 

Olive-trees in the south of Europe suffer from the attacks of aspecies of _Antennaria_, as do also orange and lemon trees from a_Capnodium_, which covers the foliage as if with a coating of soot. Infact most useful plants appear to have some enemy to contend with, andit is fortunate, not only for the plant, but its cultivators, if thisenemy is less exacting than is the case with the potato, the vine, andthe hop. 

Forestry in Britain is an insignificant interest compared to whatit is in some parts of Europe, in the United States, and in ourIndian possessions. In these latter places it becomes a matter ofimportance to inquire what influence fungi exert on forest trees. It may, however, be predicated that the injury caused by fungi is faroutstripped by insects, and that there are not many fungi whichbecome pests in such situations. Coniferous trees may be infestedwith the species of _Peridermium_, which are undoubtedly injurious, _Peridermium elatinum_, Lk. , distorting and disfiguring the silverfir, as _Peridermium Thomsoni_, B. , [j] does those of _AbiesSmithiana_ in the Himalayas. This species occurred at an elevation of8, 000 feet. The leaves become reduced in length one-half, curved, and sprinkled, sometimes in double rows, with the large sori ofthis species, which gives the tree a strange appearance, and atlength proves fatal, from the immense diversion of nutriment requisiteto support a parasite so large and multitudinous. The dried specimenshave a sweet scent resembling violets. In Northern Europe _Cæomapinitorquum_, D. By. , seems to be plentiful and destructive. Allspecies of juniper, both in Europe and the United States, areliable to be attacked and distorted by species of _Podisoma_[k] and_Gymnosporangium_. _Antennaria pinophila_, Fr. , is undoubtedlyinjurious, as also are other species of _Antennaria_, which probablyattain their more complete development in _Capnodium_, of which_Capnodium Citri_ is troublesome to orange-trees in the south ofEurope, and other species to other trees. How far birch-trees areinjured by _Dothidea betulina_, Fr. , or _Melampsora betulina_, Lév. , or poplars and aspens by _Melampsora populina_, Lév. , and _Melampsoratremulæ_, Lév. , we cannot say. The species of _Lecythea_ found onwillow leaves have decidedly a prejudicial effect on the growth ofthe affected plant. 

Floriculture has to contend with many fungoid enemies, which sometimescommit great ravages amongst the choicest flowers. Roses have tocontend against the two forms of _Phragmidium mucronatum_ as well as_Asteroma Rosæ_. Still more disastrous is a species of _Erysiphei_, which at first appears like a dense white mould. This is named_Sphærotheca pannosa_. Nor is this all, for _Peronospora sparsa_, whenit attacks roses in conservatories, is merciless in its exactions. [l]Sometimes violets will be distorted and spoiled by _Urocystis Violæ_. The garden anemone is freely attacked by _Æcidium quadrifidum_. Orchids are liable to spot from fungi on the leaves, and recently thewhole of the choicest hollyhocks have been threatened with destructionby a merciless foe in _Puccinia malvacearum_. This fungus was firstmade known to the world as an inhabitant of South America many yearsago. It seems next to have come into notoriety in the Australiancolonies. Then two or three years ago we hear of it for the first timeon the continent of Europe, and last year for the first time in anythreatening form in our own islands. During the present year itsravages are spreading, until all admirers of hollyhocks begin to feelalarm lest it should entirely exterminate the hollyhock fromcultivation. It is common on wild mallows, and cotton cultivators mustbe on the alert, for there is a probability that other malvaceousplants may suffer. 

A writer in the "Gardener's Chronicle" has proposed a remedy for thehollyhock disease, which he hopes will prove effectual. He says, "Thisterrible disease has now, for twelve months, threatened the completeannihilation of the glorious family of hollyhock, and to baffle allthe antidotes that the ingenuity of man could suggest, so rapidly doesit spread and accomplish its deadly work. Of this I have had very sadevidence, as last year at this time I had charge of, if not thelargest, one of the largest and finest collections of hollyhocksanywhere in cultivation, which had been under my special care foreleven years, and up to within a month of my resigning that position Ihad observed nothing uncommon amongst them; but before taking my finalleave of them I had to witness the melancholy spectacle of bed afterbed being smitten down, and amongst them many splendid seedlings, which had cost me years of patience and anxiety to produce. Andagain, upon taking a share and the management of this business, another infected collection fell to my lot, so that I have been doingearnest battle with this disease since its first appearance amongstus, and I must confess that, up to a very short time back, I had comein for a great deal the worst of the fight, although I had made use ofevery agent I could imagine as being likely to aid me, and all thatmany competent friends could suggest. But lately I was reminded ofCondy's patent fluid, diluted with water, and at once procured abottle of the green quality, and applied it in the proportion of alarge tablespoonful to one quart of water, and upon examining theplants dressed, twelve hours afterwards, was delighted to find it hadeffectually destroyed the disease (which is easily discernible, aswhen it is living and thriving it is of a light grey colour, but whenkilled it becomes of a rusty black). Further to test the power atwhich the plant was capable of bearing the antidote without injury, Iused it double the strength. This dose was instant death to the pest, leaving no trace of any injury to the foliage. As to its application, I advocate sponging in all dressings of this description. Syringing isa very ready means, but very wasteful. No doubt sponging consumes moretime, but taking into consideration the more effectual manner in whichthe dressing can be executed alone, it is in the end most economical, especially in regard to this little parasite. I have found itdifficult by syringing, as it has great power of resisting andthrowing off moisture, and if but a very few are left living, it isastonishing how quickly it redistributes itself. I feel confident, that by the application of this remedy in time another season, I shallkeep this collection clean. I believe planting the hollyhock in largecrowded beds should be avoided, as I have observed the closer they aregrowing the more virulently does the disease attack them, whereasisolated rows and plants are but little injured. "[m]

The "Gardener's Chronicle" has also sounded a note of warning that aspecies of Uredine has been very destructive to pelargoniums at theCape of Good Hope. Hitherto these plants have not suffered much inthis country from parasites. Besides these, there are many other lesstroublesome parasites, such as _Uredo filicum_, on ferns; _PucciniaLychnidearum_, on leaves of sweet-william; _Uredo Orchidis_, on leavesof orchids, &c. 

If we would sum up the influences of fungi in a few words, it could bedone somewhat in the following form. 

Fungi exert a deleterious influence--

 On _Man_, When eaten inadvertently. By the destruction of his legitimate food. In producing or aggravating skin diseases. 

 On _Animals_, By deteriorating or diminishing their food supplies. By establishing themselves as parasites on some species. 

 On _Plants_, By hastening the decay of timber. By establishing themselves as parasites. By impregnating the soil. 

But it is not proved that they produce epidemic diseases in man oranimals, or that the dissemination of their multitudinous spores inthe atmosphere has any appreciable influence on the health of thehuman race. Hence their association with cholera, diarrhoea, measles, scarlatina, and the manifold ills that flesh is heir to, as producingor aggravating causes, must, in the present state of our knowledge andexperience, be deemed apocryphal. 

 [A] A detailed account of the peculiar properties of this fungus and its employment as a narcotic will be found in Cooke's "Seven Sisters of Sleep, " p. 337. It is figured in Greville's "Scottish Cryptogamic Flora, " plate 54. 

 [B] Pour chaque 500 grammes de champignons coupes en morceaux d'assez mediocre grandeur, il faut un litre d'eau acidulée par deux ou trois cuillerées de vinaigre, ou deux cuillerées de sel gris. Dans le cas ou l'on n'aurait que de l'eau à sa disposition, il faut la renouveler une ou deux fois. On laisse les champignons macérer dans le liquids pendant deux heures entières, puis on les lave à grande eau. Ils sont alors mis dans de l'eau froide qu'on porte à l'ébullition, et après un quart d'heure ou une demi-heure, on les retire, on les lave, on les essuie, et ou les apprête soit comme un mets spécial, et ils comportent les mêmes assaisonnements que les autres, soit comme condiment. --_Morel Traité des Champignons_, p. Lix. Paris, 1865. 

 [C] Smith's "Chart of Poisonous Fungi, " fig. 10. 

 [D] Ibid. Fig. 27. It would be well to become acquainted with all these figures. 

 [E] "Skin Diseases of Parasitic Origin, " by Dr. Tilbury Fox. London, 1863. 

 [F] Robin, "Hist. Nat. Des Végétaux Parasites. " Paris, 1853. Kuchenmeister, "Animal and Vegetable Parasites of the Human Body. " London, Sydenham Society, 1857. 

 [G] Berkeley, in "Intellectual Observer, " Nov. , 1862. "Mycetoma, " II. Vandyke Carter, 1874. 

 [H] Hallier and Zurn, "Zeitschrift fur Parasitenkunde. " Jena, 1869-71. 

 [I] Dr. Lauder Lindsay, "On Microscopical and Clinical Characters of Cholera Evacuations, " reprinted from "Edinburgh Medical Journal, " February and March, 1856; also "Clinical Notes on Cholera, " by W. Lauder Lindsay, M. D. , F. L. S. , in "Association Medical Journal" for April 14, 1854. 

 [J] "Microscopic Examinations of Air, " from the "Ninth Annual Report of the Sanitary Commissioner, " Calcutta, 1872. 

 [K] "Gardener's Chronicle, " March 26, 1864. 

 [L] Gray, G. , "Notices of Insects that are Known to Form the Bases of Fungoid Parasites. " London, 1858. 

 [M] Halsey, "Ann. Lyceum, " New York, 1824, p. 125. 

 [N] Tulasne, "Selecta Fung. Carp. " vol. Iii. P. 17. 

 [O] "Berlin Entom. Zeitung, " 1858, p. 178. 

 [P] "Smithsonian Contributions to Knowledge, " v. P. 53. 

 [Q] "Wiegmann Archiv. " 1835, ii. P. 354; "Ann. Nat. Hist. " 1841, 405. 

 [R] Leidy, "Proc. Acad. Nat. Sci. Phil. " 1851, p. 204. 

 [S] "Gardener's Chronicle, " November 21, 1868. 

 [T] Corda, "Prachtflora, " pl. Ix. 

 [U] Leidy, "Fauna and Flora within Living Animals, " in "Smithsonian Contributions to Knowledge. "

 [V] Murie, in "Monthly Microscopical Journal" (1872), vii. P. 149. 

 [W] See genus _Mycetophagus_, "Stephen's Manual Brit. Coleopt. " p. 132. 

 [X] Sowerby's "Fungi, " plates 289 and 387, fig. 6. 

 [Y] Schacht, "Fungous Threads in the Cells of Plants, " in Pringsheim's "Jahrbuch. " Berlin, 1863. 

 [Z] "Proceedings of the Agri. Hort. Soc. Of India" (1871), p. 85. 

 [a] "Gardener's Chronicle" (1852), p. 643, with fig. 

 [b] Berkeley, "On the Potato Murrain, " in "Jour. Hort. Soc. " vol. I. (1846), p. 9. 

 [c] De Bary, "Die gegenwartig herrschende Kartoffelkrankheit. "

 [d] De Bary, "Memoir on Peronospora, " in "Annales des Sci. Nat. "

 [e] "Reports of H. M. Secretaries of Embassy and Legation on the Effects of the Vine Disease on Commerce, 1859;" "Reports of H. M. Secretaries of Embassy, &c. , on Manufactures and Commerce, Vine Disease in Bavaria and Switzerland, 1859, " pp. 54 and 62. 

 [f] C. H. Peek, "On the Black Knot, " in "Quekett Microscopical Journal, " vol. Iii. P. 82. 

 [g] Cooke, "Microscopic Fungi, " p. 177. 

 [h] "Grevillea, " i. P. 90. 

 [i] "Gardener's Chronicle, " 1873. 

 [j] "Gardener's Chronicle, " 1852, p. 627, with fig. 

 [k] "Podisoma Macropus, " Hook, "Journ. Bot. " vol. Iv. Plate xii. Fig. 6. 

 [l] Berkeley, in "Gardener's Chronicle, " 1862, p. 308. 

 [m] "Gardener's Chronicle, " August 22, 1874, p. 243. 

XI. 

HABITATS. 

It commonly happens that one of the first inquiries which the studentseeks to have answered, after an interest is excited in fungi, is--Where, and under what circumstances, are they to be found? Theinexperienced, indeed, require some guide, or much labour will beexpended and patience lost in seeking microscopic forms in just suchplaces as they are least likely to inhabit. Nor is it whollyunprofitable or uninteresting for others, who do not claim to bestudents, to summarize the habitats of these organisms, and learn howmuch the circumstances of their immediate surrounding elementsinfluence production. For reasons which will at once be recognized bythe mycologist, the most satisfactory method of study will be somewhatthat of the natural groups into which fungi are divided. 

AGARICINI. --There is such a close affinity between all the genera ofthis group that it will be a manifest advantage to take together allthose fleshy pileate fungi, the fruit of which is borne on foldedplates or gills. It must be premised of this group that, for themajority, shade, a moderate amount of moisture, and steady warmth, butnot too great heat, are required. A stroll through a wood in autumnwill afford good evidence of the predilection of _Agaricini_, as wellas some smaller groups, for such spots. A larger proportion will befound in woods, where shade is afforded, than on open heaths orpastures. These wood-loving forms will consist, again, of those whichappear on the soil, and those which are found on rotten stumps anddecaying trees. Many of those which grow on trees have a lateralstem, or scarcely any stem at all. It may be remarked, that somespecies which spring from the soil delight most in the shelter ofparticular trees. The Agarics of a beech wood will materially differlargely from those in an oak wood, and both will differ from thosewhich spring up beneath coniferous trees. 

It may be accepted as true of the largest proportion of terrestrialspecies, that if they do not spring directly from rotten leaves, andvegetable débris in the last stage of decay, the soil will be rich invegetable humus. A few only occur on sandy spots. The genus_Marasmius_ is much addicted to dead leaves; _Russula_, to openplaces in woods, springing immediately from the soil. _Lactarius_prefers trees, and when found in exposed situations, occurs mostlyunder the shadow of trees. [A] _Cantharellus_, again, is a woodlandgenus, many of the species loving to grow amongst grass or moss, and some as parasites on the latter. _Coprinus_ is not a genus muchaddicted to woods, but is rather peculiar in its attachment toman--if such expression, or one even implying domesticity, mightbe employed--farmyards, gardens, dunghills, the base of old gatepostsand railings, in cellars, on plaster walls, and even on old dampcarpets. _Hygrophorus_ loves "the open, " whether pastures, lawns, heaths, commons, or up the slopes of mountains, nearly to the top ofthe highest found in Great Britain. _Cortinarius_ seems to have apreference for woods, whilst _Bolbitius_ affects dung, or a richsoil. _Lentinus_, _Panus_, _Lenzites_, and _Schizophyllum_ all grow onwood. Coming to the subgenera of _Agaricus_, we find _Pleurotus_, _Crepidotus_, _Pluteus_, _Collybia_, _Pholiota_, _Flammula_, _Hypholoma_, and some species of _Psathyra_ growing on wood, oldstumps, or charcoal; _Amanita_, _Tricholoma_, and _Hebeloma_ mostattached to woods; _Clitocybe_ and _Mycena_ chiefly amongst leaves;_Nolanea_ amongst grass; _Omphalia_ and _Galera_ chiefly in swampyplaces; _Lepiota_, _Leptonia_, _Psalliota_, _Stropharia_, _Psilocybe_, and _Psathyrella_ mostly in open places and pastures; _Deconica_and _Panæolus_ mostly on dung; _Entoloma_ and _Clitopilus_ chieflyterrestrial, and the rest variable. 

Of special habitats, we may allude to _Nyctalis_, of which the speciesare parasitic on dead fungi belonging to the genus _Russula_. One ortwo species of _Agaricus_, such as _Agaricus tuberosus_ and _Agaricusracemosus_, P. , grow on decaying Agarics, whilst _Agaricus Loveianus_flourishes on _Agaricus nebularis_ even before it is thoroughlydecayed. A few species grow on dead fir cones, others on old ferns, &c. _Agaricus cepoestipes_, Sow. , probably of exotic origin, grows onold tan in hothouses. _Agaricus caulicinalis_, Bull, flourishes on oldthatch, as well as twigs, &c. _Agaricus juncicola_, Fr. , affects deadrushes in boggy places, whilst _Agaricus affricatus_, Fr. , and_Agaricus sphagnicola_, B. , are attached to bog moss in similarlocalities. Some few species are almost confined to the stems ofherbaceous plants. _Agaricus petasatus_, Fr. , _Agaricus cucumis_, P. , and _Paxillus panuoides_, F. , have a preference for sawdust. _Agaricuscarpophilus_, Fr. , and _Agaricus balaninus_, P. , have a predilectionfor beech mast. _Agaricus urticoecola_, B. And Br. , seems to confineitself to nettle roots. _Coprinus radians_, Fr. , makes its appearanceon plaster walls, _Coprinus domesticus_, Fr. , on damp carpets. Theonly epizoic species, according to M. Fries, is _Agaricus cerussatusv. Nauseosus_, which has been met with in Russia on the carcase of awolf; this, however, might have been accidental. Persoon described_Agaricus Neapolitanus_, which was found growing on coffee-grounds atNaples; and more recently Viviani has described another species, _Agaricus Coffeæ_, with rose-coloured spores, found on old fermentingcoffee-grounds at Genoa. [B] Tratinnick figures a species named_Agaricus Markii_, which was found in wine casks in Austria. A_Coprinus_ has, both in this country and on the Continent, been found, after a very short time, on the dressing of wounds, where there hasbeen no neglect. A curious case of this kind, which at the timeexcited great interest, occurred some fifty years since at St. George's Hospital. Some species appear to confine themselves toparticular trees, some to come up by preference on soil in gardenpots. Certain species have a solitary, others a gregarious habit, and, of the latter, _Agaricus grammopodius_, Bull, _Agaricus gambosus_, Fr. , _Marasmius oreades_, Fr. , and some others grow in rings. Hence itwill be seen that, within certain limits, there is considerablevariation in the habitats of the _Agaricini_. 

_Boleti_ do not differ much from _Agaricini_ in their localization. They seem to prefer woods or borders of woods to pastures, seldombeing found in the latter. One species, _B. Parasiticus_, Bull, growson old specimens of _Scleroderma_, otherwise they are for the mostpart terrestrial. 

_Polypori_ also have no wide range of habitat, except in choice oftrees on which to grow, for the majority of them are corticolous. Thesection _Mesopus_, which has a distinct central stem, has some specieswhich prefer the ground. _Polyporus tuberaster_, P. , in Italy springsfrom the _Pietra funghaia_, [C] and is cultivated for food as well as_Polyporus avellanus_, which is reared from charred blocks of cob-nuttrees. 

In other genera of the _Polyporei_ similar habitats prevail. _Meruliuslacrymans_, Fr. , one form of dry rot, occurs in cellars, and too oftenon worked timber; whilst _Merulius himantoides_, Fr. , is much moredelicate, sometimes running over plants in conservatories. 

HYDNEI. --There is nothing calling for special note on the habitats ofthese fungi. The stipitate species of _Hydnum_ are some of them foundin woods, others on heaths, one on fir-cones, while the rest havesimilar habitats to the species of _Polyporus_. 

AURICULARINI. --The genera _Hymenochoete_, _Stereum_, and _Corticium_, with some species of _Thelephora_, run over corticated or decorticatedwood; other species of _Thelephora_ grow on the ground. The Pezizoidforms of _Cyphella_ and _Solenia_, like species of _Peziza_, sometimesoccur on bark, and of the former genus some on grasses and others onmoss. 

CLAVARIEI. --The interesting, often brightly-coloured, tufts of_Clavaria_ are usually found amongst grass, growing directly from theground. Only in rare instances do they occur on dead leaves orherbaceous stems. _Calocera_ probably should be classed with the_Tremellini_, to which its structure seems more closely allied. Thespecies are developed on wood. The species of _Typhula_ and_Pistillaria_ are small, growing chiefly on dead herbaceous plants. One or two are developed from a kind of _Sclerotium_, which is in facta compact perennial mycelium. 

TREMELLINI. --These curious gelatinous fungi are, with rare exceptions, developed on branches or naked wood; _Tremella versicolor_, B. AndBr. , one of the exceptions, being parasitic on a species of_Corticium_, and _Tremella epigæa_, B. And Br. , spreading over thenaked soil. This completes our rapid survey of the habitats of the_Hymenomycetes_. Very few of them are really destructive tovegetation, for the Agarics and Polypori found on growing trees areseldom to be seen on vigorous, but rather on dead branches orpartly-decayed trunks. 

