^^^mM ^mmmmmm NlliODUC'ilON TO L ^ )TUDY m:GpCOOKE (lIIjFi.H.HtUaitbrara Qii603 U63 Introductio xhe sTiudy ol" rung! ISSUED TO 7773G This BOOK may be kept out TWO WEEKS ONLY, and is subject to a fine of FIVE CENTS a day thereafter. It is due on the day indicated below: Jc 2 ^ THE STUDY OF FUNGI INTEODUCTION TO THE STUDY OF FUNGI THEIR ORGANOGRAPHY, CLASSIFICATION, AND DISTRIBUTION FOR THE USE OF COLLECTORS M. C. COOKE, M.A., LL.D., A.L.S. adthor of "fungi: their nature, uses, etc."; "handbook of British fungi"; illustrations of british fungi " ; "microscopic fungi " ; "british edii fungi": "handbook of Australian fungi," etc. etc. LONDON ADAM AND CHARLES BLACK 1895 PREFACE The Introduction to Cryptogamic Botany, puljlishcd by Berkeley in 1857, was for a long time the only volume, in English, which could introduce the inquiring student to a systematic knowledge of Fungi. Later on, this work was discovered to be insufficient, inasmuch as it was more suited to the requirements of an advanced student than an inquirer ; so that the field was left open for a more popular and ele- mentary work, which, under the title of Fungi : their Nature, Influence, and Uses, appeared in 1875, subsequently passing through several editions. The rapid advance in knowledge of the life-history and development of these organisms during the past ten years, and especially the large scheme of classification carried out by Professor Saccardo, made it essential that, in order to keep pace with the times, a guide and introduction should be prepared and pul)lished for the use of students, which, whilst not superseding the volume of 187 5 as a popular instructor, should treat the subject more after the manner of a text-book, adapted to the illustration of recent discoveries, and an explanation of the methods of classification. The following pages are the result of an effort to supply an acknow- ledged want, which I have executed under the impression that it is probably my last contribution of any importance to British ]\lycology. For many of the illustrations the publishers and myself duly acknowledge the kindness with which they have been placed at our disposal by the publishers of the works from 77736 vi INTRODUCTION TO THE STUDY OF FUNGI whence they are taken. A large number of the woodcuts will be recognised as formerly belonging to my Hanclhooh of British Fungi, the use of which has now been granted by Messrs. Swan Sonnenschein and Co. We are also under obligations to the publishing committee of the Society for Promoting Christian Knowledge, to the proprietors of the Gardeners Chronicle, to Messrs. Kegan Paul, Trench, Trubner, and Co., Messrs. Macmillan and Co., and Messrs. Chatto and Windus ; for which they will please accept our acknowledg- ments. Beyond this brief prelude I need not advance, as, under any circumstances, readers would prefer taking their evidence from the chapters which follow than from any professions or explanations in a preface. To the student who seeks for assistance I have offered all that I had to give, in the hope that it will be found sufficient for his need. M. C. COOKE. London, 1895. CONTENTS CHAPTER I PAGE Introduction ....... 1 PART I OEGANOGEAPHY CHAPTER II The Mycelium ....... 9 CHAPTER III The Carpophore . . . . . .22 CHAPTER IV The Receptacle . . . . . .31 CHAPTER V The Fructification . . . . . .41 CHAPTER VI Fertilisation . . . . . . .53 viii INTRODUCTION TO THE STUDY OF FUNGI CHAPTER VII PAGE DiCHOCAUPISM . . . . . . .64 CHAPTER VIII Saprophytes and Parasites . . . . .73 CHAPTER IX Constituents . . . . . . .84 PART II CLASSIFICATION CHAPTER X Fungi in General . . . . . .95 CHAPTER XI Naked -Spored Fungi — Basidioiitcetes . . .119 CHAPTER Xn Hymenomycetes . . . . . . .126 CHAPTER XIII Puff-Ball Fungi — Gasthomycetes . . . .149 CHAPTER XIV AsciGERous Fungi — Ascomycetes . . . .164 CHAPTER XV Discoid Fungi — Discomycetes . . . . .173 CONTENTS CHAPTER XVI PAGE Subterranean Fungi — Tureraceae . . . .189 CHAPTER XVH Capsular Fungi — Pyrenomycetes . . . .197 CHAPTER XVm Gaping Fungi — Hysteriaceae . . . . .222 CHAPTER XIX Conjugating Fungi — Phycomycetes . . . .227 CHAPTER XX Rust Fungi — Uredineae . . . . .242 CHAPTER XXI Smut Fungi — Ustilagines . . . . .251 CHAPTER XXII Imperfect Capsular Fungi — Sphaeropsideae . . . 259 CHAPTER XXIII Moulds — Hyphomycetes . . . . .277 CHAPTER XXIV Microbes — Schizomycetes and Saccharomycetes . . 290 CHAPTER XXV Slime Fungi — Myxomycetes . . . . .304 X INTRODUCTION TO THE STUDY OF FUNGI PART III DISTEIBUTION CHAPTER XXVI PAGE Census of Fungi . . . . . .319 CHAPTER XXVn Geographical Distribution . . • . . . 324 CHAPTER XXVm Appendix on Collecting ..... 345 GLOSSARY . . . . . . .353 INDEX ........ 358 CHAPTER I INTRODUCTION The student will expect to find in an Introduction to the study of any subject some definition and delimitation of that subject — a task difficult in all cases to accomplish with brevity, and within the compass of a technical description, but one of in- creased difficulty when the subject is so extensive and com- plicated as Fungi. In past times definitions have been hazarded which appeared at the time to be incontestable and complete, but within a short period they became insufficient. That they are plants of a low organisation must be conceded, and also that they belong to the lowest section, or the Cryptogamia, in which the reproductive organs are more or less concealed ; but the old characteristics of Algae as cellular plants subsisting in water ; of Lichens as subsisting in air, and not upon the matrix on which they flourish ; and, finally, of Fungi, which derived their sustenance from the matrix, have had to be discarded as in- sufficient. It is now known that aquatic Fungi are not an knpossibility, that Algae may grow in a damp atmosphere, and that some portion of the substance of Lichens may be derived from their matrix. Seeing the difficulty of obtaining positive characters, negative ones have been tried ; but these again have failed to give satisfaction. In one of the most recent works which has attempted to deal with this difficulty we meet with the following as one of tlie " leading characters." It is to the effect that " Chlorophyll, the green colouring matter so general in the vegetable kingdom, is entirely absent from fungi." ^ Admitting this to be true, may it not be maintained that there 1 Massce, British Fungi (1891). ]>. 1. 1 c. r No..:. college 2 INTRODUCTION TO THE STUDY OF FUNGI are probably some lichens or some algae in which true chloro- phyll is not present ? But speaking of them as a whole, we are justified in saying of Fungi that they are " cryptogams without chlorophyll," and in this we shall embody the most important characters of the group " — a general definition which may be accepted without reservation. Except for one or two small fiimilies, we could add also " without determinate sexuality." Previous to this, Berkeley had pointed out that the definition was imperfect which described Fungi as " deriving nourishment by means of a mycelium from the matrix, and never producing from their component threads green bodies resembling chlorophyll," -^ for, he goes on to observe, " it is true that a few Algae, such as Botrydium, do probably imbibe some- thing from the soil by means of their rootlets, which can scarcely be mere holdfasts " ; and again, " When we examine Fungi more closely, we shall have reason to believe that there are exceptions here also as to their deriving nutriment from their matrix. I have, for instance, found a Cyphella on the hardest gravel stones, where the fine mycelioid threads, by which it was attached, could not possibly derive any nutriment except from matters conveyed to it by the air or falling moisture." To the latter portion of the paragraph, giving the negative character of the absence of chlorophyll, Berkeley, however, gives his adhesion. A logical definition, therefore, so commonly fails, that we shall excuse ourselves from attempting a new one, simply indicating a few points to be borne in mind whilst perusing the following pages, from whence alone a general idea can be obtained of such a polymorphous group. Lindley divided all the Cryptogamic plants into two sections, the Acrogens, growing at the summit, including the Ferns, Mosses, and their allies, and the ThaUogens, which embraced Algae, Fungi, and Lichens. Hence we conclude that Fungi are not only Cryptogams, but of that section in which there is no true root or distinct stem with foliaceous appendages. Although the Rev. M. J. Berkeley was, in the main, responsible for Lindley's classification of the Cryptogams, it is out of date and inapplicable in the present ^ Introduction to Cryjriogamic Botany, p. 235. INTRODUCTION day, when other and improved methods have been brought into use. Instead of the term Thallogcns for the celhilar Crypto- gamia, it would be preferable to call them Thallojihytes, and, for the rest, Brj/ophytes would include Mosses and their allies, whilst Fteridophytes would be represented by the Ferns. Thallophytes, in a general sense, which will be sufficient for practical purposes, consist of those plants which grow in water, and obtain their sustenance therefrom, conmionly known as Algae ; and those which Hourish in the air, l^eing sustained by the decomposition of the matrix on which they flourish, as Fungi ; or drawing their sustenance from the air, and rarely, or but slightly, from the matrix, as in Lichens. Here again a negative feature may be interposed with advantage, to the effect that Lichens are not of a Heshy or putrescent, but of a dry and leathery consistence, whereas in the bulk of Fungi the substance is, either entirely or in the early stage, soft and fleshy, becoming indurated or putrescent with age. The distinctions between Algae and Fungi will never cause any practical difficulty, because the Saprolegnieac, which are aquatic, and approach Algae most nearly in habit, derive their sustenance from the matrix on which they are parasitic by means of penetrating mycelial threads, whereas Algae are simply attached by root-like or sucker-like extensions to the matrix, from which nothing is absorbed. The relations between Fungi and Lichens are much more intimate, and in extreme cases approach each other so closely as to be distinguished with difficulty even by experts. Whole genera are still claimed by mycologists on the one hand, and by lichenologists on the other. Still it must be remembered that these are extreme cases, and that amongst the larger Fungi, especially in the great group of Hymenomycetal Fungi, there is but little suggestion of Lichen affinity except in such genera as Cora, Dictyonema, Pavonia, etc. Another exceptional case may be found in the Nostoes, which are Algae, simulating or so closely resembling Tremella, a genus of Fungi, that microscopical examination may be necessary for their discrimination. Habitat may in some cases serve to indicate the character of the Thallophyte. For instance, all the parasites on living leaves which are not of insect origin are Fungi, such as the 4 INTRODUCTION TO THE STUDY OF FUNGI smuts and rusts which are so destructive to crops. There are often to be seen discoloured spots upon living leaves which cannot be attributed either to insects or Fungi. It is a common mistake with novices to infer that all leaf spots are necessarily caused by parasitic Fungi. Again, all the fixed or vegetable parasites on insects are Fungi, whether moulds or the larger club-shaped species of Cordyceps. Another caution becomes necessary lest the pollinidia of Orchids, which are sometimes seen temporarily attached to living insects, should be con- founded with true parasites. Putrescent vegetable, and some- times animal substances, give rise to Fungi, but dead wood and the bark of trees may also support Lichens as well as the living bark, on which Fungi are rarely found, except in cases of incipient decay. No difficulty need be anticipated in respect to Thallophytes found growing upon the ground, inasmuch as the Lichens which have a terrestrial habit would scarcely be con- founded with Fungi at any time, but especially after the perusal of succeeding chapters on the details of structure in the several orders. It should be understood that the above- named distinctions are not so much of scientific value as they may be useful as guides to collectors. The mycelium of Fungi is so general, although at times nearly obsolete, tliat it must be regarded as somewhat analogous to the thallus of Lichens, but not to be confounded therewith. In the Agarics this mycelium is commonly termed the " spawn," and consists of delicate threads, which traverse the soil or the rotten wood upon which the Fungus is grown. In some instances a strong mycelium is developed, but no perfect Fungus is produced upon it. An instance may be found in the substance called Xylostroma giganteum, which forms thick sheets like leather, destructive of wood of solid texture. It is doubt- less a degraded form of wood-destroying Hymenomycete.^ The moulds and the mucors produce at first decumbent barren threads, which constitute the mycelium out of which sub- sequently the fertile threads arise. In the " rusts " or Uredines the cushion-like base of the pustules is surrounded by the delicate threads of mycelium. Going back to its origin, we discover that the initial spore, or spores, upon germination pro- ^ See next cliapter, p. 10. INTRODUCTION duces a delicate thread wliicli, either directly or indirectly, origin- ates the mycelium upon wliicii the Fungus of the new generation is developed. In the Agarics it is held that a large numl)er of spores germinate, and produce the mycelium from which a single individual or a cluster of young Agarics are evolved. In some instances the mycelium is undoubtedly perennial, and produces a crop of Agarics in successive years, but much remains still to be known of the life -history of the Agarics in the interval between the maturity of the spore and the first evidence of the genesis of a new plant.^ In some of the smut Fungi the germinating spore produces a thread which develops secondary spores, and these in their turn produce tertiary spores before the true mycelium-forming spores are developed. In the Uredincs the earliest spore-forms, called "pro-mycelial spores," are produced from the germinating threads of the latest spore-forms or teleutospores, which in turn give rise to the mycelial threads '' that enter and form a new mycelium within the tissues of the invaded host-plant. In the Erysiphei the mycelium forms an external coating on the surface of the living leaves, producing at first conidia, and ultimately the perithecia or spore^capsules of the perfect Fungus. Indeed, as a rule, the mycelium repre- sents the vegetative system of the Fungus upon which, under varied forms, the reproductive organs with their appendages are produced. The universality of this mycelium in Fungi was formerly held to be as certain an indication of distinction between a Fungus and a Lichen as the production of a thallus was then held to be a sufficient distinct,ion between a Lichen and a Fungus. In later times it has come to be understood that the hyphal elements in Lichens and Fungi are virtually the same. ' In this connection may be consulted Brefeld's researches into the life-liistory of Coprimis stereo rarius. - See j)ust, chap. xx. BIBLIOGRAPHY Beiikeley, M. J. Outlines of British Fungology — Introductory Matter. 8vo. Plates. London, 1860. • Introduction to Cryptogamic Botany. Roy. 8vo. Cuts. London, 1857. Articles on " Vegetable Pathology," in Gardener s Chronicle, from 1855. LiNDLEY, J. Vegetable Kingdom. 8vo. Cuts. London. 2nd Edition. 1847. CouKE, M. C. Fungi: their Nature, Influence, and Uses. Sm. 8vo. Cuts. London, 1875. A plain and easy Account of British Fungi. Sni. 8vo. Plates. London. Itomance of Low Life amongst Plants. 8vo. Cuts. Loudon, 1893. BouDiER, E. "Considerations sur I'fitude microscopique des Champignons." Bulletin de la Socitti Mycologique de France, vol. i., 1885, p. 134. De Bary, a. Comparative lUorphology and Biology of the Fungi, Mycetozoa, and Bacteria. English Translation. Roy. 8vo. Cuts. Oxford, 1887. Tavel, F. von. Vcrgleichende Morphologic der Pilze. Jena, 1892. PAKT I OKGANOGEAPHY CHAPTER II MYCELIUM In such an imineiise group as the present, incUiding ahnost an infinite variety of form, it is extremely difficult to generalise, even the morphology, beyond that of the mycelium, which re- presents the vegetative system, the carpophore, which supports the fructification, and, finally, the fructification itself, with the organs associated therewith. This, in fact, reduces the whole scheme of structure to its lowest terms, that of the vegetative system and the reproductive, since the carpophore is but a development of the vegetative, and a link between that and the fructification which it is intended ultimately to bear. The details of the varied modifications, which are to accomplish the two purposes of growth and rejuvenescence, can only be de- scribed under the great primary divisions of Fungi, where both vegetation and reproduction conform to some definite type. As a whole, the organisms which are associated to- gether under the common denomination of Fungi are the most protean and polymorphic in the entire vegetable kingdom, and present great difficulties in the way of generalisation. If we gather a mushroom from a mushroom bed, as usually cultivated, we shall discover, if we remove it carefully, that the stem, which represents in this instance the carpophore, or fruit-bearer, is attached to the soil by a mass of delicate white hyphae, or threads, which are the mycelium, or spawn. And if we remove the soil anywhere, we shall find that it is per- meated in all directions with these white threads. The artificial "bricks," or spawn, which were employed in the construction of the bed, consisted of this mycelium in a quiescent condition, and by supplying sufficient moisture and lo INTRODUCTION TO THE STUDY OF FUNGI heat, with a suitable matrix, the filaments of this mycelium have been revivified, and by a profuse and rapid growth they have spread over, and penetrated the whole of the soil of which the mushroom bed is composed, and constitute the vegetative system of the mushrooms which afterwards appear on the surface. This mycelium represents an important element in the morphology of all Fungi. It is rarely reduced to such small proportions as not to be recognised, but, practically, it is possibly never wholly absent. We may start, therefore, with what we may regard as an essential attribute of Fungi, and the representative of the purely vegetative system. Where- ever we see a Fungus of the mushroom type, whether we please to call it a mushroom or a toadstool, we may find the mycelium in the soil from which it springs. In the autumn, if we stir up and turn over any clump of dead leaves or other decaying vegetable matter in a damp situation, we shall be sure to find a profusion of this mycelium, even though no perfect Fungus makes its appearance, and it is at work on every dead stump and every fragment of rotten wood. Mycelium consists of hyphae or threads, usually septate, sometimes simple, but mostly branched, increasing by growth at the extremities, and gregarious, so as to form reticulated interwoven masses, either in a thin network or a densely-felted mass. In a certain sense they are analogous to the roots of flowering plants, and, like them, draw moisture and inorganic constituents from the soil or other matrix on which they may be developed. It is another axiom with Fungi that, by means of the mycelium, they derive their sustenance from the matrix on which they grow. It cannot be doubted that the growing points of the mycelium possess the power of penetration by the production of a ferment, since they are capable of pene- trating the hardest wood, disintegrating the cells, and reducing it to powder. The ordinary mycelium found amongst dead leaves has a power of disintegration, and soon reduces them, as well as twigs and stems, to a condition of humus ; but the progress of mycelium in a dead trunk is quite as definite and certain. Who can doubt the disintegrating power of the mycelium of the " dry rot," and it must be borne in mind that it is the mycelium in this instance which works the M YCELIUM mischief. Tlie hyphae forming this vegetative system may be immersed, and prohaljly are so in the majority of instances, but they may also form a stratum on the surface, and adhere by haustoria or suckers, which are short brandies designated for the purpose, or for that combined with the absorption of nutriment. Tlie hyphae when young have colourless cell walls, but as they grow older the walls thicken and acquire colour, sometimes with an appearance of stratification. In some cases cross branches anastomose, or form clamp connections (Fig. 1). Gardeners are well aware that immense masses of white mycelium are some- times met with in turning over tlie soil. These mark the site of an old tree when part of the stump or dead roots have been left to rot in the ground. Numerous instances are on record in which trees or shrubs, when planted in soil overrun in this manner with mycelium, have been killed, and when taken up the roots Ibund ^^^ ^ _ (^;^ to be enveloped in mycelium. I'ractical men connections. are quite aware that this has occurred over ^^"^^ ^ '''^^'" and over again, and yet some theorists contend that it is not possible, because the mycelium is a saprophyte, that is to say, flourishes upon dead organic matter, and not upon living tissues. Observation has nevertheless decided that in some instances a saprophyte may become parasitical, and a parasite may acquire the habits of a saprophyte. The instances may not be common, but are not impossible. Against theory we are prepared to contend, from experience, that we have seen plants killed, after planting in a soil overrun with mycelium, from no other assignal)le cause, and afterwards dug up with the roots enveloped in mycelium. It has been stated above that mycelium is usually colour- less, and it is generally so with the Basidiomycetes, but there may be exceptions, as in Corticium sangitineum, with its mycelium of a blood red, in Elaphoviyces LcveiUci, of a yellowish green, in Chlorosplenium aeruginosum, of a verdigris green, and in many of the Dematiaei, of a dark brown, or almost black. And so also it may differ considerably in quantity, from a few scattered threads to a dense matted felt. Even in tliis country 12 INTRODUCTION TO THE STUDY OF FUNGI it sometimes forms thick Laminae many inches broad in old trunks, but in warmer countries it develops into a spongy- mass, called Xylostroma in past times. These masses will fill up holes in a log nearly as thick as the wrist, and a foot or two in length, or they will spread in layers of an inch in thickness, a foot in breadth, and several feet long. The whole mass is made up of interwoven threads, almost as dense as cork when felted together, but wholly barren, so that it is uncertain whether they are the mycelium of a Polyporus or an Agaric. Having been furnished with a redundant supply of nutriment, they never advance beyond the vegetative stage. In the case of entomogenous Fungi, the mycelium will replace the whole of the tissues, even to the legs and feet, so as to form a com- plete cast of the insect, of which only the dermal covering remains unchanged. In such genera as Cordyceps and Empusa the filamentous structure is only seen in the earliest stage ; this soon gives way to a compact granular mass. The mycelium of the Mucedines, or moulds, when abundantly supplied with moisture, develop rapidly and vigorously, but do not proceed with the fructification whilst the nutriment supplied is abnor- mally great. The conidial stage of the Erysvphei will furnish examples of a thin superficial mycelium adhering by haustoria. In these cases a thin white web runs over the surface of living leaves, as in the vine mildew, and a mildew on the leaves of the maple, but it does not penetrate deeply into the tissues of its host, which it injures by choking up the stomata. Another superficial mycelium is that of Fumago, which forms black patches on the leaves of the lime and other trees, being especi- ally vigorous on those subject to honey-dew. In the sphaeria- like or capsular Fungi, the mycelium is confined, usually, to a few delicate threads at the base of the perithecia, but there are exceptions to this in some superficial species, where a subiculum or conidia-bearing mycelium is present. Another form assumed by mycelia is that condition whicli has long been known under the name of Rhizomorpha, when it was suspected to be an independent Fungus, although no form of fruit had been discovered. It is now admitted that the several species are only the vegetative condition of other Fungi. One kind may be seen running between the bark and wood oi MYCELIUM 13 dead trunks in long brown or black cords, as thick as whip- cord, flexible, but tirm, and either branched or joined by cross connectives of the same substance, into a coarse net- work. These Ioiil;' cords may be many feet in length, and whitish internally, with a dark-coloured outer coat or skin. The tips of the growing branches are paler. This peculiar growth is very connnon in mines and other dark places, and glows sometimes with a phosphorescent light. Tulasne examined some specimens with a view to the discovery of the cause of their luminosity, of which Humboldt, amongst others, had given such an elaborate account. He found that all the young branches brightened with a uniform phosphoric light the whole of their length, and also the surface of some of the older branches. The latter when split open were dull, but after exposure for a time to the air they also became luminous. By keeping them moist, they preserved their phos- phorescence for several days. He also states that branches which had been dried for more than a month, when plunged into water, revived, and began to vegetate afresh, in a few days, by sending forth numerous branches, but they were only luminous on the surface of the new parts. One of our commonest Agarics, to be found on nearly every rotten stump, Agaricus melleus, is credited with being the complete develop- ment of one of the species of Rhizomoiyha, which may be stated in this way — the cord-like Rhizomorjpha is simply the persistent mycelium of Agaricus melleus, which grows on rotten stumps. We have no doubt that another form or variety of lihizoviorpha is the mycelium, or vegetative con- dition of Polyporus squamosus, and others, with more or less certainty, are referred to other species of Agaric and Polyponis. Something of the nature of Rhizomorpha is found amongst dead leaves, mostly in long, simple, rigid black threads, which in size and appearance are not unlike horse hair. These are believed to be the mycelium — or rather, we should say, the permanent mycelium, to distinguish it from the filamentouf. white mycelium — of some species of Marasmiits. In tropical and sub-tropical regions these horse- hair filaments are very common amongst dead leaves, and are known to be sterile conditions of several species of Marasmiits. INTRODUCTION TO THE STUDY OF FUNGI There is another condition which the mycelium of some Fungi assume that is something of a resting stage, and in former days these were classed under a genus called Sclerotium. They are in the form of hard, compact, irregular nodules, from the size of a pin's head to that of a child's head, according to the species. They are mostly dark coloured externally, and nearly white and horny within, with a firm cellular substance. We will conmience with one that is well known, under the name of Ergot, and occurs on the spikes of rye, wheat, and many grasses, converting the ovary into a Sclerotium, or replacing the ovary with a Fungus growth, whichever view pleases best. These abnormal growths are three times as long as the ordinary seed of the rye or grass, elongated, and a little curved, so that they look like a horn or spur projecting from the ear of grain. If a thin slice of the substance is placed under the microscope, it will be seen to consist of a densely compact mass of cells, somewhat irregular from mutual pressure, with thick walls and rather oily contents. At last they are liable to become dissociated from the spike, and fall to the ground, where they will lie quiescent and unchanged through the winter. When spring arrives, active vitality recommences, and the sclero- tium germinates by producing one, two, or more — generally several — little slender twisted stems, with a globose head, reminding one of a pin. The stem is whitish, and the head of a pale purple. It is within the globose head that the fructification is produced. This latter is the mature Fungus of the Ergot sclerotium, and is then called Claviceps jmrpurea, one of the Sphaeriacei (Fig. 2). By way of illustration, we have indicated briefly the history and development of the Ergot sclerotium, but it will scarcely be consistent with the design of this chapter to repeat the process for other species. Another example may be found inhabiting the dead haulms of potato. . First of all the haulms FiQ. 2. — Ergot Sclerotia germinating. After Tulasne. MYCELIUM 15 are covered with a dense felted mass of wliite mycelium. When this is fully developed, scores and hundreds of little black points appear in the midst of the hyphae, averaging in size I'roni a u;rain of sand to that of a small bean. These become indurated and hard, and, in fact, properly-constituted sclerotia, internally composed of polygonal cells. These also subside into a con- dition of rest, in which they spend the winter, and germinate in spring. The re- sulting Fungus in this instance consists of similar slender twist- ed stems, but the head, instead of being globose, is cup-shaped, then flattened, bear- ing the name of Sclerotinia Libertiana , or, as known in former years, a species of Peziza, one of the Dis- comycetes (Fig. 3). Several other instances might be quoted in which the Sderotium, when germinating, produced a species of Peziza, especially a large one common in company with the roots of the Wood Anemone. A large species of Russula, common in the woods, turns quite black when dead and decaying. On the gills of these decaying Bussulae many sclerotiae will be seen, resembling in form small grains of barley. These germinate speedily, and produce a little Agaric {Collyhia tuherosa). In Australia a sclerotium nearly as large as the fist develops a tough gill-bearing Fungus, shaped like a wine-glass, named Lcniinits ajathus. But a still larger sclerotium, which has been known for years as " Native liread," and grows as large as a cliild's bead, has been recently found to develop a white Polyponts with a central sttMu, and has been named Pulyporus MyLiltac} 1 Orcvillca, Dec. 1892, \\ 37. Fig. 3. — Sclerotia gerniiuating and producing Pezizae, A to D. Ascus and sporidia, E. Gard. Vhron. 