The GASTEROMYCETES are far less numerous in species, and also inindividuals, but their habitats are probably more variable. The_Hypogæi_, or subterranean species, are found either near the surfaceor buried in the soil, usually in the neighbourhood of trees. 

PHALLOIDEI. --In most cases the species prefer woody places. They aremostly terrestrial, and have the faculty of making their presenceknown, even when not seen, by the fetid odour which many of themexhale. Some of them occur in sandy spots. 

PODAXINEI. --These resemble in their localities the _Trichogastres_. Species of _Podaxon_ affect the nests of Termites in tropicalcountries. [D] Others are found growing amongst grass. 

TRICHOGASTRES. --These are chiefly terrestrial. The rare but curious_Batarrea phalloides_, P. , has been found on sand-hills, and inhollow trees. _Tulostoma mammosum_, Fr. , occurs on old stone walls, growing amongst moss. _Geaster striatus_, D. C. , was at one timeusually found on the sand of the Denes at Great Yarmouth. Although_Lycoperdon giganteum_, Batsch, occurs most frequently in pastures, oron hedge banks in fields, we have known it to occur annually forsome consecutive years in a garden near London. The species of_Scleroderma_ seem to prefer a sandy soil. _Agloeocystis_ is ratheran anomalous genus, occurring on the fruit heads of _Cyperus_, inIndia. _Broomeia_ occurs at the Cape on rotten wood. 

MYXOGASTRES. --Rotten wood is one of the most favoured of matrices onwhich these fungi develop themselves; some of them, however, areterrestrial. _Æthalium_ will grow on spent tan and other substances. Species of _Diderma_ flourish on mosses, jungermanniæ, grass, deadleaves, ferns, &c. _Angioridium sinuosum_, Grev. , will run overgrowing plants of different kinds, and _Spumaria_, in like manner, encrusts living grasses. _Badhamia_ not only flourishes on dead wood, but one species is found on the fading leaves of coltsfoot which arestill green. _Craterium_ runs over almost any substance which lies inits way. _Licea perreptans_ was found in a cucumber frame heated withspent hops. One or two _Myxogastres_ have been found on lead, or evenon iron which had been recently heated. Sowerby found one on cinders, in one of the galleries of St. Paul's Cathedral. 

NIDULARIACEI grow on the ground, or on sticks, twigs, chips, and othervegetable substances, such as sawdust, dung, and rotten wood. 

The CONIOMYCETES consist of two sections, which are based on theirhabitats. In one section the species are developed on dead or dyingplants, in the other they are parasitic on living plants. The formerincludes the _Sphæronemei_, which are variable in their proclivities, although mostly preferring dead herbaceous plants and the twigs oftrees. The exceptions are in favour of _Sphæronema_, some of which aredeveloped upon decaying fungi. In the large genera, _Septoria_, _Ascochyta_, _Phyllosticta_, _Asteroma_, &c. , the favourite habitat isfading and dying leaves of plants of all kinds. In the majority ofcases these fungi are not autonomous, but are merely the stylosporousconditions of _Sphæria_. They are mostly minute, and the stylosporesare of the simplest kind. The _Melanconiei_ have a preference for thetwigs of trees, bursting through the bark, and expelling the spores ina gelatinous mass. A few of them are foliicolous, but the exceptionsare comparatively rare, and are represented chiefly in _Gloeosporium_, species of which are found also on apples, peaches, nectarines, andother fruits. The _Torulacei_ are superficial, having much of theexternal appearance of the black moulds, and like them are found ondecaying vegetable substances, old stems of herbaceous plants, deadtwigs, wood, stumps of trees, &c. The exceptions are in favour of suchspecies as _Torula sporendonema_, which is the red mould of cheese, and also occurs on rats' dung, old glue, &c. , and _SporendonemaMuscæ_, which is only the conidia of a species of _Achlya_. Onespecies of _Bactridium_ is parasitic on the hymenium of _Peziza_, and_Echinobotryum atrum_, on the flocci of black moulds. 

In the other section of _Coniomycetes_ the species are parasitic upon, and destructive to, living plants, very seldom being found onreally dead substances, and even in such rare cases undoubtedlydeveloped during the life of the tissues. Mostly the ultimate stageof these parasites is exhibited in the ruptured cuticle, and thedispersion of the dust-like spores; but in _Tilletia caries_, _Thecaphora hyalina_, and _Puccinia incarcerata_, they remain enclosedwithin the fruit of the foster-plant. The different genera exhibitin some instances a liking for plants of certain orders on whichto develop themselves. _Peridermium_ attacks the _Coniferæ_;_Gymnosporangium_ and _Podisoma_ the different species of Juniper;_Melampsora_ chiefly the leaves of deciduous trees; _Roestelia_attaches itself to pomaceous trees, whilst _Graphiola_ affects the_Palmaceæ_, and _Endophyllum_ the succulent leaves of houseleek. In_Æcidium_ a few orders seem to be more liable to attack thanothers, as the _Compositæ_, _Ranunculaceæ_, _Leguminosæ_, _Labiatæ_, &c. , whilst others, as the _Graminaceæ_, _Ericaceæ_, _Malvaceæ_, _Cruciferæ_, are exempt. There are, nevertheless, very few naturalorders of phanerogamous plants in which some one or more species, belonging to this section of the _Coniomycetes_, may not be found; andthe same foster-plant will occasionally nurture several forms. Recent investigations tend to confirm the distinct specificcharacters of the species found on different plants, and to provethat the parasite of one host will not vegetate upon another, however closely allied. This admission must not, however, beaccepted as universally applicable, and therefore it should not beassumed, because a certain parasite is found developed on a specialhost, that it is distinct, unless distinctive characters, apart fromhabitat, can be detected. _Æcidium compositarum_ and _Æcidiumranunculacearum_, for instance, are found on various composite andranunculaceous plants, and as yet no sufficient evidence has beenadduced to prove that the different forms are other than varietiesof one of the two species. On the other hand, it is not improbablethat two species of _Æcidium_ are developed on the common berberry, as De Bary has indicated that two species of mildew, _Pucciniagraminis_, and _Puccinia straminis_, are found on wheat. 

HYPHOMYCETES. --The moulds are much more universal in their habitats, especially the _Mucedines_. The _Isariacei_ have a predilection foranimal substances, though not exclusively. Some species occur on deadinsects, others on decaying fungi, and the rest on sticks, stems, androtten wood. The _Stilbacei_ have also similar habitats, except thatthe species of _Illosporium_ seem to be confined to parasitism onlichens. The black moulds, _Dematiei_, are widely diffused, appearingon herbaceous stems, twigs, bark, and wood in most cases, but also onold linen, paper, millboard, dung, rotting fruit, &c. , whilst forms of_Cladosporium_ and _Macrosporium_ are met with on almost every kind ofvegetable substance in which the process of decay has commenced. 

_Mucedines_, in some instances, have not been known to appear onmore than one kind of matrix, but in the far greater number of casesthey nourish on different substances. _Aspergillus glaucus_ and_Penicillium crustaceum_ are examples of these universal _Mucedines_. It would be far more difficult to mention substances on whichthese moulds are never developed than to indicate where they have beenfound. With the species of _Peronospora_ it is different, for theseare truly parasitic on living plants, and, as far as already known, the species are confined to certain special plants, and cannot bemade to vegetate on any other. The species which causes the potatomurrain, although liable to attack the tomato, and other species of_Solanaceæ_, does not extend its ravages beyond that natural order, whilst _Peronospora parasitica_ confines itself to cruciferous plants. One species is restricted to the _Umbelliferæ_, another, or perhapstwo, to the _Leguminosæ_, another to _Rubiaceæ_, two or three to_Ranunculaceæ_, and two or three to _Caryophyllaceæ_. All theexperiments made by De Bary seem to prove that the species of_Peronospora_ will only flourish on certain favoured plants, to theexclusion of all others. The non-parasitic moulds are scarcelyexclusive. In _Oidium_ some species are parasitic, but probably allthe parasitic forms are states of _Erysiphe_, the non-parasiticalone being autonomous; of these one occurs on _Porrigo lupinosa_, others on putrefying oranges, pears, apples, plums, &c. , and oneon honeycomb. _Acrospeira_ grows in the interior of sweet chestnuts, and we have seen a species growing within the hard testa of theseeds of _Guilandina Bondue_, from India, to which there was noexternal opening visible, and which was broken with considerabledifficulty. Several _Mucedines_ are developed on the dung ofvarious animals, and seldom on anything else. 

The _Physomycetes_ consist of two orders, _Antennariei_ and_Mucorini_, which differ from each other almost as much in habitat asin external appearance. The former, if represented by _Antennaria_, runs over the green and fading leaves of plants, forming a dense blackstratum, like a congested layer of soot; or in _Zasmidium_, the commoncellar fungus, runs over the walls, bottles, corks, and othersubstances, like a thick sooty felt. In the _Mucorini_, as in the_Mucedines_, there is usually less restriction to any specialsubstance. _Mucor mucedo_ occurs on bread, paste, preserves, andvarious substances; other species of _Mucor_ seem to have a preferencefor dung, and some for decaying fungi, but rotting fruits are nearlysure to support one or other of the species. The two known species ofthe curious genus _Pilobolus_, as well as _Hydrophora_, are confinedto dung. _Sporodinia_, _Syzygites_, &c. , nourish on rotten Agarics, where they pass through their somewhat complicated existence. 

The _Ascomycetes_ contain an immense number of species, and in generalterms we might say that they are found everywhere. The _Tuberacei_ aresubterraneous, with a preference for calcareous districts. The_Perisporiacei_ are partly parasitical and partly not. The _Erysiphei_include those of the former which flourish at the expense of the greenparts of roses, hops, maples, poplars, peas, and many other plants, both in Europe and in North America, whilst in warmer latitudes thegenus _Meliola_ appears to take their place. 

The _Elvellacei_ are fleshy fungi, of which the larger forms areterrestrial; _Morchella_, _Gyromitra_, and _Helvella_ mostly growingin woods, _Mitrula_, _Spathularia_, and _Leotia_ in swampy places, and_Geoglossum_ amongst grass. The very large genus _Peziza_ is dividedinto groups, of which _Aleuriæ_ are mostly terrestrial. This groupincludes nearly all the large-sized species, although a few belong tothe next. _Lachneæ_ are partly terrestrial and partly epiphytal, themost minute species being found on twigs and leaves of dead plants. In_Phialea_ the species are nearly entirely epiphytal, as is also thecase in _Helotium_ and allied genera. Some species of _Peziza_ aredeveloped from the curious masses of compact mycelium called_Sclerotia_. A few are rather eccentric in their habitats. _P. Viridaria_, _P. Domestica_, and _P. Hoemastigma_, grow on damp walls;_P. Granulata_ and some others on dung. _Peziza Bullii_ was foundgrowing on a cistern. _P. Theleboloides_ appears in profusion on spenthops. _P. Episphæria_, _P. Clavariarum_, _P. Vulgaris_, _Helotiumpruinosum_, and others are parasitic on old fungi. One or two speciesof _Helotium_ grow on submerged sticks, so as to be almost aquatic, acircumstance of rare occurrence in fungi. Other _Discomycetes_ aresimilar in their habitats to the _Elvellacei_. The group to which theold genus _Ascobolus_ belongs is in a great measure confined to thedung of various animals, although there are two or three lignicolousspecies; and _Ascophanus saccharinus_ was first found on old leather, _Ascophanus testaceus_ on old sacking, &c. _Ascomyces_ is, perhaps, the lowest form which ascomycetous fungi assume, and the species areparasitic on growing plants, distorting the leaves and fruit, constituting themselves pests to the cultivators of peach, pear, andplum trees. 

The _Sphæriacei_ include a very large number of species which grow onrotten wood, bark, sticks, and twigs; another group is developed ondead herbaceous stems; yet another is confined to dead or dyingleaves. One genus, _Torrubia_, grows chiefly on insects; _Hypomyces_is parasitic on dead fungi; _Claviceps_ is developed from ergot, _Poronia_ on dung, _Polystigma_ on living leaves, as well as somespecies of _Stigmatea_ and _Dothidea_. Of the genus _Sphæria_, aconsiderable number are found on dung, now included by some authorsunder _Sordaria_ and _Sporormia_, genera founded, as we think, oninsufficient characters. A limited number of species are parasitic onlichens, and one species only is known to be aquatic. 

[Illustration: FIG. 109. --_Torrubia militaris_ on pupa of a moth. ]

We have thus rapidly, briefly, and casually indicated the habitats towhich the majority of the larger groups of fungi are attached, regarding them from a systematic point of view. There is, however, another aspect from which we might approach the subject, takingthe host or matrix, or in fact the habitat, as the basis, andendeavouring to ascertain what species of fungi are to be found insuch positions. This has partly been done by M. Westendorp;[E] butevery year adds considerably to the number of species, and what mighthave been moderately accurate twelve years since can scarcely be sonow. To carry this out fully a special work would be necessary, sothat we shall be content to indicate or suggest, by means of a fewillustrations, the forms of fungi, often widely distinct instructure and character, to be found in the same locality. 

The stems of herbaceous plants are favourite habitats for minutefungi. The old stems of the common nettle, for example, perform theoffice of host to about thirty species. [F] Of these about nine are_Pezizæ_, and there are as many sphæriaceous fungi, whilst threespecies of _Dendryphium_, besides other moulds, select this plant. Some of these have not hitherto been detected growing on any otherstems, such as _Sphæria urticæ_ and _Lophiostoma sex-nucleatum_, towhich we might add _Peziza fusarioides_ and _Dendryphium griseum_. These do not, however, include the whole of the fungi found on thenettle, since others are parasitic upon its living green parts. Ofthese may be named _Æcidium urticæ_ and _Peronospora urticæ_, as wellas two species described by Desmazières as _Fusisporium urticæ_ and_Septoria urticæ_. Hence it will be seen how large a number of fungimay attach themselves to one herbaceous plant, sometimes whilstliving, but most extensively when dead. This is by no means a solitaryinstance, but a type of what takes place in many others. If, on theother hand, we select such a tree as the common lime, we shall findthat the leaves, twigs, branches, and wood bear, according to M. Westendorp, [G] no less than seventy-four species of fungi, and ofthese eleven occur on the leaves. The spruce fir, according to thesame authority, nourishes one hundred and fourteen species, and theoak not less than two hundred. 

It is curious to note how fungi are parasitic upon each other in someinstances, as in that of _Hypomyces_, characteristic of the genus, inwhich sphæriaceous fungi make hosts of dead _Lactarii_, &c. We havealready alluded to _Nyctalis_, growing on decayed _Russulæ_, to_Boletus parasiticus_, flourishing on old _Scleroderma_, and to_Agaricus Loveianus_, on the pileus of _Agaricus nebularis_. To thesewe may add _Torrubia ophioglossoides_ and _T. Capitata_, whichflourish on decaying _Elaphomyces_, _Stilbum tomentosum_ on old_Trichia_, _Peziza Clavariarum_ on dead _Clavaria_, and many others, the mere enumeration of which would scarcely prove interesting. A verycurious little parasite was found by Messrs. Berkeley and Broome, andnamed by them _Hypocrea inclusa_, which makes itself a home in theinterior of truffles. Mucors and moulds flourish on dead and decayingAgarics, and other fleshy forms, in great luxuriance and profusion. _Mucor ramosus_ is common on _Boletus luridus_, and _Syzygitesmegalocarpus_ on Agarics, as well as _Acrostalagmus cinnabarinus_. Avery curious little parasite, _Echinobotryum atrum_, occurs likeminute nodules on the flocci of black moulds. _Bactridium Helvellæ_usurps the fructifying disc of species of _Peziza_. A small_Sphinctrina_ is found both in Britain and the United States on old_Polypori_. In _Sphæria nigerrima_, _Nectria episphæria_, and two orthree others, we have examples of one sphæriaceous fungus growingupon another. 

Mr. Phillips has recently indicated the species of fungi found by himon charcoal beds in Shropshire, [H] but, useful as it is, that onlyrefers to one locality. A complete list of all the fungi which havebeen found growing on charcoal beds, burnt soil, or charred wood, would be rather extensive. The fungi found in hothouses and stoves arealso numerous, and often of considerable interest from the fact thatthey have many of them never been found elsewhere. Those found inBritain, [I] for instance, are excluded from the British Flora asdoubtful, because, growing upon or with exotic plants, they are deemedto be of exotic origin, yet in very few cases are they known to beinhabitants of any foreign country. Some species found in suchlocalities are not confined to them, as _Agaricus coepestipes_, _Agaricus cristatus_, _Æthalium vaporarium_, &c. It is somewhatsingular that certain species have a predilection for growing inproximity with other plants with which they do not appear to have anymore intimate relation. Truffles, for instance, in association withoaks, _Peziza lanuginosa_ under cedar-trees, _Hydnangium carneum_about the roots of _Eucalypti_, and numerous species of _Agaricini_, which are only found under trees of a particular kind. As might beanticipated, there is no more fertile habitat for fungi than the dungof animals, and yet the kinds found in such locations belong to but afew groups. Amongst the _Discomycetes_, a limited number of the genus_Peziza_ are fimicolous, but the allied genus _Ascobolus_, and its ownimmediate allies, include amongst its species a large majority thatare found on dung. If we take the number of species at sixty-four, there are only seven or eight which do not occur on dung, whilstfifty-six are fimicolous. The species of _Sphæria_ which are found onthe same substances are also closely allied, and some Continentalauthors have grouped them under the two proposed genera _Sporormia_and _Sordaria_, whilst Fuckel[J] proposes a distinct group of_Sphæriacei_, under the name of _Fimicoli_, in which he includes asgenera _Coprolepa_, _Hypocopra_, _Delitschia_, _Sporormia_, _Pleophragmia_, _Malinvernia_, _Sordaria_, and _Cercophora_. The twospecies of _Pilobolus_, and some of _Mucor_, are also found on dung, _Isaria felina_ on that of cats, _Stilbum fimetarium_ and a few othermoulds, and amongst Agarics some species of _Coprinus_. Animalsubstances are not, as a rule, prolific in the production of fungi. _Ascobolus saccharinus_ and one or two others have been found upon oldleather. _Onygena_ of two or three species occurs on old horn, hoofs, &c. Cheese, milk, &c. , afford a few forms, but the largest numberinfest dead insects, either under the mouldy form of _Isaria_ or themore perfect condition of _Torrubia_, and occasionally under otherforms. 

Robin[K] has recorded that three species of _Brachinus_, of the orderColeoptera, have been found infected, whilst living, with a minuteyellow fungus which he calls _Laboulbenia Rougeti_, and the samespecies has been noted on other beetles. _Torrubia Melolonthæ_[L] hasbeen described by Tulasne as occurring on the maybug or cockchafer, which is allied to, if not identical with, _Cordyceps Ravenelii_, B. And C. , and also that described and figured by M. Fougeroux deBondaroy. [M] _Torrubia curculionum_, Tul. , occurs on several speciesof beetles, and seems to be by no means uncommon in Brazil and CentralAmerica. _Torrubia coespitosa_, Tul. , which may be the same as_Cordyceps Sinclairi_, B. , [N] is found on the larvæ of _Orthoptera_ inNew Zealand, _Torrubia Miquelii_ on the larvæ of _Cicada_ in Brazil, and _Torrubia sobolifera_ on the pupæ of _Cicada_ in the West Indies. A romantic account is given of this in an extract cited by Dr. Watsonin his communication to the Royal Society. [O] "The vegetable fly isfound in the island Dominica, and (excepting that it has no wings)resembles the drone, both in size and colour, more than any otherEnglish insect. In the month of May it buries itself in the earth andbegins to vegetate. By the latter end of July, the tree is arrived atits full growth, and resembles a coral branch, and is about threeinches high, and bears several little pods, which, dropping off, become worms, and from thence flies, like the English caterpillar. "_Torrubia Taylori_, which grows from the caterpillar of a large mothin Australia, is one of the finest examples of the genus. _TorrubiaRobertsii_, from New Zealand, has long been known as attacking thelarva of _Hepialus virescens_. There are several other species onlarvæ of different insects, on spiders, ants, wasps, &c. , and one ortwo on mature Lepidoptera, but the latter seem to be rare. 

That fungi should make their appearance and flourish in localities andconditions generally considered inimical to vegetable life is no lessstrange than true. We have already alluded to the occurrence of somespecies on spent tan, and some others have been found in locations asstrange. We have seen a yellow mould resembling _Sporotrichum_ in theheart of a ball of opium, also a white mould appears on the samesubstance, and more than one species is troublesome in the opiumfactories of India. A mould made its appearance some years since in acopper solution employed for electrotyping in the Survey Department ofthe United States, [P] decomposing the salt, and precipitating thecopper. Other organisms have appeared from time to time in variousinorganic solutions, some of which were considered destructive tovegetable life, and it is not improbable that some of these organismswere low conditions of mould. It may well occasion some surprise thatfungi should be found growing within cavities wholly excluded from theexternal air, as in the hollow of filberts, and the harder shellednuts of _Guilandina_, in the cavities of the fruit of tomato, or inthe interior of an egg. It is scarcely less extraordinary that_Hypocrea inclusa_ should flourish in the interior of a kind oftruffle. 

From the above it will be concluded that the habitats of fungi areexceedingly variable, that they may be regarded as almost universalwherever decaying vegetable matter is found, and that under someconditions animal substances, especially of vegetable feeders, such asinsects, furnish a pabulum for their development. 

A very curious and interesting inquiry presents itself to our minds, which is intimately related to this subject of the habitats of fungi. It shapes itself into a sort of "puzzle for the curious, " but at thesame time one not unprofitable to think about. How is the occurrenceof new and before unknown forms to be accounted for in a case like thefollowing?[Q]

It was our fortune--good fortune as far as this investigation wasconcerned--to have a portion of wall in our dwelling persistently dampfor some months. It was close to a cistern which had become leaky. Thewall was papered with "marbled" paper, and varnished. At first therewas for some time nothing worthy of observation, except a dampwall--decidedly damp, discoloured, but not by any means mouldy. Atlength, and rather suddenly, patches of mould, sometimes two or threeinches in diameter, made their appearance. These were at first of asnowy whiteness, cottony and dense, just like large tufts of cottonwool, of considerable expansion, but of miniature elevation. Theyprojected from the paper scarcely a quarter of an inch. In the courseof a few weeks the colour of the tufts became less pure, tinged withan ochraceous hue, and resembling wool rather than cotton, lessbeautiful to the naked eye, or under a lens, and more entangled. Soonafter this darker patches made their appearance, smaller, dark olive, and mixed with, or close to, the woolly tufts; and ultimately similarspots of a dendritic character either succeeded the olive patches, orwere independently formed. Finally, little black balls, like small pinheads, or grains of gunpowder, were found scattered about the dampspots. All this mouldy forest was more than six months under constantobservation, and during that period was held sacred from thedisturbing influences of the housemaid's broom and duster. 

Curiosity prompted us from the first to submit the mouldy denizens ofthe wall to the microscope, and this curiosity was increased week byweek, on finding that none of the forms found vegetating on nearly twosquare yards of damp wall could be recognized as agreeing specificallywith any described moulds with which we were acquainted. Here was aproblem to be solved under the most favourable conditions, a forest ofmould indoors, within a few yards of the fireside, growing quitenaturally, and all strangers. Whence could these new forms proceed?

The cottony tufts of white mould, which were the first to appear, hadan abundant mycelium, but the erect threads which sprang from thiswere for a long time sterile, and closely interlaced. At lengthfertile threads were developed in tufts, mixed with the sterilethreads. These fruit-bearers were shorter and stouter, more sparinglybranched, but beset throughout nearly their whole length with shortpatent, alternate branchlets. These latter were broadest towards theapex, so as to be almost clavate, and the extremity was beset with twoor three short spicules. Each spicule was normally surmounted by anobovate spore. The presence of fertile threads imparted the ochraceoustint above alluded to. This tint was slight, and perhaps would nothave been noticed, but from the close proximity of the snow-whitetufts of barren threads. The fertile flocci were decumbent, probablyfrom the weight of the spores, and the tufts were a little elevatedabove the surface of the matrix. This mould belonged clearly to the_Mucedines_, but it hardly accorded well with any known genus, although most intimately related to _Rhinotrichum_, in which it wasplaced as _Rhinotrichum lanosum_. [R]

The white mould having become established for a week or two, smallblackish spots made their appearance on the paper, sometimes amongstthin patches of the mould, and sometimes outside them. These spots, atfirst cloudy and indefinite, varied in size, but were usually lessthan a quarter of an inch in diameter. The varnish of the paper wasafterwards pushed off in little translucent flakes or scales, anerect olivaceous mould appeared, and the patches extended to nearly aninch in diameter, maintaining an almost universal circular form. Thisnew mould sometimes possessed a dirty reddish tint, but was commonlydark olive. There could be no mistake about the genus to which thismould belonged; it had all the essential characters of _Penicillium_. Erect jointed threads, branched in the upper portion in a fasciculatemanner, and bearing long beaded threads of spores, which formed atassel-like head, at the apex of each fertile thread. Although atfirst reminded of _Penicillium olivaceum_, of Corda, by the colour ofthis species, it was found to differ in the spores being oblonginstead of globose, and the ramifications of the flocci weredifferent. Unable again to find a described species of _Penicillium_with which this new mould would agree, it was described under the nameof _Penicillium chartarum_. [S]

Almost simultaneously, or but shortly after the perfection of thespores of _Penicillium_, other and very similar patches appeared, distinguished by the naked eye more particularly by their dendriticform. This peculiarity seemed to result from the dwarfed habit of thethird fungus, since the varnish, though cracked and raised, was notcast off, but remained in small angular fragments, giving to the spotstheir dendritic appearance, the dark spores of the fungus protrudingthrough the fissures. This same mould was also found in many casesgrowing in the same spots amongst _Penicillium chartarum_, but whetherfrom the same mycelium could not be determined. 

The distinguishing features of this fungus consist in an extensivemycelium of delicate threads, from which arise numerous erectbranches, bearing at the apex dark brown opaque spores. Sometimes thebranches were again shortly branched, but in the majority of instanceswere single. The septate spores had from two to four divisions, manyof them divided again by cross septa in the longitudinal direction ofthe spore, so as to impart a muriform appearance. As far as thestructure and appearance of the spores are concerned, they resembledthose of _Sporidesmium polymorphum_, under which name specimens wereat first published, [T] but this determination was not satisfactory. The mycelium and erect threads are much too highly developed for agood species of _Sporidesmium_, although the name of _Sporidesmiumalternaria_ was afterwards adopted. In fresh specimens of this fungus, when seen _in situ_ by a half-inch objective, the spores appear to bemoniliform, but if so, all attempts to see them so connected, whenseparated from the matrix, failed. On one occasion, a very immaturecondition was examined, containing simple beaded, hyaline bodies, attached to each other by a short neck. The same appearance of beadedspores, when seen _in situ_, was recognized by a mycological friend, to whom specimens were submitted for confirmation. [U]

The last production which made its appearance on our wall-paper burstthrough the varnish as little black spheres, like grains of gunpowder. At first the varnish was elevated by pressure from beneath, thenthe film was broken, and the little blackish spheres appeared. Thesewere, in the majority of cases, gregarious, but occasionally a few ofthe spheres appeared singly, or only two or three together. As thewhole surface of the damp paper was covered by these differentfungi, it was scarcely possible to regard any of them as isolated, or to declare that one was not connected with the mycelium of theothers. The little spheres, when the paper was torn from the wall, were also growing from the under surface, flattened considerably bythe pressure. The spherical bodies, or perithecia, were seated on aplentiful hyaline mycelium. The walls of the perithecia, rather morecarbonaceous than membranaceous, are reticulated, reminding one ofthe conceptacles of _Erysiphe_, to which the perithecia bearconsiderable resemblance. The ostiolum is so obscure that we doubtits existence, and hence the closer affinity of the plant to the_Perisporiacei_ than to the _Sphæriacei_. The interior of theperithecium is occupied by a gelatinous nucleus, consisting ofelongated cylindrical asci, each enclosing eight globose hyalinesporidia, with slender branched paraphyses. A new genus has beenproposed for this and another similar form, and the presentspecies bears the name of _Orbicula cyclospora_. [V]

The most singular circumstance connected with this narrative is thepresence together of four distinctly different species of fungi, allof them previously unknown and undescribed, and no trace amongst themof the presence of any one of the very common species, which would besupposed to develop themselves under such circumstances. It is not atall unusual for _Sporocybe alternata_, B. , to appear in broad blackpatches on damp papered walls, but in this instance not a trace was tobe found. What were the peculiar conditions present in this instancewhich led to the manifestation of four new forms, and none of the oldones? We confess that we are unable to account satisfactorily for themystery, but, at the same time, feel equally unwilling to inventhypotheses in order to conceal our own ignorance. 

 [A] These predilections must be accepted as general, to which there will be exceptions. 

 [B] Viviani, "I Funghi d'Italia. "

 [C] Badham's "Esculent Funguses, " Ed. I. Pp. 42, 116. 

 [D] An excellent white Agaric occurs on ant nests in the Neilgherries, and a curious species is found in a similar position in Ceylon. 

 [E] Westendorp, "Les Cryptogams après leurs stations naturelles. "

 [F] Cooke, "On Nettle Stems and their Micro-Fungi, " in "Journ. Quekett Micro. Club, " iii. P. 69. 

 [G] Westendorp, "Les Cryptogams après leurs stations naturelles, " 1865. 

 [H] "Gardener's Chronicle, " 1874. 

 [I] W. G. Smith, in "Journ. Botany, " March, 1873; Berkeley, in "Grevillea, " vol. I. P. 88. 

 [J] Fuckel, "Symbolæ Mycologicæ, " p. 240. 

 [K] Robin, "Végét. Parasites, " p. 622, t. Viii. F. 1, 2. 

 [L] Tulasne, "Selecta Fung. Carp. " iii. P. 12. 

 [M] "Hist. De l'Acad. Des Sciences, " 1769. Paris, 1772. 

 [N] Berkeley, "Crypt. Bot. " p. 73; Hooker, "New Zealand Flora, " ii. 338. 

 [O] "Philosophical Transactions, " liii. (1763), p. 271. 

 [P] Berkeley's "Outlines, " p. 30. 

 [Q] "Popular Science Review, " vol. X. (1871), p. 25. 

 [R] Specimens of this mould were distributed in Cooke's "Fungi Britannici Exsiccati, " No. 356, under the name of _Clinotrichum lanosum_. 

 [S] Cooke's "Handbook of British Fungi, " p. 602. 

 [T] Cooke's "Fungi Britannici Exsiccati, " No. 329, under the name of _Sporidesmium polymorphum_ var. _chartarum_. 

 [U] This reminds one of Preuss's _Alternaria_, figured in Sturm's "Flora;" it has been suggested that the mould, as seen when examined under a power of 320 diam. , is very much like a _Macrosporium_. Again arises the question of the strings of spores attached end to end. 

 [V] "Handbook of British Fungi, " vol. Ii. P. 926, No. 2, 788. 

XII. 

CULTIVATION. 

The cultivation of fungi in this country for esculent purposes isconfined to a single species, and yet there is no reason why, by aseries of well-conducted experiments, means should not be devised forthe cultivation of others, for instance, _Marasmius orcades_, and themorel. Efforts have been made on the Continent for the cultivation oftruffles, but the success has hitherto been somewhat doubtful. For thegrowth of the common mushroom, very little trouble and care isrequired, and moderate success is certain. A friend of ours some yearssince was fortunate enough to have one or two specimens of the largepuff-ball, _Lycoperdon giganteum_, growing in his garden. Knowing itsvalue, and being particularly fond of it when fried for breakfast, hewas anxious to secure its permanence. The spot on which the specimensappeared was marked off and guarded, so that it was never desecratedby the spade, and the soil remained consequently undisturbed. Yearafter year, so long as he resided on the premises, he counted upon andgathered several specimens of the puff-ball, the mycelium continuingto produce them year after year. All parings, fragments, &c. , notutilized of the specimens eaten were cast on this spot to rot, so thatsome of the elements might be returned to the soil. This was not truecultivation perhaps, as the fungus had first established itself, butit was preservation, and had its reward. It must be admitted, however, that the size and number of specimens diminished gradually, probablyfrom exhaustion of the soil. This fungus, though strong, is muchapproved by many palates, and its cultivation might be attempted. Burying a ripe specimen in similar soil, and watering ground with thespores, has been tried without success. [A]

As to the methods adopted for cultivation of the common mushroom, it is unnecessary to detail them here, as there are several specialtreatises devoted to the subject, in which the particulars aremore fully given than the limits of this chapter will permit. [B]Recently, M. Chevreul exhibited at the French Academy some splendidmushrooms, said to have been produced by the following method: hefirst develops the mushrooms by sowing spores on a pane of glass, covered with wet sand; then he selects the most vigorous individualsfrom among them, and sows, or plants their mycelium in a cellar ina damp soil, consisting of gardener's mould, covered with a layerof sand and gravel two inches thick, and another layer of rubbish fromdemolitions, about an inch deep. The bed is watered with a dilutedsolution of nitrate of potash, and in about six days the mushroomsgrow to an enormous size. [C] The cultivation of mushrooms for themarket, even in this country, is so profitable, that curiousrevelations sometimes crop up, as at a recent trial at the Sheriffs'Court for compensation by the Metropolitan Railway Company forpremises and business of a nurseryman at Kensington. The Railway hadtaken possession of a mushroom-ground, and the claim for compensationwas £716. It was stated in evidence that the profits on mushroomsamounted to 100 or 150 per cent. One witness said if £50 wereexpended, in twelve months, or perhaps in six months, the sumrealized would be £200. 

Immense quantities of mushrooms are produced in Paris, as is wellknown, in caves, and interesting accounts have been written of visitsto these subterranean mushroom-vaults of the gay city. In one of thesecaves, at Montrouge, the proprietor gathers largely every day, occasionally sending more than 400 pounds weight per day to market, the average being about 300 pounds. There are six or seven miles' runof mushroom-beds in this cave, and the owner is only one of a largeclass who devote themselves to the culture of mushrooms. Largequantities of preserved mushrooms are exported, one house sending toEngland not less than 14, 000 boxes in a year. Another cave nearFrépillon was in full force in 1867, sending as many as 3, 000 poundsof mushrooms to the Parisian markets daily. In 1867, M. Renaudot hadover twenty-one miles of mushroom-beds in one great cave at Méry, andin 1869 there were sixteen miles of beds in a cave at Frépillon. Thetemperature of these caves is so equal that the cultivation of themushroom is possible at all seasons of the year, but the best cropsare gathered in the winter. 

Mr. Robinson gives an excellent account, not only of the subterranean, but also of the open-air culture of mushrooms about Paris. Theopen-air culture is never pursued in Paris during the summer, andrarely so in this country. [D] What might be termed the domesticcultivation of mushrooms is easy, that is, the growth by inexperiencedpersons, for family consumption, of a bed of mushrooms in cellars, wood-houses, old tubs, boxes, or other unconsidered places. Even intowns and cities it is not impracticable, as horse-dung can always beobtained from mews and stables. Certainly fungi are never soharmless, or seldom so delicious, as when collected from the bed, andcooked at once, before the slightest chemical change or deteriorationcould possibly take place. 

Mr. Cuthill's advice may be repeated here. He says:--"I must notforget to remind the cottager that it would be a shilling or two aweek saved to him during the winter, if he had a good little bed ofmushrooms, even for his own family, to say nothing about a shilling ortwo that he might gain by selling to his neighbours. I can assure himmushrooms grow faster than pigs, and the mushrooms do not eatanything; they only want a little attention. Addressing myself to theworking classes, I advise them, in the first place, to employ theirchildren or others collecting horse-droppings along the highway, andif mixed with a little road-sand, so much the better. They must bedeposited in a heap during summer, and trodden firmly. They will heata little, but the harder they are pressed the less they will heat. Over-heating must be guarded against; if the watch or trial stickwhich is inserted into them gets too hot for the hand to bear, theheat is too great, and will destroy the spawn. In that case artificialspawn must be used when the bed is made up, but this expedient is tobe avoided on account of the expense. The easiest way for a cottagerto save his own spawn would be to do so when he destroys his old bed;he will find all round the edges or driest parts of the dung one massof superior spawn; let him keep this carefully in a very dry place, and when he makes up his next bed it can then be mixed with his summerdroppings, and will insure a continuance and excellent crop. Theselittle collections of horse-droppings and road-sand, if kept dry inshed, hole, or corner, under cover, will in a short time generateplenty of spawn, and will be ready to be spread on the surface of thebed in early autumn, say by the middle of September or sooner. Thedroppings during the winter must be put into a heap, and allowed toheat gently, say up to eighty or ninety degrees; then they must beturned over twice daily to let off the heat and steam; if this isneglected the natural spawn of the droppings is destroyed. Thecottager should provide himself with a few barrowfuls of strawy dungto form the foundation of his bed, so that the depth, when all isfinished, be not less than a foot. Let the temperature be up to milkheat. He will then, when quite sure that the bed will not overheat, put on his summer droppings. By this time these will be one mass ofnatural spawn, having a grey mouldy and thready appearance, and asmell like that of mushrooms. Let all be pressed very hard; then letmould, unsifted, be put on, to the thickness of four inches, andtrodden down hard with the feet and watered all over; and the back ofa spade may now be used to make it still harder, as well as to plasterthe surface all over. "[E] Mushrooms are cultivated very extensively byMr. Ingram, at Belvoir, without artificial spawn. There is a greatriding-house there, in which the litter is ground down by the horses'feet into very small shreds. These are placed in a heap and turnedover once or twice during the season, when a large quantity ofexcellent spawn is developed which, placed in asparagus beds or laidunder thin turf, produces admirable mushrooms, in the latter case asclean as in our best pastures. [F]

Other species will sometimes be seen growing on mushroom-beds besidesthe genuine mushroom, the spawn in such cases being probablyintroduced with the materials employed. We have seen a pretty crispedvariety of _Agaricus dealbatus_ growing in profusion in such a place, and devoured it accordingly. Sometimes the mushrooms will, when in anunhealthy condition, be subject to the ravages of parasitic species ofmould, or perhaps of _Hypomyces_. _Xylaria vaporaria_ has, in morethan one instance, usurped the place of mushrooms. Mr. Berkeley hasreceived abundant specimens in the Sclerotioid state, which hesucceeded in developing in sand under a bell glass. Of course undersuch conditions there is much loss. The little fairy-ring champignonis an excellent and useful species, and it is a great pity that someeffort should not be made to procure it by cultivation. In Italy akind of _Polyporus_, unknown in this country, is obtained by wateringthe _Pietra funghaia_, or fungus stone, a sort of tufa impregnatedwith mycelium. The _Polypori_, it is said, take seven days to come toperfection, and may be obtained from the foster mass, if properlymoistened, six times a year. There are specimens which were fullydeveloped in Mr. Lee's nursery at Kensington many years since. Anotherfungus is obtained from the pollard head of the black poplar. Dr. Badham says that it is usual to remove these heads at the latter endof autumn, as soon as the vintage is over, and their marriage with thevine is annulled; hundreds of such heads are then cut and transportedto different parts; they are abundantly watered during the firstmonth, and in a short time produce that truly delicious fungus_Agaricus caudicinus_, which, during the autumn of the year, makes thegreatest show in the Italian market-places. These pollard blockscontinue to bear for from twelve to fourteen years. 

Another fungus, which Dr. Badham himself reared (_Polyporusavellanus_), is procured by singeing, over a handful of straw, a blockof the cob-nut tree, which is then watered and put by. In about amonth the fungi make their appearance, and are quite white, of fromtwo to three inches in diameter, and excellent to eat, while theirprofusion is sometimes so great as entirely to hide the wood fromwhence they spring. [G] It has been said that _Boletus edulis_ may bepropagated by watering the ground with a watery infusion of theplants, but we have no knowledge of this method having been pursuedwith success. 

The culture of truffles has been partially attempted, on the principlethat, in some occult manner, certain trees produced truffles beneaththeir shade. It is true that truffles are found under trees of specialkinds, for Mr. Broome remarks that some trees appear more favourableto the production of truffles than others. Oak and hornbeam arespecially mentioned; but, besides these, chestnut, birch, box, andhazel are alluded to. He generally found _Tuber oestivum_ underbeech-trees, but also under hazel, _Tuber macrosporum_ under oaks, and_Tuber brumale_ under oaks and abele. The men who collect trufflesfor Covent Garden Market obtain them chiefly under beech, and in mixedplantations of fir and beech. [H]

Some notion may be obtained of the extent to which the trade oftruffles is carried in France, when we learn that in the market of Aptalone about 3, 500 pounds of truffles are exposed for sale every weekduring the height of the season, and the quantity sold during thewinter reaches upwards of 60, 000 pounds, whilst the Department ofVaucluse yields annually upwards of 60, 000 pounds. It may beinteresting here to state that the value of truffles is so great inItaly that precautions are taken against truffle poachers, much in thesame way as against game poachers in England. They train their dogs soskilfully that, while they stand on the outside of the trufflegrounds, the dogs go in and dig for the fungi. Though there aremultitudes of species, they bring out those only which are of marketvalue. Some dogs, however, are employed by botanists, which will huntfor any especial species that may be shown to them. The greatdifficulty is to prevent them devouring the truffles, of which theyare very fond. The best dogs, indeed, are true retrievers. 