1 6 INTRODUCTION TO THE STUDY OF FUNGI We have biietly directed attention to the ordinary develop- ments of mycelium, whether filamentous or sclerotioid, but there are still one or two special modifications which must obtain a passing reference. Of these the mycelium of the Uredineae is deserving of mention, being formed within the tissues of living plants, and often starting centrifugally from a definite point of infection. The hyphae resemble ordinary mycelial filaments, but, like all internal mycelia, are delicate, branching and anastomosing so as to form compact cushions or spore beds, or, in other cases, much diffused and scattered. In annuals or upon deciduous parts the mycelium is, of course, only annual, but if it passes into perennial parts, as it may readily do in shrubs and other perennials, the mycelium becomes perennial. Take, for instance, the Juniper, in which the Crymnosporangium may be sought for and expected regularly year after year. In such species as have a scattered mycelium there is not much difference between the mycelium of these and that of other endophytes, but when the mycelium is circumscribed, the tissues are hypertroj)hied, and starch seems to be accumulated in the deranged cells. Leaves thus attacked never repair the injury, and the diseased spots are the first to die, and occasionally drop out, as we have seen with the large clusters of perfect-spored pustules in Puccinia deanthi. The mycelium of the Feronosporeae is more diffused than that of the Uredines, commonly penetrating the whole plant, descend- ing into the stem and roots, and in the stems producing oospores, as the result of a sexual conjugation. In the Ustilagineae the mycelium is much more diffused than is usual in the Uredines, permeating the entire plant, and in perennial hosts producing fruit regularly year after year. The Phycomycetcs, which include those mould-like Fungi which bear inflated sacs at the apices of their fertile branches containing numerous spores (Ilucors), have a mycelium without septae. The Mucors themselves are mostly saprophytes, and some of them have a profuse mycelium. The reproduction is both asexual and sexual, the sexual being developed from the mycelium ; hence the mycelium in these Fungi, although at first only vegetative, becomes finally reproductive, and thus assumes a higher function. The process is after this kind : two short MYCELIUM 17 branches of the mycelium approach each other until they touch at their apices. The branches swell and become club-shaped, including a rich store of protoplasm. At length the upper portion of each club is cut off by a transverse septum, and the two apical segments are fused into a globose body, the walls at the point of contact being dissolved. Thus we have two thick supporters, with a globose body suspended between them, which is to become the zygospore, resulting from the conjugation and coalition of the club-shaped branches (Fig. 4). The succeeding steps need not be detailed ; the zygospore acquires a thick outer coat, and then becomes a resting spore, which only germinates after a period of rest. The same mycelium therefore produces Fia. 4. — Zygospore of Mucor in course of formation. After De erect carpophores, or couidiophores, surmounted by an inflated vesicle containing conidia, an asexual generation, and also pairs of nearly sessile branches, which collide and form a zygospore between them, a sexual generation. Similarly, in other families the two kinds of reproduction are developed, asexual and sexual, from different parts of the same mycelium, but not precisely in the same way, yet the details do not affect the mycelium greatly, except in the family to be presently alluded to. The Entomophthoraccac^ are those Fungi which are parasitic and destructive to insects, including the ordinary fly mould, ' The Enlomophthorcac of the United States, by Roland Thaxter, 1888, Boston, U.S. i8 INTRODUCTION TO THE STUDY OF FUNGI Fig. 5. — Hyplial bodies in Entomophthoraceae. After Thaxter. Empusa iiuiscae. When the spore of one of these moulds alights upon the body of its favourite host-insect it sends out a germ tube, which enters the body at any favourable spot, and when this is once accomplished, it develops rapidly, at the expense of the tissues it replaces. It does not form a branched mycelium, but grows by the production of hyphal bodies (Fig. 5), which are short, thick bodies of variable size and shape, and these continue to nmltiply, by budding or gem- mation, until they hll the insect. It is possible that in some cases a mycelium of the ordinary kind may be produced. When the whole interior is absorbed, and of course the insect is dead, the vegetative stage ends, and the raproductive begins, by the protrusion into the atmosphere of conidiophores terminated by conidia, either singly or in bundles, until the body is covered with the conidia, ready to be dispersed. This is the asexual reproduction of conidia, but resting spores are also formed, which may be sexual or asexual, according to the species. In some cases the conjugation of two threads of the mycelium, and in others the conjugation of two of the hyphal bodies (Fig. 6), results in the formation of a zygospore. There is a peculiarity about the conidia which may be noticed, which is, that should a ripe conidium not be able to find or enter a host-insect, it can proceed to germinate and form a secondary conidium, which has the same power of infection, and may be more fortunate. If this also fails, the secondary conidium may pro- duce a third, so that the vigour of the conidia is kept preserved until able to infect a host. Possibly the Isaria moulds, in the interior of insects, extend their mycelium in a similar manner by budding, as they are also granular rather than filamentous. In opposition to the views of some mycologists of ex- perience and repute, we still remain persistent in our adhesion Fig. 6. — Hyphal bodies in Entomophthoraceae con- jugating. ; After Thaxter. MYCELIUM 19 to the vegetable nature of the Myxomycetes, and consequently regard the vegetative condition as upon an equality in function, if not in structure, with the mycelium. This was clearly the view of ]\I. Luveille, who termed it " a malacoid or pulpous mycelium." We see no objection to its being called a Plas- modium — the name does not alter its character or functions. Dc Bary was content to admit that the wall of plasmodia, as well as the cell-walls of spores and other parts, gave a distinct cellulose reaction, and possil.)ly cellulose in some form is general in ]\Iyxomycetes. And further, according to the same eminent authority, the presence of cellulose is the only character show- ing that these organisms are in touch with the vegetable kingdom. This question we are not anxious to discuss further here. Swarm-cells with the power of movement are produced on germination from the spores of ]\Iyxomycetes ; these swarm- cells ultimately coalesce and form a plasmodium, which is capable of passing into a resting stage, and sometimes to become sur- rounded by a colourless membrane. There are no threads or filaments, as in a filamentous mycelium, neither in the sclerotioid mycelium is there a similar resemblance ; in fact, there is no greater difference between a plasmodium and a sclerotioid my- celium than there is between a sclerotioid and a filamentous my- celium. From the plasmodium are differentiated the carpophores, the receptacles, and the fructification of a Fungus, even although the Plasmodium or analogue of mycelium is not filamentous, but rather resembles a sclerotiuni in a soft and pulpy condition. Theoretically, mycelium originates with the germ -tubes which are protruded by spores or conidia upon their germina- tion. It is easy enough to observe the process thus far, produced artificially by placing the spores in a nutritive fluid, but in the case of the larger Fungi the operation cannot be carried much further under ordinary circumstances. In the case of Agarics it is concluded that the mycelium produced by a number of spores unite in the production of a single Agaric, so that one specimen is the produce of several germinating spores. We know that the soil contains a great mass of mycelium in places where Fungi are found growing. Worth- ington Smith says ^ that the Agarics of the autumn spring up ' Reproduction in Coprinus, Grevillca, iv. (1876), p. 53. 20 INTRODUCTION TO THE STUDY OF FUNGI from the mycelium formed during the fall of the previous year, and this mycelium has rested in the ground for twelve months. In digging up old pasture ground, or the dead leaves of an autumn which has passed, mycelium in a resting state is invariably found. We can hardly conceive of the preservation of the spores of an Agaric through the winter and an entire year, until the succeeding autumn, in any other way than by the production of a hibernating mycelium. The spores them- selves have too delicate an epispore to resist the effects of cold, and we know from analogy that the resting spores of Algae and Fungi, when known to be such, are provided with a special thick outer envelope. The spores of Agarics are not thick coated, and are incapable of hibernation ; hence we are driven to the alternative of a perennial mycelium. A theory was once propounded that a conjugation takes place in the threads of mycelium which results in the production of a fertile Agaric, the whole of whose fructification is thereafter rendered fertile, but this view has never been accepted. Notwithstanding all the theories, w^e are still in search of the process of fecundation in Hymenomycetal Fungi. All that we can contend for is the persistency of the mycelium as the means whereby the Mush- room Fungi are carried through the winter and reproduced in the succeeding year. There is a prevalent opinion, in Germany at least, that " root fungi " are not always injurious to trees, but sometimes, on the contrary, beneficial. Frank ^ states that certain trees are unable to derive nutriment direct from the soil, but do this by means of a mass of Fungus hyphae which entirely invests the root, to which he gives the name of Mijcorhiza. It makes its appearance first on young seedlings, and is replaced by fresh formations on older roots. He found it on the roots of every tree examined belonging to the Cupuliferae, and occasionally on willows and conifers, but considers it may only be formed in soils which contain a large amount of humus, or undecomposed vegetable remains. Through the Mycorhiza the tree absorbs not only water and mineral con- stituents, but organic substances derived from the humus. Two or three other authors have since confirmed this in 1 Journ. Roy. Micr. Soc, vol. v. (1885), p. 844 ; vol. vi. (1886), pp. 113, 663. MYCELIUM the most important particulars, but not as to its constant presence. The mycelium is the active a«,fent l)y wliich Fungi disin- tegrate decaying organic matter, or prey upon and destroy the living, and so far as they derive nourishment from the sub- stratum, their nutrition resembles that of flowering plants, but beyond this the mycelium is active in decomposing the organic matrix, the product of which is not required or taken up by the Fungus. Hence there are forms which are satisfied with taking up from living or dead substrata only so much as is needed for the construction of their bodies, as well as those which in addition produce copious decompositions in the substratum and destroy it. We may assume that the mycelium exerts a ferment action upon the matrix, although the quantity of the ferment may be small, and that these ferment actions first take place in order to convert a portion of the substratum into a form which is capable of nourishing the Fungus. In the headings of the several chapters we have used terms in their general sense, representing the mycelntm as equivalent to the vegetative system, the carpopliore as the supporter of the fructification, or intermediary between the vegetative and reproductive systems, whilst receptacle is employed in a sense different from that which it holds in other branches of botanical science, and should be accepted literally as representing the envelope of the fructification, whatever its form may be, when any envelope is present. This definition is necessary so as to prevent confusion of the terms we have employed in a general sense, with their special application elsewhere. CHAPTEK III THE CARPOPHORE The mycelium, in all its forms and variations, is but the prelude and preparation for the development of such parts or organs as may be necessary for the subsequent processes of reproduction. The production of the carpophore is, in itself, only a continuation of the process of vegetation, but that vegetation is no longer subterranean, subcuticular, or creeping ; invariably it is more or less, in development, at right angles to the mycelium, and may be accomplished by the production of special erect branches, or a stem compounded of an indefinite number of erect threads, agglutinated and consolidated together ; whether it is to be the conidiophore of a mould, the stroma of a Cordyceps, the club of a Gcoglossum, or the stalk of an Agaric or Boletus, it is the fruit-bearer, or carpophore, which is destined to bear the fructification of -Unbranched the spccics. It may be reduced to its lowest carpophore of terms, and be practically obsolete, so that the RhojKi.lomyces. ^ " receptacle is sessile, or nearly sessile, upon the mycelium ; still there is normally and technically a carpophore, which supports the organs of reproduction. In the larger moulds generally the ascending hyphae are branches of the mycelium, and do not alter much in character except in being rather thicker and with more rigid walls, so as to maintain an erect position. These erect threads are in most cases clustered together, and are modified in ramification ^ The term " carpophore," in its special sense, is usually restricted to forms of a distinct fruit, consisting of an aggregate of reproductive organs. THE CARPOPHORE according to the different genera. In certain cases, as in Aspcrcjillus and Iiho2)alomyccs, tliey are simple and unbranched up to the top (Fig. 7), but in the hirger number of genera they are branched in the upper portion. Very often a great number of these car- pophores are produced in a large woolly - looking patch, not rarely for an inch or two in length. Endo- genous moulds, which produce mycelium in the interior of the tissues, send up little tufts of carpophores through the stomata, and these grow in patches. Well-known examples are to be found in the genus Peroiiospora, such as the mould on parsnips and onions (Fig. Raimdaria the mycelium is internal, and the conidiophores pass in the same manner out into the atmosphere ; but they are usually short, often unbranched, with a single conidium. In Oidium the mycelium is external, and the erect hyphae are simple, but it is only the short lower portion which is truly a carpophore, for the upper portion is constricted successively, and the joints fall off as they are formed, and become conidia. There are also genera in which the carpophore is compound — that is to say, a number of threads are combined so as to form a common stem, which is consequently thicker and more permanent. Either these individual hyphae diverge at the apex, or they remain united and form a ca]»itulum, as in Stilhum. When- the combined threads form only .1 sliort erumpent stroma, as in Tiibercularia (Fig. 9), the carpophore is reduced nearly to its lowest denomination, and is scarcely more than an erumpent pustule. .Ml the foregoing forms are repeated in Fi>i. 8. Br.iiiehed c-uriiopliorf of l't:ronospora. 8). In the genus INTRODUCTION TO THE STUDY OF FUNGI "xjI. — Compound carpophore of Tubercularia. the Dematioei, or black moulds, the chief difference being in the dark-coloured, more rigid, and carbonised hyphae. Eesembling the moulds in external habit, the Mucors resemble them also in the carpophore, which is sometimes forked two or three times, but not dendritically branched. In Pilobolus the carpophore is curiously inflated, like a bladder (Fig. 10). We have in remembrance a pseudo-analogy which some few years since became current — that the type of organisation in a Muce- dinous mould was repeated, with modifications, in the structure of Agarics. The mycelium, it was con- tended, was common to both. From the mycelium arose the carpophore, which was a compound stalk, in which a myriad of erect hyphae were combined ; in the pileus the combination was continued of the branches, and then down to the basidia, which were the terminals of the branchlets, with the spores, or conidia on spicules, as in such a genus as Bhiiiotrichinn. This was a fanciful representation, since the analogy, even if it held good elsewhere, was broken at the hymenium, and the basidia were therefore not in continuity with the trama. In the Hymenomycetcs, or at least in the Agaricini, the stem is continued from the mycelium at right angles, as in the moulds, and is compounded of an infinity of elongated parallel cells ; these are sometimes deficient in the centre, and the carpophore, or stem, becomes hollow. Leaving the appendages to the stem out of question, it is still an erect carpophore, and hence its func- tions are the same — that of elevating the re- fig. lo.— inflat- productive organs into the atmosphere. In ed carpophore the same manner also the materials of nutrition, derived by the mycelium from the soil, are conveyed upwards to the residue of the plant. The veil, where it exists, is jupplementary appendage, not found in the moulds, and THE CARPOPHORE simply an extension of the margin of the receptacle, or pileus, for the projection of the young hymenium. In Boletus and the stipitate Polyporci, Htjdnci, etc., the carpophore is of the same type. In such of the species of Flcurotus, Fomes, etc., as have no stem the pileus, or receptacle, is sessile, and the carpophore is reduced to a mere disc, or is obsolete. The external surface of the stipe or stem is sometimes glutinous, as in the section Myxacium of the genus Cortinarius ; or it is velvety, as in such species as Collyhia longipes and C. vehitipes ; or it may be woolly, chiefly at the base, or broken up into scales ; and all these conditions doubtless serve in some way to fulfil some purpose. AVorthington Smith has suggested that they are probably of service to arrest the spores as they fall from the hymenium, and, as he thinks, also the deciduous cystidia. Of the internal structure M. de Seynes remarks that the collective cells, which form the stipe, and afterwards expand into the cap, are generally rather uniform, long, fibrous, often much separated, rarely ramified, presenting at times in their distance from each other, at others in their dimensions, differences which, on the fissure of the stipe, present an aspect either fibrous, granulated, spongy, or woolly. The cellular fibres are always closer and more compact at the cortical part. Those peculiar lactiferous vessels which convey the milk, so conspicuous in Ladarius, are not confined to the cap, but are present also in the stem, although possibly not quite so abundant, but they must be very numerous in the stems of one section of the genus Mycena where the milk is almost confined to the stem. In Mycena leucogalus it is quite white, in Mycena haematopus, of a blood red ; in Mycena crocatus it is saffron yellow, and in Mycena yalo2ms it is described as white, but it is often watery, or with a tinge of white, like milk and water. The quantity of milk depends much on the dampness of the habitat. In such degraded forms as Cortirium, liachdum, etc., the carpophore is obsolete, and the receptacle is reduced to a fibrous stratum, which is seated directly upon the mycelium, and only the hymenium receives its proper development. Other genera require little observation, since in some forms of Theleplwra, in Lachnocladiuvi, and in Clavaria and its allies, D. . -r Nortli i^c. o..r.- , .. College 26 INTRODUCTION TO THE STUDY OF FUNGI we have the closest resemblance to the carpophores of the moulds, even to dendritic branching, but of a larger and more robust habit. Isaria is often closely imitated in external appearance by Clavaria. The most anomalous of all groups in respect to the carpophore is the Tremellini, but even in this there is a link in Chicjnnia, Gyrocephalus, and Ditiola. We have not forgotten that in some of the Basidiomycetes the whole of the Fungus, in its earliest stage, when seated upon the mycelium, and before the development of the carpophore, is enveloped in a volva. This is not, however, more than a generic distinction, in any case, and reaches its highest de- velopment in Amanita, Volvaria, Ithyphallus, Clathrus, etc. It might be compared to the calyptra in mosses and liver- worts, but is by no means so general, and without so much significance. The Gastromycetes are not so well provided with a carpo- phore as the Symenomycetes, but at the same time there is no degradation to resupinate or overturned forms. The majority of the Phalloid Gastromycetes have a distinct carpophore, which is functionally the same as in Agarics, but the structure is more loosely cellular (Fig. 11), and, from rapidity of growth, lacunose. It is only in Fungi like these, which are quick to decay, that we encounter such a loose texture of cells in the carpophore. In Podaxis the form of the entire plant resembles that of Coprinus, but the carpophore is rigid, almost it is also in Batarrea, Xylopodium, and The carpophore in Secotium approaches of the coriaceous Agaricini, such as There are no other genera which call hhyphaiius for Special notice respecting the carpophore, which impudicus. ^g short, and almost spurious in Scleroderma and Polysaccum, rare in Lycoperdon, and then only a prolongation of the spongy base of the receptacle. In nearly every genus except Gyrophragmmm, Podaxis, and Secotium, it expands into, and is confluent with the receptacle. The subterranean species, like the truffles, have no carpophore. It is not difficult to comprehend the functions of the woody, as Tylostoma. the type Lentinus. THE CARPOPHORE 27 carpophore in the llymcnoiiiycctcs, in till of which the hymenium is inferior, and therefore it is essential to its development that the receptacle should be raised sufficiently above the matrix to permit of a free development of the hymenium. The carpophore is only suppressed or obsolete when the receptacle grows out at riifht anj^des to the matrix, and then no stem is essential. Furthermore, so many species grow on vegetaljle deln-is and dead leaves, hence a stem is necessary to push the pileus into the light. All collectors know how much the stems are lengtliened beyond their normal proportions when the mycelium is deeply imbedded in the loose soil, and that the hymenium is not developed until the pileus is elevated into the light. In the Gastromycetes the hymenium is not inferior, so that it is sufficient if the receptacle is just above the soil, and hence the carpophore is short. The Phcdloichi are exceptional, as the hymenium is not concealed, but must be well exposed, in order to mature speedily. All the remainder of the large fleshy Pungi belong to the Discomycetes, in which the hymenium is exposed on the upper surface, and therefore, as might be expected, the carpophore is often short or absent. The Morels and Hclvellas are all stipitate, and the receptacle is like a cap or hood ; l)ut as they are terrestrial, often grow- ing in loose soil and amongst debris, a carpophore long enough to bring the receptacle into the light is essential. In this case the substance scarcely differs from that of the cap, but it is robust, and the external stratum is not car- tilaginous. In several genera of ter- restrial habit tlie form is clavate, with a carpophore long enough to l)ring the hymenium through the short grass into the light, just as in simple club - shaped forms of Clavaria. We need only to allude to the old genus Pcziza, whatever the modern designation may be, for all of the species are cup-shaped in form (Fig. 1 '1), and the liymenium is turned to the light, hence all the carpophore which is necessary is that wliicli is suflicient for such a purpose. Fig. 12. — Receptacle or cup of Pcziza. 28 INTRODUCTION TO THE STUDY OF FUNGI SO that usually the carpophore is short, and often reduced to a mere point. Species such as that which grows on the sclerotium of anemone roots are variable in the length of the carpophore in proportion to the depth at which the sclerotium is buried, or of such as grow on acorns or beech-mast lying on the ground the carpophore is long enough to bring the hymenium to the light. Pcziza aurantia or Peziza ladia, growing on naked soil, are fully exposed, and hence are sessile. Wherever, from its matrix or peculiar habit of growth, a species, if sessile, could not expose its hymenium to the light under ordinary circumstances, a carpophore is usually present. Species which grow beneath the bark of branches, and break through, have invariably a short carpophore to raise the disc to the surface. Some special forms of carpophore are to be found in the Pyrcnomycetes, where the fructification is capsular, and the receptacle small and simple. In this case the carpophore is not, except rarely, that of a single individual, but of a colony or an agglomeration of individuals, each individual being represented by the fruit receptacle, the carpophore being a vegetative branch, developed from the mycelium, specialised to carry the fruc- tification, as the conidiophore of a mould is specialised to carry a great number of conidia. For example, the pupa of a moth becomes filled with mycelium, which, in the first instance, developed ^ ,„ , conidia under the form of Isaria farinosa (Fig. 13) ; Fig. 13. — Isa- "^ \ g / ' riafarinosa finally, a club-shapcd fleshy protuberance called on pupa of ^ stroma grows from the surface of the pupa in connection with and continuation of the internal mycelium. This fleshy stroma is at first only a sterile branch from the mycelium, like the stem of an Agaric, but ultimately the whole of its upper surface is covered with an indefinite number of minute receptacles, which are developed in a colony at the apex of a carpophore. The insects, M'hether larvae or pupae, on which these Fungi are developed are at the time buried in the soil, and the function of the carpophore is to carry the fructification into the light, so that sometimes it has to be prolonged several inches before THE CARPOPHORE 29 Fio. 14.— Clav- ate stroma of Cordyceps. the fructifying suiface is sufficiently raised above tlie soil to attain its development (Fig. 14). The carpophores vary not only in length for the same species, according to circumstances, Init also in form, according to the species. In some it is simple, and in others branched, but the receptacles are always densely accumulated al)out the apices in this genus of Cordyceps. Hence we recognise again that a carpoi)hore is a contrivance which is resorted to in order to bring the fructification into the air and liglit, and is lengthened or sliortened in con- formity with that o])ject. In the genus Xylaria the form of carpophore is similar, but its texture different. The colour is normally black exter- nally, white antl corky within, autl it is wholly tough and hard. The species grow on putrid wood and rotting leaves. In an allied genus, Thamnomyces, the carpophore is very long and thin, often like horse hair, running amongst dead leaves and vegetable debris. It is notable how some of the simplest forms of carpophore are repeated in different groups of Fungi far removed from each other in structure. This is the case where the whole Fungus is club- shaped, as it is in Clavaria jnstillaris, and again, even as to colour, in Xylaria invohUa. Others of a smaller size, but of a like form, will be found in Clavaria ligula, Zcptoglossum olivaccum ; Xylaria rhopaloidcs ; Geoglossum, hirsutum, and Hypocrca ophioglossoides. No one can doubt, after tracing the gradations of form in Xylaria, that the spherical carpophores, not only in Xylaria, but also in Daldinia, Glaziclla, Sarcoxylon, and the Sphaeroxylon section of Hypoxylon, are of the same character, and have a similar purpose to the foregoing (Fig. 15). Possibly the globose forms may primarily serve to expose the largest surface of immersed receptacles to the light, rather than elevate Fig. 15. — Globose stroma of Hypoxylon. 30 INTRODUCTION TO THE STUDY OF FUNGI them from darkness into light, as was seen to be the first function of the long - stemmed carpophores. Everything indicates in the Pyrenomycetes that there is some necessity for exposing the fructifying surface to the light ; whether on carpophores or effused in a stroma, only one stratum of perithecia is the rule, a double series the very rare exception. CHArTEK IV THE KECEI'TACLE Having descril)ed the mycelium, already designated as the vegetative Fungus, and which is always present, we passed to an outgrowth of the mycelium (soiuetimes suppressed), which, as the carpophore, is destined to support the rcceiitadc. It is the latter which contains the fructitication, or, in the ease of naked fruits, supports the fructification itself. It may be urged that the receptacle is part and parcel of the fructifica- tion, but it is really no more intimately so than are the receptacle or the calyx and corolla in flowering plants. This, however, need not be discussed, as it is only a question of analogies. What we desire to include under the present designation is the development, or modification, of the superior continuation of the carpophore, which encloses or supports the essentials of fructification. In the absence of any distinct or evident carpophore, it is still the immediate supporter or envelope of the fructification, which in that case is sessile upon the mycelium. This receptacle may be varial)lc in form, and be known under different designations, but its function is the same — that of supporting or enclosing the hymenium, wherever a hymenium or its analogue is present. This organ will be represented in some cases by a pileus, in others by a peridium, an e.xcipulum, a perithecium, a sporangium, or even a proliferous stratum. The best-known form, because the largest and most con- spicuous, is the pileus, which is characteristic of the Hijmnio- mycetes. It forms the cap in Agarics and the pileus in Fomcs, Polystictns, etc. This cap in Agarics and allied genera 32 INTRODUCTION TO THE STUDY OF FUNGI surmouuts the stem or carpophore, and bears on its under sur- face the hymenium or fructiferous surface. It follows the same type in the Agaricini, Boleti, some Pohji^orei, and Hydnei. This type is a convex, or primarily convex, orbicular expansion of the apex of the stem, with a more or less distinct pellicle on its upper surface, an intermediate stratum, and its lower sur- face covered by the hymenium. In this type, then, it is a hymenophore, as it is in other forms of Hymenomycetcs. This cap (Fig. 16) not only surmounts, but it is continuous with the stem, and for the most part conforms to it in texture. In some cases it passes down in plates on the under surface between Fig. 16. — Agaric. A, young ; B, mature ; C, section ; p, pileus s, stipe ; v, volva ; g, lamellae or gills ; a, annulus or ring. the folds of the membrane which bears the hymenium, and is the trama. The superior cuticle or pellicle is sometimes so distinct from the subjacent stratum that it may be stripped off, but in other species it is so intimately incorporated with the substratum that it is inseparable. From the margin of the cap this cuticle is sometimes extended inwards and united to the stem, covering the young hymenium, and forming a veil. Externally the cuticle may be quite dry or viscid, or even covered with a slimy gluten, as in Agaricus mucidus and Agaricus aeniginosus. In some cases the cuticle is compara- THE RECEPTACLE 33 tively thick, and consists of an outer and inner layer, the former breaking up as the cap expands, and adhering in patches or scales, as in A(jaricus procerus, whilst the inner silky, fibrous layer is closely adnate to the flesh. Not uncom- monly the cuticle, without breaking up, is finely striate with innate silky fibrils, or shining with a satiny lustre. The flesh beneath the cuticle differs somewhat in different species, in texture and in comparative thickness, but is always thinnest about the margin, sometimes scarcely exceeding that of the cuticle. The cells of the fleshy substance of the pileus in Agarics are more branched than those of the stipe. They will form, by anastomosing and crossing each other, a sort of poly- gonal trellis-work, and in the meshes so formed there is a second system of larger cells. Corda alludes to them, especially in the Biissulac, and he says, " These two forms are not always neatly separated, but pass, as the organ requires, more or less rapidly, one into the other, or, what is more rare, they are sub- stituted the one for the other. These two forms of tissue take part, generally both together, in the structure of the hymenium, each giving birth, or botli together, to one or many organs of the hymenium." ^ The lactiferous tubes in such a genus as Ladarius are often of larger dimensions than the ordinary tissue, and M. de Seynes protests against their being called " vessels," because, if the cells are very long, yet it is possible to see that they are divided " transversely. In Fistulina, which contains an abundant red juice but more fluid, it is contained in special varicose and sinuous tubes, like the laticifers, but furnished with transverse divisions. On approaching the gills the same series of cells are curved and recurved, showing that the milky secretion is there more abundant. As to the functions or import of this juice, that is still an obscure point, for there are so very many Agarics which do not possess it at all, or if pre- sent, it is in smaller quantity, and not equally visible. It is well enough known that in Lactarius the milky juice descends into the hymenium, for if the gills are cut or bruised, it oozes out, and hangs suspended in drops. "When dried it is readily seen to be resinous. * Corda, Iconcs FioKjuriDn. 3 )^ 34 INTRODUCTION TO THE STUDY OF FUNGI Xo oue has yet paid much uttentiun to the coloration of the pileus in Agaricini, which is subject to much variation, due in part to external circumstances, as was pointed out by ]\I. de Seynes. Albinism is one of the variations which he observed in well-recognised species. It occurs in Hyyropliorus calyptraeformis, Amanitoims vaginata, Russula fragilis, and some others. " By the side of this fact there is another quite opposite, the greater intensity of coloration, according to the temperature." For instance, he found during the winter Tricholoma nuda, according as the temperature falls, of a dark violet, almost black, or a deep brown. When spring arrives it is found almost white, shaded with lilac or fawn colour. Tricholoma terreus and Collyhia dryophilus will present the same phenomena. He found also, in a cold December, Volvaria media of which the pileus was almost black ; ordinarily it is nearly white. Upon microscopical examination he found that there was no new production of cellular elements, but simply a greater agglomeration of pigmentary granules. He also indicates that he has often been struck with the deep colora- tion of Armillaria mellea and Hyplwlowxi siQAateritius, which were seen by hundreds during a low temperature (41° to 42° Fahr.), the aspect of which differed very much from the same species found in the woods during the fine days of autumn.