The Count de Borch and M. De Bornholz give the chief accounts of theefforts that have been made towards the cultivation of these fungi. They state that a compost is prepared of pure mould and vegetable soilmixed with dry leaves and sawdust, in which, when properly moistened, mature truffles are placed in winter, either whole or in fragments, and that after the lapse of some time small truffles are found in thecompost. [I] The most successful plan consists in sowing acorns over aconsiderable extent of land of a calcareous nature; and when the youngoaks have attained the age of ten or twelve years, truffles are foundin the intervals between the trees. This process was carried on in theneighbourhood of Loudun, where truffle-beds had formerly existed, butwhere they had long ceased to be productive--a fact indicating theaptitude of the soil for the purpose. In this case no attempt wasmade to produce truffles by placing ripe specimens in the earth, butthey sprang up themselves from spores probably contained in the soil. The young trees were left rather wide apart, and were cut, for thefirst time, about the twelfth year after sowing, and afterwards atintervals of from seven to nine years. Truffles were thus obtained fora period of from twenty-five to thirty years, after which theplantations ceased to be productive, owing, it was said, to the groundbeing too much shaded by the branches of the young trees. It is theopinion of the Messrs. Tulasne that the regular cultivation of thetruffle in gardens can never be so successful as this so-calledindirect culture at Loudun, but they think that a satisfactory resultmight be obtained in suitable soils by planting fragments of maturetruffles in wooded localities, taking care that the other conditionsof the spots selected should be analogous to those of the regulartruffle-grounds, and they recommend a judicious thinning of the treesand clearing the surface from brushwood, etc. , which prevents at oncethe beneficial effects of rain and of the direct sun's rays. A trufflecollector stated to Mr. Broome that whenever a plantation of beech, orbeech and fir, is made on the chalk districts of Salisbury Plain, after the lapse of a few years truffles are produced, and that theseplantations continue productive for a period of from ten to fifteenyears, after which they cease to be so. 

M. Gasparin reported to the jurors of the Paris Exhibition of 1855, concerning the operations of M. Rousseau, of Carpentras, on theproduction of oak truffles in France. The acorns of evergreen and ofcommon oaks were sown about five yards apart. In the fourth year ofthe plantation three truffles were found; at the date of the reportthe trees were nine years old, and over a yard in height. Sows wereemployed to search for the truffles. Although these plantationsconsist both of the evergreen and common oak, truffles cannot begathered at the base of the latter species, it so happening that itarrives later at a state of production. The common oak, however, produces truffles like the evergreen oak, this report states, for agreat number of the natural truffle-grounds at Vaucluse are plantedwith common oaks. It is remarked that the truffles produced fromthese are larger but less regular than those of the evergreen oak, which are smaller, but nearly always spherical. The truffles aregathered at two periods of the year; in May only white truffles are tobe found, which never blacken and have no odour; they are dried andsold for seasoning. The black truffles (_Tuber melanosporum_) commenceforming in June, enlarging towards the frosty season; then they becomehard, and acquire all their perfume. They are dug a month before and amonth after Christmas. It is also asserted that truffles are producedabout the vine, or at any rate that the association of the vine isfavourable to the production of truffles, because truffle-plots nearvines are very productive. The observation of this decided M. Rousseauto plant a row of vines between the oaks. The result of thisexperiment altogether does not appear to have been by any meansflattering, for at the end of eight years only little more thanfifteen pounds were obtained from a hectare of land, which, if valuedat 45 francs, would leave very little profit. M. Rousseau also calledattention to a meadow manured (_sic_) with parings of truffles, whichwas said to have given prodigious results. 

The cultivation of minute fungi for scientific purposes has beenincidentally alluded to and illustrated in foregoing chapters, andconsequently will not require such full and particular detailshere. Somewhat intermediately, we might allude to the species of_Sclerotium_, which are usually compact, externally blackish, rounded or amorphous bodies, consisting of a cellular mass of thenature of a concentrated mycelium. Placed in favourable conditions, these forms of _Sclerotium_ will develop the peculiar species offungus belonging to them, but in certain cases the production is morerapid and easy than in others. In this country, Mr. F. Currey hasbeen the most successful in the cultivation of _Sclerotia_. Themethod adopted is to keep them in a moist, somewhat warm, butequable atmosphere, and with patience await the results. Thewell-known ergot of rye, wheat, and other grasses may be socultivated, and Mr. Currey has developed the ergot of the commonreed by keeping the stem immersed in water. The final conditionsare small clavate bodies of the order _Sphæriacei_, belonging tothe genus _Claviceps_. The _Sclerotium_ of the _Eleocharis_ has beenfound in this country, but we are not aware that the _Claviceps_developed from it has been met with or induced by cultivation. Onemethod recommended for this sort of experiment is to fill agarden-pot half full of crocks, over which to place sphagnum brokenup until the pot is nearly full, on this to place the _Sclerotia_, and cover with silver sand; if the pot is kept standing in a pan ofwater in a warm room, it is stated that production will ensue. Ergot of the grasses will not always develop under these conditions, but perseverance may ultimately ensure success. 

A species of _Sclerotium_ on the gills of dead Agarics originates_Agaricus tuberosus_, another _Agaricus cirrhatus_, [J] but this shouldbe kept _in situ_ when cultivated artificially, and induced to developwhilst still attached to the rotten Agarics. _Peziza tuberosa_, inlike manner, is developed from _Sclerotia_, usually found buried inthe ground in company with the roots of _Anemone nemorosa_. At onetime it was supposed that some relationship existed between the rootsof the anemone and the _Sclerotia_. From another _Sclerotium_, foundin the stems of bulrushes, Mr. Currey has developed a species of_Peziza_, which has been named _P. Curreyana_. [K] This _Peziza_ hasbeen found growing naturally from the _Sclerotia_ imbedded in thetissue of common rushes. De Bary has recorded the development of_Peziza Fuckeliana_ from a _Sclerotium_ of which the conidia take theform of a species of _Polyactis_. _Peziza ciborioides_ is developedfrom a _Sclerotium_ found amongst dead leaves; and recently we havereceived from the United States an allied _Peziza_ which originatedfrom the _Sclerotia_ found on the petals of _Magnolia_, and which hasbeen named _Peziza gracilipes_, Cooke, from its very slender, thread-like stem. Other species of _Peziza_ are also known to bedeveloped from similar bases, and these Fuckel has associatedtogether under a proposed new genus with the name of _Sclerotinia_. Two or three species of _Typhula_, in like manner, spring from formsof _Sclerotium_, long known as _Sclerotium complanatum_ and_Sclerotium scutellatum_. Other forms of _Sclerotium_ are known, fromone of which, found in a mushroom-bed, Mr. Currey developed _Xylariavaporaria_, B. , by placing it on damp sand covered with a bellglass. [L] Others, again, are only known in the sclerotioid state, suchas the _Sclerotium stipitatum_ found in the nests of white ants inSouth India. [M] From what is already known, however, we feel justifiedin the conclusion that the so-called species of _Sclerotium_ are asort of compact mycelium, from which, under favourable conditions, perfect fungi may be developed. Mr. Berkeley succeeded in raising fromthe minute _Sclerotium_ of onions, which looks like grains of coarsegunpowder, a species of _Mucor_. This was accomplished by placing athin slice of the _Sclerotium_ in a drop of water under a glass slide, surrounded by a pellicle of air, and luted to prevent evaporation andexternal influences. [N]

As to the cultivation of moulds and _Mucors_, one great difficulty hasto be encountered in the presence or introduction of foreign spores tothe matrix employed for their development. Bearing this in mind, extensive cultivations may be made, but the conditions must influencethe decision upon the results. Rice paste has been used with advantagefor sowing the spores of moulds, afterwards keeping them covered fromexternal influences. In cultivation on rice paste of rare species, theexperimenter is often perplexed by the more rapid growth of the commonspecies of _Mucor_ and _Penicillium_. Mr. Berkeley succeeded indeveloping up to a certain point the fungus of the Madura Foot, butthough perfect sporangia were produced, the further development wasmasked by the outgrowth of other species. In like manner, orangejuice, cut surfaces of fruits, slices of potato tubers, etc. , havebeen employed. Fresh, horse-dung, placed under a bell glass and keptin a humid atmosphere, will soon be covered with _Mucor_, and in likemanner the growth of common moulds upon decayed fruit may be watched;but this can hardly be termed cultivation unless the spores of someindividual species are sown. Different solutions have been proposedfor the growth of such conditions as the cells which inducefermentation, to which yeast plants belong. A fly attacked by _Empusamuscæ_, if immersed in water, will develop one of the _Saprolegniæ_. 

The _Uredines_ and other epiphyllous _Coniomycetes_ will readilygerminate by placing the leaf which bears them on damp sand, orkeeping them in a humid atmosphere. Messrs. Tulasne and De Bary have, in their numerous memoirs, detailed the methods adopted by themfor different species, both for germination of the pseudospores andfor impregnating healthy foster plants. The germination of thepseudospores of the species of _Podisoma_ may easily be induced, andsecondary fruits obtained. The germination of the spores of _Tilletia_is more difficult to accomplish, but this may be achieved. Mr. Berkeley found no difficulty, and had the stem impregnated as well asthe germen. On the other hand, the pseudospores of _Cystopus_, when sown in water on a slip of glass, will soon produce thecurious little zoospores in the manner already described. 

The sporidia of the _Discomycetes_, and some of the _Sphæriacei_, germinate readily in a drop of water on a slip of glass, although notproceeding further than the protrusion of germ-tubes. A form of slidehas been devised for growing purposes, in which the large coveringglass is held in position, and one end of the slip being kept immersedin a vessel of water, capillary attraction keeps up the supply for anindefinite period, so that there is no fear of a check from theevaporation of the fluid. Even when saccharine solutions are employedthis method may be adopted. 

The special cultivation of the _Peronosporei_ occupied the attentionof Professor De Bary for a long time, and his experiences aredetailed in his memoir on that group, [O] but which are too longfor quotation here, except his observations on the development of thethreads of _Peronospora infestans_ on the cut surface of the tubersof diseased potatoes. When a diseased potato is cut and sheltered fromdessication, the surface of the slice covers itself with the myceliumand conidiiferous branches of _Peronospora_, and it can easily beproved that these organs originate from the intercellulary tubes ofthe brown tissue. The mycelium that is developed upon these slicesis ordinarily very vigorous; it often constitutes a cottony mass of athickness of many millimetres, and it gives out conidiiferousbranches, often partitioned, and larger and more branched than thoseobserved on the leaves. The appearance of these fertile branchesordinarily takes place at the end of from twenty-four to forty-eighthours; sometimes, nevertheless, one must wait for many days. Thesephenomena are observed in all the diseased tubercles withoutexception, so long as they have not succumbed to putrefaction, which arrests the development of the parasite and kills it. 

Young plants of the species liable to attack may be inoculated withthe conidia of the species of _Peronospora_ usually developed on thatparticular host, in the same manner that young cruciferous plants, watered with an infusion of the spores of _Cystopus candidus_, willsoon exhibit evidence of attack from the white rust. 

It is to the cultivation and close investigation of the growth andmetamorphoses of the minute fungi that we must look for the mostimportant additions which have yet to be made to our knowledge of thelife-history of these most complex and interesting organisms. 

 [A] Experiments were made at Belvoir, by Mr. Ingram, in the cultivation of several species of _Agaricini_, but without success, and a similar fate attended some spawn of a very superior kind from the Swan River, which was submitted to the late Mr. J. Henderson. No result was obtained at Chiswick, either from the cultivation of truffles or from the inoculation of grass-plots with excellent spawn. Mr. Disney's experiments at the Hyde, near Ingatestone, were made with dried truffles, and were not likely to succeed. The Viscomte Nôe succeeded in obtaining abundant truffles, in an enclosed portion of a wood fenced from wild boars, by watering the ground with an infusion of fresh specimens; but it is possible that as this took place in a truffle country, there might have been a crop without any manipulation. Similar trials, and it is said successfully, have been made with _Boletus edulis_. Specimens of prepared truffle-spawn were sent many years since to the "Gardener's Chronicle, " but they proved useless, if indeed they really contained any reliable spawn. 

 [B] Robinson, "On Mushroom Culture, " London, 1870. Cuthill, "On the Cultivation of the Mushroom, " 1861. Abercrombie, "The Garden Mushroom; its Culture, &c. " 1802. 

 [C] This has, however, not been confirmed, and is considered (how justly we cannot say) a "canard. "

 [D] This method is pursued with great success by Mr. Ingram, at Belvoir, and by Mr. Gilbert, at Burleigh. 

 [E] Cuthill, "Treatise on the Cultivation of the Mushroom, " p. 9. 

 [F] Mr. Berkeley lately recommended, at one of the meetings of the Horticultural Society at South Kensington, that the railway arches should be utilized for the cultivation of mushrooms. 

 [G] Badham, "Esculent Funguses, " 1st ed. P. 43. 

 [H] Broome, "On Truffle Culture, " in "Journ. Hort. Soc. " i. P. 15 (1866). 

 [I] No faith, however, is, in general, placed on these treatises, as they were merely conjectural. 

 [J] Dr. Bull has been very successful in developing the _Sclerotium_ of _Agaricus cirrhatus_. 

 [K] Currey, "On Development of _Sclerotium roseum_, " in "Journ. Linn. Soc. " vol. I. P. 148. 

 [L] Currey, in "Linn. Trans. " xxiv. Pl. 25, figs. 17, 26. 

 [M] Berkeley, "On Two Tuberiform Veg. Productions from Travancore, " in "Trans. Linn. Soc. " vol. Xxiii. P. 91. 

 [N] Berkeley, "On a Peculiar Form of Mildew in Onions, " "Journ. Hort. Soc. " vol. Iii p. 91. 

 [O] De Bary, "Ann. Des Sci. Nat. " 4th series, vol. Xx. 

XIII. 

GEOGRAPHICAL DISTRIBUTION. 

Unfortunately no complete or satisfactory account can be given of thegeographical distribution of fungi. The younger Fries, [A] with all thefacilities at his disposal which the lengthened experience and largecollections of his father afforded, could only give a very imperfectoutline, and now we can add very little to what he has given. Thecause of this difficulty lies in the fact that the Mycologic Flora ofso large a portion of the world remains unexplored, not only in remoteregions, but even in civilized countries where the Phanerogamic Florais well known. Europe, England, Scotland, and Wales are as wellexplored as any other country, but Ireland is comparatively unknown, no complete collection having ever been made, or any at leastpublished. Scandinavia has also been well examined, and the northernportions of France, with Belgium, some parts of Germany and Austria, in Russia the neighbourhood of St. Petersburg, and parts of Italy andSwitzerland. Turkey in Europe, nearly all Russia, Spain, and Portugalare almost unknown. As to North America, considerable advances havebeen made since Schweinitz by Messrs. Curtis and Ravenel, but theircollections in Carolina cannot be supposed to represent the whole ofthe United States; the small collections made in Texas, Mexico, etc. , only serve to show the richness of the country, not yet halfexhausted. It is to be hoped that the young race of botanists in theUnited States will apply themselves to the task of investigating theMycologic Flora of this rich and fertile region. In Central Americavery small and incomplete collections have as yet been made, and thesame may be said of South America and Canada. Of the whole extent ofthe New World, only the Carolina States of North America can really besaid to be satisfactorily known. Asia is still less known, the wholeof our vast Indian Empire being represented by the collections made byDr. Hooker in the Sikkim Himalayas, and a few isolated specimens fromother parts. Ceylon has recently been removed from the category of theunknown by the publication of its Mycologic Flora. [B] All that isknown of Java is supplied by the researches of Junghuhn; whilst allthe rest is completely unknown, including China, Japan, Siam, theMalayan Peninsula, Burmah, and the whole of the countries in the northand west of India. A little is known of the Philippines, and theIndian Archipelago, but this knowledge is too fragmentary to be ofmuch service. In Africa no part has been properly explored, with theexception of Algeria, although something is known of the Cape of GoodHope and Natal. The Australasian Islands are better represented in theFloras published of those regions. Cuba and the West Indies generallyare moderately well known from the collections of Mr. C. Wright, whichhave been recorded in the journal of the Linnæan Society, and in thesame journal Mr. Berkeley has described many Australian species. 

It will be seen from the above summary how unsatisfactory it must beto give anything like a general view of the geographical distributionof fungi, or to estimate at all approximately the number of species onthe globe. Any attempt, therefore, must be made and accepted subjectto the limitations we have expressed. 

The conditions which determine the distribution of fungi are notprecisely those which determine the distribution of the higher plants. In the case of the parasitic species they may be said to follow thedistribution of their foster-plants, as in the case of the rust, smut, and mildew of the cultivated cereals, which have followed thosegrains wherever they have been distributed, and the potato disease, which is said to have been known in the native region of the potatoplant before it made its appearance in Europe. We might also allude to_Puccinia malvacearum_, Ca. , which was first made known as a SouthAmerican species; it then travelled to Australia, and at length toEurope, reaching England the next year after it was recorded on theContinent. In the same manner, so far as we have the means of knowing, _Puccinia Apii_, Ca. , was known on the Continent of Europe for sometime before it was detected on the celery plants in this country. Experience seems to warrant the conclusion that if a parasite affectsa certain plant within a definite area, it will extend in time beyondthat area to other countries where the foster-plant is found. Thisview accounts in some part for the discovery of species in thiscountry, year after year, which had not been recorded before; someallowance being made for the fact that an increased number ofobservers and collectors may cause the search to be more complete, yetit must be conceded that the migration of Continental species must tosome extent be going on, or how can it be accounted for that suchlarge and attractive fungi as _Sparassis crispa_, _Helvellas gigas_, and _Morchella crassipes_ had never been recorded till recently, oramongst parasitic species such as the two species of _Puccinia_ abovenamed? In the same manner it is undoubtedly true that species which atone time were common gradually become somewhat rare, and at lengthnearly extinct. We have observed this to apply to the larger speciesas well as to the microscopic in definite localities. For instance, _Craterellus cornucopioides_ some ten years ago appeared in one wood, at a certain spot, by hundreds, whereas during the past three or fouryears we have failed to find a single specimen. As many years since, and in two places, where the goat's-beard was abundant, as it is now, we found nearly half the flowering heads infested with _Ustilagoreceptaculorum_, but for the past two or three years, although we havesought it industriously, not a single specimen could be found. It iscertain that plants found by Dickson, Bolton, and Sowerby, have notbeen detected since, whilst it is not improbable that species commonwith us may be very rare fifty years hence. In this manner it wouldreally appear that fungi are much more liable than flowering plants toshift their localities, or increase and diminish in number. 

The fleshy fungi, _Agaricini_ and _Boleti_ especially, are largelydependent upon the character of woods and forests. When theundergrowth of a wood is cleared away, as it often is every few years, it is easy to observe a considerable difference in the fungi. Speciesseem to change places, common ones amongst a dense undergrowth arerare or disappear with the copsewood, and others not observed beforetake their place. Some species, too, are peculiar to certain woods, such as beech woods and fir woods, and their distribution willconsequently depend very much on the presence or absence of suchwoods. Epiphytal species, such as _Agaricus ulmarius_, _Agaricusmucidus_, and a host of others, depend on circumstances which do notinfluence the distribution of flowering plants. It may be assumed thatsuch species as flourish in pastures and open places are subject tofewer adverse conditions than those which affect woods and forests. 