^ The same writer adds that, from numerous observations, he is certain that, although the cold has an influence upon the intensity of coloration amongst Agarics, it does not follow that in the middle of winter specimens may not be found of the normal colour, either by being shaded, or in proximity to heat. The effects of external circumstances on the variation of the fleshy Fungi deserves more serious attention. In some few instances the fleshy stratum is almost obsolete over the entire cap, as in Hiatula, some species of Coprinus, Bolhitius, etc., and in some exotic species of Marasmius. In such cases the cap is so thin — like a membrane — that when moist the gills may be seen through the substance. In Boletus the cuticle is sometimes distinctly velvety, and the flesh is comparatively thicker than in Agarics. In Polyporus, Fomes, Polystidus, Hydnum, etc., the entire substance is more ^ Grevilka, vol. ii. p. 12. THE RECEPTACLE 35 woody, contains less moisture, and consequently dries with but little shrinking or change of loriii. As the carpophore is souietinics obsolete in the ILjmcno- mycetcs, so also is the receptacle or pileus reduced to a simple stratum, which intervenes between the mycelium and the spore- bearing suriace. These are undoubtedly rudimentary forms, but they are very numerous, sometimes constituting entire genera, as in Poria, Co7iiophora, Corticium, etc., besides numerous species in other genera. For the most part a thin tibrous stratum, difl'erentiated from the fibres of the mycelium, forms, and supports the hymenium. Possibly the old genus Ozonium consists entirely of these suppressed pilei, which never form a hymenium. The supporting stratum is very peculiar in Astcrosfroma, where the hyphae are stellate, and in Thele- phora pcdiccUata they assume a dendritic form. It is not uncommon to find specimens of Corticium in which the hymenium is only in patches, or, in some cases, never formed at all, so that the whole Fungus remains in the vegetative stage, that is to say, mycelium, and a sterile fibrous stratum to represent suppressed carpophore and atrophied receptacle. The second type is deficient in any appreciable carpophore or stem, and con- sists of a pileus of a semicircular out- line, attached at its base to the matrix and its own my- celium (Fig. 17). In these also there is a superior stra- tum, which may be thicker than in the preceding, an inter- mediate substance, and an inferior hy- menium. Tlie upper stratum in Foli/purus and Fisitdina is hardly distinct from the intermediate ; but in Fames it usually forms a firm hard crust, very hard and Ikhmv in Fnurs ai/s(ralis and Flo. v.— Fust III Ilia hepatici, .sessile iiileiis. 36 INTRODUCTION TO THE STUDY OF FUNGI Fomes cornu-hovis, Lut smooth, and mostly shining, often laccate, as if varnished. According to Wettstein,^ this is due to the secretion of resin which oozes from pecviliar hyphae and flows over the surface of the pileus. The exterior of the pileus exhibits deep concentrated channels, which mark the annual additions at the circumference. The substance is often very thick and fibrous, the fibres radiating in every direction from the base. They may continue growing by the addition of external zones for many years, always the oldest posteriorly. From these Polystictus differs in being much thinner, and the cuticle is fibrous, hairy, woolly, or strigose, and concentrically zoned. The substance is dry, tough, and leathery, usually flexible. In so far as these features are concerned, Stereum not only resembles Polystictus in appearance, but also in texture, and so does Hymenochacte ; whilst Hexagona differs more in the hymenium than in anytliing else. These, therefore, may be accepted as representing the two forms of the sessile receptacle in Hymenomycetal Fungi — the woody by Fomes, to which might be added Daedalea, and the coriaceous by Polystictus, and the others above named. The next form of receptacle to be adduced is the periclium, which completely encloses the reproductive organs, and may also be supported on a distinct carpophore, or it may be sessile on the mycelium, or invested by it, as in some subterranean species. The Gastromycetes furnish this kind of receptacle, which is very often double, typically globose, the outer coat or exoperidium being a continuation of the cortex uf the carpophore when the latter exists. The internal cavity is filled with the reproductive bodies, which are only liberated by the rupture of the coat of the peridium. The inner Fig. 18.— Lycoperdo7i, peridium coat or endoperidium is often thin and and section. membranaceous, and may either be wholly separated from the outer or adnate therewith (Fig. 18). A prolongation from the carpophore sometimes protrudes into the central cavity in the form of a columella. The outer coat or 1 Verhand. Zool. Bot. Gescll., Wien, xxxv. (1886), p. 29. THE RECEPTACLE 37 exoperidium may be tough and leathery, and in Geastcr it sphts downwards from the apex into several triangular lobes. In Bovifitd it is fragile and evanescent. In Lycopcrdon it breaks uj) into gruimlcs, warts, or spines, wliich adhere for some time to the inner and persistent peridium. In Polysaccnm and Scleroderma the periderm is not differentiated into two coats, but in the latter the exterior cracks into warts or frustules. In this form the receptacle is an entirely closed envelope, in which the fructification is completely concealed until it is quite mature, and then it either opens with a small orifice or is irregularly ruptured. Hence the light is not essential to the perfection of the fruit, and the peridium might almost as well remain in the soil, which it has a tendency to do in some species of Scleroderma, and does completely in the Hyj)0(jaei. In the majority of species the substance of the peridium is tough and leathery, and so persistent that it often remains behind long after dehiscence and the dispersal of the spores. A third form of receptacle is the excipulum or cup-shaped receptacle, which, although often closed when young, is soon expanded so as to expose the disc or hymenium to the full light ; in fact they are heliotropic, for they turn the disc as much as possible towards the sun. The type of this form is to be found in the old genus Peziza, now split up into many genera, but the form and structure of the excipulum is the same throughout (Fig. 19). The external stratum of cells does not form a separate cuticle, but is continuous wuth the subjacent cells, and usually consists 1"'ig.19.- of smaller or elongated cells, w-liich may be coloured, and either mixed with or prolonged into hairs, usually most strongly developed about the margin of the excipulum. Within the cuticular layer lie the subhymenial cells, on which rests the hymenium or fruit-bearing surface. The attributes of this form, therefore, are a cup -shaped receptacle, with the mouth turned to the light, and composed of an external and internal series of cells, the latter su]>porting section aiul ascus. 38 INTRODUCTION TO THE STUDY OF FUNGI a compact hymenium. The substance of the cup and entire Fungus is most often soft and fleshy, and therefore they are more or less hygrometric, closing when dry and expanding when moist. Whether naked or clothed with hairs, the exterior is usually dull and sombre-coloured, so as scarcely to be distinguished from the matrix on which they grow. A similarly-shaped receptacle is to be found in CypheUa amongst the Hymenoraycetal Fungi, in Cyathus and Crucihuluon amongst the Gastromycetes, and in Aecidium amongst the Uredines ; besides partial resemblances amongst the Siihaerop- sidcae, and a few of the compact moulds, such as Volutclla and Chactostroma. The closing of the margins of the cups, and the long marginal hairs which in dry weather cover the hymenium, serve as a protection against evaporation, to which, from their fleshy substance and exposure, they are peculiarly liable. Some minute species, which are erumpent, retract themselves within shelter of the cuticle as they lose their moisture, and can only be distinguished with difficulty. Another form of receptacle is represented by thousands of species, and that is the ijcrithccnim. This is a minute form, #^^ seldom exceeding a rape-seed in size, yT ;= ^^V ^^^^^ usually very much less. It may C-'^/:!^! be characterised as a globose flask \& ^iii^^ g^ with a very short neck, but this Fio. 20.— Peritiieciuiii witii iomi is variously modified (Fig. 20). '''''^^*'°"- Sometimes it is seated directly upon its mycelium, and sometimes simk in a stroma which arises from a mycelium. These receptacles may be superficial, on the surface of the matrix, or either wholly or partially immersed. The globose form may be flattened at the base, and the neck be very much elongated, like a horn, or absent altogether ; and. they may grow singly or in company. In some genera the perithecium is soft and fleshy, and then pale or brightly coloured, as in Nedria. It may be thin and membranaceous, as in Sphaerella ; or it may be coriaceous and tough, as in Botryosphaeria ; or carbonaceous and brittle, as in Rosellinia. Externally it may either be smooth and shining, or mealy, or warted, or bristly, or woolly. The apex is always closed, except for a minute pore or ostiolum, and this is only THE RECEPTACLE 39 absent in a lew genera. In one group only, the Lophiostomaceac, the mouth is broad and compressed. The fructification there- fore is always enclosed, as it is in the case of a peridium, but this is their only point of agreement. Whatever the ibrra of the carpophore, the perithecia are always crowded together on the upper portion, and even when the carpophore is globose it is flattened at the base, and as the perithecia approach the base they are smaller, less numerous, and often imperfect. As already stated, the perithecia are always peripherical, and in a single series ; but if, in rare cases, there is a second series, the necks of the perithecia are elongated so as to reach the surface of the stroma. When a great number of perithecia are collected together, and immersed in the matrix, a kind of stroma is formed from the matrix, as in EiUypa ; but when on the surface, a regular stroma is formed upon the mycelium, which is fleshy in Hi/pocrca and carbonaceous in Hypoxylon, and the perithecia are closely packed and immersed in the stroma, which is per- forated by the ostiola. The densely aggregated perithecia may sometimes be fused together so as to resemble an effused stroma. There are some genera in which the perithecia seem |v to be obsolete, or only formed from the stroma, in which the perithecia appear only as cells, as in Phyllaclwra ; but the walls of the perithecia are possibly fused with the stroma and M ^ ^ ' ' ^ ^^^ ( not wholly absent. The character of the fructification may be entirely fig. 21. -Receptacle of sporo- different, while that of the perithecia "'ega in Hysteriacme, with . m • ascus. remanis the same. The same peri- thecium, to all external appearances, may belong either to the Pyrenomycctcs or tlie Sphacropsidcac. It may be a Diplodia or a Plaeospora. It may be necessary to refer incidentally to a modification which is almost intermediate between an excipulum and a peri- tliecium, which is prevalent in the comparatively small family, the Hystcriaccac. Here the excipulum closes from two opposite sides, leaving: a slit down the centre. When well moi-stened 40 INTRODUCTION TO THE STUDY OF FUNGI these excipuli expand so as to be nearly cup-shaped, and a com- pact disc is exposed (Fig. 21). This corresponds to the cups of the Discomycctes, but the substance is leathery or carbonaceous, and when closed the receptacles approach the Zophiostomaceae, which is sphaeriaceous. Nevertheless the most evident affinity is with an excipulum, in the broad expanding mouth and the definite disc, very evident in Tryhlidiella mfula, and its relationship with the Discomycctes would be through Phacidiacei. Other modifications need not be particularised, since these principal types will be sufficient to indicate the character of the receptacle in the majority of Fungi. We have the vegetative system represented in the mycelium, which sends up erect or compound branches in the form of a carpophore, for the support of the receptacle in all cases where the receptacle is stipitate, or, where the receptacle is wanting, then to support the naked fruit. CHAPTKU V THE FRUCTIFICATION The contents of the various forms of receptacle already described, and those forms of fructification which are capable of being produced nukcil, withoiiL a receptacle, next demand attention. The best-known to the general public, and there- fore the most interesting, are those large and conspicuous Fungi which pass under the name of Mushrooms or Agarics, and the woody Polypores, with the spore-bearing surface on the under side. In more scientific language, these are the Hymenomycetal Fungi, and so called because the hymenium or fructifying surftice is naked, and produces naked spores. From what has preceded it will be remembered that a fleshy or woody pileus or receptacle, sometimes with, and sometimes without a stem, is the supporter of this kind of fructification. To the eye it presents the appearance of a continuous surface extending over plates or gills in the Agaricini, lining the interior of parallel tubes in the Polyporci, covering the outer surface of teeth or spines in the Hydnci, disposed over a nearly even plane in the Thdcphorci, effused over an erect, simple, or branched carpophore, but without receptacle in the Clavarici, and immersed in a gelatinous stratum in the Trcmcllinci. Under all these modifications the primary elements of the hymenium are the same, or chiefiy so ; that is to say, there are one, two, or three kinds of elongated cells, packed side by side and called respectively hasidia, cystidia, and sterile cells. Only the first kind are fertile, and bear at the apex four spores, surmounted on short slender spicules ; the cystidia ^ are ' The usual interpretation of the function of cystidia is, that they arc simply mechanical contrivances projectinj,' fruni the surface of the hjTiionium, and thus keeping the gills or lamellae apart. 42 INTRODUCTION TO THE STUDY OF FUNGI usually present, mixed with the basidia but rather larger, and the sterile cells are smaller and almost of the nature of, or analogous to, paraphyses (Fig. 22). De Seynes regards all three forms as modifications of the same organ, -i.e. the basidia, of which the spore-bearing are the fertile basidia, the cystidia are hypertrophied basidia, and the sterile cells atrophied basidia. All these cells are continuations and terminations of the tissues of the receptacle, sometimes with three or four subspherical cells intervening. The basidia are elongated clavate cells, or sporophores, filled with a granular fluid, surmounted by four short slender tubes, or spicules, each of which expands at the apex and becomes a spore ; into which FiQ. 22.-Ba,sidia (6) and cystidia t^g contents of the basidium pass, leaving the basidium empty, so are completed it collapses and shrivels, then falls away. The spores thus formed by budding or gemmation, as far as known at present, are asexual and only gemmae. Many efforts have been made to prove them otherwise, but none of these have been con- firmed. The spores themselves are unicellular (except in the Tremdlini), and may be colourless or coloured. Modifications seem to take place in the cystidia, in different genera, inde- pendent of any difference in size. In the genus Peniophora they evidently become encrusted with lime and granular, so "as to present quite a distinct appearance ; in this condition they have been called "metuloids." In Hymenochaete and some species of Fomes the normal cystidia are replaced by rigid coloured setae, which may be modifications of cystidia. Corda regarded these peculiar cells as representatives of male organs, and called them antheridia ; and a similar interpretation has been given to their functions by Worth- ington Smith. Most mycologists coincide in the opinion that a sexual apparatus has not yet been discovered in the (c) of Agaricus ; {a) jiaraphyses. that when its duties t THE FRUCTIFICATION 43 Hymenomycdcs, and tliat it is scarcely probable that sexuality exists. The contents of the closed receptacle of the second type enumerated in the preceding chapter — the peridium — differ in some features from the foregoing, although they accord in the spores being i)roduced upon basidia. In this case there is no effused and exposed hymenium, but the interior of the peridium is occupied and filled with the gleba, or entire reproductive mass, which is at first homogeneous. Afterwards minute rifts are to be observed in tlie gleba, which increase in size, and ultimately form a labyrinth of cavities. The walls of these cavities are composed of hyphae, and the inner face is converted into a hymenium, the basidia of which are the terminations of the hyphae of the walls. These basidia are more variable than in the Hymeno- mycetes, and the number of spores not so constant (Fig. 23) : in the Eymcnogastrcac from one to four ; in the Phalloidcac from four to eight ; in Bovista and Lycojicrdon four and _^ ^^^ terminal ; but in TuJostoma four and lateral. "^ Hence it will be observed that the spores are Fui. 23.— Basi- , , , . ,. ... . , . . , (liuiu ami spores produced on basidia, within special cavities and oiLi/coperdon. lining the walls ; but the entire mass, or gleba, is contained within a closed peridium, wliicli is not ruptured until the spores are mature. When this takes place the entire gleba will be found in most cases (exclusive of the Phalloidcac and the Nidulariacci) to be converted into a finely pulverulent mass, mixed with fine fibres. The powdery mass consists of the ripe spores, and the fine fibres are the remains of the internal hyphae, now called the capillitiuvi. In the Hymcnogastreac, which are the subterranean Gastro- mycetcs, the walls of the cavities are more persistent, and therefore there is no capillitium, and the peridium is not ruptured when mature. One or two features of the spores are in contrast with those of the Hymcnomycctcs, that they are for the most part coloured, often warted, or spinulose, whereas the majority are also globose in form, except in the subterranean species. The basidia can be seen only whilst the glelia is young, for before the spores are mature they are dissolved away 44 IXTRODUCTION TO THE STUDY OF FUNGI The Elapliomyceteae correspond to the Hymenogastreae in being subterranean, similar in form, and alike enclosed within an indehiscent peridium ; but they differ in the spores being enclosed within asci, instead of being produced on basidia, and in this respect are allied to the Pyrenomycdes. In so far as their final, and reproductive, stage is concerned, the Myxomycetes resemble the Gastromycetes ; they are some- times stipitate, possess a distinct peridivim, in which the spores are enclosed until maturity, and the latter are mostly coloured, globose, sometimes rough, mixed with the threads of a capillitium. On the other hand, the early or vegetative stage is so different, that the ancient notion of their affinity must be abandoned, although they are entitled to mention in this place as Fungi which produce their fructification enclosed within a peridium. Notwithstanding this, thei*e are those who regard it as heresy to mention the Myxomycetes on the same page as the Gastromycdcs. The fructification, which is produced witliin an open cup- is of more than one kind, but the most important is that of shaped excipuh 6—/ Fig. 24. — Section of hyiuenium iu Peziza. the Discomycetes, in which the spores are ascomycetous — that is to say, they are pro- duced within asci. In describing the recep- tacles it was stated that the fructiferous surface was a compact stratum or hymenium, which overspread the interior of the expanded receptacle. In this instance the fruit-bearing surface is superior, and soon fully exposed to the light. It is plane or slightly convex when moist, depressed and concave when dry, from the contraction of the receptacle,and often brightly coloured (Fig. 24). The hymenium, or disc, is composed of elongated cylindrical or clavate cells, which are formed of a delicate hyaline membrane, splitting at the apex, or opening with an operculum. These cylindrical cells are closely packed side l:)y side and constitute the asci, THE FRUCTIFICATION 45 which are generally mixed with slender threads termed })arap]iy.ses, and these two bodies together compose the hymcnium. Each ascus when mature encloses eight, more rarely Iniir, or sixteen, sporidia,^ often globose or cIlipLical, and uncoloured. The paraphyses may or may not be abortive asci, the apex may be attenuated, or it may be thickened in various ways, and in the latter case often replete with a coloured protoplasm which imparts the colour to the disc. We arc only desirous of explaining the normal form and structure, without regard to the minor differences which enter into the char- acters of the different genera. We may term the above the Pezizaeform type, which is repre- sented by some two thousand species. The question as to the nature and mode \ I u^ "of derivation of the ascospores is at present scarcely more than problematical. No male organs have yet been found in consort with the thecae, and there is no reason to assume that ascospores are the result of sexual union. The only evidence is that offered of conjuga- tion in the earliest stage of the receptacle, by means of which the entire cup and its contents fig is the sequence of a sexual act. De Bary, Woronin, and Tulasne are the observers on whom this jihenomcnon rests. It is to the effect that 25. — Ascus with sporidia and parajibyses. ^ It will be well to indicate here the names which are api)lied by tlie best authorities to the spore in its relation to the different families of Fungi. Although these names are somewhat arbitrary, the student will find them employed almost universally in systematic books. H-porc, without asci, in perfect Fungi, such as the Basidioraycetes. Sporklium, enclosed in asci, in perfect Fungi, such as the Ascomycetes. Sporulc, without asci, in imi)erfect Fungi, enclosed in perithceia, such as the Sphaerojisideae. ConuHum, without asci, in inijierfect Fungi without a perithccium, such a.s the moulds, or Ilyphomycetes, and Melancuniaceac. In Uredines and Phycomycetcae special modifications arc employed which have reference to their development. Spermatia, stijlosporcs, and clinosporcs are merged in sporulc. 46 INTRODUCTION TO THE STUDY OF FUNGI specialised branch of the mycelium, which is thicker than the rest, is always to be found in close proximity to certain fila- ments, the short curved branches of which rest their ex- tremities on the turgid branch first named, and which is termed the vermiform body or scolecite. At the point where these two organs meet there is a circular perforation, and one of the cells appears to transfer to the other a portion of its contents. The scolecite is stated to be the rudiment of the fertile cup, to become septate, and to Fig. 26.— Scolecit( Bary. collect around itself other filaments which grow and develop into a perfect cvip (Fig. 26). This process is reported to have taken place in Ascoholus furfuraceus and in Pyroncma om- phcdodes, and it is as- sumed to be general throughout all the fleshy Discomycetes. It is very evident that such a conclusion cannot be accepted, so that the above remarks must illustrating the nearest observers have obtained be received as historical, and as approach which some of the best towards establishing sexuality in the higher Fungi, such as Hymenomycetes and Ascomycetes. The Gasteromycetal Fungi also include a small family in which the receptacle assumes a cup shape, especially in the genera Cyathus and Crucibulnm ; but here again there is great divergence in the character of the fructification. In the latter genera the cups are at first covered with a tympanum or membranaceous veil, and when this is ruptured, are seen to contain a small number of lentil -shaped bodies, which are attached by a slender elastic cord to the inner surface of the cup. These are the peridiola which enclose spores produced upon basidia within the firm interior (Fig. 27). rilE FRUCTIFICATION 47 The excipulum, or cup-shaped receptacle, is also the form whicli is assumed in some genera of the Sphacroimdeae in which the external resemblance is again to tliat of the Dis- comycetes. The cups are sessile, often erunipent on the stems of herbaceous plants, and externally smooth or covered witli bristles — for example, in Excipula, Discella, and U^^helis, and many others. The spores are produced on short sporophores which grow side by side from the inner surface of the recep- tacle, as the asci are produced in Przizrt, Init without forming a compact hymenium. From these brief notices it is evident that fructification of widely diverse types may be found to be produced within receptacles which are open above and therefore cup-shaped. The most prevalent form is the asci- gerous, in which the sporidia are produced in asci, packed close- ly side by side and forming a compact disc, as in the Disco- mycetes. An ana- logous genus is found in Hymenomycetes, in which the spores are produced upon basidia, as they are in Corticium. Amongst the Gastro- mycetes the cup- shaped receptacles enclose lenticular peridiola which con- tain basidiospores. Fig, 27. — Vi-ucibulum vuhja C'hioii. And in Sphacropsideae certain genera with an open, cup -shaped receptacle produce naked spores, or conidia, ujiou short sporopliores. To these might be added also, I'lnm ihe Uredines, the " cluster-cups " of ^<«(/« manner tlie growing point enters one So INTRODUCTION TO THE STUDY OF FUNGI of the stomata of the host-plant, where it becomes the new mycelium of a spore-bed, which may either be that of a uredo- spore or a teleutospore. The violet leaves which display on their under surface the pale-brown scattered- pustules of the uredospores, will, later in the season, exhibit also similar pustules mixed with them, and nearly of the same size and form, but much darker in colour, or the leaf may be occupied entirely with these darker pustules, which contain the teleutospores. Seen under the microscope, these spores of the third generation will be found to differ from the aecidiospores and the uredospores in being two-celled — that is to say, they are divided across the centre by a trans- verse septum into two superimposed cells of a somewhat hemi- spherical form, supported upon a longer and more persistent hyaline pedicel. They are produced, like the uredospores, from a spore-bed of mycelium arranged more or less compactly side by side. The apex of the upper cell has gener- ally a more or less conspicuous hyaline nipple in the centre. In this species the coat of the spore is smooth, but in some others it is war ted or spinulose (Fig. 45). The mature teleutospore may germinate almost immediately, or in some species only after a con- siderable period of rest, in which latter case they are practically resting spores. The germ tube from either cell, projecting through the germ-pore, is at first a simple tube into which the contents of the cell pass, and retreat to the upper end, which continues to grow and become a promycelium. The extremity becomes divided off from above downwards by one or more septa, and then each compartment sends off a short pointed branch, which is soon dilated at the point. This expanded end then assumes an oval or kidney shape, and receives the contents of the com- partment to which it belongs. In the course of a few hours these new bodies are abstricted, and become promycelial spores. Fig. 45. — Germinating teleutospore of Picccinia. After Tiilasne. SAPROPHYTES AND PARASITES which soon fall away. The germination of teleutosporcs results therefore in a proniyceliuni, which develops small secondary or promycelial spores, and these latter are ready to germinate at once. \\'\\v\\ these promycelial spores are placed on the damp surface uf the leaves of the host-plant they germinate, and the growing point enters one of the stomata, where it forms a mycelium, the contents of the promycelial spore passing down the tube, whilst the empty spore-case soon falls away. This new mycelium may produce spermogonia and aceidiospores, thus reverting to the original point of departure ; or it may give rise to a crop of uredospores, without the intervention of aecidiospores ; or it may pro- duce teleutospores, which are functionally alike or unlike the parental teleutospores from which tlie promycelium was derived. Throughout all these mutations there is no diver- gence from the endophytal character of tlie parasite, which is of a peculiar and characteristic type. Here, then, we have in brief the typical life-hist(jry of one of the Uredineae — the teleutospores in some instances being unicellular, and then Uromyces ; or bicellular, and then Puccinia ; or multiseptate, and then Phragmidium ; tlie character of the teleutospore determining the generic name to be applied to the cycle. There have from time to time been suggestions of hereditary transmission in Uredinous infection, but as the frank accept- ance of such a possibility would weaken the effects of such results as are claimed to follow upon artificial cultivation, the advocates of heteroecisni ignore as much as possible all sugges- tions of hereditary transmission. Analogy nevertheless favours the probability of inheritance, and some few stubborn facts seem to support this view. Some years since we had occasion to examine some celery plants, the leaves of which were badly attacked by Puccinia, whilst other plants in the same garden did not show a single diseased leaf Upon inquiry it was found that the diseased plants were raised from seed which had been derived from plants badly diseased at the time, but that the healthy plants were reared from seed which had been saved from plants without trace of disease, either in the past year or in their progenitors of preceding years. The foliage of all the diseased plants was destroyed, and no disease appeared G 82 INTRODUCTION TO THE STUDY OF FUNGI in that same garden, upon celery plants, during the succeeding ten years. The inference certainly must be that the seeds contained, in some occult manner, the germs of the disease, transmitted in this way from generation to generation, and not obtained by local infection of the seedling leaves, from germinating promycelial spores. If the latter had occurred, then the infection would not have been confined to plants descending from infected parents, whilst other plants growing within less than three feet did not show a spotted leaf; but both series of plants would, on the contrary, have suffered in an equal manner. Another case is related l)y ]\lr. Worthington Smith, wherein he says it is common to tind hollyhock seedlings show- ing the Puccinia on their seed leaves. This he had traced to the presence of pustules of the disease outside the seeds or carpels, of which he gave a detailed account in the Gardener s Chronicle. Yet another instance is upon record, in which a well-known nurseryman had imported Dianthus seeds direct from Japan. These seeds were carefully grown under glass, and, immediately they were up in the seed-pans, they were all attacked and destroyed by the characteristic Puccinia. On making a microscopical examination of a series of these seeds mycelium was detected inside the integument which surrounds the embryo, or infant plant, and within the coat of the seed. Another and equally conclusive incident has been narrated by the Eev. M. J. Berkeley, in which plants of Pyracantlia, raised from seeds imported from Eussia, were all killed by a species e Seynes terms them, " atrophied basidia." So that the three kinds of cells on the hymenium are but three forms or conditions of the same organ — the true basidia, the hyper- 122 INTRODUCTION TO THE STUDY OF FUNGI tiophied basidia, and the atropliied basidia. It is not necessary to discuss the question, when we are occupied rather with the form than the functions of the hymenium. It will, however, be borne in mind that it has of late been the custom of some writers to apply the term " basidia " also to the short sporophores which are present in the Sphaeropsideae and else- where, which support the solitary spores. Against such a mis- appropriation of terms it will be advisable to guard ourselves, and restrict the name of basidia to the spore-supporters in the Basidiomycdes, where they are not simple sporophores in the sense that they support a single spore, but tetrasporous hymenial cells, surmounted by spicular sporophores. The same term cannot, therefore, be equally applied to the ap- pendages of a proper and distinct hymenium and the filiform spore - bearers developed from the base or side walls of a diminutive receptacle. A true hymenium always consists of closely -packed hymenial cells; and wt shall find in the Hyuunomycetes that not only may it assume the form of gill- plates, as in the Agaricini, but also as a lining to porous tubes, as in the Polyporei, be diffused over the surface of teeth or spines, as in the Hydnei, spread over a plane on one side only, as in the Thelcphorci, or covering both sides of a vertical hymenopliore, as in the Clavariei. In the other order, the Gastromycctcs, the basidia closely resemble those of the Hymenoviycetes, and have the same func- tion, bearing spicules at the apex, usually quaternary, some- times in pairs, and each surmounted by a spore. The examination must be made in a young state to discover the basidia, because when mature, and the periderm is ruptured, nothing will be observed except a mass of free spores, some- times with the spicule attached and a number of threads. This is the normal condition in the Lycoperdaceae, but varied in the Phalloideae, and also in the Nididariaceae and Hypogeae. In all it will be recognised at once that the hymenium is less highly developed than in the Hyyncnomycetcs, and more fugitive. Paraphyses may be present as abortive basidia, but tJie cystidia are scarcely distinct. Berkeley records the results of his examination of a cut section of young Lycoperdon. " If a very thin slice be taken, NAKED-SPORED FUNGI— BASIDIOMYCETES 123 while the mass is yet firm, and before there is the slightest indication of a change of colonr, the outer stratum of the walls of these cavities is found to consist of pellucid obtuse cells, placed parallel to each other like the pile of velvet, exactly as in the hymenium of an Agaric or Boletus, but without any trace of those processes which have been regarded by some authors as male organs {cystidia). Occasionally one or two filaments cross from one wall to the other, and once I have seen these anastomose. At a more advanced stage of growth four little spicules are developed at the tips of the sporo- phores — all of which, as far as I have been able to observe, are fertile and of equal height — and on each of these spicules a globose spore is seated (Fig. 48). It is clear that we have here a structure identical with that of the true Hy- menomycetes, a circumstance which accords well with the fleshy habit and mode of growth." In his further observations, in reference to the Phalloidei, he says that " the fructifying mass consists of a highly sinuated hymenium. The walls are composed of elongated, somewhat spathulate, cells, surmounted with from four to six spicules, each of which bears an oblong ^ig. 48.