Any one who has observed any locality with reference to its MycologicFlora over a period of years will have been struck with the differencein number and variety caused by what may be termed a "favourableseason, " that is, plenty of moisture in August with warm weatherafterwards. Although we know but little of the conditions ofgermination in Agarics, it is but reasonable to suppose that asuccession of dry seasons will considerably influence the flora of anylocality. Heat and humidity, therefore, are intimately concerned inthe mycologic vegetation of a country. Fries has noted in his essaythe features to which we have alluded. "The fact, " he says, "must notbe lost sight of that some species of fungi which have formerly beencommon in certain localities may become, within our lifetime, more andmore scarce, and even altogether cease to grow there. The cause ofthis, doubtless, is the occurrence of some change in the physicalconstitution of a locality, such as that resulting from thedestruction of a forest, or from the drainage, by ditches andcuttings, of more or less extensive swamps, or from the cultivation ofthe soil--all of them circumstances which cause the destruction of theprimitive fungaceous vegetation and the production of a new one. If wecompare the fungal flora of America with that of European countries, we observe that the former equals, in its richness and the variety ofits forms, that of the phanerogamous flora; it is probable, however, that, in the lapse of more or fewer years, this richness willdecrease, in consequence of the extension of cultivation--as isillustrated, indeed, in what has already taken place in the morethickly peopled districts, as, for example, in the vicinity of NewYork. "

Although heat and humidity influence all kinds of vegetation, yet heatseems to exert a less, and humidity a greater, influence on fungi thanon other plants. It is chiefly during the cool moist autumnal weatherthat the fleshy fungi flourish most vigorously in our own country, andwe observe their number to increase with the humidity of the season. Rain falls copiously in the United States, and this is one of the mostfruitful countries known for the fleshy fungi. Hence it is areasonable deduction that moisture is a condition favourable to thedevelopment of these plants. The _Myxogastres_, according to Dr. HenryCarter, are exceedingly abundant--in individuals, at least, if not inspecies--in Bombay, and this would lead to the conclusion that themembers of this group are influenced as much by heat as humidity intheir development, borne out by the more plentiful appearance of thespecies in this country in the warmer weather of summer. 

In the essay to which we have alluded, Fries only attempts therecognition of two zones in his estimate of the distribution of fungi, and these are the temperate and tropical. The frigid zone produces nopeculiar types, and is poor in the number of species, whilst noessential distinction can be drawn between the tropical andsub-tropical with our present limited information. Even these twozones must not be accepted too rigidly, since tropical forms will insome instances, and under favourable conditions, extend far upwardsinto the temperate zone. 

"In any region whatever, " writes Fries, "it is necessary, in the firstinstance, to draw a distinction between its open naked plains andits wooded tracts. In the level open country there is a more rapidevaporation of the moisture by the conjoined action of the sun andwind; whence it happens that such a region is more bare of fungithan one that is mountainous or covered by woods. On the other hand, plains possess several species peculiar to themselves; as, forexample, _Agaricus pediades_, certain _Tricholomata_, and, aboveall, the family _Coprini_, of which they may be regarded as thespecial habitat. The species of this family augment in number, inany given country, in proportion to the extent and degree of itscultivation; for instance, they grow more luxuriantly in theprovince of Scania, in Sweden--a district farther distinguishedabove all others by its cultivation and fertility. In well-woodedcountries moisture is retained a much longer time, and, as aresult, the production of fungi is incomparably greater; and it ishere desirable to make a distinction between the fungi growing inforests of resinous-wooded trees (_Coniferæ_) and those whichinhabit woods of other trees, for these two descriptions of forestsmay be rightly regarded, as to their fungaceous growths, as twodifferent regions. Beneath the shade of _Coniferæ_, fungi areearlier in their appearance; so much so, that it often happens theyhave attained their full development when their congeners in forestsof non-resinous trees have scarcely commenced their growth. In woodsof the latter sort, the fallen leaves, collected in thick layers, actas an obstacle to the soaking of moisture into the earth, andthereby retard the vegetation of fungi; on the other hand, suchwoods retain moisture longer. These conditions afford to severallarge and remarkable species the necessary time for development. Thebeech is characteristic of our own region, but, further north thistree gives place to the birch. Coniferous woods are, moreover, divisible into two regions--that of the pines and that of the firs. The latter is richer in species than the former, because, as is wellknown, fir-trees flourish in more fertile and moister soils. Whether, with respect to the South of Europe, other subdivisions intoregions are required, we know not; still less are we able todecide on the like question in reference to the countries beyondEurope. "[C]

In very cold countries the higher fungi are rare, whilst in tropicalcountries they are most common at elevations which secure a temperateclimate. In Java, Junghuhn found them most prolific at an elevation of3, 000 to 5, 000 feet; and in India, Dr. Hooker remarked that they weremost abundant at an elevation of 7, 000 to 8, 000 feet above the sealevel. 

For the higher fungi we must be indebted to the summary made by Fries, to which we have little to add. 

The genus _Agaricus_ occupies the first place, and surpasses, in thenumber of species, all the other generic groups known. It appears, from our present knowledge, that the _Agarici_ have their geographiccentre in the temperate zone, and especially in the colder portion ofthat zone. It is a curious circumstance that all the extra-Europeanspecies of this genus _Agaricus_ may be referred to various Europeansubgenera. 

In tropical countries it appears that the _Agarici_ occupy only asecondary position in relation to other genera of fungi, such as_Polyporus_, _Lenzites_, etc. North America, on the other hand, isricher in species of _Agaricus_ than Europe; for whilst the majorityof typical forms are common to both continents, America furtherpossesses many species peculiar to itself. In the temperate zone, soclose is the analogy prevailing between the various countries inrespect to the _Agaricini_, that from Sweden to Italy, and as well inEngland as North America, the same species are to be found. Of 500_Agaricini_ met with in St. Petersburg, there are only two or threewhich have not been discovered in Sweden; and again, of fifty speciesknown in Greenland, there is not one that is not common in Sweden. Thesame remarks hold good in reference to the _Agaricini_ of Siberia, Kamtschatka, the Ukraine, etc. The countries bordering upon theMediterranean possess, however, several peculiar types; and Easternand Western Europe present certain dissimilarities in their Agaricinhabitants. Several species, for example, of _Armillaria_ and_Tricholoma_, which have been found in Russia, have been met with inSweden only in Upland, that is, in the most eastern province; all thespecies which belong to the so-called _abiegno-rupestres_ and_pineto-montanæ_ regions of Sweden are wanting in England; and it isonly in Scotland that the species of northern mountainous andpine-bearing regions are met with--a circumstance explicable from thesimilarity in physical features between Sweden and the northernportions of Great Britain. 

The species of _Coprinus_ appear to find suitable habitats in everyquarter of the globe. 

The _Cortinariæ_ predominate in the north; they abound in Northernlatitudes, especially on wooded hills; but the plains offer also somepeculiar species which flourish during the rainy days of August andSeptember. In less cold countries they are more scarce or entirelyabsent. The species of the genus _Hygrophorus_ would at first seem tohave a similar geographical distribution to those of the last group;but this is really not the case, for the same _Hygrophori_ are to befound in nearly every country of Europe, and even the hottestcountries (and those under the equator) are not destitute ofrepresentatives of this wide-spread genus. 

The _Lactarii_, which are so abundant in the forests of Europe andNorth America, appear to grow more and more scarce towards both thesouth and north. The same may be stated in regard to _Russula_. 

The genus _Marasmius_ is dispersed throughout the globe, andeverywhere presents numerous species. In inter-tropical countries theyare still more abundant, and exhibit peculiarities in growth whichprobably might justify their collection into a distinct group. 

The genera _Lentinus_ and _Lenzites_ are found in every region of theworld; their principal centre, however, is in hot countries, wherethey attain a splendid development. On the contrary, towards the norththey rapidly decrease in number. 

The _Polypori_ constitute a group which, unlike that of the Agarics, especially belongs to hot countries. The _Boleti_ constitute the onlyexception to this rule, since they select the temperate and frigidzones for their special abode, and some of them at times find theirway to the higher regions of the Alps. No one can describe theluxuriance of the torrid zone in _Polypori_ and _Trametes_, genera of_Hymenomycetes_, which flourish beneath the shade of the virginforests, where perpetual moisture and heat promote their vegetationand give rise to an infinite variety of forms. But though the genus_Polyporus_, which rivals _Agaricus_ in the number of its species, inhabits, in preference, warm climates at large, it neverthelessexhibits species peculiar to each country. This arises from thecircumstance that the _Polypori_, for the most part, live upon trees, and are dependent on this or that particular tree for a suitablehabitat; and the tropical flora being prolific in trees of all kinds, a multitude of the most varied forms of these fungi is a necessaryconsequence. _Hexagona_, _Favolus_, and _Laschia_ are common ininter-tropical countries, but they are either entirely absent orextremely rare in temperate climes. 

When the majority of the species of a genus are of a fleshyconsistence, it may generally be concluded that that genus belongs toa Northern region, even if it should have some representatives inlands which enjoy more sunshine. Thus the _Hydna_ are the principalornaments of Northern forests, where they attain so luxuriant a growthand beauty that every other country must yield the palm to Sweden inrespect to them. In an allied genus, that of _Irpex_, the textureassumes a coriaceous consistence, and we find its species to be moreespecially inhabitants of warm climates. 

Most of the genera of _Auricularini_ are cosmopolitan, and the same istrue of some species of _Stereum_, of _Corticium_, etc. , which are metwith in countries of the most different geographical position. Intropical countries, these genera of fungi assume the most curious andluxuriant forms. The single and not considerable genus _Cyphella_appears to be pretty uniformly distributed over the globe. The_Clavariæi_ are equally universal in their diffusion, although moreplentiful in the north; however, the genus _Pterula_ possesses severalexotic forms, though in Europe it has but two representative species. That beautiful genus of _Hymenomycetes_, _Sparassis_, occupies asimilar place next the _Clavariæi_, and is peculiarly a production ofthe temperate zone and of the coniferous region. 

The fungi which constitute the family of _Tremellini_ prevail inEurope, Asia, and North America, and exhibit no marked differencesamongst themselves, notwithstanding the distances of the severalcountries apart. It must, however, be stated that the _Hirneolæ_ forthe most part inhabit the tropics. 

We come now to the _Gasteromycetes_--an interesting family, whichexhibits several ramifications or particular series of developments. The most perfect _Gasteromycetes_ almost exclusively belong to thewarmer division of the temperate, and to the tropical zone, wheretheir vegetation is the most luxuriant. Of late the catalogue of thesefungi has been greatly enriched by the addition of numerous genera andspecies, proper to hot countries, previously unknown. Not uncommonly, the exotic floras differ from ours, not merely in respect of thespecies, but also of the genera of _Gasteromycetes_. It must, besides, be observed that this family is rich in well-defined genera, thoughvery poor in distinct specific forms. Among the genera found inEurope, many are cosmopolitan. 

The _Phalloidei_ present themselves in the torrid zone under the mostvaried form and colouring, and comprise many genera rich in species. In Europe their number is very restricted. As we advance northwardthey decrease rapidly, so that the central districts of Sweden possessonly a single species, the _Phallus impudicus_, and even this solitaryrepresentative of the family is very scarce. In Scania, the mostsouthern province of Sweden, there is likewise but one genus and onespecies belonging to it, viz. , the _Mutinus caninus_. Among othermembers of the _Phalloidei_, may be further mentioned the _Lysurus_ ofChina, the _Aseröe_ of Van Diemen's Land, and the _Clathrus_, onespecies of which, _C. Cancellatus_, has a very wide geographicalrange; for instance, it is found in the south of Europe, in Germany, and in America; it occurs also in the south of England and the Isle ofWight; whereas the other species of this genus have a very limiteddistribution. 

The _Tuberacei_[D] are remarkable amongst the fungi in being all ofthem more or less hypogeous. They are natives of warm countries, andare distributed into numerous genera and species. The _Tuberacei_constitute in Northern latitudes a group of fungi very poor inspecific forms. The few species of the _Hymenogastres_ belonging toSweden, with the exception of _Hyperrhiza variegata_ and one exampleof the genus _Octaviana_, are confined to the southern provinces. Thegreater part of this group, like the _Lycoperdacei_, are met with inthe temperate zone. Most examples of the genus _Lycoperdon_ arecosmopolitan. 

The _Nidulariacei_ and the _Trichodermacei_ appear to be scatteredover the globe in a uniform manner, although their species are noteverywhere similar. The same statement applies to the _Myxogastres_, which are common in Lapland, and appear to have their central point ofdistribution in the countries within the temperate zone. At the sametime, they are not wanting in tropical regions, notwithstanding thatthe intensity of heat, by drying up the mucilage which serves as themedium for the development of their spores, is opposed to theirdevelopment. [E]

Of the _Coniomycetes_, the parasitic species, as the _Cæomacei_, the_Pucciniei_, and the _Ustilagines_, accompany their foster-plants intoalmost all regions where they are found; so that smut, rust, andmildew are as common on wheat and barley in the Himalayas and in NewZealand as in Europe and America. _Ravenelia_ and _Cronartium_ onlyoccur in the warmer parts of the temperate zone, whilst _Sartvellia_is confined to Surinam. Species of _Podisoma_ and _Roestelia_ are ascommon in the United States as in Europe, and the latter appears alsoat the Cape and Ceylon. Wherever species of _Sphæria_ occur there the_Sphæronemei_ are found, but they do not appear, according to ourpresent knowledge, to be so plentiful in tropical as in temperatecountries. The _Torulacei_ and its allies are widely diffused, andprobably occur to a considerable extent in tropical countries. 

_Hyphomycetes_ are widely diffused; some species are peculiarlycosmopolitan, and all seem to be less influenced by climaticconditions than the more fleshy fungi. The _Sepedoniei_ arerepresented by at least one species wherever _Boletus_ is found. The_Mucedines_ occur everywhere in temperate and tropical regions, _Penicillium_ and _Aspergillus_ flourishing as much in the latter asin the former. _Botrytis_ and _Peronospora_ are almost as widelydiffused and as destructive in warmer as in temperate countries, andalthough from difficulty in preservation the moulds are seldomrepresented to any extent in collections, yet indications of theirpresence constantly occur in connection with other forms, to such anextent as to warrant the conclusion that they are far from uncommon. The _Dematiei_ are probably equally as widely diffused. Species of_Helminthosporium_, _Cladosporium_, and _Macrosporium_ seem to be ascommon in tropical as temperate climes. The distribution of thesefungi is imperfectly known, except in Europe and North America, buttheir occurrence in Ceylon, Cuba, India, and Australasia indicated acosmopolitan range. _Cladosporium herbarum_ would seem to occureverywhere. The _Stilbacei_ and _Isariacei_ are not less widelydiffused, although as yet apparently limited in species. _Isaria_occurs on insects in Brazil as in North America, and species of_Stilbum_ and _Isaria_ are by no means rare in Ceylon. 

The _Physomycetes_ have representatives in the tropics, species of_Mucor_ occurring in Cuba, Brazil, and the southern states of NorthAmerica, with the same and allied genera in Ceylon. _Antennaria_ and_Pisomyxa_ seem to reach their highest development in hot countries. 

The _Ascomycetes_ are represented everywhere, and although certaingroups are more tropical than others, they are represented in allcollections. The fleshy forms are most prolific in temperatecountries, and only a few species of _Peziza_ affect the tropics, yetin elevated districts of hot countries, such as the Himalayas ofIndia, _Peziza_, _Morchella_, and _Geoglossum_ are found. Two or threespecies of _Morchella_ are found in Kashmir, and at least one or twoin Java, where they are used as food. The genus _Cyttaria_ is confinedto the southern parts of South America and Tasmania. The United Statesequal if they do not exceed European states in the number of speciesof the _Discomycetes_. The _Phacidiacei_ are not confined to temperateregions, but are more rare elsewhere. _Cordierites_ and _Acroseyphus_(?) are tropical genera, the former extending upwards far into thetemperate zone, as _Hysterium_ and _Rhytisma_ descend into thetropics. Amongst the _Sphæriacei_, _Xylaria_ and _Hypoxylon_ are wellrepresented in the tropics, such species as _Xylaria hypoxylon_ and_Xylaria corniformis_ being widely diffused. In West Africa anAmerican species of _Hypoxylon_ is amongst the very few specimens thathave ever reached us from the Congo, whilst _H. Concentricum_ and_Ustulina vulgaris_ seem to be almost cosmopolitan. _Torrubia_ and_Nectria_ extend into the tropics, but are more plentiful in temperateand sub-tropical countries. _Dothidea_ is well represented in thetropics, whilst of the species of _Sphæria_ proper, only the moreprominent have probably been secured by collectors; hence the_Superficiales_ section is better represented than the _Obtectæ_, andthe tropical representatives of foliicolous species are but few. _Asterina_, _Micropeltis_, and _Pemphidium_ are more sub-tropical thantemperate forms. The _Perisporiacei_ are represented almosteverywhere; although species of _Erysiphe_ are confined to temperateregions, the genus _Meliola_ occupies its place in warmer climes. Finally, the _Tuberacei_, which are subterranean in their habits, arelimited in distribution, being confined to the temperate zone, neverextending far into the cold, and but poorly represented out of Europe. One species of _Mylitta_ occurs in Australia, another in China, andanother in the Neilgherries of India; the genus _Paurocotylis_ isfound in New Zealand and Ceylon. It is said that a species of _Tuber_is found in Himalayan regions, but in the United States, as well as inNorthern Europe, the _Tuberacei_ are rare. 

The imperfect condition of our information concerning very manycountries, even of those partially explored, must render any estimateor comparison of the floras of those countries most fragmentary andimperfect. Recently, the mycology of our own islands has been moreclosely investigated, and the result of many years' application on thepart of a few individuals has appeared in a record of some 2, 809species, [F] to which subsequent additions have been made, to an extentof probably not much less than 200 species, [G] which would bring thetotal to about 3, 000 species. The result is that no materialdifference exists between our flora and that of Northern France, Belgium, and Scandinavia, except that in the latter there are a largernumber of Hymenomycetal forms. The latest estimates of the flora ofScandinavia are contained in the works of the illustrious Fries, [H]but these are not sufficiently recent, except so far as regards the_Hymenomycetes_, for comparison of numbers with British species. 

The flora of Belgium has its most recent exponent in the posthumouswork of Jean Kickx; but the 1, 370 species enumerated by him can hardlybe supposed to represent the whole of the fungi of Belgium, for insuch case it would be less than half the number found in the BritishIslands, although the majority of genera and species are the same. [I]

For the North of France no one could have furnished a more completelist, especially of the microscopic forms, than M. Desmazières, but weare left to rely solely upon his papers in "Annales des Sc. Nat. " andhis published specimens, which, though by no means representative ofthe fleshy fungi, are doubtless tolerably exhaustive of the minutespecies. From what we know of French _Hymenomycetes_, their number andvariety appear to be much below those of Great Britain. [J]

The mycologic flora of Switzerland has been very well investigated, although requiring revision. Less attention having been given to theminute forms, and more to the _Hymenomycetes_ than in France andBelgium, may in part account for the larger proportion of the latterin the Swiss flora. [K]

In Spain and Portugal scarce anything has been done; the smallcollection made by Welwitsch can in no way be supposed to representthe Peninsula. 

The fungi of Italy[L] include some species peculiar to the Peninsula. The _Tuberacei_ are well represented, and although the _Hymenomycetes_do not equal in number those of Britain or Scandinavia, a goodproportion is maintained. 

Bavaria and Austria (including Hungary, and the Tyrol) are being morethoroughly investigated than hitherto, but the works of Schæffer, Tratinnick, Corda, and Krombholz have made us acquainted with thegeneral features of their mycology, [M] to which more recent lists andcatalogues have contributed. [N] The publication of dried specimens hasof late years greatly facilitated acquaintance with the fungi ofdifferent countries in Europe, and those issued by Baron Thümen fromAustria do not differ materially from those of Northern Germany, although Dr. Rehm has made us acquainted with some new and interestingforms from Bavaria. [O]

Russia is to a large extent unknown, except in its northernborders. [P] Karsten has investigated the fungi of Finland, [Q] andadded considerably to the number of _Discomycetes_, for which theclimate seems to be favourable; but, as a whole, it may be concludedthat Western and Northern Europe are much better explored than theEastern and South-Eastern, to which we might add the South, if Italybe excepted. 

We have only to add, for Europe, that different portions of the Germanempire have been well worked, from the period of Wallroth to thepresent. [R] Recently, the valley of the Rhine has been exhaustivelyexamined by Fuckel;[S] but both Germany and France suffered checksduring the late war which made their mark on the records of sciencenot so speedily to be effaced. Denmark, with its splendid Flora Danicastill in progress, more than a century after its commencement, [T] hasa mycologic flora very like to that of Scandinavia, which is as wellknown. 

If we pass from Europe to North America, we find there a mycologicflora greatly resembling that of Europe, and although Canada and theextreme North is little known, some parts of the United States havebeen investigated. Schweinitz[U] first made known to any extent theriches of this country, especially Carolina, and in this state thelate Dr. Curtis and H. W. Ravenel continued their labours. With theexception of Lea's collections in Cincinnati, Wright's in Texas, andsome contributions from Ohio, Alabama, Massachusetts, and New York, agreat portion of this vast country is mycologically unknown. It isremarkably rich in fleshy fungi, not only in _Agaricini_, but also in_Discomycetes_, containing a large number of European forms, mostlyEuropean genera, with many species at present peculiar to itself. Tropical forms extend upwards into the Southern States. 