— Basici- spore. The sporophores here again appear to ium and spores be all fertile and of nearly the same height. It ° ycopenon. will be observed that when the number exceeds four, the additional spicule is seated between the two, which form one side of a square, and that if a sixth is present it is placed opposite to the fifth. Here again we have an Hymeno- mycetous fungus, and there can be no doubt that the same structure will be found in all the Phalloidei." Thus, then, the relationship between Hymenoinycetes and Gastromycetes may be regarded as established. But Mr. George Massee, who is nothing if not evolutionist, has some pertinent remarks on this subject in a recent monograph.^ He observes that in the Hymenomyceteae " the progressive differentiation of the sporophore persistently aims at one object, that of con- cealing the hymenium until the spores are mature — a statement ^ Monograph of the Brilish Gastromycetes, by George Massee, p. 2. London, 1889. 124 INTRODUCTION TO THE STUDY OF FUNGI which is not in harmony with the general conception that the hynienium is from tlie first exposed. In the Thelephoreae, Clavarieae, and Hydneae the hymenium is exposed from the earliest stage ; whereas in the Polyporeae and the Agaricineae the hymenium, in the higher forms, is completely differentiated while yet concealed by a structure known as the veil, which in many species is only ruptured by the expansion of the pileus when the spores are mature. The idea of concealing the hymenium from the light is equally apparent in the various orders enumerated, except in the Clavarieae. In the Thele- phoreae the simplest genera — Corticium, Coniophora, and Penio- phora — have the hymenium covering the whole of the upper- most or free surface of the hymenophore, and consequently, from the earliest period of development, exposed to the light ; whereas in the genera Stereum and Thelephora a portion of the hymenophore becomes free from the substratum and bends over, thus turning the hymenium away from the light ; and by a series of transitions we find the higher species of the two last-named genera assuming umbrella -shaped forms with a central stem and inferior hymenium, but not at any period covered by a veil. In the Agaricineae -we meet with the same sequence of the evolution. In such low forms as Cantharellus rctirugis and Agaricus (Pleurotus) hyjjnophilus the plants are fixed to the substratum by the pileus with the hymenium uppermost, and may be compared to a Corticium, with the hymenium imperfectly broken up into gills ; whereas in such species as Agaricus (Fholiotct) praccox and Agaricus (Amanita) muscarius the hymenophore is supported on a stem with the hymenium on the under side, and concealed by a veil until the spores are mature." It might also have been urged here, in confirmation, that specimens of Fames and Polystictus from tropical or sub-tropical regions, where the light is strong, are constantly to be met with, in which the log has become turned and the hymenium of the Polypores growing thereon exposed to the full light. In such cases, and especially in such common species as Polystictus sangidneus and Polystictus occidcntalis, the old hymenium gradually becomes obliterated, and a new hymenium is formed upon what previ- ously was the upper surface, but accidentally inverted so as to NAKED-SPORED FUNGI—BASIDIOMYCETES 125 become the under, and consequently turned away from the light. " In the Gastromycetes, with the exception of the species constituting the genus Gaidiera, the hymenium is completely concealed by a continuous wall or peridium, until the spores are mature. ... As already stated, two leading features stand out prominent in the evolution of the Hymenomycctcs : the conversion of the primitive even hymenial surface into gills, thereby increasing the spore-bearing area, and secondly, the gradual concealment of the hymenium until the spores are mature. In the Gastromycetes these two conditions are present in the lowest forms, and persist throughout the group, the very varied forms presented by the different orders being the outcome of modifications of the sporophore in connection with spore dissemination." We may now proceed to a closer analysis of the two separate orders of Hymcnomycetes and Gastromycetes. CHAPTER XII IIYMENOMYCETES As lately as 1830 the Butanicon Gallicum included under the term " Fungi " only the Hymenomycetes and the Disco- mycetes ; whilst at a much later period the ordinary observer recognised only a few forms, chiefly of the Discomycetes, as Fungi beyond the Hymenomycetes. The puff-balls came at length to be included, but even these for a long time were regarded doubtfully as to whether they were true Fungi or not. In this country it was not until 1836, when Berkeley's volume of Hooker's Eiiglisli Flora was published, that the proper limits of " Fungi," as then known, came to be under- stood. Under any circumstances the Hymenomycetes have held the first place amongst Fungi, are usually the first to attract the attention of students, and stand at the head of every list, catalogue, or "Fungus flora." In 1825 Elias Fries himself included Discomycetes within his order " Hymenomycetes," and did not practically dissociate them until 1849, when he constituted the Discomycetes as a distinct and separate order. At that period the two orders followed each other, whilst the Gastromycetes were at a distance and scarcely became approxi- mate until the basidia had been discovered in them. The limits of the order Hymenomycetes were thus briefly expressed : " Spores naked. Hymenium free, mostly naked, or if enclosed at first, soon exposed." This again was more expanded and rendered clearer by Berkeley, thus : " Mycelium floccose, giving rise at once to a distinct hymenium or produc- ing a variously shaped naked or volvate receptacle, even or bearing on its upper or under surface various folds, plates, prickles, etc., clothed with fertile hymenial cells." The pre- H YMENOM YCE TES 127 ceding chapter having prepared us for the general attributes of the order, we may proceed to indicate the six groups into which the genera naturally fall. Four of these have the hymeniuin normally inferior, in the other two either superior or on all sides. The four first are the Agaricini, Pohjporci, Hyclnci, Thdcpliorci, and the two latter Clavariei and Trcmellini. The Agaricini are pre-eminently soft, fleshy, putrescent Fungi, of the mushroom type, in which the inferior hymenium, or spore-bearing surface, is spread over folds, or gills, which ^. ^\f^ Fig. 49. — Agaric. A, young state ; B, mature ; C, section, radiate from a central stem to the circumference of a pileus or cap. In the typical form there is a floccose mycelium of delicate threads, surmounted by a stem, more or less developed, and crowned by a hood or cap of umbrella-like form, with gills on the under surface. In the earliest condition the form is nearly globose, enclosed like an egg within a thin shell or membrane. As it progresses in growth the egg-shaped body splits round the centre, the upper hemispherical portion being carried upwards by a quick-growing stem, forming the cap, the lower half remaining behind to constitute the base. At the margin of the pileus the jagged remains of the fissured mem- brane often adhere for some time, and in like manner there 128 INTRODUCTION TO THE STUDY OF FUNGI may be traces of the fissure on the basal portion. In the most highly developed forms patches of the broken envelope, or volva, adhere like warts to the top of the pileus, whilst the basal portion remains as a loose sheath at the bottom of the stem, where it is for some time persistent as a kind of sheath, called the mlva. By cutting through the entire Fungus longi- tudinally from the apex to the base, the cut section exhibits the following features — a rooting mycelium, or spawn ; an erect stem rising therefrom (.s), winch is sometimes solid and some- times hollow (Fig. 49) ; the base either equal in dimensions or swollen like a bulb, occasionally with a distinct outer coat or volva {v), which is adnate below to the bulb and free above ; the stem is surmounted by a more or less hemispherical or conical cap or pileus (/?), the under surface covered with parallel plates, or gills, which radiate from the stem to the margin of the cap {g). When the cap is hemispherical the gills are often covered at first by a thin membrane, which extends from the stem to the edge of the cap ; and, as growth and expansion proceed, this veil is torn away from the margin of the pileus, and hangs like a collar or frill around the upper part of the stem, forming an anuulus or ring (a). When the cap is conical the edges of the gills are closely applied to the stem vertically, and the edge of the cap is only slightly attached to the stem, not forming a ring. When the substance of the cap descends between the folds of the gills it is the trama, and then the gills do not part freely from the cap ; but when the trama is thin or obsolete, the gills part freely from the flesh of the pileus. The gills are formed by a membrane, which constitutes the hymen- ium, and is folded like a fim ; so that each gill is a double membrane, applied back to back, giving as much surface as is possible for the production of the spores. The appendages of the hymenium have already been described as basidia, cystidia, and paraphyses, with the resulting tetraspores. Thus much may be seen of the structure in a longitudinal section of the pileus and stem. Modifications in some one or more of these general details give rise to the different genera into which the Agaricini are now divided. In former times, when the system adopted by Fries absolutely prevailed, the greater part of the species of Agaricini were comprised in one large genus, that of HYMENOMYCETES 129 Agaricus, in which the gills were membranaceous, and persistent, — that is to say, not melting or deliquescent when mature ; the trama was continuous with the substance of the pileus, passing down between the folds of the hymenium, and the edge of the gills was acute. The substance was fleshy and putrescent, not reviving after being dried. In other genera, as in Coprinus and BolUtius, the gills deliquesced when mature. In such genera as Panus, Lentinus, and Lenzites the substance was not fleshy but somewhat leathery, and not putrescent. In the large genus Marasmius, as well as in Xerotus and Trogia, the substance was thin but dry, not putrescent ; readily desiccated, and reviving when moistened. In Bussula the substance was fleshy and putrescent, but there were peculiar and special features which severed it from Agaricus, approaching Laetarius, in which latter a peculiar milky secretion afforded a distinctive feature. Hijgroplwrus and Cortinarius were two other rather large genera with distinctive characters, to be alluded to here- after. Cantharellus and Scliizophyllum afforded prominent characters in their thickened or splitting gills. Hence it will be seen that the old genus Agaricus had one or two prominent characters, which distinguished it from all the other genera of the Agaricini, and held together one of the largest genera of Fungi, which at the present time would not number less than 3000 species. For the purposes of classification Fries sub- divided this genus into five groups, according to the colour of the spores — the Leucosporac, in which the spores were typically white or but slightly coloured ; the Hyporhoclii, in which the spores were pink or salmon-coloured ; the Dermini, in which the spores were tawny or some shade of rusty brown; the Pratellac, in which the spores were brownish purple or very dark brown ; and the Coprinarii, in which the spores were black. These divisions are substantially maintained in more recent times, but applied to the whole of the Agaricini. In the Friesian system each of these groups was sub- divided into subgenera, which had their analogues in part in the kindred groups. In a Clavis published by Mr. Worth- ington Smith he indicated the corresponding subgenera in each of the five sections, as far as they were represented in the British flora. All this disappeared when Professor Saccardo I30 INTRODUCTION TO THE STUDY OF FUNGI propounded his scheme for the classitication of the Agariciiii, for wliich previous authors had prepared the way, by at once elevating the sul)geuera of Fries to the rank of genera, and ranking them upon an equality with the other old Friesian genera. This was the inherent weakness of the Saceardiau arrangement, although it will doubtless come into universal use where expedients are valued rather for their utility than their consistency. No one of experience would contend that Triclwloma and CollyUa bear absolutely the same relation to each other that Triclwloma would bear to CantharcUas, or Collyhia to Lentinus. In the Saccardian system the four primary groups into which the whole of the Agaricini are divided, depend upon the colour of the spores. The Leucosporac, having the spores colourless or but faintly coloured ; the Bhodosporac, in which the spores are pink or salmon-coloured, corresponding absolutely to the HyporJiodii of Fries ; the Ochrosporae, in which the spores are ochraceous, tawny, or some tint of light brown ; and the Mclanosiwrar, in which the spores appear to be black but in reality are dark brown, purple brown, or black, and thus combining the attributes of the Pratcllae with the Coprinarii of Fries. Of all these groups the first and largest is the Leucosporae, containing upwards of 3000 species, or more than half of the whole Agaricincac, which numbers about 5245 species. These are represented by thirty-two genera, and these latter arrange themselves in two groups or subdivisions — the larger, or Haplopliyllae, with the edge of the gills entire, and the Schizophyllae, in which the edge of the gills is split or appendiculate. The latter is a very small series, consisting of four genera but numbering in all not more than fifteen species. Hence, then, the HcqilopliyUae are the only series which require any special notice in this place ; and these are subdivided once more into two subsections, in which the chief distinction con- sists of the texture of the substance. In the first, or Mollcs, the substance is more or less fleshy, and putrescent, not reviving after -desiccation. In the second, or Tcnaces, the substance is tough and persistent, reviving after being dried. These are useful distinctions to be borne in mind, and will soon commend themselves to the practical Fungus - hunter. The // YMENOM YCE TES 131 common mushroom may be taken as an illustration of the former, and some species of Marasmiiis or Lcntinus of the latter. This brings us in face of the fleshy, or Molles, section of white-spored Agarics, containing in 1893 about 1750 species, of which not more than 430 are British, having the edge of the gills acute and the folds of the hymenium separable. This corresponds therefore with the Leucosporae section of the old genus Agaricus. Nevertheless there are additional genera which agree in their fleshy substance but differ in other particulars. In this category Hygroj^horus is a genus by itself, with the gills continuous with the pileus, and not separable from the trania. Thus the gills and the pileus are practically of one piece. Many, and indeed most of them, are more or less glutinous when fresh, and perhaps for this reason are capable of enduring more frost than others of the fleshy Agarics. In addition to these are two genera which have the substance of the pileus of a peculiar vesicular character, soft and fragile, but which have also another remarkable feature of affinity with each other in the spores being normally globose. These two genera are Russula and Lactarms, the latter with and the former tvithout a milky juice (Fig. 50). In habit and appearance they most resemble Ti'icho- loma, but a little experience will soon distinguish the difference. They are almost absolutely terrestrial and soli- tary, with a short robust stem, and many of the Bussulae have a brightly coloured pileus. Commonly, but not universally, the gills in Russula reach from the margin to the stem without intervening short gills; or, when shorter gills are present, these usually anastomose with the long gills, so as to appear as if the latter were forked. Finally there is a small group — consisting of four genera, of which Cantharellus is the chief — in which the edge of the gills is obtuse or vein-like. All these subsidiary groups together con- tain about 500 species, bringing the total of fleshy, white- Fia. 50. — Lactarius deliciosus, with section and spores. 132 INTRODUCTION TO THE STUDY OF FUNGI spored Agarics of all kinds up to 2250 species, or nearly one half of the whole gill-bearing Hijmenomycctcs. The other section of the HaiTlopliyllac, with a tough per- sistent substance, includes six genera in which the substance is at first fleshy, or gelatinous, and then becoming leathery, and three genera in which the substance is always more or less corky or woody. As might be anticipated, these are almost the only representatives of the gill-bearing Hymcnomycetes which extend into tropical countries. Of the six genera first alluded to, Marasmius approaches nearest to the soft-fleshed Agarics, such as Colhjbia and Myccna, and might readily be confounded, save for their tougher and drier substance. The larger pro- portion are of a small size, and these affect dead wood and leaves. Lcntinus often attains a large size, and, with the exception of a few European species, is a tropical or sub- tropical genus. The technical distinction between Panus and Lcntinus is that in the former the edge of the gills is even, and in the latter toothed or ragged. In order to complete our numerical estimate, we may add that the Tenaces section of Ha'ploi^liyllac is represented by about 810 species. The next order of Hymenomycctcs, the Polyporcae, is approached most nearly in one direction by Lenzites, which is the analogue in the Agaricineae of Daedalca in the Polyporcae. It seems unnecessary in this place to descend any lower with an analysis of the Lcncosporac. The analytical key to the genera in any good local flora will indicate the salient features in each genus, which it would be rather tedious to introduce into a book having the character of a general introduction, and would moreover extend this chapter to an inordinate length. We must now revert to Saccardo's second primary group of the Agaricineae — that of the PJiodosporae, so called on account of the spores being pink or of a salmon colour. It may at the same time be intimated that, although in some instances these spores are elliptical and smooth, they are often coarsely warted and angular. The group in itself seems to be a very natural one, for the species are all soft and fleshy, and even more putrescent than the softer of the Lcucosjporac. In all countries they constitute the smallest of the four primary groups of the Agaricineae, and have often a disagreeable odour. The total HYMENOMYCETES 133 number of known species does not exceed 366, or about one- eighth of the number of white-spored species. There are no genera, recognised as such, in the Sylloge, except such as were included by Fries as subgenera in his genus Agaricus, and these correspond to analogous genera in the Leucosporae. For instance, the recent genus Metraria corresponds to Amanita, and Volvaria to Amanitopsis ; Annularia is an analogue of Lepiota, as Pluteus is of Schidzeria, but there is no correspond- ent to Armillaria. Entoloma is analogous to Tricholoma, Clitopilus to Clitocyle, Claudopus to Pleurotus, Lcptonia to Collyhia, Nolanea to Mycena, and Eccilia to Omphalia. In this way the characteristic features of the genera which have been learned in connection with the Leucosp)orae may serve again with the Rhodosporac, conditional upon the difference in the colour of the spores. It is somewhat remarkable that the genus Metraria is only known from Australia, and yet there are known at present only twenty-five other species of the Rhodosporae in that large continent, which are spread over ten genera, and fifteen of the species are European. In the British flora upwards of 100 species are recorded, or about one to seven of the Leucosporae. In Australia the proportion is one to thirteen and a half of the Leucosporae. This indicates that the Rhodosporac prefer a cold to a warm climate, or at least a moist to a dry one. In Ceylon the proportion is much the same as it is in Britain. The third primary group is Oclirosporac, which includes the Dermini section of Agaricus, with the addition of the large genus Cortinarius, and the small genus Paxillns — to which, we contend, should also be added Bolhitius, placed by Saccardo in Melanosporae, but evidently the colour of the spores is against this position. The genus Paxillus is distinct from all the rest in the facility with which the gills separate from the hynieno- phore ; and Cortinarius differs from all in the universal veil being of delicate threads like a spider's web. The residue are the same as the Friesian subgenera of the section Dermini. Exception might be taken to the term Ochrosporae, as not being characteristic of the general colour of the spores, which are much too deep for " ochraceous," approximating more to ferruginous, and hence the name is misleading. As we have 134 IXTRODUCTIOX TO THE STUDY OF FUNGI done with the liliodos2)orae, so we might indicate the analogues of the Lencospcrrde in the Ochrosporde, in so far as they are represented. There is no genus which corresponds with Amanita, hut LoccUina or Acdabularia, whichever name we select, is equivalent to Amanitopsis. Lepioia and Schulzcria have no analogue, but Armillaria has a correspondent in Pholiota. Tricholoma is most nearly represented by Hchdoma, and in some degree by Inocyhc, the essential difference between these two genera being the fibrillose cuticle in the latter, and the smooth viscid cuticle in the former, both of which are represented in subsections of Tricholoma. CUtocyhc is repre- sented by Flammula in some of its species only, which have decurrent gills, whilst Pkurotus has its analogue in Crqyidotus. For Collyhia we have Naucoria ; for Mycena there is Galera ; and Omphalia is recognised in Tuharia. It is only in Tnocyle that we meet with irregular spores such as are not uncommon in the Rhodosporac. The total number of recorded species is estimated at 1157, as against 3 6 6 of the Rhodosporac. The large genus Cortinarius comprises some 400 species, all of which are terrestrial, and only subtropical at considerable elevations. Should Bolbitius be included, it differs from all the rest in the thin membra- naceous pileus, in which respect it is analogous to Hiatula in the Leucosporae, and to some species of Cop)rinus in the Melanosporac. The fourth and last primary division of the Agaricincac, according to Saccardo, is Melanosporac, in which he combines the Pratcllae of Fries with the Coprinai^ii, and adds thereto the genera Coprinus, Bolbitius (ochrosporous), Gomphidius, Anthra- cophyllum, and Monta.gnitcs. In some cases it is difficult to distinguish dark purple -brown spores from black, but this is hardly sufficient reason for combining them. Mr. G. Massee felt this to be the case, and in his British Fungus Flora he adopts two divisions instead of one, namely, the Porphyrosporac and the Melanosporac. After all there is no great principle at stake, although personally we would rather, if a coalition be considered advisable, that the two subdivisions were kept separate as Porphyrosporac and Melanosporac under a common designation. Following the same course that we have adopted HYMENOMYCETES 135 in the other primary divisions, we would intimate the analogies of the several genera of the Forphyrosporac. The representa- tives of Amanita and Amanitopsis must be sought in a single volvate genus — that of Chitonia, in which one or two species are annulate, whilst the residue are not. Lc2nota has its analogue in Agaricus proper, which includes the old subgenus Psalliota of Fries, and Sehuhzeria has its correspondent in the ringless Pilosacc. As for Armillaria, we shall find an analogue in Stropharia ; and Tricholoma will have its nearest representa- tive, but not a very perfect one, in Hypiholoma. Up to the present no purple-spored species with decurrent gills has been found to occupy the place of Clitocyhe, which is so largely represented in the Leucosporae, and Pleurotus has also no analogue. As for the rest, we have Collylia replaced by Fsilocyhe, Myccna by Psathyra, and Omphalia by Dcconica. But the same process cannot be applied to the veritable black- spored species, unless we include the deliquescent Coprinus, and can, by a little stretch of fancy, find in the pseudo-volvate species some approach to Amanita, in Anellaria a suggestion of Lepiota, in Panacolus a suggestion of Collyhia, and in PsathyreUa of Myccna. At the best these are little more than fanciful analogies. The combined brown and black -spored species do not exceed a total of 630 species. It will be observed that throughout the whole of this long series of about 5200 species we have but one type, with all its modifications, of a pileate Fungus, with a stem, sometimes nearly obsolete, supporting a cap or pileus, bearing on its inferior surface the radiating folds of a hymenium, on which the basidia support four naked spores. All the groups, divisions, subdivisions, genera, and species are dependent upon the variations in this common type. There need, therefore, be no surprise that a cultivated eye and experience are essential for the accurate discrimination of distinctions, often so subtle as to puzzle the young student and bewilder the casual observer, whose knowledge has never extended beyond a soft fleshy thing with a stem supporting a cap with parallel radiating gills. The second group of the Hyiiicnomycctcs is the Polyporci, in which the hymenium is still inferior, but is no longer repre- 136 INTRODUCTION TO THE STUDY OF FUNGI sented by a folded membrane, in the form of parallel plates or gills. Instead thereof the gills are replaced by parallel tubes, more or less adnate to each other, presenting a surface punctured with an infinity of minute pores, sometimes as small as if pricked with a pin. The membrane which lines the sides of these tubes or pores is the hymenium, so that the spores are produced within the tubes and not so fully exposed as in the Affaricincae. If we take as a type one of the species of the soft and fleshy genus Boletus, we shall see that in some re- spects it resembles the ordinary mushroom, and at the same time detect its more prominent differences (Fig. 51). In the presence of mycelium, stem, and cap the Boletus agrees with the Agarics, but the section will show the parallel tubes replacing the gills. But this is not so complete a type of the whole Pohjporei as was the Agaric of the Agaricini. In the first place the stem is often absent and the cap or pileus sessile, attached by the margin. And, in the second place, the pileus, or what corresponds to the pileus, adheres to the matrix by its whole upper surface, and only the hymenium, or pore -bearing surface, is exposed. This resupinate condition is Fig. 5i.-5o^d«,9, with section ^^^.y common, SO that the essential and spores. •' character is a porous hymenium, seated upon the least possible development of a pileus. And yet, as far as practicable, the hymenium is inferior, or turned away from the light. We are prepared, then, to meet with a greater variety of form than in the Agaricini, as well as greater ex- tremes of texture. The nearest approach to Agaricini in habit is to be found in the four genera Boletus, Strohilomyces, Boleti^ius, and Gyrodon. All these were, in their earlier history, associated together as Boletus, but at length came to be dissevered and recognised as distinct genera. Strohilomyces is Boletus with a scaly pileus ; Boletinus is Boletus with short, large, radiating pores; and Gyrodon is Boletus with elongated, sinuate, irregular pores. All of these are fleshy but firm, soon putrescent, but mostly HYMENOMYCETES 137 -with the tubes of the hymenium adhering so slightly to the under side of the cap that they are easily removed. Otherwise expressed, the trama of the pileus does not descend into the tubes, the mouths of which constitute the pores. In all of these a stem is invariably present, and sometimes a manifest ring, but without a volva. They are usually of a robust habit, sometimes attain a very large size, and are wholly terrestrial. Like the fleshy Agaricini, they are most prolific in temperate regions, being replaced in the tropics by woody Fomes or leathery Polystidi, as fleshy Agarics are replaced by Lentinus and Lenzites. The whole total of described species is some- what under 300. Fistulina has a similar fleshy substance, but the stem may be present or absent, and the tubes are not laterally adherent, and nearly all the species grow upon decayed wood. The genus Polyporus, as originally characterised by Fries, was a large one and spread all over the world, but in recent times it has shared the fate of other large genera, and been subdivided into the genera Pohjporus, Fomes, Polystidus, and Porta, as suggested by Fries in one of his latest works. These appear to be well defined, and no difficulty will be found to occur practically in their discrimination. The original name is retained for the section Anodcrmei of the old, undivided genus. The pileus is at first soft and fleshy but tough, becoming indurated, rarely fragile, without furrows or zones on the pileus, and with only a single stratum of tubes, so that practi- cally they are not perennial. Some of the species have a central stem, and then resemblf" Boletus, only that the trama of the pileus is continuous with » ^e tubes, which are not easily separable from the flesh of the cap. Other species have a lateral stem, or even a common stem, much divided above, and bearing several pilei (Fig. 52). Finally, other species have no stem at all, and the pileus is broadly attached to the matrix, so as to be semi-orbicular or kidney-shaped. Earely the pileus is reduced to a thin stratum, adherent by its whole surface, as in Poria, but with a slightly reflexed margin. In Fomes the substance is woody from the first, becoming very hard, and covered with a rigid crust ; not truly zoned, but becoming con- centrically sulcate. The substance is floccose and interwoven, 138 INTRODUCTION TO THE STUDY OF FCNGI often zoned, and the tubes are typically stratose, each stratum being the growth of a year, so that the species are truly per- ennial. Some have a central, others a lateral stem, but most commonly they are attached by a broad '"'* '" H /^ base, where they are very thick, and not uncommonly of the shape of a horse's hoof, or more rarely several pilei grow together in an imbricate manner. The species of Polyporus, as now restricted, t^^enerally shrink and become contorted m the process of drying ; but in Fomes the substance is so rigid that no shrink- ing or alteration of form takes place, and, except for the depredation of in- FiG. h2.