The islands of the West Indies have been more or less examined, butnone so thoroughly as Cuba, at first by Ramon de la Sagra, andafterwards by Wright. [V] The three principal genera of _Hymenomycetes_represented are _Agaricus_, _Marasmius_, and _Polyporus_, representedseverally by 82, 51, and 120 species, amounting to more than half theentire number. Of the 490 species, about 57 per cent. Are peculiar tothe island; 13 per cent. Are widely dispersed species; 12 per cent. Are common to the island and Central America, together with the warmerparts of South America and Mexico; 3 per cent. Are common to it withthe United States, especially the Southern; while 13 per cent. AreEuropean species, including, however, 13 which may be considered ascosmopolitan. Some common tropical species do not occur, and, on thewhole, the general character seems sub-tropical rather than tropical. Many of the species are decidedly those of temperate regions, or atleast nearly allied. Perhaps the most interesting species are thosewhich occur in the genera _Craterellus_ and _Laschia_, the lattergenus, especially, yielding several new forms. The fact that theclimate is, on the whole, more temperate than that of some otherislands in the same latitudes, would lead us to expect the presence ofa comparatively large number of European species, or those which arefound in the more northern United States, or British North America, and may account for the fact that so small a proportion of speciesshould be identical with those from neighbouring islands. 

In Central America only a few small collections have been made, whichindicate a sub-tropical region. 

From the northern parts of South America, M. Leprieur collected inFrench Guiana. [W] Southwards of this, Spruce collected in thecountries bordering on the River Amazon, and Gardner in Brazil, [X]Gaudichaud in Chili and Peru, [Y] Gay in Chili, [Z] Blanchet inBahia, [a] Weddell in Brazil, [b] and Auguste de Saint Hiliare[c] inthe same country. Small collections have also been made in theextreme south. All these collections contain coriaceous species of_Polyporus_, _Favolus_, and allied genera, with _Auricularini_, together with such _Ascomycetes_ as _Xylaria_, and such forms of_Peziza_ as _P. Tricholoma_, _P. Hindsii_, and _P. Macrotis_. Asyet we cannot form an estimate of the extent or variety of theSouth American flora, which has furnished the interesting genus_Cyttaria_, and may yet supply forms unrecognized elsewhere. 

The island of Juan Fernandez furnished to M. Bertero a goodrepresentative collection, [d] which is remarkable as containing morethan one-half its number of European species, and the rest possessingrather the character of those of a temperate than a sub-tropicalregion. 

Australasia has been partly explored, and the results embodied in theFloras of Dr. Hooker and subsequent communications. In a note to anenumeration of 235 species in 1872, the writer observes that "many ofthem are either identical with European species, or so nearly alliedthat with dried specimens only, unaccompanied by notes or drawings, itis impossible to separate them; others are species which are almostuniversally found in tropical or sub-tropical countries, while a fewonly are peculiar to Australia, or are undescribed species, mostly ofa tropical type. The collections on the whole can scarcely be said tobe of any great interest, except so far as geographical distributionis concerned, as the aberrant forms are few. "[e]

The fungi collected by the Antarctic Expedition in Auckland andCampbell's Islands, and in Fuegia and the Falklands, [f] were few andof but little interest, including such cosmopolitan forms as _Sphæriaherbarum_ and _Cladosporium herbarum_, _Hirneola auricula-judæ_, _Polyporus versicolor_, _Eurotium herbariorum_, etc. 

In New Zealand a large proportion have been found, and these may betaken to represent the general character of the fungi of the islands, which is of the type usually found in temperate regions. [g]

The fungi of Asia are so little known that no satisfactory conclusionscan be drawn from our present incomplete knowledge. In India, thecollections made by Dr. Hooker in his progress to the SikkimHimalayas, [h] a few species obtained by M. Perottet in Pondicherry, and small collections from the Neilgherries, [i] are almost all thathave been recorded. From these it may be concluded that elevationssuch as approximate a temperate climate are the most productive, andhere European and North American genera, with closely allied species, have the preponderance. The number of _Agaricini_, for instance, islarge, and amongst the twenty-eight subgenera into which the genus_Agaricus_ is divided, eight only are unrepresented. Casual specimensreceived from other parts of India afford evidence that here is a vastfield unexplored, the forests and mountain slopes of which woulddoubtless afford an immense number of new and interesting forms. 

Of the Indian Archipelago, Java has been most explored, both byJunghuhn[j] and Zollinger. [k] The former records 117 species in 40genera, Nees von Esenbeck and Blume 11 species in 3 genera, andZollinger and Moritzi 31 species in 20 genera, making a total of 159species, of which 47 belong to _Polyporus_. Léveillé added 87species, making a total of 246 species. The fungi of Sumatra, Borneo, and other islands are partly the same and partly allied, but of asimilar tropical character. 

The fungi of the island of Ceylon, collected by Gardner, Thwaites, andKönig, were numerous. The Agarics comprise 302 species, closelyresembling those of our own country. [l] It is singular that every oneof the subgenera of Fries is represented, though the number of speciesin one or two is greatly predominant. _Lepiota_ and _Psalliota_ alonecomprise one-third of the species, while _Pholiota_ offers only asingle obscure species. The enumeration recently published of thesucceeding families contains many species of interest. 

In Africa, the best explored country is Algeria, although unfortunatelythe flora was never completed. [m] The correspondence between thefungi of Algeria and European countries is very striking, and theimpression is not removed by the presence of a few sub-tropical forms. It is probable that were the fungi of Spain known the resemblance wouldbe more complete. 

From the Cape of Good Hope and Natal collections have been made byZeyher, [n] Drége, and others, and from these we are enabled to form atolerable estimate of the mycologic flora. Of the _Hymenomycetes_, thegreater part belong to _Agaricus_: there are but four or five_Polypori_ in Zeyher's collection, one of which is protean. The_Gasteromycetes_ are interesting, belonging to many genera, andpresenting two, _Scoleciocarpus_ and _Phellorinia_, which were foundedupon specimens in this collection. _Batarrea_, _Tulostoma_, and_Mycenastrum_ are represented by European species. There are also twospecies of _Lycoperdon_, and one of _Podaxon_. Besides these, there isthe curious _Secotium Gueinzii_. The genus _Geaster_ does not appearin the collection, nor _Scleroderma_. Altogether the Cape flora is apeculiar one, and can scarcely be compared with any other. 

At the most, only scattered and isolated specimens have been recordedfrom Senegal, from Egypt, or from other parts of Africa, so that, withthe above exceptions, the continent may be regarded as unknown. 

From this imperfect summary it will be seen that no general scheme ofgeographical distribution of fungi can as yet be attempted, and themost we can hope to do is to compare collection with collection, andwhat we know of one country with what we know of another, and notedifferences and agreements, so as to estimate the probable characterof the fungi of other countries of which we are still in ignorance. Itis well sometimes that we should attempt a task like the present, since we then learn how much there is to be known, and how much goodwork lies waiting to be done by the capable and willing hands that mayhereafter undertake it. 

 [A] Mr. E. P. Fries, in "Ann. Des Sci. Nat. " 1861, xv. P. 10. 

 [B] Berkeley and Broome, "Enumeration of the Fungi of Ceylon, " in "Journ. Linn. Soc. " xiv. Nos. 73, 74, 1873. 

 [C] Fries, "On the Geographical Distribution of Fungi, " in "Ann. And Mag. Nat. Hist. " ser. Iii. Vol. Ix. P. 279. 

 [D] The _Hypogæi_ are evidently intended here by Fries. 

 [E] Fries, "On the Geographical Distribution of Fungi" in "Ann. And Mag. Nat. Hist. " ser. 3, vol. Ix. P. 285. 

 [F] Cooke's "Handbook of British Fungi, " 2 vols. 1871. 

 [G] "Grevillea, " vols. I. And ii. London, 1872-1874. 

 [H] Fries, "Summa Vegetabilium Scandinaviæ" (1846), and "Monographia Hymenomycetum Sueciæ" (1863); "Epicrisis Hymenomycetum Europ. " (1874). 

 [I] "Flore cryptogamique des Flanders" (1867). 

 [J] "Ainé Plantes Cryptogames-cellulaires du Départment de Saone et Loire" (1863); Bulliard, "Hist. Des Champignons de la France" (1791); De Candolle, "Flore Française" (1815); Duby, "Botanicon Gallicum" (1828-1830); Paulet, "Iconographie des Champignons" (1855); Godron, "Catalogue des Plantes Cellulaires du Départment de la Meurthe" (1845); Crouan, "Florule du Finistëre" (1867); De Seynes, "Essai d'une Flore Mycologique de la Région de Montpellier et du Gard" (1863). 

 [K] Secretan, "Mycographie Suisse" (1833); Trog, "Verzeichniss Schweizerischer Schwämme" (1844). 

 [L] Passerini, "Funghi Parmensi, " in "Giorn. Bot. Italiano" (1872-73); Venturi, "Miceti dell' Agro Bresciano" (1845); Viviani, "Funghi d'Italia" (1834); Vittadini, "Funghi Mangerecci d'Italia" (1835). 

 [M] Schæffer, "Fungorum qui in Bavaria, " &c. (1762-1774); Tratinnick, "Fungi Austriaci" (1804-1806 and 1809-30); Corda, "Icones Fungorum" (Prague, 1837-1842); Krombholz, "Abbildungen der Schwämme" (1831-1849). 

 [N] Reichardt, "Flora von Iglau;" Niessl, "Cryptogamenflora Nieder-Oesterreichs" (1857, 1859); Schulzer, "Schwämme Ungarns, Slavoniens, " &c. 

 [O] Rehm, "Ascomyceten, " fasc. I. -iv. 

 [P] Weinmann, "Hymeno-et Gasteromycetes, " in "Imp. Ross" (1836); Weinmann, "Enumeratio Stirpium, in Agro Petropolitano" (1837). 

 [Q] Karsten, "Fungi in insulis Spetsbergen collectio" (1872); Karsten, "Monographia Pezizarum fennicarum" (1869); Karsten, "Symbolæ ad Mycologiam fennicam" (1870). 

 [R] Rabenhorst, "Deutschlands Kryptogamen Flora" (1844); Wallroth, "Flora Germanica" (1833); Sturm, "Deutschlands Flora, iii. Die Pilze" (1837, &c. ). 

 [S] Fuckel, "Symbolæ mycologicæ" (1869). 

 [T] "Flora Danica" (1766-1873); Holmskjold, "Beata ruris otia Fungis Danicis impensa" (1799); Schumacher, "Enumeratio plantarum Sellandiæ" (1801). 

 [U] Schweinitz, "Synopsis Fungorum, " in "America Boreali, " &c. (1834). Lea, "Catalogue of Plants of Cincinnati" (1849); Curtis, "Catalogue of the Plants of North Carolina" (1867); Berkeley, "North American Fungi, " in "Grevillea, " vols. I. -iii. ; Peck, in "Reports of New York Museum Nat. Hist. "

 [V] Berkeley and Curtis, "Fungi Cubensis, " in "Journ. Linn. Soc. " (1868); Ramon de la Sagra, "Hist. Phys. De l'Isle de Cuba, Cryptogames, par Montagne" (1841); Montagne, in "Ann. Des Sci. Nat. " February, 1842. 

 [W] Montagne, "Cryptogamia Guyanensis, " "Ann. Sci. Nat. " 4^me sér. Iii. 

 [X] Berkeley, in "Hooker's Journal of Botany" for 1843, &c. 

 [Y] Montagne, in "Ann. Des Sci. Nat. " 2^me sér. Vol. Ii. P. 73 (1834). 

 [Z] Gay, "Hist. Fisica y politica de Chile" (1845). 

 [a] Berkeley and Montagne, "Ann. Des Sci. Nat. " xi. (April, 1849). 

 [b] Montagne, in "Ann. Des Sci. Nat. " 4^me sér. V. No. 6. 

 [c] Montagne, in "Ann. Des Sci. Nat. " (July, 1839). 

 [d] Montagne, "Prodromus Floræ Fernandesianæ, " in "Ann. Des Sci. Nat. " (June, 1835). 

 [e] Berkeley, "On Australian Fungi, " in "Journ. Linn. Society, " vol. Xiii. (May, 1872). 

 [f] Hooker's "Cryptogamia Antarctica, " pp. 57 and 141. 

 [g] Hooker's "New Zealand Flora. "

 [h] Berkeley, "Sikkim Himalayan Fungi, " in Hooker's "Journal of Botany" (1850), p. 42, &c. 

 [i] Montagne, "Cryptogamæ Neilgherrensis, " in "Ann. Des Sci. Nat. " 2^me sér. Xviii. P. 21 (1842). 

 [j] Junghuhn, "Premissa in Floram Crypt. Javæ. "

 [k] Zollinger, "Fungi Archipalegi Malaijo Neerlandici novi. "

 [l] Berkeley and Broome, "Fungi of Ceylon, " in "Journ. Linn. Soc. " for May, 1871. 

 [m] "Flore d'Algerie, Cryptogames" (1846, &c. ). 

 [n] Berkeley, in Hooker's "Journal of Botany, " vol. Ii. (1843), p. 408. 

XIV. 

COLLECTION AND PRESERVATION. 

The multitudinous forms which fungi assume, the differences ofsubstance, and variability in size, render a somewhat detailed accountof the modes adopted for their collection and preservation necessary. The habitats of the various groups have already been indicated, sothat there need be no difficulty in selecting the most suitable spots, and as to the period of the year, this will be determined by the classof objects sought. Although it may be said that no time, except whenthe ground is covered with snow, is entirely barren of fungi, yetthere are periods more prolific than others. [A] Fleshy fungi, such asthe _Hymenomycetes_, are most common from September until the frostsset in, whereas many microscopic species may be found in early spring, and increase in number until the autumn. 

The collector may be provided with an ordinary collecting box, butfor the Agarics an open shallow basket is preferable. A great numberof the woody kinds may be carried in the coat-pocket, and foliicolousspecies placed between the leaves of a pocket-book. It is a goodplan to be provided with a quantity of soft bibulous paper, inwhich specimens can be wrapped when collected, and this willmaterially assist in their preservation when transferred to box orbasket. A large clasp-knife, a small pocket-saw, and a pocket-lenswill complete the outfit for ordinary occasions. In order topreserve the fleshy fungi for the herbarium, there is but onemethod, which has often been described. The Agaric, or othersimilar fungus, is cut perpendicularly from the pileus downwardsthrough the stem. A second cut in the same direction removes a thinslice, which represents a section of the fungus; this may be laidon blotting paper, or plant-drying paper, and put under slightpressure to dry. From one-half of the fungus the pileus is removed, and with a sharp knife the gills and fleshy portion of the pileusare cut away. In the same manner the inner flesh of the half stem isalso cleared. When dried, the half of the pileus is placed in itsnatural position on the top of the half stem, and thus a portrait ofthe growing fungus is secured, whilst the section shows thearrangement of the hymenium and the character of the stem. Theother half of the pileus may be placed, gills downward, on a pieceof black paper, and allowed to rest there during the night. In themorning the spores will have been thrown down upon the paper, which may be placed with the other portions. When dry, the section, profile, and spore paper may be mounted together on a piece of stiffpaper, and the name, locality, and date inscribed below, with anyadditional particulars. It is advisable here to caution the collectornever to omit writing down these particulars at once when thepreparations are made, and to place them together, between thefolds of the drying paper, in order to prevent the possibility of amistake. Some small species may be dried whole or only cut down thecentre, but the spores should never be forgotten. When dried, eitherbefore or after mounting, the specimens should be poisoned, inorder to preserve them from the attacks of insects. The best mediumfor this purpose is carbolic acid, laid on with a small hog-hairbrush. Whatever substance is used, it must not be forgotten by themanipulator that he is dealing with poison, and must exercisecaution. If the specimens are afterwards found to be insufficientlypoisoned, or that minute insects are present in the herbarium, freshpoisoning will be necessary. Some think that benzine or spirits ofcamphor is sufficient, but as either is volatile, it is not to betrusted as a permanent preservative. Mr. English, of Epping, by aningenious method of his own, preserves a great number of the fleshyspecies in their natural position, and although valueless for anherbarium, they are not only very ornamental, but useful, if spacecan be devoted to them. 

Leaf parasites, whether on living or dead leaves, may be dried in theusual way for drying plants, between folds of bibulous paper underpressure. It may be sometimes necessary with dead leaves to throw themin water, in order that they may be flattened without breaking, andthen dry them in the same manner as green leaves. All species producedon a hard matrix, as wood, bark, etc. , should have as much as possibleof the matrix pared away, so that the specimens may lie flat in theherbarium. This is often facilitated in corticolous species byremoving the bark and drying it under pressure. 

The dusty _Gasteromycetes_ are troublesome, especially the minutespecies, and if mounted openly on paper are soon spoiled. A good planis to provide small square or round cardboard boxes, of not more thana quarter of an inch in depth, and to glue the specimen to the bottomat once, allowing it to dry in that position before replacing thecover. The same method should be adopted for many of the moulds, suchas _Polyactis_, etc. , which, under any circumstances, are difficult topreserve. 

In collecting moulds, we have found it an excellent plan to go outprovided with small wooden boxes, corked at top and bottom, such asentomologists use, and some common pins. When a delicate mould iscollected on a decayed Agaric, or any other matrix, after clearingaway with a penknife all unnecessary portions of the matrix, thespecimen may be pinned down to the cork in one of these boxes. Anothermethod, and one advisable also for the _Myxogastres_, is to carry twoor three pill-boxes, in which, after being wrapped in tissue paper, the specimen may be placed. 

A great difficulty is often experienced with microscopic fungi, such, for instance, as the _Sphæriacei_, in the necessity, whenever a newexamination is required, to soak the specimen for some hours, and thentransfer the fruit to a slide, before it can be compared with anynewly-found specimen that has to be identified. To avoid this, mountedspecimens ready for the microscope are an acquisition, and may besecured in the following manner. After the fungus has been soaked inwater, where that is necessary, and the hymenium extracted on thepoint of a penknife, let it be transferred to the centre of a cleanglass slide. A drop of glycerine is let fall upon this nucleus, thenthe covering glass placed over it. A slight pressure will flatten theobject and expel all the superfluous glycerine around the edges of thecovering glass. A spring clip holds the cover in position, whilst acamel-hair pencil is used to remove the glycerine which may have beenexpelled. This done, the edges of the cover may be fixed to the slideby painting round with gum-dammar dissolved in benzole. In from twelveto twenty-four hours the spring clip may be removed, and the mountplaced in the cabinet. Glycerine is, perhaps, the best medium formounting the majority of these objects, and when dammar and benzoleare used for fixing, there is no difficulty experienced, as is thecase with Canada balsam, if the superfluous glycerine is not whollywashed away. Specimens of _Puccinia_ mounted in this way when freshgathered, and before any shrivelling had taken place, are as plump andnatural in our cabinet as they were when collected six or seven yearsago. 

Moulds are always troublesome to preserve in a herbarium in a statesufficiently perfect for reference after a few years. We have found itan excellent method to provide some thin plates of mica, the thinnerthe better, of a uniform size, say two inches square, or even less. Between two of these plates of mica enclose a fragment of the mould, taking care not to move one plate over the other after the mould isplaced. Fix the plates by a clip, whilst strips of paper are gummed orpasted over the edges of the mica plates so as to hold them together. When dry, the clip may be removed, and the name written on the paper. These mounts may be put each in a small envelope, and fastened down inthe herbarium. Whenever an examination is required, the object, beingalready dry-mounted, may at once be placed under the microscope. Inthis manner the mode of attachment of the spores can be seen, but ifmounted in fluid they are at once detached; and if the moulds are onlypreserved in boxes, in the course of a short time nearly every sporewill have fallen from its support. 

Two or three accessories to a good herbarium may be named. For fleshyfungi, especially Agarics, faithfully coloured drawings, side by sidewith the dried specimens, will compensate for loss or change of colourwhich most species undergo in the process of drying. For minutespecies, camera lucida drawings of the spores, together with theirmeasurements, will add greatly to the practical value of a collection. In mounting specimens, whether on leaves, bark, or wood, it will be ofadvantage to have one specimen glued down to the paper so as to beseen at once, and a duplicate loose in a small envelope beside it, sothat the latter may at any time be removed and examined under themicroscope. 

In arranging specimens for the herbarium, a diversity of taste andopinion exists as to the best size for the herbarium paper. It isgenerally admitted that a small size is preferable to the large oneusually employed for phanerogamous plants. Probably the size offoolscap is the most convenient, each sheet being confined to a singlespecies. In public herbaria, the advantage of a uniform size for allplants supersedes all other advantages, but in a private herbarium, consisting entirely of fungi, the smaller size is better. 

The microscopic examination of minute species is an absolute necessityto ensure accurate identification. Little special remark is called forhere, since the methods adopted for other objects will be available. Specimens which have become dry may be placed in water previous toexamination, a process which will be found essential in such genera as_Peziza_, _Sphæria_, etc. For moulds, which must be examined as opaqueobjects, if all their beauties and peculiarities are to be made out, ahalf-inch objective is recommended, with the nozzle bevelled as muchto a point as possible, so that no light be obstructed. [B]

In examining the sporidia of minute _Pezizæ_ and some others, the aidof some reagent will be found necessary. When the sporidia are verydelicate and hyaline, the septa cannot readily be seen if present; toaid in the examination, a drop of tincture of iodine will be ofconsiderable advantage. In many cases sporidia, which are veryindistinct in glycerine, are much more distinct when the fluid iswater. 

The following hints to travellers, as regards the collection of fungi, drawn up some years since by the Rev. M. J. Berkeley, have been widelycirculated, and may be usefully inserted here, though at the risk ofrepetition:--

"It is frequently complained that in collections of exotic plants, notribe is so much neglected as that of fungi; this arises partly fromthe supposed difficulty of preserving good specimens, partly fromtheir being less generally studied than other vegetable productions. As, however, in no department of botany, there is a greaterprobability of meeting with new forms, and the difficulties, thoughconfessedly great in one or two genera, are far less than is oftenimagined, the following hints are respectfully submitted to suchcollectors as may desire to neglect no part of the vegetable kingdom. 

"The greater proportion, especially of tropical fungi, are dried, simply by light pressure, with as much ease as phoenogamous plants;indeed, a single change of the paper in which they are placed isgenerally sufficient, and many, if wrapped up in soft paper whengathered, and submitted to light pressure, require no furtherattention. Such as are of a tough leathery nature, if the paper bechanged a few hours after the specimens have been laid in, preserveall their characters admirably; and if in the course of a few weeksthere is an opportunity of washing them with a solution of turpentineand corrosive sublimate, submitting them again to pressure for a fewhours merely to prevent their shrinking, there will be no fear oftheir suffering from the attacks of insects. 

"Many of the mushroom tribe are so soft and watery that it is verydifficult to make good specimens without a degree of labour which isquite out of the question with travellers. By changing, however, thepapers in which they are dried two or three times the first day, ifpracticable, useful specimens may be prepared, especially if a fewnotes be made as to colour, etc. The more important notes are as tothe colour of the stem and pileus, together with any peculiarities ofthe surface, _e. G. _, whether it be dry, viscid, downy, scaly, etc. , and whether the flesh of the pileus be thin or otherwise; as to thestem, whether hollow or solid; as to the gills, whether they areattached to the stem or free; and especially what is their colour andthat of the spores. It is not in general expedient to preservespecimens in spirits, except others are dried by pressure, or copiousnotes be made; except, indeed, in some fungi of a gelatinous nature, which can scarcely be dried at all by pressure. 

"The large woody fungi, the puff-balls, and a great number of thosewhich grow on wood, etc. , are best preserved, after ascertaining thatthey are dry and free from larvæ, by simply wrapping them in paper orplacing them in chip-boxes, taking care that they are so closelypacked as not to rub. As in other tribes of plants, it is veryrequisite to have specimens in different stages of growth, and notesas to precise habitats are always interesting. 

"The attention of the traveller can scarcely be directed to any moreinteresting branch, or one more likely to produce novelty, than thepuff-ball tribe; and he is particularly requested to collect these inevery stage of growth, especially in the earliest, and, if possible, to preserve some of the younger specimens in spirits. One or twospecies are produced on ant-hills, the knowledge of the early state ofwhich is very desirable. 

"The fungi which grow on leaves in tropical climates are scarcely lessabundant than in our own country, though belonging to a differenttype. Many of these must constantly come under the eye of thecollector of phoenogams, and would be most acceptable to themycologist. But the attention of the collector should also be directedto the lichen-like fungi, which are so abundant in some countries onfallen sticks. Hundreds of species of the utmost interest would rewardactive research, and they are amongst the easiest to dry; indeed, intropical countries, the greater proportion of the species are easy topreserve, but they will not strike the eye which is not on the watchfor them. The number of fleshy species is but few, and far lesslikely to furnish novelty. "

 * * * * *

In conclusion, we may urge upon all those who have followed us thusfar to adopt this branch of botany as their speciality. Hithertoit has been very much neglected, and a wide field is open forinvestigation and research. The life-history of the majority ofspecies has still to be read, and the prospects of new discoveriesfor the industrious and persevering student are great. All who have asyet devoted themselves with assiduity have been in this mannerrewarded. The objects are easily obtainable, and there is a constantlyincreasing infatuation in the study. Where so much is unknown, not afew difficulties have to be encountered, and here the race is not tothe swift so much as to the untiring. May our efforts to supply thisintroduction to the study receive their most welcome reward in anaccession to the number of the students and investigators of thenature, uses, and influences of fungi. 

 [A] The genus _Chionyphe_ occurs on granaries under snow, as well as in that formidable disease, the Madura fungus-foot. (_See_ Carter's "Mycetoma. ")

 [B] Bubbles of air are often very tiresome in the examination of moulds. A little alcohol will remove them. 

INDEX. 

 _Æcidiacci_, structure of, 41. _Æcidium_ and _Puccinia_, 199. Germination, 141. _Agaricini_, habitats of, 233. Structure of, 17. Agaric of the olive, 108. Agarics, growth of, 138. Algo-lichen hypothesis, 10. Alveolate spores, 130. Amadou, 103. American floras, 281. Fungi, 281. Antheridia, presumed, 171. Appearance of new forms, 248. Arrangement of families, 80. Asci and sporidia, 131. In Agarics (?), 23. Their dehiscence, 59. _Ascobolei_, structure of, 56. _Ascomycetes_, classification of, 75. Distribution of, 277. Habitats of, 241. Structure of, 55. _Aspergillus glaucus_, 187. Atmosphere, spores in, 214. 

 Barberry cluster-cups, 201. Barren cysts of _Lecythea_, 37. Basidiospores, 120. Beech morels, 101. Beefsteak fungus, 96. Berberry and mildew, 199. _Boletus_, esculent species, 95. Books on structure, 63. _Bulgaria_, its dualism, 198. Bunt and smut, 225. Spores, germination of, 150. 

 _Cæomacei_, structure of, 36. Camp measles and fever, 213. Caudate sporidia, 134. Champignon, fairy-ring, 94. Change of colour, 114. Chantarelle, the, 93. Cholera fungi, 213. Ciliated stylospores, 124-6. Classification of _Ascomycetes_, 75. _Coniomycetes_, 69. Fungi, 64. _Gasteromycetes_, 66. _Hymenomycetes_, 65. _Hyphomycetes_, 73. _Physomycetes_, 74. Tabular view, 80. Collecting fungi, 287. Colour and its variation, 117. Conditions of growth, 269. Conidia of _Erysiphei_, 62. _Mucor_, 53. _Peziza_, 46. _Sphæriæ_, 192. _Coniomycetes_, classification of, 69. _Coniomycetes_, habitats of, 38. Conjugating cells, 165. Conjugation in _Peronospora_, 171. _Peziza_, 175. Copulation in _Discomycetes_, 173. Fungi, 163. Corn, mildew, and rust, 224. _Cortinarius_, species of, 91. Cotton plant diseases, 228. Cultivation of fungi, 253. _Sclerotia_, 261. Truffles, 258. Currant twig fungus, 193. Cystidia, 21. 

 _Dacrymyces_, germination of, 140. De Bary, on conditions of study, 183. Decay rapid, 9. Dehiscence of asci, 58. Dimorphism in moulds, 187. Of _Mucor_, 53. Disappearance of species, 268. _Discomycetes_, 56. Dissemination of spores, 119. Distribution, geographical, 266. Dried fungi, esculent, 87, 94. Drying of fungi, 289. Dry rot, 223. Dualism in _Melanconis_, 197. _Podisoma_, 203. _Polyactes_, 45. _Uredines_, 185. 

 Edible fungi in America, 88. Ergotized grass, 217. _Erysiphe_, conjugation, 176. _Erysiphei_, polymorphism, 191. Esculent fungi, 82. European floras, 279. Examination of fungi, 289. Exotic floras, 280-5. 

 False truffles, 98. Fairy-ring champignon, 94. Families and orders, table of, 80. Fenestrate sporidia, 135. Fetid fungi, 116. _Fistulina hepatica_, 96. Floras of Europe, &c. , 279. Fly Agaric, 210. Food, fungi as, 81. Forestry and its foes, 229. Fungi collecting abroad, 292. In disease, 215. Mines, 111. Of America, 281. Asia, 284. Parasitic on animals, 246. Each other, 244. True plants, 5. 

 Garden pests, 230. _Gasteromycetes_, classification of, 66. Geographical distribution, 266. Germinating pseudospores, 144. Germination of fungi, 137. _Mucor_, 157, 164. _Podisoma_, 147. Gonosphere, in _Peronospora_, 171. Growth of Agarics, 138. 

 Habitats of fungi, 233. Helicoid spores, 129. Herbarium for fungi, 291. Hints for travellers, 292. Hollyhock disease, 230. House-fly fungus, 219. _Hydnum gelatinosum_, 24. Hymenium of fungi, 18. _Hymenomycetes_, classification of, 65. _Hyphomycetes_, classification of, 73. Habitats of, 240. Structure of, 42. _Hypogæi_, structure of, 29. 

 Influences of fungi, 209. Influence on lower animals, 217. Man, 209. Influence on vegetation, 222. Of woods, 271. Injurious moulds, 230, 240. Insect, parasites on, 7, 218. Fungi, 7, 218, 246. _Isaria_ and _Torrubia_, 205. 

 Ketchup, or catchup, 89. 

 Lactescent fungi, 115. Lichen-gonidia question, 10. Lichens and fungi, 9. Little man's bread, 102. Luminous Agarics, 105. Wood, 113. 

 Meadow mushroom, 83. Medicinal fungi, 102. _Melanconiei_, structure of, 35. Microscopical mounting, 290. Mildew in corn, 199. Milky fungi, 92. Juice, 115. Morels, 99, 159. Germination of, 159. Mould cultivation, 263. Moulds, and dimorphism, 187. Structure of, 43. To preserve, 290. _Mucedines_, habitats of, 240. Structure of, 44. _Mucor_, dualism of, 205. Growth of, 157. Structure of, 50. Mushroom, analysis of, 19. Caves of Paris, 255. Cultivation, 254. Spawn, 256. The edible, 83. _Myxogastres_, habitats of, 237. Structure of, 31. 

 Nature of fungi, 1. New forms, appearance of, 248. _Nidulariacei_, structure of, 34. 

 Oak truffles, 260. Odours of fungi, 116. _Oidium_ and _Erysiphe_, 191. Oocysts in _Erysiphe_, 176. Oogonia, 136, 169. Of _Saprolegniæ_, 169. Orders and families, table of, 80. Oyster mushroom, 86. 

 Paper moulds, 248. Paraphyses and asci, 49. Parasites on plants, 238. _Perisporiacei_, structure of, 62. _Peronospora_, growth of, 152. Pests of forest trees, 229. The garden, 230. _Peziza_, conidia of, 46. _Fuckeliana_, 48. _Pezizæ_, their habitats, 242. _Phalloidei_, structure of, 28. Phenomena of fungi, 105. Phosphorescence, 105. _Physomycetes_, classification of, 74. Habitats of, 241. Structure of, 50. _Podaxinei_, structure of, 29. _Podisoma_, and its allies, 40, 72. And _Roestelia_, 203. Germination of, 147. Poisonous fungi, 209. Polymorphism, 182. Polymorphy in _Erysiphe_, 191. Polyporei, structure of, 23. _Polyporus_, edible species, 96. Potato disease, 225. Mould, germination, 155. Preservation of fungi, 288. Pseudospores, 126. _Puccinia_ and _Æcidium_, 199. _Puccinia_, germination of, 145. _Pucciniæi_, structure of, 38. Puff-balls, edible, 98. Puff-balls, structure of, 29. Spores, 123. Pycnidia, 62, 180. And spermatia, 62. 

 _Roestelia_ and _Podisoma_, 203. Red rust and cattle food, 217. Reproduction, sexual, 163. _Rhizomorphæ_, 111. _Russula_, edible species of, 93. 

 St. George's mushroom, 85. _Saprolegnei_, conjugation of, 168. _Sclerotia_, 47, 261. Cultivation, 261. Scolecite in _Peziza_, &c. , 173. Septate stylospores, 124. Sexual reproduction, 163. Silkworm disease, 220. Skin diseases and fungi, 212. Slides for the microscope, 290. Spawn of fungi, 256. Special cultivation, 264. Species determinate, 5. Spermatia, 128, 179. Of _Roestelia_, 42. In _Tremella_, 26. Spermogonia, 178. _Sphæria_, sporidia of, 133. _Sphæriacei_, structure of, 61. _Sphæriæ_, polymorphy, 192. _Sphæronemei_, structure of, 35. Spiral threads, 32. Spontaneous generation, 3. Sporangia, 51, 129. Of _Mucor_, 51. Spores in chaplets, 143. Of _Agaricini_, 121. _Gasteromycetes_, 122. Truffles, 130. Stellate and crested, 36. Their dissemination, 119. Sporidia, germination of, 160. Of _Ascomycetes_, 130. _Sporidiifera_, structure of, 50 _Sporifera_ and _Sporidiifera_, 64. Star-spored fungus, 125. Structure of fungi, 17. _Agaricini_, 17. Books written upon, 63. Of _Æcidiacei_, 41. _Ascomycetes_, 55. _Cæomacei_, 36. _Hyphomycetes_, 42. _Hypogæi_, 29. _Melanconiei_, 35. _Mucedines_, 44. _Mucor_, 50. _Myxogastres_, 31. _Nidulariacei_, 34. _Perisporiacei_, 62. _Phalloidei_, 28. _Physomycetes_, 50. _Podaxinei_, 29. _Polyporei_, 23. _Pucciniæi_, 38. _Sphæriacei_, 61. _Sphæronemei_, 35. _Torulacei_, 36. _Tremellini_, 25. _Trichogastres_, 29. Truffles, 55. _Ustilaginei_, 40. Study of development, 183. Stylospores, 123. Subterranean puff-balls, 29. Summer and winter spores, 37. Supposed animal nature, 2. 

 Table of classification, 80. Thecaspores, 13 _Torrubia_ and _Isaria_, 205. _Torulacei_, structure of, 36. Travellers, hints for, 292. _Tremella_, germination of, 139. _Tremellini_, structure of, 24. _Trichogastres_, habitats of, 237. Structure of, 29. Trichospores, 128. Tropical fungi, 272. Truffle cultivation, 258. Truffles, 55, 101, 258. Structure of, 55. _Tuberacei_, structure of, 55. _Tubercularia_ and _Nectria_, 194. 

 _Uredines_, germination of, 143. Polymorphy of, 186. Structure of, 37. Uses of fungi, 82. _Ustilaginei_, structure of, 40. Germination of, 149. 

 "Vegetable wasp, " 218. Vegetative and reproductive system, 7. Viennese fungi, 84. Vine and hop disease, 227. 

 White rust germination, 151. Winter and summer spores, 37. 

 Zones of distribution, 270. Zoospores of _Cystopus_, 38. White rust, 151. Zygospores of _Mucor_, 158, 164. 

_International Scientific Series. _

D. APPLETON & CO. Have the pleasure of announcing that they have madearrangements for publishing, and have recently commenced the issue of, a SERIES OF POPULAR MONOGRAPHS, or small works, under the above title, which will embody the results of recent inquiry in the mostinteresting departments of advancing science. 

The character and scope of this series will be best indicated by areference to the names and subjects included in the subjoined list, from which it will be seen that the coöperation of the mostdistinguished professors in England, Germany, France, and theUnited States, has been secured, and negotiations are pending forcontributions from other eminent scientific writers. 

The works will be issued in New York, London, Paris, Leipsic, Milan, and St. Petersburg. 

The INTERNATIONAL SCIENTIFIC SERIES is entirely an American project, and was originated and organized by Dr. E. L. Youmans, who spent thegreater part of a year in Europe, arranging with authors andpublishers. The forthcoming volumes are as follows:

 Prof. LOMMEL (University of Erlangen), _Optics. _ (In press. )

 Rev. M. J. BERKELEY, M. A. , F. L. S. , and M. COOKE, M. A. , LL. D. , _Fungi; their Nature, Influences, and Uses. _ (In press. )

 Prof. W. KINGDON CLIFFORD, M. A. , _The First Principles of the Exact Sciences explained to the non-mathematical. _

 Prof. T. H. HUXLEY, LL. D. , F. R. S. , _Bodily Motion and Consciousness. _

 Dr. W. B. CARPENTER, LL. D. , F. R. S. , _The Physical Geography of the Sea. _

 Prof. WILLIAM ODLONG, F. R. S. , _The Old Chemistry viewed from the New Standpoint. _

 W. LAUDER LINDSAY, M. D. , F. R. S. E. , _Mind in the Lower Animals. _

 Sir JOHN LUBBOCK, Bart, F. R. S. , _The Antiquity of Man. _

 Prof. W. T. THISELTON DYER, B. A. , B. Sc. , _Form and Habit in Flowering Plants. _

 Mr. J. N. LOCKYER, F. R. S. , _Spectrum Analysis. _

 Prof. MICHAEL FOSTER, M. D. , _Protoplasm and the Cell Theory. _

 Prof. W. STANLEY JEVONS, _Money: and the Mechanism of Exchange. _

 H. CHARLTON BASTIAN, M. D. , F. R. S. , _The Brain as an Organ of Mind. _

 Prof. A. C. RAMSAY, LL. D. , F. R. S. , _Earth Sculpture: Hills, Valleys, Mountains, Plains, Rivers, Lakes; how they were produced, and how they have been destroyed. _

 Prof. RUDOLPH VIRCHOW (Berlin University), _Morbid Physiological Action. _

 Prof. CLAUDE BERNARD, _Physical and Metaphysical Phenomena of life. _

 Prof. H. SAINTE-CLAIRE DEVILLE, _An Introduction to General Chemistry. _

 Prof. WURTZ, _Atoms and the Atomic Theory. _

 Prof. DE QUATREFAGES, _The Negro Races. _

 Prof. LACAZE-DUTHIERS, _Zoology since Cuvier. _

 Prof. BERTHELOT, _Chemical Synthesis. _

 Prof. J. ROSENTHAL, _General Physiology of Muscles and Nerves. _

 Prof. JAMES D. DANA, M. A. , LL. D. , _On Cephalization; or, Head-Characters in the Gradation and Progress of Life. _

 Prof. S. W. JOHNSON, M. A. , _On the Nutrition of Plants. _

 Prof. AUSTIN FLINT, Jr. , M. D. , _The Nervous System and its Relation to the Bodily Functions. _

 Prof. W. D. WHITNEY, _Modern Linguistic Science. _

 Prof. C. A. YOUNG, Ph. D. (of Dartmouth College), _The Sun. _

 Prof. BERNSTEIN (University of Halle), _Physiology of the Senses. _

 Prof. FERDINAND COHN (Breslau University), _Thallophytes (Algæe, Lichens, Fungi). _

 Prof. HERMANN (University of Zurich), _Respiration. _

 Prof. LEUCKART (University of Leipsic), _Outlines of Animal Organization. _

 Prof. LIEBREICH (University of Berlin), _Outlines of Toxicology. _

 Prof. KUNDT (University of Strasburg), _On Sound. _

 Prof. REES (University of Erlangen), _On Parasitic Plants. _

 Prof. STEINTHAL (University of Berlin), _Outlines of the Science of Language. _

 E. ALGLAVE (Professor of Constitutional and Administrative Law at Douai, and of Political Economy at Lille), _The Primitive Elements of Political Constitutions. _

 P. LORAIN (Professor of Medicine, Paris), _Modern Epidemics. _

 Prof. SCHÜTZENBERGER (Director of the Chemical Laboratory at the Sorbonne), _On Fermentations. _

 Mons. DEBRAY, _Precious Metals. _

_Opinions of the Press on the "International Scientific Series. "_

I. 