-Poiyporus, with gg^j- ^^^^ |^^ i^g preserved unaltered for conimoii stem. ° ^ a century. Such species as Fomes cornubovis, when sawn through, resemble sections of buffalo- horn, although generally the internal substance is more fibrous. Puhjstidus includes thinner, smaller, and more delicate species, which are of a somewhat tough and leathery consist- ency, usually flexible, and either hairy or velvety, or becoming smooth. The surface of the pileus may be concentrically sulcate, normally zoned, Init not encrusted. The intermediate stratum is fibrillose, passing down into the hymenophore, so that the tubes are not separable. The latter are short, and developed from the centre towards the circumference. Commonly the whole thickness behind does not exceed a quarter of an inch, often less, sometimes more ; but the pilei may be confluent laterally, or densely imbricated, and the hymenium may run down the matrLx for a considerable dis- tance. The habit and appearance often closely resemble species of Stereum. Additional to the sessile species, there are some which have a central stem, others with a very short lateral stem, expanded at the base into a sort of disc, for attach- ment to the matrix ; but most of the European species are sessile, extended at the base, and more or less imbricate. The pores are very variable in size in different species ; in some they are so small as scarcely to be visible to the naked eye, HYMENOMYCETES 139 \v others they may he broad and shallow. The walls or dissepiments are normally thin, even so thin as to split down- wards very readily in process of growth, leaving little appear- ance of pores, except at the base. In some species the edges of the pores are fringed and toothed, so as to resemble Ir-pex. The last group of those which constituted the old genus Pohfporus, contains the resupinate species, under the name of Poria. The pileus is reduced to a thin stratum, mostly spread over, and adhering closely to the matrix, the outer surface covered with the crowded pores. In habit the resemblance is to Corticmm, but instead of a smooth horizontal hymenium it is a porous one. Normally the pores are in a single series, whilst in resupinate forms, or species, of Fomes they are thicker, firmer, and stratose. Allied to Fomes rather than to Polystidus, the genus Trametes is to be recognised chiefly by the thick obtuse dissepiments of the pores, the tubes deeply sunk into the substance of the pileus, and not stratose, and with- 1 out the hardened crust to the pileus. The pores are rounded and often unequal, whereas in Sderodepsis they are large, sometimes an- gular, with the edge acute or toothed. Daedalea is in substance and general appearance very like Trametes, with the pores sinuous or labyrinthiform (Fig. 53). Hexagonia rather approaches Polystidus than Trametes, but the pores ar with firm entire dissepiments Fig. 53. — Daedalea quercina. mostly large and hexagonal, Favolus differs from Hexagonia in the pores being less hexagonal, but angular and radiating from the stem ; most species being substipitate, and fleshy rather than rigid. In Laschia the substance is still softer, and more gelatinous, whilst the dissepiments are vein-like 140 INTRODUCTION TO THE SI ^ NCI and the pores shallower and irregular. The latter gc""\us leads to Mcridius, with its soft, waxy hymenium, the surface of which is reticulated with obtuse folds, forming irregular areolae, the folds sometimes rather toothed. This is possibly the lowest and most imperfect of the Polyporei. A recent genus, Campbellia, is a higher development, with a pileus and stem and more distinct pits or pores. Porothdmm has the habit of Porta, but the tubes are more scattered, reduced to papillae, and at length pierced and open. Some authors add Solenia to the Pohjporei, whilst others have associated it with Cyphella in the Thelcpliorei. The third primary group of the Hymcnomyccteac is the Hydnci, in which the gills of the Agaricincae and the tubes of the Polyporei are replaced by teeth or spines, the outer surface of which is clothed with the hymenium, which is therefore wholly exposed. There is at no time, and in no known species, any kind of veil covering the hymenium in its early stage. The most typical genus is Hydnum, which remains much the same as Fries left it, although there has been more than one pro- posal to split it up into smaller genera (Fig. 54). In the stipitate species some have a central stem, others a lateral stem, and in others the common stem is branched and subdivided, but the pilei are imperfect. In another section there is no stem, but the pileus is sessile or imbricate, and there are a large number of species which are as entirely resupinate as in the porous genus Poria, to which this section is analogous. There is also considerable difference in texture, some being fleshy, others waxy or leathery, and others becoming quite hard and corky. At one time a gelatinous species was included, but this has been removed on account of its affinity in fructification with Trevidla. The teeth are variable in length and thickness in different species, but they agree in being more or less pointed at the apex, and free from each other at the base. o — Section oi Hydnum repmidui MENOMYCETES Fig. 55. — Radulum. ' A nunibe'^'^^^i^^ai'iall genera are associated together in this family, t\\rciuiiv; 'xcations consisting cliiefly in the teeth or spines ; for luotance, in Irpex the teeth are flattened at the base, and connected so as to form irregular pits ; and in Badulum the teeth more resemble obtuse tubercles, and are often distorted (Fig. 55). In Phlebia, an aberrant genus, the hymenium is corrugated, with fold-like crests, so as to resemble Auricularia almost as much as anything else, and Hydnum scarcely at all. Then in the wholly resupinate genera, Ghundinia has the hymenium granular, Odontia has the granules or warts crested, and in Knciffia the hymenium is clad with rigid setae. Except in Mucronclla, and probably KneiJJia, the basidia are tetrasporous. The whole family does not include more than about 470 species. The last of the four primary families of Hymenomyceteae which have an inferior hymenium, is the Thelephoreae, which nearly corresponds to the section Auricularini of Fries, with the exception of the genus Auricidaria, transferred to Tremellineae. The hymenium is typically even, but rarely rugose, approaching the Hydneaceae by such genera as Cladoderris and Beccariella, in which the hymenium is veined, and the veins are warted or almost aculeate. Mr. G. Massee has intimated ■^ that " the Thelephoreae constitute the base, and also the starting-point, in the evolution of the Hymenomycetes, and, further, that from the Thelejjhoreae all the other orders have directly originated." In this family, as in the others, the species are variable in form as well as in texture. Only in Cratcrellus is the substance fleshy, attenuated in some species to membranaceous, often with a central stem and a funnel-shaped pileus, the outer or under sur- face being clothed with a ribbed or rugose hymenium (Fig. 56). Cladoderris and Beccariella are tough and leathery, mostly fan- shaped, sometimes funnel-shaped, but with a warted hymenium. In Thelephora the substance is tough, but softer and more p. 112. " Monograph of the Thelephoreae," by G. Massee, in Linnean Journal, xxv. INTRODUCTION TO THE ^t^uDY OF FUNGI Si Alii 1 —Craterellus cornu- cojdoides. spongy, without distinct cuticle to the pilei. rpj^^ n Ji|termediate stratum ; hence homogeneous, the hymeniui,-^^^^ ^^^^ ven or a little ribbed. The fornl is ariable, from stipitate and funnel-shaped to closely adnate and resupinate. It is notable that in the majority of species ^S^''^^^" ' ' "^"-'' // the spores are globose and rough, mostly \ // slightly coloured. We are disposed to place here the genus Lachnodadium, which some authors include in the Clavarieae, on account of the erect, branched habit, resembling some species of Clavaria, forgetting that there are also erect, branching species of Tlicle- pliora, to which these species of Lachno- dadium are closely allied in texture rather than to fleshy Clavariae. Stereum in form approaches Thelephora, but the substance is firmer, more leathery, and the pileus has a distinct outer stratum analogous to that in Polystidus, with an intermediate stratum, and a smooth, even hymenium (Fig. 57). Closely resembling in appearance is Hymenochacte, with the exception that the hymenium is velvety, with processes resembling bristles. With the exception of Skep- peria, in which the pileus is vertical, most of the remaining genera are wholly resupinate. These are : Conio- phora, in which the effused substance is membranaceous and smooth, with coloured spores ; Corticium , in which the effused substance is usually thicker and firmer, but without an intermediate stratum, the hymenium smooth and rather waxy, and the spores uncoloured ; Peniophora, with the habit of Corticium , hut with a velvety hymenium; and Hypochnus, with the habit and appearance of Corticmm, but with the sub- stance softer, floccose, and more lax, and the hymenium less com- pact, but still the spores are uncoloured. To these must be added the small genera — Aleurodiscns, with a somewhat saucer-shaped Fig. 57. — Stereum hirsutum. hymenomycetes 143 pileus, and pec ..j.^Aties of structure which prohibit its unison with Corticium , ' Michenera, with a placentiform habit, a waxy JijmeniuE^, and pedicellate spores ; and Exobasidium and Helico- hasidium, which are encrusting and waxy, growing upon living plants, and distorting them. Finally, Cyi^hclla, having the form of Feziza but the fruit of Corticium, being in fact a cup-shaped Corticium ; and Solcnia, the cups of which are elongated into tubes, so that it seems doubtful whether they should be placed in relationship with Poria, in Polyporeae, or with Cyphclla in Thcleplioreac. Briefly and succinctly, these are the principal genera of Thclephoreae, but before dismissing them we must advert to certain appendages of the hymenium which distinguish some of the genera above enumerated. In addition to the basidia there are to be found in the genus Pcnio- phora stout projecting cells, which are either the modified cystidia, or analogues of cystidia, but which have been called metuloids. They are fusiform, colourless, and at first smooth, but afterwards rough and brittle ri«- 58.-Cystidia of ° Peniophora. from the deposit of oxalate of lime on their surface. These are conspicuous objects upon the otherwise smooth hymenium, giving it a velvety appearance, and by this character separating the species from Corticium. In another genus, that of Hymenocliaetc, the same place and posi- tion on the hymenium is occupied by projecting, acute, non- septate brown bristles, which spring from the hyphae of the subiculum, and impart also a velvety appearance. Exter- nally in habit the species resemble Stercum, but they are readily distinguished by the presence of these brown project- ing bristles. A similar kind of appendage to the hymenium has been detected in some species of the Polyporei, for which the generic distinction of Mueronoporus has been proposed. In a small section of the genus Hymenochaete, according to Saccardo, but generically separated by Cooke and by Massee under the name of Veluticeps, the hairs of the hymenium are produced generally in bundles, and are flexuous and septate, in which respect they differ from the setae of Hymenochaete. 144 INTRODUCTION TO THE STUDY OF FUNGI A type of structure iu the hyphae of thVrrnsal stratum in some species of Corticium is worthy of note, as aflbrding a means of discrimination in allied forms ; and this constitutes the basis of a new genus, proposed by Massee, under the name of Asterostoma. The species alluded to are distinguished by the brown stellate hyphae that are present in the subiculum, "Erect branches at about the level of the base of the basidia develop at the apex a stellate arrangement of branchlets, all situated in one plane, parallel to the surface of the hymenium ; the number of rays varies from three to seven, five being the most frequent, and differ from the supporting hyphae in being aseptate, with very thick walls, which soon become bright brown. When the spores are ripe, the erect hy23hae, sup- porting both stellate threads and basidia, along with the latter disappear, leaving the coloured star-shaped bodies mixed with the spores, resting on the horizontal interwoven basal stratum of the plant." An analogous differentiation is pointed out as existing in the basal stratum of Bovista, in the Gastromycetes. Thus, then, we close our remarks on the first four primary sections or families of the Hymenomycetes, in which the hymenium is normally inferior, and either spread over radi- ating gills, lining the cavities of tubes, investing teeth, warts, or projections, or finally forming a plane, even, or nearly even, fructifying surface. The fifth family, or Clavaricae, has a vertical hymeno- phore, with the hymenium on all sides, and not distinct from the stem. Sometimes the entire Fungus is a simple club, and at other times it is much branched, with the lower portion barren, forming the stem, and the upper portion fertile, covered with the even or wrinkled hymenium. In most genera the substance is either fleshy or waxy, rarely somewhat gelatinous. The most highly developed genus is Sparassis, in which the branched hymenophore has the branches flattened into leaf-like expansions. The largest genus, however, is Clavaria (Fig. 59), in which the hymenophore is club-shaped and simple, sometimes solitary and sometimes in clusters or branched, often very much branched, but always fleshy. In Calocera the form is similar, but the sub- stance is toughly gelatinous, becoming horny when dry. The species of Clavaria are for the most part terrestrial, those of H YMENOM YCE TES 145 Calocera usually growing on dead wood. Saccardo includes also Zachnpdadium, which resembles a branched Clavaria, but the substance is coriaceous, and the stem tomentose. For these and other reasons we prefer to place it in ThelepJwreae. In Fterula the sub- stance is dry and cartilaginous, but in form resembling very slender Clavariae. Typhula and Pistillaria include minute species, mostly waxy and delicate, in the former with a very long, and in the latter a very short stem. Physalacria is Pistillaria with a subglobose, vesicular head or capitulum. Most of the species in this group are white, whitish, or brightly coloured, and but few of them attain any considerable size. The spores are simple, small, and either uncoloured or yellowisb. The sixth, and last, family is the TrcmcUincac, in which the dis- tinguishing feature is the tremelloid substance, collapsing when dry and ''^ ■ reviving with moisture, combined with fig. a peripherical, somewhat peculiar, basidiosporous fructification. The basidia are not super- ficial, but immersed, and either undivided or forked at the apex, or globulose and cruciately divided. The spores are typically reniform or globose and continuous, and these on germination give rise to sporidiola. The structure of this family was investigated at first by Tulasne, but more recently by Brefeld, and the classification now adopted is based chiefly upon the records of the latter. In this manner three subfamilies have been recognised — viz. the Auricularieac, in which the basidia are elongated or fusoid, and transversely many-celled ; the Tremcllincae, in which the basidia are globose, or nearly so, and when mature divided, in a cruciate manner ; and the Dacnjomyccteac, with the basidia 10 J9. — Clavaria jnstillaris. 146 INTRODUCTION TO THE STUDY OF FUNGI clavate, forked at the apex, each limb furnished with a single spicule. Under these three subfamilies the different genera are located after the following manner. (1) The Auricularieae includes the typical genus Auricularia (Fig. 60), in which the Fungi are leathery and somewhat resemble Stereum, but with a gelatinous hymenium, which is veined in a reticulate manner. (2) Hirneola differs in the substance being more membranaceous, and often cup- shaped or ear-shaped, becoming carti- laginous when dry ; the gelatinous hymenium being either even or plicate. Fig. QO.-Auriculariamesen- ^^^ (^) Pl^tVOlaea is wholly gelatinous, terica, with section and mostly small, erumpent or superficial, ^^°^^^- either wart-like or effused. Perhaps the nearest relation of this small group will be found in Lascliia, amongst the Polyporeae. The most important subfamily is that of the Tremel- lineae, in which the basidia are subglobose. Of these, Exidia includes a variety of forms, either discoid, cup-shaped, gyrose, tubercular, or effused (Fig. 61); some of which are even, and others papillose or spiculose. The basidia are rather ovoid, immersed in the gelatine, partite in a cruciate manner, and typically tetrasporous. Spores reniform, and for a long time continuous ; at length, - preparatory to germination, two or more celled, each cell producing a very short filament crowned with a narrow curved sporidio- lium. In the genus TremcUa the form may be pulvinate or effused, often Fig. qi.— Exidia, with section brain-like, with sinuosities, but with- '^^ spores, out papillae. The basidia are globose, and divided as in Exidia, and the spores subglobose. The promycelium result- ing from germination produces globose or elliptic sporidiola. Conidia have been observed in some species, but neither spores, sporidiola, nor conidia are ever septate. In form HYMENOMYCETES 147 Ulocolla resembles Tremella, but the germinating spores are bilocular. Naematelia also resembles Tremella, but enclos- ing a hard central nucleus. The genus Femsjonia presents cup-shaped or pezizoid forms, with globose basidia and curved spores. In Craterocolla the form is less cup-shaped, but there are two kinds — one somewhat tremelliform, bearing basidia ; the other more regular and rather truncate, bearing conidia. In Sehacinia the whole Fungus is effused like a Corticmm, bearing conidia at first, and afterwards reniform spores. The genus Gyrocephalus is analogous to Gucpinia ; the species are erect in habit and spathulate, with basidia of the Tremella kind and pear-shaped spores. The genus Tremellodon, with the form of Hydnum but the fruit of Tremella, properly belongs here. The subfamily Baeryomyeeteae includes the lowest Tremel- loid forms, in which the basidia are clavate, or nearly of the ordinary Hymenomycetal type, forked above, and each apex bearing a single spicule. The genus Dacryomyeetes includes normally small pulvinate species, the spores of which are trans- versely or muriformly divided when mature, and the conidia (when present) growing in chains. The genera Arrhyticlia and Ceraeca are North American, and of minor import. Guepinia consists mostly of irregularly cup-shaped or spathulate species, with a more or less developed, and often woolly, stem. The hymenium is discoid or one-sided, and the basidia linear and bisporous. The genus Dacryomitra has the fructification of Dacryomyces, but the form and habit are those of Typhula or Mitrula, being minute and club-shaped. Collyria is a North American genus, of a single species, resembling a large Dacryo- mitra, with an inflated capitulum. Two or three other little- known genera have been added provisionally to this subfamily, but their position has not yet been satisfactorily determined. Thus closes our survey of the groups, and genera, of the Hymcnomyceteae, in which the most distinctive features have been indicated ; but there are many cross relationships and analogies which could scarcely be alluded to. It has been pertinently observed that no linear arrangement can possibly illustrate completely the relationship of the families and genera which approach each other at various points, but it is useful as a guide to the classification of corresponding forms. 148 INTRODUCTION TO THE STUDY OF FUNGI BIBLIOGRAPHY Saccaudo, p. a. "Sylloge Hymcn^niycetum," in S)jllo(je Fungorum, vols. v., vi. Padua, 1887-88. Cooke, M. C. Handbook of British Fjiugi. Edit. II. " Hymenomycetes." 8vo. London. 1888-92. Illustrations of British Fungi. "Hymenomycetes." Roy. 8vo. Coloured plates, 1882-92. A plain and easy Account of British Fungi. 12mo. Coloured plates. London, 1870, etc. Edible and Poisonous Mushrooms. 12mo. Coloured plates. London, 1894. British Edible Fungi. Sni. 8vo. Coloured plates. London, 1891. Cooke, M. C, et Quei.et, L. Claris Synoptica Hymenfymycct^hm Europa^orum. 8vo. London, 1878. Stevexsox, Jxo. Hymenomycetes Britannici. {British Fungi — Hymeno- mycetes.) 2 vols. 8vo. Edinburgh, 1886. Fries, E. Epicrisis Systematis Mycologici, scu Synopsis Hymenomycetum. 8vo. Upsal, 1836. Rones Selectae Hymenomycetxim. Fol. 2 vols. Coloured plates. Stock- holm, 1867-82. Monographia Hyinencmiycetum Sueciae. 8vo. 2 vols. Upsal, 1857. Sverigcs atliga och giftiga Svampar. Fol. Coloured plates. Stockholm, 1861. Gillet, C. C. Lcs Chamjngnons de France. "Tableaux analytiques des Hymenomycetes." 8vo. Coloured plates. Alen^on, 1878-94. Kalchbrenker, C. Icones Selectae Hymenomycetum Hungariae. Fol. Coloured plates. Budapest, 1873. Massee, Geo. "Monograph of the Thelephoreae, " in Journal Linnean Society. 8vo. London, 1889-91. Persoon, C. H. Synopisis Methodica Fungorum. 8vo. Gottingen, 1801-8. QuELET, L. Les Champignons du Jura et des Vosges. 8vo. Plates. Montbellard, 1873-75. Heese, H. Die Anatomic der Lamelle und ihrc Bedexdung fur die Systematik der Agaricineen. Roy. 8vo. Berlin, 1883. Favod, M. V. "Prodrome d'une Histoire Naturelle des Agaricines." Ann. des Sci. Kat., 7th series, vol. ix. Patouillard, N. Les Hymenomycetes d' Europe Anat. gener. Paris, 1887. Britzelmayr, M. Die Hyinenomijceten Augsburgs, 8 (1879), Hymenomyceten aiis Sildbayern. 8vo. Plates. Augsburg, 1885. CHAPTER XIII PUFF-BALL FUNGI GASTROMYCETES Every schoolboy is supposed to know what a puff-hall is, and therefore they may be accepted as a type of the peculiar order of Fungi to which this chapter is devoted. During the summer the little white puff-balls, growing in the grass of pastures and on heaths, resemble small snowballs, soft and spongy, and scarcely tinged with colour in the pulpy interior. As autumn advances the outer surface at first becomes creamy or ochra- ceous, covered with small warts or spines, which are readily rubbed off with the fingers. Later on the colour becomes brownish, the coating is split irregularly, or opens with a round mouth, and the interior is seen to be filled with a fine olive or purplish powder like snuff, mixed with delicate threads, called the capillitium. Such are the ordinary pufi-balls which schoolboys puft' in each other's faces, the distinguishing feature being that the myriads of minute spores are wholly enclosed at first within the outer case or peridium, and remain so until mature, when the coating is ruptured. The Gastromycetes, therefore, are Fungi which, as a rule, produce their spores at the apex of basidia wholly enclosed within the substance of the Fungus. They constitute a portion of the Basidiomycctcs, because the spores are developed on basidia, but are specially denominated Gastromycetes, because the basidia and spores are not exposed, as in Hymenomycetes. If an ordinary Lyco-perdon be cut downwards through the centre, it will be observed that the basal portion is cellular and does not contain spores ; moreover, in some species this sterile portion projects upwards into the interior as a columella — which, however, is not always present. The peridium or outer coating in this instance is ISO INTRODUCTION TO THE STUDY OF FUNGI double, the exterior warty, spinulose, or powdery, and the inner paper- like. In other genera, as in Bovista, the two coats are more distinct. In Geaster they are still more distinct, the outer peridium splitting in stellate rays. Thus much for the general character, but the varied modifications must be noted hereafter. In some concise observations on this group Mr. Massee remarks that no sexual organs have been observed, but he alludes to the peculiar form of coalescence between two hyphal cells under the name of clamp-connections, which are not un- common (Fig. 62). "A slender lateral branch," he says, " springs close to a transverse septum separating two superposed cells, and, after growing for some time, its tip comes in contact with the wall of the adjoining cell just beyond the septum, absorption of the walls takes place at the point of contact, and thus at first an open communication is established, by means of the lateral branch, between the two adjoining cells ; at an early period this channel of communication is usually interrupted by the appearance of a septum at the point of origin of the lateral branch, and a second septum is in some in- stances formed at the point of contact with Fig. 62.— Clamp- ^^le sccond Cell. The lateral branch is usually counections. "^ closely pressed to the hypha from which it springs, but sometimes becomes arched and free from the hypha between the two points of attachment." ^ Eeference is also made to the differentiation of the hyphae which are contained within the peridium. In the gleba, or hymenial pulp, of the Zycojmxlaceae " at a very early period two sets of hyphae are present. One, thin- walled, colourless, septate, and rich in protoplasm, gives origin to the trama and elements of the hymenium, and usually disappears entirely after the formation of the spores ; the second type consists of long, thick-walled, aseptate or sparsely septate, often coloured hyphae, which are persistent and form the capillitium. The latter are branches of the hyphae forming the hymenium." There are three somewhat aberrant groups which offer ^ Massee, Monograph of British Gastromyces, p. 4. PUFF-BALL FUNGI— GASTROMYCETES 151 consideralile variations in structure from the genuine puff- balls. These are the Phalloideae, the Nididariaceae, and the subterranean or Hypogeae. The latter come in for notice under the head of " subterranean Fungi." The Phalloideae, or stink-horn Fungi, have mostly a very fetid odour, and instead of enclosing within themselves pul- verulent spores mixed with threads, present externally a gelatinous mass of agglutinated spores, which is collected upon some superior and exposed surface. The whole number of described species in this family is about eighty, and they are most common in warm climates. Some are stipitate and others clathrate or latticed, but all are at first enclosed in a general volva of an egg -shape, with a gelatinous inner stratum. The entire plant is of a soft, watery texture, quick in growth, and rapid in decay. As the gelatinous dark- coloured mass of the hymenium is greedily devoured by insects, it is reasonably assumed that it is by this agency that the spores are dispersed. Mr. T. Wemyss Fulton devoted some attention to this subject,^ and the following is a digest of his observations, en- tirely confined to the common stink-horn, Itliypliallus impiidicus, which grows freely in woods and gardens : — " The hymeno- phore or reproductive portion consists, in its earliest stages, of minute swellings, which arise on the underground mycelium. These at first are homogeneous, but gradual differentiation goes on, so that towards maturity the following parts may be recognised. (1) An enclosing cortical portion, the volva or peridium, composed of three layers — an outer firm skin, an inner thin membrane, and an intermediate gelatinous layer. At the base there is a cup-shaped portion, which supports the stem, and is continuous by its margin with the peridial layers, and below with the mycelium. (2) A central medullary portion, composed of two very different structures, the gleba or spore-bearing part, which forms a hollow conical cap, lying within the inner peridium, and surrounding the upper portion of the stem, to the apex of which it is attached. Its outer surface bears the hymenium, and is honeycombed by a number 1 " Dispersion of Spores of Fungi by Agency of Insects, with special reference to the Phalloidei," by T. Wemyss Fulton, in Annals of Botany, vol. iii., 1889. INTRODUCTION TO THE STUDY OF FUNGI of irregular depressions, in which the mass of spores is lodged. The stem, consisting of a cylinder whose walls at this stage look firm and solid, is composed of a multitude of small com- pressed cells filled with jelly. " The volva is at first concealed beneath the surface of the soil, but towards maturity it breaks through the ground, and the exposed part gradually becomes conical, and finally ruptures, the stem rapidly lengthening and elevating the gleba in the air. The gelatinous contents of the flattened cavities disappear, and they become dilated, the previously compact stem increasing threefold or fourfold in magnitude, and becoming open and spongy, the cavities .being distended with air. The elevation of the gleba takes place with great rapidity, and may be completed in half an hour or from two to three hours, attaining a height of from six to ten inches. The utility of this sudden elevation by a mechanical process, instead of the slower process of simple growth, will hereafter be evident (Fig. 63). " At the time of emergence, and for a brief interval after, the hymenial surface is firm and solid, greenish gray in colour, and emits a faint, mawkish, but sweetish and honey-like odour, which is attractive to house-flies. Very soon, and before the elonga- tion of the stem is completed, it begins to darken, the odour becomes fetid, and the consistency changes so that it gets rather sticky and tenacious. A little later it is dark green, almost black, the odour is strong and repulsively fetid, and in con- sistence slimy or almost fluid. These changes begin at the apex and proceed downwards ; they seem to depend largely upon the influence of light, for if one side be protected from its action the change in consistency and colour is retarded i__ui,,j. on that side. When examined microscopically the dius^ ivi- fg|^j(-[ ^^j(j jg gggjj ^Q contain myriads of spores (each 3 /x. long). These changes occur during hot months of the year, from the early part of July till the end of September, at a time when insect life abounds. " As soon as the strong, dung-like odour is develoj)ed, the PUFF-BALL FUNGL—GASTROMYCETES 153 liquefying hymeniuin is visited by large numbers of flies, which sometimes almost cover it, and suck up the fluid mass with great avidity during hot sunny days ; but when the weather is cloudy or cold, fewer flies are to be seen." Examinations were made of flies taken from the deli- quescing gleba, and thousands of spores were found adhering to the feet and proboscis. The flies placed in confinement showed that their excrements were almost exclusively com- posed of spores. To determine if the excrementary spores retained their vitality they were placed in tubes on sterilised earth. The tubes were then closed with cotton -wool and buried with the contained spores, and different substances with them. In about two months the spores had germinated, and in some produced a plentiful mycelium. Hence it is clear that the spores after passing through the stomachs of insects do not lose their power of germination. This family is remarkable for the prevalence of a bright red colour near the hymenium, and also for the peculiarity of many of tlie forms. In Bidyo'pliora., Ithyphallus, and Mutimis the form is columnar and phalloid ; in Clathrus and Colus it is clathrate. In Calathiscus and Aseroe the disc is stellate, and in Kalclibrcnnera it is coralloid. The spores in all the species are very profuse and minute, generally involved in mucus. In the family of Nidulariaceae we meet with other peculiarities, and of these the common species of Cyatlms or Crucihulum, called the " bird's-nest Fungus," may be taken as the type (Fig. 64). There are altogether only about sixty described species, and the family, under some of its forms, is pretty widely distributed. When mature the Fungus is not more than from one to two centimetres high, and resembles in form little inverted bells, at first covered across the mouth with a white membrane or operculum, which when ruptured exposes a number of lentil-shaped bodies, packed like eggs in a little bird's-nest. These are the peridioles, each of which is attached to the inner surface of the cup by a long elastic cord, proceeding from the under face of the sporangiole. Each of these sporangioles, when cut in section, reveals a central cavity, into which the basidia project, with their INTRODUCTION TO THE STUDY OF FUNGI attached spores. These lentil-shaped bodies are analogous to the peridiola in such genera as Polysaccvm and Arachnion, but all the inter- vening plasma has been dissolved away, so that they remain free within the peri- dium. In all the species the sporan- gioles are very hard I |-'.^ "^(^Hj^^^ and firm when mature, and the con- tents are never powdery. In some species the external peridium has a squa- mose or hairy surface but in a few species it is nearly smooth. Sometimes the upper third of its length is marked with con- spicuous parallel channels or striae. In Cyathus the peri- dium is composed of three superimposed layers, and in Crucibulum of two. Having disposed, in a summary manner, of these two families, we return to the Trichogasters which form the bulk of the order, and especially the Zycoperdaceae. Probably the genera which contain the largest number of known species are Lycoperdon, Geaster, and Bovista. In these the peridium is more or less distinctly double, but there are allied genera in which the peridium is simple. The delicate threads, found mixed with the spores when mature, forming the capillitium, are an important element in classification. In the mature gleba they seem to be entangled, and indefinite as to their origin in Lycoperdon and Bovista, but in other genera they dis- tinctly radiate from the columella to the inner wall of the Fig. 64. — Ciucibuluni tubjait. Aftei Greville PUFF-BALL FUNGI— GASTROMYCETES 155 Fi(i. 65. — Lycuperdon, with sterile base and columella. peridium (Fig. 65). This columella is only a continuation of the spongy base in Lycoperdon, but in Diplodcrma it is hard and woody. In some species of Geasfpr the columella is distinct and club- shaped, extending half-way up, with the threads of the capillitium radiat- ing towards the periphery. De By M. J. Berkeley, London, 1S57, p- 315. 