Tyndall's Forms of Water. 

 1 vol. , 12mo. Cloth. Illustrated Price, $1. 50. 

"In the volume now published, Professor Tyndall has presented a nobleillustration of the acuteness and subtlety of his intellectual powers, the scope and insight of his scientific vision, his singular commandof the appropriate language of exposition, and the peculiar vivacityand grace with which he unfolds the results of intricate scientificresearch. "--_N. Y. Tribune_. 

"The 'Forms of Water, ' by Professor Tyndall, is an interesting andinstructive little volume, admirably printed and illustrated. Preparedexpressly for this series, it is in some measure a guarantee of theexcellence of the volumes that will follow, and an indication that thepublishers will spare no pains to include in the series the freshestinvestigations of the best scientific minds. "--_Boston Journal_. 

"This series is admirably commenced by this little volume from the penof Prof. Tyndall. A perfect master of his subject, he presents in astyle easy and attractive his methods of investigation, and theresults obtained, and gives to the reader a clear conception of all thewondrous transformations to which water is subjected. "--_Churchman_. 

II. 

Bagehot's Physics and Politics. 

 1 vol. , 12mo. Price, $1. 50. 

"If the 'International Scientific Series' proceeds as it has begun, itwill more than fulfil the promise given to the reading public in itsprospectus. The first volume, by Professor Tyndall, was a model oflucid and attractive scientific exposition; and now we have a second, by Mr. Walter Bagehot, which is not only very lucid and charming, butalso original and suggestive in the highest degree. Nowhere since thepublication of Sir Henry Maine's 'Ancient Law, ' have we seen so manyfruitful thoughts suggested in the course of a couple of hundredpages. .. . To do justice to Mr. Bagehot's fertile book, would require along article. With the best of intentions, we are conscious of havinggiven but a sorry account of it in these brief paragraphs. But we hopewe have said enough to commend it to the attention of the thoughtfulreader. "--Prof. JOHN FISKE, in the _Atlantic Monthly_. 

"Mr. Bagehot's style is clear and vigorous. We refrain fromgiving a fuller account of these suggestive essays, only because weare sure that our readers will find it worth their while toperuse the book for themselves; and we sincerely hope that theforthcoming parts of the 'International Scientific Series' will beas interesting. "--_Athenæum_. 

"Mr. Bagehot discusses an immense variety of topics connected with theprogress of societies and nations, and the development of theirdistinctive peculiarities; and his book shows an abundance ofingenious and original thought. "--ALFRED RUSSELL WALLACE, in_Nature_. 

III. 

Foods. 

By Dr. EDWARD SMITH. 

 1 vol. , 12mo. Cloth Illustrated. Price, $1. 75. 

In making up THE INTERNATIONAL SCIENTIFIC SERIES, Dr Edward Smith wasselected as the ablest man in England to treat the important subjectof Foods. His services were secured for the undertaking, and thelittle treatise he has produced shows that the choice of a writer onthis subject was most fortunate, as the book is unquestionably theclearest and best-digested compend of the Science of Foods that hasappeared in our language. 

 "The book contains a series of diagrams, displaying the effects of sleep and meals on pulsation and respiration, and of various kinds of food on respiration, which, as the results of Dr Smith's own experiments, possess a very high value. We have not far to go in this work for occasions of favorable criticism; they occur throughout, but are perhaps most apparent in those parts of the subject with which Dr. Smith's name is especially linked. "--_London Examiner. _

 "The union of scientific and popular treatment in the composition of this work will afford an attraction to many readers who would have been indifferent to purely theoretical details. .. . Still his work abounds in information, much of which is of great value, and a part of which could not easily be obtained from other sources. Its interest is decidedly enhanced for students who demand both clearness and exactness of statement, by the profusion of well executed woodcuts, diagrams, and tables, which accompany the volume. .. . The suggestions of the author on the use of tea and coffee, and of the various forms of alcohol, although perhaps not strictly of a novel character, are highly instructive, and form an interesting portion of the volume. "--_N. Y. Tribune. _

IV. 

Body and Mind. 

THE THEORIES OF THEIR RELATION. 

By ALEXANDER BAIN, LL. D. 

 1 vol. , 12mo. Cloth Price, $1. 50. 

PROFESSOR BAIN is the author of two well-known standard works upon theScience of Mind--"The Senses and the Intellect, " and "The Emotions andthe Will. " He is one of the highest living authorities in the schoolwhich holds that there can be no sound or valid psychology unless themind and the body are studied, as they exist, together. 

 "It contains a forcible statement of the connection between mind and body, studying their subtile interworkings by the light of the most recent physiological investigations. The summary in Chapter V. , of the investigations of Dr. Lionel Beale of the embodiment of the intellectual functions in the cerebral system, will be found the freshest and most interesting part of his book. Prof. Bain's own theory of the connection between the mental and the bodily part in man is stated by himself to be as follows: There is 'one substance, with two sets of properties, two sides, the physical and the mental--a _double-faced unity_. ' While, in the strongest manner, asserting the union of mind with brain, he yet denies 'the association of union _in place_, ' but asserts the union of close succession in time, ' holding that 'the same being is, by alternate fits, under extended and under unextended consciousness. '"--_Christian Register. _

V. 

The Study of Sociology. 

By HERBERT SPENCER. 

 1 vol. , 12mo. Cloth Price, $1. 50. 

 "The philosopher whose distinguished name gives weight and influence to this volume, has given in its pages some of the finest specimens of reasoning in all its forms and departments. There is a fascination in his array of facts, incidents, and opinions, which draws on the reader to ascertain his conclusions. The coolness and calmness of his treatment of acknowledged difficulties and grave objections to his theories win for him a close attention and sustained effort, on the part of the reader, to comprehend, follow, grasp, and appropriate his principles. This book, independently of its bearing upon sociology, is valuable as lucidly showing what those essential characteristics are which entitle any arrangement and connection of facts and deductions to be called a _science_. "--_Episcopalian. _

 "This work compels admiration by the evidence which it gives of immense research, study, and observation, and is, withal, written in a popular and very pleasing style. It is a fascinating work, as well as one of deep practical thought. "--_Bost. Post. _

 "Herbert Spencer is unquestionably the foremost living thinker in the psychological and sociological fields, and this volume is an important contribution to the science of which it treats. .. . It will prove more popular than any of its author's other creations, for it is more plainly addressed to the people and has a more practical and less speculative cast. It will require thought, but it is well worth thinking about. "--_Albany Evening Journal_. 

VI. 

The New Chemistry. 

By JOSIAH P. COOKE, Jr. , Erving Professor of Chemistry and Mineralogy in Harvard University. 

 1 vol. , 12mo. Cloth Price, $2. 00. 

 "The book of Prof. Cooke is a model of the modern popular science work. It has just the due proportion of fact, philosophy, and true romance, to make it a fascinating companion, either for the voyage or the study. "--_Daily Graphic. _

 "This admirable monograph, by the distinguished Erving Professor of Chemistry in Harvard University, is the first American contribution to 'The International Scientific Series, ' and a more attractive piece of work in the way of popular exposition upon a difficult subject has not appeared in a long time. It not only well sustains the character of the volumes with which it is associated, but its reproduction in European countries will be an honor to American science. "--_New York Tribune. _

 "All the chemists in the country will enjoy its perusal, and many will seize upon it as a thing longed for. For, to those advanced students who have kept well abreast of the chemical tide, it offers a calm philosophy. To those others, youngest of the class, who have emerged from the schools since new methods have prevailed, it presents a generalization, drawing to its use all the data, the relations of which the newly-fledged fact-seeker may but dimly perceive without its aid. .. . To the old chemists, Prof. Cooke's treatise is like a message from beyond the mountain. They have heard of changes in the science; the clash of the battle of old and new theories has stirred them from afar. The tidings, too, had come that the old had given way; and little more than this they knew. .. . Prof. Cooke's 'New Chemistry' must do wide service in bringing to close sight the little known and the longed for. .. . As a philosophy it is elementary, but, as a book of science, ordinary readers will find it sufficiently advanced. "--_Utica Morning Herald. _

VII. 

The Conservation of Energy. 

By BALFOUR STEWART, LL. D. , F. R. S. 

_With an Appendix treating of the Vital and Mental Applications of theDoctrine. _

 1 vol. , 12mo. Cloth. Price, $1. 50. 

"The author has succeeded in presenting the facts in a clear andsatisfactory manner, using simple language and copious illustration inthe presentation of facts and principles, confining himself, however, to the physical aspect of the subject. In the Appendix the operationof the principles in the spheres of life and mind is supplied by theessays of Professors Le Conte and Bain. "--_Ohio Farmer. _

"Prof Stewart is one of the best known teachers in Owens College inManchester. 

"The volume of THE INTERNATIONAL SCIENTIFIC SERIES now before us is anexcellent illustration of the true method of teaching, and will wellcompare with Prof. Tyndall's charming little book in the same serieson 'Forms of Water, ' with illustrations enough to make clear, but notto conceal his thoughts, in a style simple and brief. "--_ChristianRegister, Boston_. 

"The writer has wonderful ability to compress much information into afew words. It is a rich treat to read such a book as this, when thereis so much beauty and force combined with such simplicity. "--_EasternPress. _

VIII. 

Animal Locomotion;

Or, WALKING, SWIMMING, AND FLYING. 

_With a Dissertation on Aëronautics. _

By J. BELL PETTIGREW, M. D. , F. R. S. , F. R. S. E. , F. R. C. P. E. 

 1 vol. , 12mo. Price, $1. 75. 

"This work is more than a contribution to the stock of entertainingknowledge, though, if it only pleased, that would be sufficient excusefor its publication. But Dr. Pettigrew has given his time to theseinvestigations with the ultimate purpose of solving the difficultproblem of Aëronautics. To this he devotes the last fifty pages of hisbook. Dr. Pettigrew is confident that man will yet conquer the domainof the air. "--_N. Y. Journal of Commerce. _

"Most persons claim to know how to walk, but few could explain themechanical principles involved in this most ordinary transaction, andwill be surprised that the movements of bipeds and quadrupeds, thedarting and rushing motion of fish, and the erratic flight of thedenizens of the air, are not only analogous, but can be reduced tosimilar formula. The work is profusely illustrated, and, withoutreference to the theory it is designed to expound, will be regarded asa valuable addition to natural history. "--_Omaha Republic. _

IX. 

Responsibility in Mental Disease. 

By HENRY MAUDSLEY, M. D. , Fellow of the Royal College of Physicians; Professor of MedicalJurisprudence in University College, London. 

 1 vol. , 12mo. Cloth. Price, $1. 50. 

"Having lectured in a medical college on Mental Disease, this book hasbeen a feast to us. It handles a great subject in a masterly manner, and, in our judgment, the positions taken by the author are correctand well sustained. "--_Pastor and People. _

"The author is at home in his subject, and presents his views in analmost singularly clear and satisfactory manner. .. . The volume is avaluable contribution to one of the most difficult, and at the sametime one of the most important subjects of investigation at thepresent day. "--_N. Y. Observer. _

"It is a work profound and searching, and abounds in wisdom. "--_PittsburgCommercial. _

"Handles the important topic with masterly power, and its suggestionsare practical and of great value. "--_Providence Press. _

X. 

The Science of Law. 

By SHELDON AMOS, M. A. , Professor of Jurisprudence in University College, London; author of "ASystematic View of the Science of Jurisprudence, " "An English Code, its Difficulties and the Modes of overcoming them, " etc. , etc. 

 1 vol. , 12mo. Cloth. Price, $1. 75. 

"The valuable series of 'International Scientific' works, prepared byeminent specialists, with the intention of popularizing information intheir several branches of knowledge, has received a good accession inthis compact and thoughtful volume. It is a difficult task to give theoutlines of a complete theory of law in a portable volume, which hewho runs may read, and probably Professor Amos himself would be thelast to claim that he has perfectly succeeded in doing this. But hehas certainly done much to clear the science of law from the technicalobscurities which darken it to minds which have had no legal training, and to make clear to his 'lay' readers in how true and high a sense itcan assert its right to be considered a science, and not a merepractice. "--_The Christian Register. _

"The works of Bentham and Austin are abstruse and philosophical, and Maine's require hard study and a certain amount of specialtraining. The writers also pursue different lines of investigation, and can only be regarded as comprehensive in the departments theyconfined themselves to. It was left to Amos to gather up the resultand present the science in its fullness. The unquestionable merits ofthis, his last book, are, that it contains a complete treatment ofa subject which has hitherto been handled by specialists, and itopens up that subject to every inquiring mind. .. . To do justice to'The Science of Law' would require a longer review than we havespace for. We have read no more interesting and instructive book forsome time. Its themes concern every one who renders obedience to laws, and who would have those laws the best possible. The tide of legalreform which set in fifty years ago has to sweep yet higher if theflaws in our jurisprudence are to be removed. The process of changecannot be better guided than by a well-informed public mind, andProf. Amos has done great service in materially helping to promotethis end. "--_Buffalo Courier. _

XI. 

Animal Mechanism, _A Treatise on Terrestrial and Aërial Locomotion. _

By E. J. MAREY, Professor at the College of France, and Member of the Academy ofMedicine. 

With 117 Illustrations, drawn and engraved under the direction of theauthor. 

 1 vol. , 12mo. Cloth. Price, $1. 75

"We hope that, in the short glance which we have taken of some of themost important points discussed in the work before us, we havesucceeded in interesting our readers sufficiently in its contents tomake them curious to learn more of its subject-matter. We cordiallyrecommend it to their attention. 

"The author of the present work, it is well known, stands at the headof those physiologists who have investigated the mechanism of animaldynamics--indeed, we may almost say that he has made the subject hisown. By the originality of his conceptions, the ingenuity of hisconstructions, the skill of his analysis, and the perseverance of hisinvestigations, he has surpassed all others in the power of unveilingthe complex and intricate movements of animated beings. "--_PopularScience Monthly. _

XII. 

History of the Conflict between Religion and Science. 

By JOHN WILLIAM DRAPER, M. D. , LL. D. , Author of "The Intellectual Development of Europe. "

 1 vol. , 12mo. Price, $1. 75. 

"This little 'History' would have been a valuable contribution toliterature at any time, and is, in fact, an admirable text-book upon asubject that is at present engrossing the attention of a large numberof the most serious-minded people, and it is no small compliment tothe sagacity of its distinguished author that he has so well gaugedthe requirements of the times, and so adequately met them by thepreparation of this volume. It remains to be added that, while thewriter has flinched from no responsibility in his statements, and haswritten with entire fidelity to the demands of truth and justice, there is not a word in his book that can give offense to candid andfair-minded readers. "--_N. Y. Evening Post. _

"The key-note to this volume is found in the antagonism between theprogressive tendencies of the human mind and the pretensions ofecclesiastical authority, as developed in the history of modernscience. No previous writer has treated the subject from this point ofview, and the present monograph will be found to possess no lessoriginality of conception than vigor of reasoning and wealth oferudition. .. . The method of Dr. Draper, in his treatment of thevarious questions that come up for discussion, is marked by singularimpartiality as well as consummate ability. Throughout his work hemaintains the position of an historian, not of an advocate. His toneis tranquil and serene, as becomes the search after truth, with notrace of the impassioned ardor of controversy. He endeavors so far toidentify himself with the contending parties as to gain a clearcomprehension of their motives, but, at the same time, he submitstheir actions to the tests of a cool and impartial examination. "--_N. Y. Tribune. _

D. APPLETON & CO. , PUBLISHERS, 549 & 551 Broadway, N. Y. 

RECENT PUBLICATIONS. --SCIENTIFIC. 

=THE PRINCIPLES OF MENTAL PHYSIOLOGY. = With their Applications to theTraining and Discipline of the Mind, and the Study of its MorbidConditions. By W. B. CARPENTER, F. R. S. , etc. Illustrated. 12mo. 737pages. Price, $3. 00. 

 "The work is probably the ablest exposition of the subject which has been given to the world, and goes far to establish a new system of Mental Philosophy, upon a much broader and more substantial basis than it has heretofore stood. "--_St. Louis Democrat. _

 "Let us add that nothing we have said, or in any limited space could say, would give an adequate conception of the valuable and curious collection of facts bearing on morbid mental conditions, the learned physiological exposition, and the treasure-house of useful hints for mental training, which make this large and yet very amusing, as well as instructive book, an encyclopædia of well-classified and often very startling psychological experiences. "--_London Spectator. _

=THE EXPANSE OF HEAVEN. = A Series of Essays on the Wonders of theFirmament. By R. A. PROCTOR, B. A. 

 "A very charming work; cannot fail to lift the reader's mind up 'through Nature's work to Nature's God. '"--_London Standard. _

 "Prof. R. A. Proctor is one of the very few rhetorical scientists who have the art of making science popular without making it or themselves contemptible. It will be hard to find anywhere else so much skill in effective expression, combined with so much genuine astronomical learning, as is to be seen in his new volume. "--_Christian Union. _

=PHYSIOLOGY FOR PRACTICAL USE. = By various Writers. Edited by JAMESHINTON. With 50 Illustrations. 1 vol. , 12mo. Price, $2. 25. 

 "This book is one of rare value, and will prove useful to a large class in the community. Its chief recommendation is in its applying the laws of the science of physiology to cases of the deranged or diseased operations of the organs or processes of the human system. It is as thoroughly practical as is a book of formulas of medicine, and the style in which the information is given is so entirely devoid of the mystification of technical or scientific terms that the most simple can easily comprehend it. "--_Boston Gazette. _

 "Of all the works upon health of a popular character which we have met with for some time, and we are glad to think that this most important branch of knowledge is becoming more enlarged every day, the work before us appears to be the simplest, the soundest, and the best. "--_Chicago Inter-Ocean. _

=THE GREAT ICE AGE, and its Relations to the Antiquity of Man. = ByJAMES GEIKIE, F. R. S. E. With Maps, Charts, and numerous Illustrations. 1 vol. , thick 12mo. Price, $2. 50. 

 "'The Great Ice Age' is a work of extraordinary interest and value. The subject is peculiarly attractive in the immensity of its scope, and exercises a fascination over the imagination so absorbing that it can scarcely find expression in words. It has all the charms of wonder-tales, and excites scientific and unscientific minds alike. "--_Boston Gazette. _

 "Every step in the process is traced with admirable perspicuity and fullness by Mr. Geikie. "--_London Saturday Review. _

 "'The Great Ice Age, ' by James Geikie, is a book that unites the popular and abstruse elements of scientific research to a remarkable degree. The author recounts a story that is more romantic than nine novels out of ten, and we have read the book from first to last with unflagging interest. "--_Boston Commercial Bulletin. _

=ADDRESS DELIVERED BEFORE THE BRITISH ASSOCIATION, = assembled atBelfast. By JOHN TYNDALL, F. R. S. , President. Revised, with additions, by the author, since the delivery. 12mo. 120 pages. Paper. Price, 50cents. 

This edition of this now famous address is the only one authorized bythe author, and contains additions and corrections not in thenewspaper reports. 

=THE PHYSIOLOGY OF MAN. = Designed to represent the Existing State ofPhysiological Science as applied to the Functions of the Human Body. By AUSTIN FLINT, Jr. , M. D. Complete in Five Volumes, octavo, of about500 pages each, with 105 Illustrations. Cloth, $22. 00; sheep, $27. 00. Each volume sold separately. Price, cloth, $4. 50; sheep, $5. 50. Thefifth and last volume has just been issued. 

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Transcriber's Notes

A few words are variably hyphenated. They are unchanged from theoriginal. They include uredospores, subglobose, and puffballs. 

Page 23 footnote K: a genus of parasitic Sph[oe]riaceous fungi. Changed to a genus of parasitic Sphæriaceous fungi. 

Page 29HYPOG[OE]I. --These are subterraneanandThe hypog[oe]ous fungi are curiously connectedChanged [oe] to æ to match others in text. 

Page 95 informs us that he has eaten _Boletus lurdius_ changed to informs us that he has eaten _Boletus luridus_

Page 188 separate themselves by a partion from the sterigma changed to separate themselves by a partition from the sterigma

Page 205 like relations to other sph[oe]riaceous fungi. Changed to like relations to other sphæriaceous fungi. 

Page 284 including such cosmopolitan forms as _Sphæria hebarum_ changed to including such cosmopolitan forms as _Sphæria herbarum_

Page 284 _Hirneola auricula-judaæ_ changed to _Hirneola auricula-judæ_