2 52 INTRODUCTION TO THE STUDY OF FUNGI attack growing plants, and produce copious soot-like spores, so that they have acquired the general name of " Smuts." The mycelium is deeply seated in the tissues, and the spores are developed in definite positions on the host : on the stem, leaves, flowers, ovaries, fruit, and sometimes in the corm, tuber, or root, but seldom in more than one of these places, and that one habitual to the species. A good example may be seen in the smutted ears of corn, or the distorted receptacles of the goat's-beard. The mycelium is an important element in this family, although so delicate and deeply seated that it is often passed over. The whole substance of the host may be penetrated and taken possession of by the mycelium before there is any external evidence of its presence ; therefore when the pustules are formed it is too late to apply remedial measures, for the plant has long been doomed. It is always tedious and difficult to trace the ramifications of mycelium in growing tissue, but in some of these species it may be seen bearing haustoria or suckers amongst the cells. Not only does the mycelium traverse the intercellular spaces, but frequently the branches pierce the walls of the cells, and though seen most readily in young plants, it is always manifest about the spore-pustules. The persistency of the mycelium is one of the agencies by which the continuity of the species is preserved. When the foster-plant dies in the winter the mycelium dies with it, but when the root-stock is perennial the mycelium also remains, to revive and penetrate the young shoots which are put forth in the spring. All the leaves of the violet may die year after year, and still every season Urocystis violae appears again, even when every infested leaf has been picked and burnt. The most important function of the mycelium in this family is its concern in the formation of the fruit. At the special spot where the development of fructification is to take place the mycelium undergoes some change in its character : the walls increase in thickness, and the contents become gelatinised. Some slight modifications take place in the different genera, but for the most part the hyphae branch and become en- tangled so as to form compact knots, or spore -beds. With this the hyphae gradually swell in places, and it is evident SMUT FUNGI— USTILAGINES 253 that a change is taking place within. The swellings are indication of spore - formation, which proceeds sometimes centripetally, so that . those on the exterior are most com- pletely developed, the circumference darkens, and an epispore is formed. In Siihacdotheca part of the hyphae are concerned in the production of the receptacle and columella, and part in the origination of the spores. In some genera the production of spores is centrifugal, and the peripheral spores are sterile. In Sorosjoorium " the spore-forming hyphae from several con- tiguous mycelial branches incline together and twist them- selves into a ball, as happens in the formation of a Lichen thallus. These convoluted and contorting spore-forming hyphae, being gelatinous, soon become so entwined and en- tangled that they cease to be individually recognisable ; to all appearances they coalesce together in part, if not entirely, and on the exterior of this gelatinous ball other hyphae are seen encircling it. These latter also being gelatinous, soon lose their individuality, although at times traces of their concentric arrangement can be made out. Spore-formation takes place only in the central gelatinous ball, in the middle of which it commences by the central part darkening in colour and becoming differentiated into spore-like bodies, which vary in number from four to sixteen. Apparently these bodies again subdivide, so that when the spores arrive at their maturity the spore-balls contain sixty to a hundred or more spores. In the young state the developing spores are polygonal from mutual pressure ; subsequently the balls increase in size, and the gelatinous zone swells also. When the spores assume their dark brown colour the gelatinous zone begins to be ab- sorbed, and entirely disappears when the spores are fully matured. In a certain sense the spore formation is centri- fugal, as it commences in the centre of the gelatinous ball, but the peripheral spores are the oldest, having been pushed outward by the formation of younger spores in the centre." ^ The spores of the Ustilagineae are practically teleuto- spores, and are called such by some writers. They are com- posed of two membranes — the outer, or exospore, the thicker and dark coloured ; the inner, or endospore, thin and colourless. ^ British Uredineae aiul Ustilagineae, by C. B. Plowright, London, 1889, p. 64. 254 INTRODUCTION TO THE STUDY OF FUNGI The surface of the epispore varies in its character, being some- times (piite smooth, in other species reticulated, in others so minutely granular as to appear to be smooth until closely examined, or in others distinctly rough and either obtusely warted or spinulose. In colour they seem to be black in a mass, but viewed obliquely sometimes with a yellowish or olive tinge ; seen under the microscope, by transmitted light they may be black or brown, violet, olive, or yellowish, and rarely hyaline. Where colour is present it resides in the epispore, and is fairly constant in each species when mature. The form is commonly globose, or approximately so, when perfectly free, but being usually closely compressed in growth, is apparently angular. The spore -masses in some genera, such as Ustilago and Tilletia, are more loosely packed, and the teleutospores do not adhere to each other in definite clusters, but are normally free. In Sorosporium and Thecaphora they form compact clusters, which in the latter genus separate with difficulty, whilst in Cintractia, although at first agglomerated, they soon separate. In Urocystis there are a few large, dark- coloured fertile spores, closely adnate to each other in the centre, and these are surrounded by hyaline sterile cells, or pseudospores, which give the appearance of a beaded border. In Entyloma, Melanotaenium, and Entorrhiza we meet with aberrant genera, which remind us of Protomyces and Syncliy- trium, and are probably more closely allied to the latter than they are to the rest of the Fhycomycetes. Germination of the teleutospores in this family has often been observed and watched. In some species a small germ- pore has been observed, but they are never so distinct as in the UrecUneae. When the spores germinate they protrude a germ-tube — usually designated, for reasons hereafter evident, a promycelium. In a certain sense it may be regarded as analogous to the protonema of mosses. This promycelium bears small hyaline bodies, which resemble spores, and are called by Continental mycologists sj^oridia, a name to which we take exception as it should be restricted to spores generated in asci. We will call them, for the time, promycelial spores, as suggested by Plowright, and much more appropriate. The promycelial spores will bud and produce secondary promycelial spores, SM UT FUNGI— US TIL A GINES '■SS and these again may continue to multiply themselves many times by budding, after the manner of yeast-spores, which is the term applied to them by Brefeld, but liable to misinter- pretation. In order the better to comprehend the process, it may be detailed as observed in Tilletia (Fig. 120). This parasite produces its teleutospores within the grains of wheat, and is known to farmers as " bunt." The appearance of the grains externally is very little changed, but slightly darkened in colour, and when crushed are seen to be filled with a sooty, rather fetid powder. These teleutospores are globose, dark coloured, almost black, and the surface minutely reticulated. When placed in water they germinate in about forty-eight hours. A germ- tube is emitted from a very small germ-pore, but it does not attain any considerable length; and this germ-tube constitutes the promycelium, into which the contents of the parent spore pass and retreat to the extremity, and are of a transverse septum, about the summit, and first promycelial spores, and colourless, to the Fig. 120. — Tilletia s^ov^a in germination, ft, producing a promycelium, ^j ; b, primary spore with promycelium, 2>i bearing conidia, of which some are conjugating ; c, conjugated gonidia in germination, with secondary gonidium at s'. After De Barv. are shut off by the formation Tuberculations are soon manifest these by lengthening become the They are thread - like, curved, number of from four to a dozen. When fully developed they are cut off from the pro- mycelium by a septum at the base. Soon afterwards these primary spores will be seen to connect themselves, mostly in pairs, by a transverse connective, performing an act of conjuga- tion. These conjugated primary spores are often separated from the promycelium, but they may remain for a long time attached. In due time liudding takes place, and the buds become converted into cylindrical curved secondary spores, the 256 INTRODUCTION TO THE STUDY OF FUNGI second generation of proniycelial spores, which in like manner are cut off by a septum at the base, and become free inde- pendent bodies. The act of conjugation, which results in their production, is not an essential, because solitary primary spores are equally capable of budding and producing secondary spores, although tliey are usually smaller than those produced by con- jugating primary spores. Hence it may be concluded that the conjugation of the linear spores is not a sexual act. The secondary spores are usually those which, by germination, enter the host-plant and form a mycelium, but they are also capable of budding and forming proniycelial spores of a third, or even of a fourth, generation, if the conditions are unfiivourable for infecting a new host-plant.^ The germination in Entyloma is similar to the above, but less complex. The spores send out a germ -tube in about twenty-four hours, and this constitutes the promycelium, which develops several branches at the apex, each of which is cut off by a septum at the base and becomes a proniycelial spore. These spores then conjugate in pairs by the formation of a connective bridge ; afterwards, by a continuation of growth at the apex, secondary spores are produced, which fall off and germinate. The growing point enters the host -plant and forms a mycelium, which starts a new infection, and in com'se of time teleutospores of a normal kind are developed in clusters. In this genus conidia are also produced direct from the mycelium, the conidia-bearers rising to the surface of the leaf through the stomata. These conidia germinate on the surface of the leaf upon which they fall, and the germ-tube enters the stomata and forms a mycelium. They are able to form secondary conidia, but this seldom takes place under normal conditions. Hence there are two forms of reproduction in this genus — that of the germinating teleutospores, forming a promycelium which gives rise to proniycelial spores, and these after conjugation developing secondary spores, capable of repro- ducing the parasite, after an alternation of generations ; and, secondly, of germinating conidia, which reproduce the parent Entyloma at once, without an intervening generation. 1 "On Bunt Spores," by M. C. Cooke, Journal of QuebcU Microscojncal Club, vol. i. p. 167, 1868. SMUT FUNGI— USriLAGINES 257 The teleutospores in some instances in this family are resting-spores — that is to say, they are capable of germination after a period of rest ; but for the most part they germinate freely when moist, and a delay of germination can only be secured by maintaining a condition of dryness which does not obtain in a state of nature. It is uncertain how the interval is connected between the matm-ity of the teleutospores and the growth of the seedling hosts, where the entire plant is annual. In the case of perennial hosts a persistent mycelium removes all difiiculty, but where mature teleutospores are produced upon an annual in summer or autumn, and there are no seedlings until two or three months afterwards, it is not evident how the continuity of the species is preserved. It has been shown that, when cultivated in a suitable medium, the promycelial spores multiply themselves almost indefinitely by budding, but the nutrient fluid must be maintained unexhausted. In this condition the growth is similar to that of yeast, and the term " yeast cells " has been applied to them. So long as the supply of nutrient fluid is maintained there is no departure from the budding process. Brefeld maintains it to be extremely probable that the conidial fructification, in a toruloid form, occurs in nature in many species of the Ustilagineae ; that they have the power of pro- pagating outside the host as " torulae," and develop their spore fructification only when they penetrate the tissues of the host- plant by means of germ threads, which takes place when the supply of nutriment ceases. The extreme assumption on this basis is that certain forms of Saccharomyces, or indistinguish- able therefrom, are in fact aquatic forms of the conidia of Ustilagines, which have become " toruloid " on account of their surrounding conditions. In fact, that some ferments are not autonomous, but depraved Ustilagines which have abandoned their parasitic habit and become saprophytes. It will therefore be evident by this time that the members of this family are universally parasitic, and that the hosts are herbaceous plants. In a great number of instances the graminaceous plants are the victims, but by no means ex- clusively. In all cases they are eminently destructive, and, from their habit, difficult to contend with. Most of the pro- 17 258 INTRODUCTION TO THE STUDY OF FUNGI posed remedies are preventive and not curative ; they could hardly be otherwise until that period in their life-history is more definitely determined which intervenes between the maturity of the teleutospores and the inoculation of seedlings of the host-plant. Assuming the total of known species to be somewhere about three hundred, upwards of one hundred of these affect the grasses, and nearly fifty attack other Monocotyledonous plants, so that scarcely half of the total are found on Dicoty- ledons. This is a peculiar fact in distribution which is perhaps without parallel in any other family of the parasitic Funsi. BIBLIOGRAPHY De Toni, J. B. " Sylloge Ustilagiuearum et Uredinearum," in Saccardo, Syllogc Fungorum. Imp. 8vo. Vol, vii. pt. ii. Padua, 1888. Fischer de Waldheim. Sur la Structure des Sjwres des Ustilaginics. Moscow, 1867. Apcrgu systimatique des Ustilaginies. 1877. "Les Ustilaginees et leiir Plantes nourricieres." Ann. des Sci. Nat., 6th series, vol. iv. Paris, 1877. "Winter, Geo., in Rabenhorst's Kryptogamen Flora — Dcv Pilzc. 8vo. Guts. 1884. WORONIN, M. Bcitrag zur Kenntniss der Ustilaginecn. 1882. Massee, Geo. British Fu7igi — Phycomycetes and Ustilagineae. 8vo. Plates. London, 1891. TuLASNE. " Memoire sur les Ustilaginees comparees aux Uredinees." Ann. des Sci. Nat., 3rd series, vol. vii. Paris, 1847. "Second Memoire." Ann. des Sci. Nat., 4tli series, vol. ii. Paris. ScHROTER, J. "Bemerkungen und Beobachtungen ii. einige Ustilaginecn. " Cohn, Beitrage z. Biol., ii. Brefeld, 0," Bot. U7itersuch. ii. Refenpilze. Leipzig, 1883. CoRNU, M. "Contributions t\ I'^^tude des Ustilaginees." Bullet. Sac. Bot. de France. August 1883. CHAPTEE XXII IMPERFECT CAPSULAR FUNGI SPHAEROPSIDEAE In the old arrangement by Fries, one of the primary divisions of Fungi was that termed Coniomycetes, which was interpreted as " Dust-fungi," and was represented as including those fungi in which the spores were the principal feature, such spores appearing like an impalpable dust. It was, perhaps, an odd mixture, but this group included not only the Si^haero^psideae, as at present limited, and the Melanconieae, which are closely related, but also the Urediiieae and the Ustilagineae, which are not related at all, and are now separated and rank as a distinct group. It need not be explained here wherefore the Uredineae and its allies were entirely out of place in an association with Fungi which either possessed a distinct perithecium, in which the spores were generated, or a pseudoperithecium formed from the matrix. The group now under consideration is analogous, in ex- ternal features, to the Pyrenomycetes, but wholly deficient of asci. The perithecia, or pseudoperithecia, include only stylo- spores, and have been assumed to be imperfect representatives, or imperfect stages or conditions, of the Pyrenomyceteae, and hence called " imperfect capsular Fungi." In some instances this may be undoubtedly true, but we think it assuming too much to affirm that all are imperfect conditions of higher Fungi, because it has been demonstrated to be the case in a comparatively few instances. It is at least premature to decline acknowledgment of thousands of very distinct forms of Fungi in a systematic position, simply because a few of them have been shown to be transitional, whilst the majority may never be demonstrated to be other than autonomous. This 26o INTRODUCTION TO THE STUD V OF FUNGI objection luis been appreciated by Saccardo, who includes all the species in his Sylloge, although he relegates them to an inferior position as " imperfect fungi." The Sj)haero23sideae must be considered apart from the Melanconieae, on the fundamental basis that the former possess a distinct perithecium, and the latter are only circumscribed by a modification of the matrix. With this limitation, there- fore, the Sphaeropsideae correspond to the Pyrenomyceteae, although dissevered by the absence of asci and paraphyses. It would be well if authors in future would respect Saccardo's definitions of the fruit in the different orders, by a restriction of the terms. Thus in the Ascomycetes, where the representa- tives of seeds, or the spores, as they are generally termed, are produced within asci, that they are sporidia. When produced naked on basidia, as in the Basidiomycetes or Myxomycetes, they should retain the name of spore. When enclosed in perithecia, but without asci, as in the Sphaeropsideae, then to be termed sporules. But when wholly naked, and without basidia, or receptacle, as in the Hyphomycetes, then to be termed co7iidia. The only modification to this arrangement which approves itself to us is the application of the term sporules to those bodies which are enclosed in a pseudo-perithecium, such as the Melanconieae, as well as those contained within a definite perithecium ; and the restriction of conidia to absolutely naked fruit, in which there is neither perithecium nor semblance of a perithecium, as in the Hyphoinycetes. Practically this means the association of the Melanconieae with the Spihaerop- sideae, in the denomination of sporules, instead of union with the Hyphomycetes under the denomination of conidia. This may be a distinction of little importance, but it is one which appears to commend itself to consideration. The Sjjhaeropsidcae, therefore, may be thus defined, as Fungi possessed of a perithecium, but without asci, the sporules, or stylo- spores, being produced internally at the apex of more or less distinct supporting hyphae or pedicels, which, for the sake of distinction, should not be termed basidia, but sporophores. This would obviate any confusion with the spore-bearers of the Basidiomycetes, and the definition would be reduced to " peri- thecia, without asci, enclosing sporules, on more or less distinct IMPERFECT CAPSULAR FUNGI— SPHAEROPSIDEAE 261 sporophores." The primary families would depend for their distinctive characters upon the nature of the perithecium. The first and largest is the Sphaerioideae, in which the perithecia are membranaceous, coriaceous, or subcarbonaceous, typically subglobose, and closed ; thus analogous to the old genus Sphaeria. The second family, Nectrioideae, with the perithecia similar in form, but fleshy or waxy, and usually brightly coloured, analogous to the old genus Nedria, or the more recent family Hypocreaceae. Then the third family, the Leptostromaceae, has the perithecium more or less dimidiate, and astomous, or with a longitudinal fissure, and black, corre- sponding in some respects to Hysteriaceae. Finally, the fourth family is JExcipulaceae, with the perithecium cup -shaped, or patellate, at first spherical, then broadly open, and making the nearest approach to analogy with the Discomycetes. Each of these families we must therefore analyse a little more in detail, bearing in mind their distinctive family features. The SjjJiaerioideae are therefore the Sphaeriaceous, or Sphaeria-like, SjjJiaerojysideae, with blackish closed perithecia ; and although we should have preferred grouping them in a similar manner to our subfamilies of the Sphaeriaceae, we will rest content with the arrangement proposed in the Sylloge, which will be the one generally adopted for some time to come. Of course this method is an artificial one, to a great extent, being based upon the character of the sporules. The Hyalo- sporae is again the largest section, including all the genera with continuous hyaline sporules ; those in which the peri- thecia are simple or distinct forming one subsection, and those in which the perithecia are composite or caespitose forming another. Amongst the simple species the larger number have the perithecia naked or smooth, and of these one genus, Fhyllostida, is often parasitic, growing upon leaves, the depressed and innate perithecia being grouped on discoloured spots ; the remaining genera have the species not seated on definite spots, and of these three are very similar to each other ; that is to say, Phoma, with the perithecia (Fig. 121) covered by the cuticle ; Aposphaeria, with the perithecia exposed, or superficial, mostly on dead wood ; and Dendrophoma, which in all things else resemble PJioma except that the sporophores are 262 INTRODUCTION TO THE STUDY OF FUNGI branched, instead of remaining simple. More recently the genus Phoma has been subjected to another mechanical sub- division into Phoma and Macrophoma, the latter to include all the species of Phoma which have sporules exceeding a definite size, so that the determination of the genus may 9 depend upon the difference of a micromillemetre. ^ <^ Another genus, Asteromdla, which is equal to Asteroma, minus a subiculum, has the minute perithecia clustered on dendritic spots. There are five or six smaller genera, consisting of but a Pig 121 Peri- thecium of few spccies, whicli Completes the series of genera Phoma with j^ which the perithecia are not rostrate. In Sphaeronema the habit is that of Phoma or Aposphaeria, but the perithecia are rostrate. In addition to these follows a series of genera in which the perithecia are seated upon a subiculum of some kind, more or less distinct and definite. In Chaetophoina the perithecia resemble those of Phoma, but are innate in a dematioid subiculum resembling Fumago or Asterina. An allied genus, Asteroma, is the ana- logue of such genera as Asterina or Dimerosporiitm, the minute perithecia being seated upon, or amongst, a subiculmn of radiat- ing black fibrils. In the remaining two genera, Ypsilonia and Cicinnobolus, each contains but a single species, and the latter is parasitic upon Oidiuvi. In the three genera which com- plete those in which the perithecium is bare, Neottiospora has the sporules cristate, and the other two genera have the sporules in chains. We pass now to the smaller series, in which the perithecia are hairy or bristly. Here are four genera, the most numerous and important of which is Vermicularia. In habit the perithecia resemble those of Venturia, or some species of Chaetomium, the long dark bristles are septate, and the sporules mostly curved. Pyreno- chaeta is similar, but the hairs of the perithecium are shorter, and the sporules ovoid or oblong. Muricularia and Staitrochaeta differ from the foregoing in the character of the external hairs. This brief review of the simple species leads us to the series in which the perithecia are composite or caespitose, usually with a definite stroma. Dothiorella resembles superficially either Botryosphaeria or Cucurhitaria. The pustules are IMPERFECT CAPSULAR FUNGI— SPHAEROPSIDEAE 263 erurapent, and consist of a number of perithecia aggregated upon a basal stroma. Rabenhorstia, and especially Fuchelia, have a subglobose stroma, in which are fertile cells, so that in habit and structure there is a similarity to some species of the ascigerous genus Fuckdia of the Melogrammeae. Flacosphaeria, on the other hand, has an effused stroma resembling Rhytisma, or certain species of Phyllaclwra. The four remaining genera possess a stroma, more or less like Vaha, especially so in Cytospora, in which the sporules are small and sausage-shaped. It is probable that all the species in this genus are stylospor- ous conditions of Valsa. The genus Cytosporella only differs from Cytospora in having the sporules either globose or ovoid ; and Fusicoccum again in the sporules being large and straight, and mostly fusiform ; so that these three genera resemble Valsa in habit, but differ amongst themselves in the form of the sporules. Centhospora might be included in the same series, but the stroma is firmer, and the spore-bearing cells have the converging necks mostly united in a central orifice. The sporules are cylindrical and typically straight. It is very usual, even if not universal, for the mature sporules which are held together in a pasty mass to be ejected in the form of a tendril, or a contorted thread. Thus concludes the section Hyalosporae of tlie Sphaerioid family of the Spthaeropsideae, including an enumeration of not less than 2625 species. The Phaeosporae section has the sporules continuous, and coloured either brown or sooty. The number of genera is comparatively small, and of these four have the perithecia subglobose and smooth. Two of these are practically old genera, since Sphaeropsis was recognised by Fries, although not limited, as now, to species with coloured sporules. It is in all respects the corresponding genus to Diplodia, but with continuous, and not uniseptate, sporules, as in that instance. Coniothyrium is closely allied to Sphaeropsis, but the perithecia are normally smaller, as are also the sporules, which are large and elliptical in Sphaeropsis, small and globose, or ovoid, in Coniothyrium. The genus Harhnessia closely resembles Melan- conium in the sporules, and also in their ejection when mature, and the consequent blackening of the matrix, but differs in the possession of a distinct perithecium. In 264 INTRODUCTION TO THE STUDY OF FUNGI Hypocenia the sporules are fusoid and pale browu. Levieuxia is a South African genus, containing a single species, with a stipitate perithecium, which is fissured at the apex when mature. The only genus with hairy perithecia is Chaetoinella, which is the analogue of Chaetomium, but deficient in asci. The residue of the section consists of genera in which the perithecia are compound or caespitose. Haplosporella is, in fact, a caespitose Sjjhaeropsis, the perithecia being aggregated in dense erumpent pustules, resembling those of some species of JBotryosphaeria. Weinmannodora has a stroma which is hemispherical and carbonaceous, with radiating fertile cells, containing globose dark sporules. Cyto2)lea consists of a single species, in which the stroma is at first pulvinate, then con- fluent and effused. Practically the entire section is repre- sented in Europe by Sphaeropsis and Coniothyrium, with smooth perithecia ; and Chaetomella, with setose perithecia ; and in the compound genera by Haplosporella. The Phaeodidymae is also a small section, with uniseptate coloured sporules, and is, in fact, entirely made up of species which entered into the old genus Diplodia, as recognised by Fries. Thus Diplodia, as limited, contains species with a smooth perithecium, and coloured sporules, not having a mucous envelope ; Macrodiplodia, with similar smooth perithecia, but coloured sporules having a mucous envelope, as in the sporidia of Massaria ; Chaetodiplodia, with hairy perithecia, and sporules as in Diplodia. The remaining genus with simple perithecia is Diplodiella, in which the perithecia are almost superficial, and flourish on decaying wood. The single com- posite genus is Botryodipilodia, with the perithecia densely aggregated in erumpent pustules as in Haplosporella. The section Hyalodidymae is characterised by hyaline uniseptate sporules. Two genera correspond to Phyllosticia in Hycdosporae, in that the species are mostly parasitic on living leaves, collected on discoloured spots. In AscocJiyta the sporules are simply uniseptate, but in Bohillarda the sporules are uni- septate and crested at the apex with long setae, resembling in this respect the genus Pestalozzia. In three other genera the smooth perithecia are scattered and not seated on discoloured spots. Actinonemu has the perithecia seated upon a radiating IMPERFECT CAPSULAR FUNGI— SPHAEROPSIDEAE 265 adnate subiculum as in Asteroma, l)iit with dili'erent sporules. Darluca has no subiculum, but the perithecia are parasitic on old Uredines, and in Di])lodina the species grow on branches the perithecia, and even the sporules, resembling Diplodia, save that they are uncoloured. In Cystotricha the perithecia dehisce as in Hysterium, with a gaping fissure, and the sporo- phores are septate and constricted, so as to possess a moniliform appearance. In the only remaining genus, EhyncJioj^homa , the perithecia resemble Fhoma externally, except that they are rostellate and the sporules are uniseptate. The succeeding section, Fhragmosporae, has the sporules multiseptate, and is represented in two divisions, in one of which the sporules are brown, and in the other hyaline. The former is the most numerous in genera and species. The old genus Hendersonia, as interpreted by Berkeley, has been divided, and is now restricted to such species as possess coloured sporules. The perithecia are papillate, covered by the cuticle. In Couturea the species have superficial perithecia, which are seated on a stellate subiculum, somewhat after the manner of Asteroma. In the two small genera Angwpovia and Lichenopsis the perithecia dehisce by an operculum at the apex. In the former the perithecia are superficial and hairy ; in the latter immersed and smooth. Cryptostictis somewhat resembles Pestcdozzia in the septate sporules being furnished at both extremities with a hyaline bristle, whereas in Pesta- lozzia the cilia are more than one, and confined to the apex of the sporule. In another small genus, that of Prosthemium, the sporules are also peculiar, in being joined together at the base in a stellate manner (Fig. 122). The compound species are confined to a single genus, in which the perithecia are immersed in a stroma, as in Dothideaceac. This genus is Hendersonula, and is, in fact, a compound Hendersonia. The Hyalophragmiae, in which the sporules are colourless, includes but two genera : Stagonospora, which is practically Hendersonia with hyaline sporules ; and Mastomyces, in which the perithecia are elongated and superficial, resembling scattered perithecia of the rather obscure genus Corynelia, which is ascigerous. The Dictyosporae, in which the sporules are coloured and 266 INTRODUCTION TO THE STUDY OF FUNGI muriform, consist almost absolutely of one type, that of Camarosporium, which resembles Hendersonia in habit and appearance, growing npon branches, covered by the cuticle. Cijtosporium only differs in the perithecia being subsuper- ficial, growing on naked wood. Dichomera, in which the perithecia are immersed in a stroma, as in Dothideaceae, is consequently compound. The doubtful genus Endohotrya, contains but one species, which is North American. A rather important section is the Scolecosporae, in which the sporules are very much elongated, so as to be thread-like, or rod-like, and either hyaline or faintly coloured. The principal genus is Septoria, of which the species are in greater part parasitic, growing on living leaves or the green parts of plants. The minute perithecia are flattened and innate, and typically Fig. 122.— Prosfhemium . i j- ^ i • section with sporules. aggregated upon discoloured spots. This genus is analogous to Pliyllosticta, from which the species cannot be distinguished except by the sporules. There is a suggestion of genetic con- nection between some of the species and the ascigerous genus Sphaerella, but this has not been demonstrated. Fhlaeospora includes such species as would otherwise find a place in Septoria, were not the sporules thickened, and com- paratively shorter. Hhahdosjjora scarcely differs from Sep)toria except that the perithecia are not seated on discoloured spots, and are confined to twigs and the stems of herbaceous plants. It bears about the same relation to Septoria that Phoma does to Pliyllosticta. Phlyctaena would otherwise be the same as Ehahdospora, only that the perithecia split with a fissure, and become deficient above. In the small genus Gelatinosporium, the perithecia dehisce broadly and irregularly, the sporules in the interior forming a gelatinous mass. There are two genera in which the perithecia are distinctly rostrate as in Sj^haero- nema, from which genus the species have been separated, on account of the difference in the sporules : Sphaerograpliium, in which the sporules are continuous ; and Cornularia, in which they are septate. Of the three compound genera, Uriosjjora IMPERFECT CAPSULAR FUNGI— SPHAEROPSIDEAE 267 has the stroma small and depressed, with the sporules con- nected in bundles of four ; Dilopliospora has a crustaceous stroma, with the sporules crested with cilia at each end; whilst Cytosporina accords with Cytospora in general features, but the sporules are thread-like and curved, or flexuous. Possibly few of the species are autonomous. There remain but two aberrant genera to be alluded to, and these are Micula and Micropera. The species occur on bark and often resemble lenticels, or are clustered like species of Cenangium, of which they are said to be the pycnidia ; the sporules are elongated and nucleate. The second family, Nectrioideae, bears the same relation to the Sphaerioideae as the Hypocreaceae to Spliaeriaceae in the Pyrenomyccteae. The perithecia and the stroma, when present, are fleshy or waxy, and pale or bright coloured. The arrange- ment here is the same as in the preceding family, primarily based on the sporules, so that the sections correspond. The first section is the Hyalosporae, in which the sporules are continuous and hyaline. Most of the genera are simple, and only one is composite. Of the four in which the perithecia are not beaked, only one needs particular reference, as the residue contain only a single species. Zythia resembles a scattered Nectria in appearance, with ovoid or oblong sporules. Sjyhaeronemella is analogous to Sphaeronema, and has the perithecia rostrate. The only composite genus is Aschersonia, of which the species might be mistaken at first for species of Hypocrea, the structure and habit being that of Hypocrea without asci. In the only species of the genus Dichlaena the perithecia have a double tunic, and the sporules are minute and globose. In Didymosporae the only genus is Fseudodiplodia, which corresponds to Diplodia in the brown uniseptate sporules, but differs in the colour and texture of the perithecia. In Phragmosporae all are hyaline. Stagonopsis corresponds to Stagonospora, with like sporules ; but in Chiastospiora the sporules are arranged in four rays. Only one species is known in each genus. The Scolecosporae has but one genus, with fili- form sporules. This is Polystigmina, a stylosporous form of the ascigerous genus Polystigma, in which the perithecia are immersed in a discoid stroma. A small group, consisting of 268 INTRODUCTION TO THE STUDY OF FUNGI three genera and three species, has been placed in proximity to the Nectrioideae, although not quite conforming thereto, on account of their approach to a cup-shaped receptacle, so that their position can only be regarded as provisional. Hysteromyxa combines the habit of a Hysterium with the fruit of a Myxomycete. Patellina with the habit of a Patellaria has stylosporous fruit. And Cyphina has the appearance of an Uxcipula, but is bright coloured and garnished with white hairs, so as to offer an analogy to Volutella. All of these require fuller investigation, and none are European. The family Leptostromaceae diverges from the previous families in losing much of the Sphaeria-like habit, and approaching that of some of the Hysteriaceae, with occasional suggestions of Fhacidiaceae. The perithecia are more or less distinctly dimidiate, or scutiform, with or without an ostiolum, or fissured longitudinally, either membranaceous or carbonace- ous, black, and either erumpent or superficial. Under the carpological arrangement, the Hyalosporae are again the most numerous, and resolve themselves into two subdivisions, in one of which, although the perithecia are destitute of a definite mouth, they dehisce in diverse ways, but not with a longitu- dinal fissure. In the other subdivision the perithecia split longitudinally after the manner of the Hysteriaceae. Lep)totliy- rium is the chief genus in the first subdivision, with a dimidiate and shield-like perithecium, which does not split by a longitudinal fissure, but soon cracks all round and falls away (Fig. 123). Some of the species are believed to be the stylo- ,^^=z=^ ^^^ spores of certain species of Coccomyces. The genus ^^"^ -=^ Piggotia has an irregular depressed perithecium Fig. i2Z.—Lep- -whieh does not fall away. Ifelasmia is allied, tothynuin. . . .... but in this genus the perithecia are innate in a black effused stroma, growing on fading leaves. The species are the stylosporous condition of Phytisma, which develop asci in the same stroma after the leaves have fallen and rested on the ground during winter. Actinothecium has an orbicular scutate perithecium, which dehisces by several radiating fissures. In the other group, in which the perithecia split longitudinally — the chief is Lep)tostroma, which corre- IMPERFECT CAPSULAR FUNGI— SPHAEROPSIDEAE 269 spends to Lej)totliyri%Lm — the perithecia are elongated and fissured after the manner of Hysterium, and some of them are probably the stylosporous condition of species of Hypoderma or of Zophodermium. Lahrella has nearly circular perithecia, which are innate, and sometimes formed from the changed matrix, dehiscing by a longitudinal crack. A final genus, Sacidium, differs from all the rest in the perithecia not being distinctly parenchymatous. The sporules are often globose. The Fhaeosporae, with coloured continuous sporules, consist of but one small genus, with scutate perithecia pierced in the centre. Of this single genus, Firostoma, only one species is known. The Fhragmosporae have all hyaline sporules, which in Discosia are fusoid and ciliate at each end. In Entomo- sporium the sporules are two-celled, with a lateral smaller cell on each side at the septum, so as to be cruciate, each with a cilium. This is the same genus as is sometimes known under the name of Morthiera. The Scolecosporae, with long filiform sporules, include the genus Acti^iothyrium, which has flat shield-like perithecia, delicately fringed all around the margin ; and Melop)hia, in which the similar perithecia are corrugated, but not fringed at the margin. Leptostromella consists of species of Leptostroma, as originally interpreted, which have long filiform sporules. In other respects with the habit and appearance of Leptostroma. The Leptostromaceae are most common on leaves, or the stems of herbaceous plants, but with only a few exceptions appear to be saprophytic. The last family is the Excipulaceae, in which there is a nearer approach to cupulate forms. In its general character the perithecium, or receptacle, is cup-shaped, patellate, discoid, or hysteriform, in all of which it is at first nearly spherical, but soon open ; and either smooth or hairy, commonly erumpent, and then superficial, so as almost to resemble minute black Fezizae, with which some of the species were formerly associated. The Hycdosporae are again the largest section, and may be divided into those which have the receptacle smooth and those in which the receptable is hairy or bristly. The smooth cupped are of two kinds, namely, those in which the receptacle is cup- shaped and those in which the receptacle is split longitudinally, or is valvate. The cup-shaped, smooth-surfaced group contains 270 INTRODUCTION TO THE STUDY OF FUNGI Godroniella, a genus in which the receptacle is composed of agglutinated hyphae, in other respects scarcely differing from the next genus, Excipula, in which the excipulum is cellular, membranaceous, or tough, and black. The genus Excipula of Fries, and many subsequent authors, was rather a heterogeneous one, even including some ascigerous species, and the residue are now distributed over six different genera. HeteQ'ojmtcIla differs in the perithecia being thicker and more leathery, with the mouth always contracted and torn, the sporules fusiform, growing upon branched sporophores. In Bothichiza the black receptacles are mostly erumpent, often gregarious, at first closed, then rather cup-shaped, and are often the spermogonia of species of Cenangium. Sporules oblong and continuous. In Lemalis the receptacles are membranaceous, or rather fleshy, coloured, but not black. Gatinula has the receptacles tough or horny, and black, rather cup -shaped, disc often bright coloured. Discula corresponds to Discella, but the sporules are continuous. The receptacles are discoid or patellate, often imperfect, black or coloured. Hereafter follow the genera in which the perithecia are hysteriform or valvate. In Sporonema the receptacles are valvate, dehiscing with angular teeth, as in Phacidium, of which they are possibly a stylosporous condition. Fleococcum is scarcely distinct from Sporonema, although the contents are assumed to be more mucilaginous. Psilospora closely resembles Dichaena, of which it is evidently a stylosporous state. The perithecia dehisce in the manner of Hysterium, with two lips, and occur upon living bark of trees. The remaining genera of the Hyalosporae possess hairy perithecia. The genus Amerosporium has the receptacles cup-shaped, and corresponds to Excipula ; but the cups are setulose, the sporules are naked at the ends. In Dinemasporium the habit and external appear- ance are the same, but the sporules have a hyaline bristle, or awn, at each end (Fig. 124). Polynema differs in having the apex of the sporules crowned with about four awns. In the next section, the Hyalodidymae, there are but two genera. In Discella the perithecia are normally discoid, sometimes imperfect, or formed from the matrix, a long time covered by the cuticle. Sporules oblong, uniseptate, and hyaline. In Pseudopatella the receptacle is cup-shaped, almost superficial IMPERFECT CAPSULAR FUNGI— SPHAEROPSIDEAE 271 tough and black, with a pallid disc. Possibly a stylosporous form of Diirella cotiqjressa is the only recorded species. The section Phragmosporae contains two genera which are offsets from the old genus Excipula. These are Exciindina, with smooth receptacles and multiseptate sporules ; and Excipularia, with setose receptacles and multi- septate sporules. In the remaining genus, Pili- dirnn, the receptacles are erumpent, discoid, and membranaceous, blackish and torn at the margin, with a pallid disc. The section Scolecosporae alone remains, containing three genera in which no definite stroma is present : Schizothyrella, with the perithecia hemispherical, then torn at the margin, the filiform sporules breaking up into Fig. cylindrical joints ; Protostegia, in which the receptacles are discoid, at first covered, then exposed, margin torn or fringed, disc gelatinous, sporules thread-like, but not breaking up ; and Oncospora, with discoid or cup-shaped receptacles, usually gregarious, erumpent, disc gelatinous and the sporules clavate, hamate (curved like a sickle) or sigmoid (like the letter S). The only compound genus is Ephelis, in which an effused, sclerotium-like l)lack stroma bears the cup-shaped receptacles, with filiform sporules. It is analogous to a genus of Discomyceteae, to which the name of Ephelina has been given. This running commentary on the Sp)haerop)sideae has made it manifest that at many points the genera, or some species, have a close relationship with some of the Ascomyceteae ; but even if all these were removed, there would still remain an imposing array of species against the autonomy of which no word of calumny has yet been offered. The Sphaeropsideae may not be so attractive or interesting as the Pyrenomyceteae, but they equally claim recognition, until the alleged dimorphism can be proved against them. The Melanconieae have undou].>tedly a close afSnity with the SjjJiaeropsideae, with which they have always been associated. The chief distinction, and the only one which can be insisted upon, is that the perithecia — so universal, under some form, in the Sphaeropsideae — are absent in the Melanconieae. The habit 272 INTRODUCTION TO THE STUDY OF FUNGI is nearly the same, except that the pustules are always erum- pent, and never supertieial, and the sporules are similar in form and size, produced similarly at the apex of short sporophores. The difference therefore is reduced to that of the character of the walls of the cavities in which the sporules are engendered. In the Melanconieae there are definite cavities, beneath the cuticle, which correspond in function to immersed perithecia ; yet these cells have no heterogeneous walls, but are simply modifications of the matrix. In many cases they are distinctly modified so as to appear as pseudoperithecia ; in some there is merely a compact base, formed by the mycelium into a spore- bed, upon which the sporules are developed, and when mature are ejected, in a more or less gelatinous mass, through fissures or orifices in the covering cuticle. The spore-bodies are termed conidia by Saccardo, as they are in the Hyphomyceteae, but we prefer to employ the same term as that adopted in the allied Sphaeropsideae, and distinguish them as spondes. The technical definition of the Melanconieae is to the effect that they are Fungi without perithecia or asci, forming sub- cuticular pustules, which are partially erumpent, discharging the sporules through openings in the cuticle, such sporules being produced on a proligerous stratum, growing upon distinct or obsolete sporophores, and either in themselves continuous or septate, either hyaline or coloured. The arrangement adopted is similar to that of the Sphaerop- sideae, the primary sections having relation to the character of the sporules. The Hyalosporae include those which have oblong, or shortly cylindrical continuous hyaline sporules, whether solitary on the sporophores or produced in chains. Four genera are indicated in which the sporules are solitary on the sporophores, two being found mostly growing on leaves, and two upon branches. The distinctions between Hainesia and Gloeosporuim, which are the two genera that flourish for the most part on living leaves or succulent fruits, are scarcely sufficient, since they resolve themselves into this, that in Hainesia the pustules are brightly coloured, and in Gloeosporium gray, pallid, or dull coloured. Hence we can treat them both as a single genus. These parasites are amonffst the most destructive with which the horticulturist IMPERFECT CAPSULAR FUNGI— SPHAEROPSIDEAE 273 has to contend, or, at the least, the most insidious, and least subject to control. They do not spread over such tracts as the potato disease and the hop mildew, but the infected plants upon which they appear are doomed, and these often the rarest and most valuable. The first external indication is usually in the form of small elevations of the cuticle, or little warts, which cover the concealed pustules ; for a long time these re- main unbroken, but when the sporules are mature the cuticle is ruptured, and a globule, or tendril, of agglutinated sporules emerge through the orifice. These sporules are either elliptical or elongated, usually much longer than broad, and often of considerable size, but without septum or colour. Including the two supposed genera, not less than some 230 species are known, to say nothing of Marsonia, which is a corresponding genus with uniseptate sporules, and similar habit and propen- sities. The two corticolous genera Myxos2Jorium and Melano- stroma are not clearly distinct from each other. The habit is similar to Gloeos]Jormm, but the species are found chiefly on dead bark, and therefore not parasitic, or destructive. Many of the species are credited with being stylosporous conditions of various ascigerous Fungi. The sporules resemble those of Gloeosporium. The series of genera in which the sporules are produced in chains is represented by only a few species. Hypodermium has black pustules, which, being elongated, re- semble the perithecia in Hypoderma, a genus of the Hysteri- aceae. Myxosporella is simply Myxosporium with the sporules catenulate. Blennoria has discoid pustules, which bear a re- semblance to Puccinia, to which Agyriella is closely allied ; but the pustules are at first gelatinous, becoming hard and shining. In Trulhda the pustules are compact and erumpent, often having the appearance of perithecia ; the sporules are sometimes coloured. In the two genera Myxormia and Bloxamia the pustules are apparently pezizoid ; that is to say, the form re- sembles a shallow cup, or concave disc, without a receptacle. In Myxormia the sporules are joined in a chain, by a narrow isthmus ; and in Bloxamia they are truncate, and closely applied to each other. There are two other genera, Colletotrichum, which is simply a Gloeosporium, with the margin of the pustules hairy ; and Pestalozziella, in which the sporules are 18 274 INTRODUCTION TO THE STUDY OF FUNGI cristate, and therefore analogous to Bolillarda but with con- tinuous sporules, or a dwarfed form of Pestalozzia without colour and without divisions. The next section is a modified one, or at least the Scoleco-aUantosporae combines Scolecosporae and Allantosporae in a single section. In one genus, that of Cylindrosporium, the sporules are really filiform ; in Crypto- sporium and Libertella elongated and falcate, but scarcely fili- form ; and in Nemaspora they are allantoid, or sausage-shaped. In Cylindrosporium the species are parasitic on living leaves, and thus correspond to Gloeosporium. In the other three genera they are saprophytic, chiefly affecting the bark of dead branches. In Cryptosporium the sporules are mostly rather large and robust, but in Libertella slender, oozing out in brightly coloured tendrils. Nemaspora somewhat resembles Lihertella, but the sporules are shorter, and allantoid. In all three genera there are many species which are regarded as stylosporous forms of ascigerous Fungi, and suggest analogy to Cytospora in the Sphaeropsoideae. The section Phaeosporae is the most typical, and includes the genus Melanconium, which is almost the same as Fries left it, with subglobose or oblong dark -coloured sporules, often oozing out and blackening the orifice of the pustules. Some of the species are associated with Sphaeriaceae of the genus Melanconis, but others may prove to be autonomous. Crypto- mela is analogous to Cryptospoi'ium, but with coloured sporules. Thyrsidium is, however, a genus by itself, in which the con- tents of the pustules are gelatinous, and the sporules are minute, but clustered in chains at the apex of elongated sporophores, in a capitate manner, involved in a mucous envelope. The Didymosporae include four genera, in which the sporules are uniseptate, and in two of them coloured, whilst in other two they are hyaline. Of the former, Didymosporium corresponds to Melanconium, but with two-celled sporules ; and Bullaria, with a single species, has the conidia connected in chains by a narrow hyaline isthmus. Of the two genera with hyaline sporules, it has already been intimated that Marsonia is the analogue of Gloeosporium, with the same habit and the same parasitic character, but the sporules are septate. Se2)to- IMPERFECT CAPSULAR FUNGI— SPHAEROPSIDEAE 275 viyxa, in like manner, corresponds to Myxosporium, growing on dead branches, but with uniseptate sporules. The section Phragmos])orae includes such species as have sporules with two or more septa, whether hyaline or coloured ; and thus we have two subsections, the Phaoeophragmiae and the Hyalojphragmiae. In the former Stilhosijora is the ana- logue of Melanconium and Didymosporium, with sporules soon oozing out and blackening the orifice ; whilst Coryneum forms compact pustules, in which the sporules are for a long time attached to their pedicels, and do not ooze out and blacken the matrix. In habit the species are more pulvinate and erumpent, being held together almost as compactly as if enclosed in a perithecium. Scolecosporium resembles Coryneum, but the sporules are beaked at the apex. Asterosporium has more the habit of Stilhospora, but the sporules are compound, or rather triradiate, resembling three sporules of Stilbosptora grown to- gether at the base and diverging above in three rays on the same plane. In another genus, Seiridium, the septate brown sporules are united to each other by a hyaline isthmus, so as to form a chain. The two remaining genera, having ciliate sporules, are Hyaloceras, in which the multiseptate brown sporules have a single curved awn at each extremity ; and Pes- talozzia, in which the sporules are crested by one or more hyaline cilia, which are usually divergent when more than one, and the central cells of the sporules are commonly coloured (Fig. 125). The Hyalophraginiae includes but three genera; that of Bhopalidmm, with one little-known ^^«- ^p%'^^l°f^^^^^ "^ species, has clavate, multiseptate, hyaline sporules, aggregated in little innate brown pustules on the leaves of plants ; and Scptoglaemn, w^hich is practically Gloeosporium, or llarsonia, with more than one septum to the sporules. The remaining genus is Prosthemiella, which is the analogue of Prosthemium, but without a perithecium, and the stellate sporules are hyaline. It will facilitate determination to remember the instances, which are so con- stantly recurring, in which Fungi possessing the same habit 276 INTRODUCTION TO THE STUDY OF FUNGI and external appearance find their place in sections widely removed from each other, as the consequence of the septation, or multiseptation, of the sporules. Thus we have, for instance, Gloeosporium with continuous sporules in Hyalosporae ; with filiform sporules, as Cylindrosporium, under Scoleco - allanto- sporae ; with uniseptate sporules, as Marsonia, under the Bidymosporae ; and with multiseptate sporules, as Septoglaeum, under Hyalophragmiae. There remains but one small section to notice, and that is the Dictyosporae, in which the sporules are divided in both directions, so as to be muriform. Of the two genera, Stegano- spormm is the analogue of Coryneum, having compact pulvinate pustules, but with mm'iform, coloured sporules ; and Phrag- motrichum, in which the sporules are concatenate, or in chains, as in Myxormia and Seiridium, and is practically Seiridium with the sporules septate in both directions. BIBLIOGRAPHY Saccabdo, p. a. "Sylloge Sphaeropsidearum et Melanconiearum," in Syllogc Fungomm, vol. iii. Imp. 8vo. Padua, 1884. Berlese, a. N., et Voglino. Un nuovo genere di Pirenomiceti d. Funghi Sferopsidei. Padua, 1866. Crie, L. a. Recherclies sur Ics Pyrenoviycetes infirieurs du group de Bepazics. 8vo. Paris, 1878. CoRDA, J. C. Icones Fiingorum. Fol. 6 vols. Prague, 1837-54. AnUitung zum Stvdium der Mycologie. 8vo. Plates. Prague, 1842. BoNORDEN. Handhuch dcT Mycologie. 8vo. Plates. Stuttgart, 1851. Zur Kcnntniss der Coniomyecten m. Cryptomyceten. 4to. Halle, 1860. CHAPTEE XXIII MOULDS HYPHOMYCETES In their internal relations to each other, and their external relations to the remaining orders, the Hyphomycetes are un- doubtedly a well-defined and natural group. It may be, and probably is, too rash an assumption to contend that all the species are form-species, and only represent the conidial stage of more perfect Fungi ; nevertheless a large nmnber of them have been demonstrated to be merely transitionary, although the precise mode of continuity has not been made clear. In such a case the only reasonable course to adopt is to recog- nise their morphological distinctions, and treat them, for all purposes of classification, on the supposition that they may be autonomous, and leave to the future, when their life-histories are thoroughly known, to develop their true affinities and relationships. The number of described species falls but little short of 5000, and such a number is too large and important to remain unrecognised, or without definite classification, within the limits of present knowledge. Because many of the species of Isaria have been ascertained to represent the conidia of Cordyceps ; because certain of the subgenus Polyactis may be the conidia of Sclerotinia; or even the entire genus Zygodesmium may be so intimately related to resupinate Thelepliorae that definite limit cannot be assigned between them, it would be folly to expunge the whole upon suspicion, and thus increase the difficulties in the way of the student in the pursuit of knowledge along a path already sufficiently thorny and stony. The general characteristics of the order are, tliat the spores, or conidia, are naked or free, as they are in no other order, except the Eymenomycetes and some of the Phijcomycdcs ; 278 INTRODUCTION TO THE STUDY OF FUNGI whilst they differ from the former in having no hymeuium and being deficient in true basidia, and from the latter in the absence of sexual reproduction. The Fungi themselves are either superficial or subsuperficial, and the hyphae or conidia- bearers are, for the most part, strongly developed. Typically there is a creeping, septate mycelium, seated upon or pene- trating the matrix, which gives rise to erect, more or less developed, hj^Dhae, or spore-bearers, which produce terminally or laterally naked spores or conidia. Most of them are saprophytic on dead animal or vegetable substances, whilst a limited number are parasitic upon living plants. The fom^ families are the Mucedineae, or " white moulds," with the threads colom^less, pale, or brightly coloured, often fasciculate, but not coherent, with conidia of the same colour ; the Dematieae, or " black moulds," having the hyphae brown, or black, rather rigid, and not coherent, rarely pale and then with the conidia blackish ; the Stilbeae, with the hyphae either pallid or brown, densely cohering in long stem-like fascicles ; and the Tubercularieae, with the hyphae pallid or brown, densely conglutinate in wart-like pustules, or sporodochia or spore-beds, often forming a rather thick stroma at the base. Thus, it will be observed that in two of the families the hyphae are free and distinct from each other, being typically pale in the one and dark coloured in the other ; whilst in the other two families the hyphae are closely coherent and elongated in the one, and shortened, conglutinate, and stromatic in the other. The latter are for the most part erumpent and pustular. This, then, is the primary division of the Hypliomycetes, of which the largest, and most typical, of the two great sections is that in which the erect threads or conidiophores are free of each other, and not united in a common stem. These are the moulds, which as yet are not known to possess any but a simple and asexual reproduction, by means of conidia, but which are considered to be genetically connected, by some means not clearly manifest, with species belonging to other orders of Fungi, and especially of the Ascomycetes. For the better understanding of the principles on which the classifica- tion of these imperfect Fungi has been reduced to a system, we must examine the sections in further detail, commencing with MO ULDS—H YPHOM YCE TES 279 the Mucedines. In this family, as in all the primary divisions of the orders devised by Saccardo, the spores, or conidia, hold the first place, so that not only are the genera limited by the septation, or non-septation, of the spores, but this also forms the basis of the first subdivision into the Amewsporae (Fig. 126), in which the conidia are spheroid or shortly cylindrical ; the Didymos2)orae, in which the conidia are oblong or fusoid, and uniseptate; the Phragmo- sporae, in which the more elongated conidia are two, three, or many septate ; the Staurosporae, in which the conidia are stellate, radiate, or trifurcate ; and the Helicosporae, in which the elongated conidia are spirally convolute. It is not clear that the last is a necessary or homo- geneous section, or that it is at best any other than a subsection of the Phragmosporae, with the elongated and septate conidia, instead of being simply curved or flexuous, curved more strongly so as to be spirally convolute. Thus, then, having discovered that any given mould has a simple or compound stem, it is incumbent to ascertain, on the assumption that the stem is simple, whether the threads are carbonised, or only hyaline, or bright coloured, and thus dis- cover the one of the four families in which its place has to be found. It being determined, for example, that the mould in question is a Mucedine, the next step is to find the conidia, and ascertain if they are continuous, or in what manner they are septate. Up to this point it may be possible to place a sterile mould, but from this point forwards it is manifestly impossible to proceed, in the absence of all fructification. This leads us to observe how utterly futile it is to attempt the determination of even the genus, much less the species, of any mould, in the absence of conidia. Novices are apt to infer that it is not only possible, but easy, to give a name to any mouldy tuft which presents itself as such to the naked eye, but possessing only mycelium and threads, without any indication of the character of the spore. The labour which is expended in any such endeavour is wasted, and it is always better to abandon the task at once, not only in this but in other orders, unless FiG.126.— i^/em■- sjiora lucida, one of the Amerosjmrac. :8o INTRODUCTION TO THE STUDY OF FUNGI conidia, or spores, of some kind can be detected, otherwise the endeavour can only terminate in vexation of spirit. Eesuming our survey of the system at the point where it is necessary to determine the character of the spore, or conidium, and if it is uniseptate to seek it in the Bidy- mosporae, but if further septate in the Phrag- mosjoorae, we shall soon discover that the greater number of species have conidia which are not septate at all, and therefore belong to the section Amerosporae. At this point we may leave the conidia and revert to the hyphae or threads which bear them. In some cases we shall observe that the conidiophores, the Macroneineae branched once, myces representing or conidia-bearers, are long threads, which are sometimes simple, but in most cases twice, or many times ; these generally form large, conspicuous woolly tufts, easily recognised by the naked eye, and constitute the subsection Macronemeae, or, as we might say, the subsection in which the threads or hyphae are strongly developed, and quite distinct from the conidia (Fig. 127). Then there is another and smaller section, the Micronemeae, in which the threads are very short, and mostly unbranched, so short, indeed, as only just to be recognised, and, at times, scarcely different from the spores or conidia themselves (Fig. 128). In nearly all the subdivisions of the various families of the Hyphomycetes, such subdivisions being based upon the char- acter of the conidia, the genera are associated in these two groups of Macronemeae or Micronemeae, according as the conidia-bearing threads are long and well developed or short and almost obsolete. It would be wearisome and unnecessary here to detail all the varied modifications of the conidia-bearers, or the conidia, which are taken advantage of in the construction of genera, or groups of genera. It must suffice to say that most of the distinctions are based upon the form, or mode of arrangement, of the conidia about the threads. For instance. Fig. 128.— One of the Microneineae Aegerita. MO ULDS—H YPHOM YCE TES Fig. 129.— FcnicilUum with the conidia iu chams. a distinction is made between such conidia as are solitary and those which are produced in chains, or catenulate (Fig. 129) ; between those which are solitary and those which are clustered at the apex of the hyphae, or its branches, so as to form more or less dense heads, or clusters of conidia ; between those in which the conidia are terminal and those in which they are lateral or dispersed. Other dis- tinctions are derived from the hyphae them- selves, whether simple or branched ; or if simple, whether inflated at the apex or not ; and if branched, whether simply furcate, repeatedly divided, or if the branches are arranged in whorls or verticillate. All these are details which are readily gathered from the diagnoses of the separate genera, and we have said sufficient to indicate the principal features which have to be taken into account in the determination of the genus to which any particular mould may belong. Although the above observations apply in the first instance to the 31'ucedines, they apply also generally to the Dematieae, with the exception that in the divisions based on the forms of the spores, or conidia, there will be found an additional division, the Dictyosporae, in which the conidia are divided in both directions, so as to be clathrate or muriform. Some of these conidia will therefore present the appearance of twenty or more simple cells, aggregated into one large complex conidium. Judging from the facility with which each cell of these compound conidia germinates, it may be inferred that each cell is a reproductive unit, and is in itself a perfect conidium, capable of reproducing the species. So in respect to uniseptate or multiseptate conidia, in a linear series, each cell is capable of germination, and even, in some instances, of separating itself from its sister cells, when arrived at maturity (Fig. 130). Mr. Worthington Smith, in his observations on Fusarium solani, has intimated that, although some of the segments of the conidia germinate at once, others are capable of undergoing a period of rest. He says, " Sometimes these little INTRODUCTION TO THE STUDY OF FUNGI Lodies do not germinate at once, but hibernate for a short time, generally varying from three weeks to three months, commonly two months, and during this period they become slightly spinulose and faintly tinted with a brownish hue. These little bodies, there- fore, hibernate after the manner of rest- ing spores, and it is possible that many of them rest during the entire winter. Assum- FiG. 130. Conidia of Fusarium. B, mature coniJium ; C, cells germinatiug ; D, cells separating, and be- coming rounded ; E, separated cell after a period of rest-germinating. After Smith. Macmillan and Co. ing that the seg- ments of the conidia of Fusarium are capable of forming a thicker integu- ment, and hibernat- ing through the winter, there is no reason why, from analogy, other conidia, belonging to other genera, may not be capable of a like modification, and thus aid in the perpetuation of the species. It is almost certain that the thin -walled conidia are unable to survive the winter, and hence the question arises as to how the rejuvenescence of the Jlyj^Jiomycetes is assured; for, although in some cases a perennial mycelium may explain the difficulty, it cannot do so in the parasitic species, such as Bamularia, Ovularia, and Cercospora, where the destructive fungus appears as a pest on the living leaves, year after year. As an example, the leaves of the " ground ivy " {Gleclwmd) through the autumn will present hundreds of leaves with the white blotches of Ramularict calcea, sometimes every leaf more or less affected, and during the winter most of these leaves will die and decay. With the spring there will be a carpet of green leaves again, without a spot of Ramularia; but as summer advances the pest appears as profusely as ever, and the 1 Diseases of Field and Garden Croi^s, by "\V. G. Smitli, London (1884), p. 33. MOULDS— HYPHOMYCETES 283 leaves are blotched with white. Can we answer the question satisfactorily and confidently as to how the continuance of the parasite has been secured ? It is possible that a perennial mycelium within such of the plant's tissues as have survived the winter may be a sufficient cause, but it is doubtful whether this is the only method in which the perpetuation of the Bamularia has been assured. If it should be contended that the decaying leaves and petioles of the previous year must contain the germs of the parasite, and that the young leaves are infected thereby, this only removes the difficulty a step further, for it has to be shown in what form the germs have been preserved, as it must have been by some form of resting spores or a resting mycelium capable of producing germinating bodies. This is one of the problems which is left for the future to solve. So many of the Mucedines and " black moulds " have been ascertained to have relationships with the higher Fungi that it is impossible to do more than briefly allude to a few. In the genus Oidium a number of the species are the conidia of species of the Urysiphei, such as Oidium leucoconium, the rose mildew, of Sphaerotheca pannosa ; Oidium erysiphoides of Erysiphe Ifartii ; Oidium monilioides of Erysiphe graminis. The common fruit mould Aspergillus glaucus has the reputation of being the conidia of Eurotium lierlariorum. Some of the species Botrytis, of the subgenus Polyactis, are the conidia of small species of Peziza, such as Sclerotinia sclerotiorum. The bright yellow mould Sepedoniumchrysospermum, vfhioh attacks decaying Boleti, and converts them into a mass of golden powder, develops Hypomyces chrysospermum, one of the Sp)hcieriaceae, of which the mould constitutes the conidia. If we investigate the British species of this genus Hypomyces} we shall find that all have their conidia in some of the moulds. As, for instance, Verticillium agaricinum of Hypomyces ochraceus, and Verticillium lactescentium of Hypomyces terrestris ; also Verticillium microspermum of Hypomyces hroomeanum ; Diplocladium p)enicilloides of Hypomyces aurantitts ; Diplosporium album of Hypomyces violaceus, etc. The same kind of association prevails also amongst the 1 Monorjra'ph of British Hypomyces, by C. B. Plowright. 284 INTRODUCTION TO THE STUDY OF FUNGI Demuticae, for TrickosjJorinm fuscum is found forming the subiculum of Bosellinia aquila, and the common Bispora monilioides is reputed to constitute the conidia of a small Peziza, hence called Bisporella monilifera ; but this appears to us a doubtful case. FusiclacUum clepressum is reported to be the conidia of Phyllacliora angelicas, and Pohjthrincium trifolii of Phyllachora trifolii. Species of Cladosporium, of Cladotrichum, and Hehnintliosporium respectively are be- lieved to be related genetically to various species of the Sphaeriacei, and especially species of Macrospoj'ium to certain species of Phospora. It is sufficient for our purpose to suggest these relationships as indicating the evidence on which the Hyphomycetes are concluded to be imperfect Fungi, and principally conidial forms of Ascomycetes. After this digression we may return to the two inferior families of the order, in which the hyphae are fused into a com- , mon stem. The Stilheae (Fig. ■^ 131) are of a more imposing .^ appearance than the Tubercu- larieae, and perhaps of a higher ^J' \\Y / ' , /,,' development. There are not more than about five hundred Fig. 131. — bliibum vulyare. . described species, and these are grouped in two parallel sections : the Hyahstilheae, in which the hyphae and conidia are pallid ; and the Phaeo stilheae, in which the hyphae and conidia are typically dusky coloured. Thus these two sections correspond to the Mucedineae and the Dematieae. The Hyalostilheae, as far as at present known, are less variable in fructification than the Phaeostilbeae, it being found necessary to recognise but two of the subsections : the Amerosporae, in which the conidia are globose or oblong, and continuous ; and the Phragrnosporae, in which the conidia are septate. The latter is a very small section, of some seven or eight species, so that practically the Hyalostilheae have small and continuous spores, or conidia. The subsidiary arrangement is very much on the same lines as in the moulds. The principal genera are the old ones of Stilhum and Isaria, with MOULDS— HYPHOMYCETES 285 their allies. The former has a capitate form, typically a com- pound stem, with a globose head ; and the latter assumes a cylindrical or club-shaped form, the stem and head being continuous. The surface is generally powdery with the minute conidia. As to their autonomy, it is known that, in several instances, the species of Stilhum represent the conidia of a peculiar genus of the Sphaeriaceae, that of SpJiaerostilhe, whilst others have given no indication of such an association. Of Isaria the greater proportion, probably all which flourish on dead insects, are the conidia of Cordyceps} The Phaeostilbeae are more variable in their conidia, being grouped in five sections, as in Dematieae, of which it is the analogue, and they represent a somewhat higher develop- ment. Some of the genera exactly correspond to genera of Dematieae, but with a compound stem, as for example Simroctjhe and Periconia, Fodosporium and Helmintliosporium, Sclero- graphmm and Mystros2')orium. Instances of undoubted rela- tionship with the higher Fungi are rare, but in some cases it is suspected. The family of Tulercularieae includes genera which recede from the moulds in their compact form, thickish stroma-like base, more or less pustular, erumpent habit, and somewhat gelatinous consistency, which suggest analogies with such genera as Dacryo- myces, amongst the Tremellinae. Here again are two parallel sections, the Mucedineae and ihe Dematieae, in the former of which the colour is whitish, or brightly coloured, and in the latter dusky or black. The subdivisions follow the same plan as in the preceding families, firstly into sections based on the septa- tion of the conidia, and afterwards into genera, or groups of genera, according to the character of the stroma. The typical genus, Tuber eularia, with some sixty species, is composed chiefly of the conidia of corticolous species of Nectria, of which a familiar example may be found upon nearly every dead twig of currant bush lying on the ground^ (^ig- 132). The whole surface of the twig will be found to be covered from end to end with little bright pink prominences, bursting ^ See Vegetable Wasps, etc., by M. C. Cooke, London (1892), p. 189. 2 "A Currant Twig and Something on It," by M. C. Cooke, in Gardener's Chronicle, 28tli Jan. 1871. !86 IXTRODUCTIOX TO THE STUDY OF FUNGI through the bark at regular distances, scarcely a quarter of an inch apart. Towards one end of the twig the prominences will doubtless appear of a darker colour, almost blood-red, and, intermediate between the two, pink pustules sprinkled with red dots. The dark red pustules are composed of a number of minute red bodies clustered together, the perfected condition of the parasite (Fig. 133). By removing the bark it will be seen that the pink bodies have a paler stem, which expands above into a rather globose head, covered with a mealy bloom. This is the Tuhercularia, which at its base penetrates to the inner bark, and there the threads of mycelium branch in all directions, within the bark, but do not extend to the woody tissues beneath. The head, more closely examined, will be found to consist of delicate parallel threads, which are compacted together into a common stem, with its head. Some threads are simple, others branched, bearing here and there little bodies, easily detached, which are the conidia, and form the mealy bloom 134). The darker clusters, when examined in the same manner, will present, instead of one uniform head, a cluster of smaller globose bodies, closely packed together, or, in some cases, a circle of these dark bodies around a smooth pink centre. These darker bodies are the mature Nectria, which grow at length upon the same stroma, and are the ultimate development of the pink pustules which produce the conidia. Each of the dark bodies is a perithecium, or receptacle, which encloses the fruit, consisting of sporidia, con- tained in asci (Fig. 1 3 3 at G). Here, then, we have the Tuhercti- laria in the first instance, as a smooth, compact, pink, erumpent pustule, the stem composed of numerous delicate threads con- glutinated together, and sprinkled with minute conidia ; then the darker capsular Nectria originates from the same stroma, these capsules containing the fully-developed sporidia enclosed in asci, — the first stage representing the Tiibercularieae family of the Hyphomycetes, the last stage belonging to the Hypocreaceae family of the Pyrenomycetes. Hence, as the first is an im- low. Gard. ^f ^j^g gurfacc (Fig. MO ULDS—H YPHOM YCE TES 287 Fig. 133.— Tubercularia, D ; with Nectria, E ; section, F ; and asci, G. Gard. Chron. perfect condition, the Fungi to which it belongs are characterised as imperfect Fungi. We might follow the same process with one or other of the species of i^Msa?'MMn, which is a genus in the present family, the con- idia of which are com- paratively large, fusi- form, and mostly three or five septate. Some of them are, in like manner, only the con- idia of some more highly developed Fun- gus, and often a species of Nectria. The pus- tules are not so com- pact, sometimes effused, seldom with a determinate stroma, and rarely with the hyphae much developed. The genus altogether is much more variable than Tubercularia, and not so well con- stituted, so that pos- sibly it will be broken up into more homo- geneous genera in the near future. On the faith of some obser- vations made by Mr. Worthington Smith, the conidia must be regarded as bodies of a much higher order than their analogues in Tubercularia. Not only are they capable of dividing at the joints, and each segment vegetating as a separate unit, but these may be converted into chlamydospores, or at least have a thickened epispore, capable of hibernation. When this is confirmed it will go far towards necessitating a revision of the classification, so far as an association with Tubercularia is concerned. Fig. 134.— B, section of Tubercularia ; C, conidia. Gard. Chron. 288 INTRODUCTION TO THE STUDY OF FUNGI Tor the purposes of classification, the genera of the Tuber- culariae are grouped according to the general principles adopted in the Mucedines and Dematiaei, and in fact throughout the Saccardian system — that is to say, the sections are based on the septation of the conidia, whether unicellular, bilocular, multi- cellular, or with stellate or helicoid forms. In each of the sections the genera are characterised by the features presented by the sporodochium, or spore-bed, and the development of the gonidia, whether produced singly or in chains. There are some forty-two genera in all, which it would be somewhat tedious to describe in detail. The Tuherculariae Bematieae contain such genera as possess the habit and development of Tuherculariae, but with coloured hyphae, and similarly coloured, or rarely of hyaline, gonidia. They are less numerous in genera and species than the previous section, but many of the genera correspond in habit and appear- ance, differing only in the coloured hyphae. Not long ago, when the septation of conidia was not held to be of generic importance, or the coloured or uncoloured hyphae a fact of moment, the few genera which were contained in the Tuber- cularieae were rather a heterogeneous collection of species, held together by some superficial character, and embracing forms which are now dispersed through several genera. The large increase of genera which has resulted from the adoption of a more precise method of classification is therefore something more than a numerical gain, since it is the result of a closer investigation, and the application of a more uniform and scientific system, which in the end must conduce to the benefit of the student, and, encouraging a more rigid examina- tion of species, tend to the advancement of this branch of biological study. BIBLIOGRAPHY Saccardo, p. a. Sylloge Fungorum, vol. iv. — " Hyphomyceteae. " Padua, 1886. CoRDA, J. C. Prachtflora Euro}). Schimmdhild. Fol. Col. plates. Leipzig, 1839. The same in French as Flore illuslrte cle Mucedinies d' Europe. 1840. "Die Pilze Deutschlands," in Sturm, De^itscldamls Flora. 12nio. 1829-41. Anleitung zum Studium dcr Mjkologic. 8vo. Prague, 1842. MOULDS— HYPHOMYCETES 289 Hakz, C. 0. Einicjc neue Hyxihomycctcn u. Beitr. z. Systcmatik dcrsdben. Moscow, 1871. BoNOiiDEN, H. F. Ilandbuch ckr Allgcmeincn Mykoloyic. 8vo. Plates. Stuttgart, 1851. Link, H. F. " Observatioues in Ordines Naturales. " Berlin Magazine. 4to. Berlin, 1809. "Species Hyphomycetnra et Gyninomycetum," in Willdenow's SiKcies' Plantamm, vol. vi. 8vo. Fresenius, G. Beitrdge zur Mykologic. 4to. Frankfurt, 1850-63. Cooke, M. C. The Hyplwmycetous Fungi of the United States. 8vo. 1877. MiYABE, KiNGO. "The Life History of Macrosporium parasiticuni." 8vo,. Annals of Botany. 1889. CONSTANTIN, J. Les Muccdinees simj)les. Paris, 1888. CHAPTEE XXIV MICROBES SCHIZOMYCETES AND SACCHAROMYCETES The recognition of the Schizomycetes, or " splitting Fungi," as an order, is of comparatively recent date, and the entire study, notwithstanding all that has been done, is still in an elementary condition. The very minute organisms of which the group is composed have long been recognised, but even now it is open to doubt whether they should be associated with Algae or with Fungi, or outside of both. As part of the Infusoria, Ehrenberg made the first attempt at their classifica- tion in 1838. Then they were transferred, almost bodily, to Algae, in 1872, whilst, more recently, they have been held to be most closely related to Fungi, and united to Fungi by Saccardo in 1889. It is of but small import whether they should, technically, be regarded as Fungi or only as allies : they evidently are closely related, and, notwithstanding their minute size, are of too great importance to be practically ignored. They are defined as " unicellular plants, which multiply by repeated subdivision, in one, two, or three dimensions of space, and also frequently reproduce themselves by spores, which are formed endogenously." Mr. Grove points out that they differ from Algae : " On account of their want of chlorophyll they are reduced to live on ready-organised substances, as are Fungi generally. The Schizomycetes, therefore, produce in their sub- stratum, or in the fluid which they inhabit, very considerable and striking decompositions. They perish in pure water con- taining no decomposable substance. They grow, therefore, exclusively in organic liquids, or in water, or on damp spots, where there is an abundance of organised matter." ^ ^ Synopsis of the Bacteria and Yeast Fungi, by W. B. Grove, B.A., London, SCHIZOMYCETES AND SACCHAROMYCETES 291 The term " Microbe " has been employed, in a general sense, by the French, and adopted from them to indicate all the minute organisms which are now recognised under Schizo- mycetes and Saccharomycetcs, /,v';"wr--V'v. whilst in many cases the former are often spoken of simply as " Bacteria " and the latter as " ferments." These " bacteria " appear " in liquids examined under the micro- scope as small cells of a spheri- cal, oval, or cylindrical shape, sometimes detached, some- Fig. 12,0.— Bacterium termo. Cliatto and times united in pairs, or in Wmdus. articulated chains and chaplets (Fig. 135). The diameter of the largest of these cells is two micromillimetres and that of the smallest is a fourth of that size, so that at least 5 of the former and 2000 of the latter must be placed end to end in order to attain the length of a millimetre. It is therefore plain that a magnifying power of 500 to 1000 diameters, or even still higher, is required to make these beings clearly visible under the microscope." ^ Besides the vegetative multiplication of these cells in one, two, or three directions, there is a double method of formation of spores, which must be described. So long as all the con- ditions remain favourable to growth and vegetative develop- ment, only vegetative multiplication prevails. If the cells can obtain sufficient food, and the food is of exactly the right kind, the rate at which they grow is marvellous. " Colin cal- culated that a single germ could produce by simple fission two of its kind in one hour, in the second hour these would be multiplied to four, and in three days they would, if their surroundings were ideally favourable, form a mass which can scarcely be reckoned in numbers — or if reckoned, could scarcely be imagined — 4772 billions. If we reduce this number to weight, we find that the mass arising from this single germ would in three days weigh no less than 7500 tons. Fortu- nately for us, they can seldom get food enough to carry on this ^ Microbes, Ferments, and Moulds, by E. L. Trouessart, Loudon, 1889. 292 INTRODUCTION TO THE STUDY OF FUNGI appalling rate of development, and a great number die both for want of food and because of the presence of other conditions unfixvourable to their existence. Vegetative multiplication only takes place when the conditions are extremely favouraljle to the growth of the organism. If nutrition is interfered with in any way, or if the removal of excretionary products is obstructed, or if there be a large amount of oxygen present, marked changes may at once be observed in the appearance of the protoplasm of the micro-organism. It becomes granular, then a small bright point appears in each cell ; this point gradually increases in size until its diameter may be greater than that of the original organism. This large, clear, rounded, ovoid, or rod-shaped node is known as a spore, or resting spore, by which the species may be continued although the parent should perish. The shape varies slightly in different species, but in every case it has a dark limiting outline ; it is devoid of colour, and is highly refractile. The dark outline of the spore is usually surrounded by a pale, soft, gelatinous envelope, the substance of which may, in some cases, be accumulated in rather larger quantity near the two poles of the refractile body. As soon as these bodies make their appearance, degeneration of the protoplasm of the bacteria in which they are found immediately follows, but the period at which the death of the protoplasm actually takes place varies in different cases. Where the spores are small they may lie for some time im- bedded in the protoplasm of the cell, which, as it degenerates, leaves the resting spore free to be carried about from place to place, by currents of air or water, to be developed when the conditions of moisture, temperature, and food supply again become sufficiently favourable. Where the diameter of the spore exceeds that of the bacterium, it may be situated in the centre, giving rise to a spindle-shaped organism ; or it may be at one end, when the organism becomes clubbed or pendulum- shaped. The spore in this case appears to escape more readily. This method is that which De Bary has called endospore formation." ^ Another kind of spore is called artlirospore, which is also 1 Bacteria and their Products, by G. S. Woodhead, M.D., London (1891), p. 33. SCHIZOMYCETES AND SACCHAROMYCETES 293 defined by De Bary. In this there is a combination of spore formation and of fission ; the mother cell undergoes division into a series of daughter cells, a few of which differ from the rest in very important and essential points. There appear to be two kinds of anthrospores : one form, met with in Leuconostoc, for example, where simple vegetative division of small round bacteria goes on regularly, so long as the conditions are favour- able, and a regular chain is formed. In this chain there appear at intervals micrococci, which differ from the remainder of the elements of the chain in the following points. As soon as the conditions of nutrition are altered they do not, like the other parts of the chain, die off, I)ut they become somewhat larger than the rest, acquire a more distinct outline, become thicker- walled, and their protoplasm grows darker. Eventually they become free by the deliquescence of the gelatinous envelope, and may claim the name of spores, because, when placed in the fresh nutrient solution, they develop into new rows of beads like those of , the mother plant. This body has most of the characteristics of the resting spore, but it is not formed within the protoplasm of the vegetative organism, but by a process of fission, and as a result of vegetative division. It is possible that there is as much differentiation of the protoplasm as there is where the spore is formed within the cell, the only distinc- tion being that the separation between the spore and the vegetative element of the chain takes place at an earlier stage, and more completely, than in endospore production. The reverse takes place in Bacterium Zopjii, which, during the vegetative stage, consists of short rods, then of motionless filaments, and, if the temperature be lowered, of short motile rods. As soon as conditions become unfavourable the rods, apparently by a simple process of fission, are divided into short roundish cells, which retain their vitality for a consider- able time, and, when placed under favourable conditions, act as spores — that is to say, they develop into the original charac- teristic rod-shaped bacteria. The functions of the Schizomycetes have been described as exciting peculiar decompositions, and transforming com- plicated chemical combinations into simpler ones. This chemical action consists in the production and excretion of 294 INTRODUCTION TO THE STUDY OF FUNGI colouring matters, such species being distinguished as chromo- genous ; in the exciting of various fermentations, and hence called zymogenous ; and in the decomposition of the humours of animal and human bodies, whereby diseases arise, and these are 2^a'i^'ogenous species. Some authors prefer to group them as pathogenous, zymogenous, and saprogenous. The classification of this order must still be regarded as imperfect and transitionary, and will be the subject of much change in proportion to the development of knowledge which experience will afford. There are some who are prepared to accept all the morphologically or physiologically distinct forms as different species, and with them the number of genera and species would be large. There are others who hold that most of the Schizomycetes pass through a series of adaptive forms, influenced by surrounding circumstances, and modified by external conditions, so that at one time it may have the form of a Bacillus or of a Bacterium, of a Micrococcus or a Spiro- chaete. In this latter case the number of genera and species would be reduced to their lowest expression. Perhaps, in the present state of knowledge, the wisest course is to accept the various forms as they appear to be, on the presumption that they are autonomous, and leave condensation and reduction to the gradual operations of the future, and the verification of facts or assumptions, in the light of experience. The arrange- ment adopted by Saccardo recognises three primary groups, or families. The Tricliogenae, with three evokitionary states — the filament, the rod, and the coccus — of which the filament is the primary condition, vaginate or evaginate, fixed at the base or radiating from a central point, rarely entirely free ; rods and cocci included in the filaments. The second family, Baculogenae, also with three evolutionary states — rods, filaments, and cocci. In this group the rod is the primary state, the filament secondary, never vaginate, or fixed, or radiating, formed by the indefinite prolongation of a single rod or the union of many. The third family, Coccogenae ; there is but one state, that of the coccus. Beyond this it would not be profitable to follow the subdivisions. No one can doubt for a moment that the pathogenous species are of immense importance as objects of study and SCHIZOMYCETES AND SACCHAROMYCETES 295 investigation, in face of the contention that in men and animals, and probably plants, they are the associates, and in many cases the causes, of disease. Since =, [1 the discovery of the Bacillus of anthrax, y^<=^^^^^J or splenic fever (Fig. 136), facts have 'MT^j rapidly developed in the association of -^^' microbes with contagious diseases, which ""^^^ previously were theoretically attributed to V^^"^^ S^ many sources. That which at first was «'^W['''^%'/' /'' an hypothesis is now an ascertained „, 51, „ ... '' ^ _ 1*10. 136. — Bamlus an- fact ; but before an infectious disease can thrads. Chatto and be considered due to the presence of a '^Vmdu.s. specific microbe, it must submit to the test of the four rules established by Koch. (1) " The microbe in question must have been found either in the blood or tissues of the man or animal which has died of the disease. (2) The microbe taken from this medium, and artificially cultivated out of the animal's body, must be transferred from culture to culture, for several successive generations, taking the precautions necessary to prevent the introduction of any other microbe into these cultures, -=— SO as to obtain the specific microbe, pure from every kind of matter proceeding Fig. 137. — Development of the Bacillus anthmcis. fi^-nm the bodv of the After Ewart. "^ animal whence it originally came. (3) The microbe thus purified by successive cultures, and reintroduced into the body of a healthy animal, capable of taking the disease, ought to reproduce the disease in question in that animal, with its characteristic symptoms and lesions. (4) Finally, it must be ascertained that the microbe in question has multiplied in the system of the animal thus inoculated, and that it exists in greater number than in the inoculating liquid." These conditions have been fulfilled in the case of a large number of diseases, such as anthrax, swine-fever, smallpox, erysipelas, etc., and the microbe theory of the origin of contagious diseases is, in principle, accepted as fact. 296 INTRODUCTION TO THE STUDY OF FUNGI The close study and prolonged investigations of patho- genous species led to important results in the practice of a system of vaccination, which has been adopted not only in anthrax but also in other contagious diseases. It has long been known that in a number of diseases of this class one attack carries some immunity against that particular disease in the future. The process had been employed in smallpox, and it was found that vaccination of a mild form commonly ensured the individual, at least for a lengthened period, against subsequent attacks from the virulent form. It was thought to apply this to animals in the case of anthrax, if a mild form could be obtained for the purpose. In 1880 Greenfield announced the first indication of the modification of anthrax virus, and from that time forward there was a steady advance in the production of a protective vaccinal fluid for anthrax. Pasteur attributed the diminution of the virulence of the bacillus to the action of heat, in the presence of oxygen, but Chauveau contended that heat alone was sufficient. By culti- vating the bacilli successively in a temperature of from 42° to 43° Cent., they were found to lose all their vitality in about six weeks, this loss going on progressively with the rise of temperature. Sheep inoculated with the culture, after twelve days' heating, only succumbed to the extent of one half. After twenty-four days of heating, inoculation did not cause the death of a single animal. After twelve days more, inocula- tion with virulent anthrax blood only caused slight febrile conditions. Absolute protection could only be secured by a second vaccination with the attenuated lymph. It was demon- strated further that the modified action of the bacilli was transmitted to their spores, and that, when produced, these sprouted, not into virulent anthrax bacilli, but into modified anthrax bacilli, suitable for vaccination. It follows, then, that when animals are inoculated with a liquid containing bacilli, of which the virulence has been attenuated by culture, carried as far as the tenth generation, their lives are preserved ; they have the disease in a very mild form, and, as a result of this treatment, they are henceforward safe from a fresh attack of the disease, — they are vaccinated af^ainst anthrax. Other methods have been tried for the SCHIZOMYCETES AND SACCHAROMYCETES 297 purpose of modifying the virulence of the original virus, and with more or less of success. As, for instance, a solution of carbolic acid, of one part in six hundred, destroys the microbes, whilst a solution of one part in nine hundred attenuates the virulence without producing spores. What- ever the means, the principle is the same — the reduction of virulence in the bacilli, so as to produce by inoculation only a mild form of the disease. We have now, writes Dr. Woodhead, " a whole series of diseases from which immunity may be conferred by the inoculation, or introduction into the tissues of an animal of the soluble products of pure cultures of micro-organisms. In America hog -cholera has been vaccinated against, the vaccinator using the sterilised cultures of the hog -cholera organism as his protective virus. Wooldridge, who was the first to adopt this principle in connection with anthrax, was followed by Pasteur and Perdrix, and by Hankin. Fowl- cnolera, certain forms of septicaemia, and a number of other diseases, amongst which may be mentioned hydrophobia — in which, however, the facts do not belong to quite the same order — all were brought within the same zone, when it was found that the introduction of the sterilised products of a specific organism, first in minute doses and then in gradually increasing doses, could confer a protection against the subse- quent action of even the most virulent organism that, under ordinary circumstances, gives rise to the same products as those injected." The discovery of bacteria in plant diseases is more recent, although Bechamp noticed the presence of microzyma, or l)acteria, in the affected parts as long since as in 1869. Still at that time, and long after, they were held to be the associates, and not the cause, of disease. In 1880 Dr. Burrill declared tlie shrivelling of pears to be due to a species of bacterium, and in 1882 Wakker of Amsterdam attributed the jaundice of hyacinth bulbs to the same cause. In 1885 a bacterium was detected in vines said to be diseased by Phylloxera, and affirmed to be the true cause of the disease. More recently still, and the California vine disease ^ was ^ Gardener's Chronicle, July 1893. 298 INTRODUCTION TO THE STUDY OF FUNGI attributed to the presence of bacteria. In 1891 Dr. Halsted ^ apparently determined that a rotting disease of cucumbers and melons was caused by microbes, and that not only could healthy plants be infected, but the virus could be transferred to tomato plants, rapidly producing decay. The destructive " Peach yellows," which long baffled all efforts to discover its cause, has been found to contain these organisms, and efforts are being made to trace its bacteriological relationships. Finally, the pear blight which Dr. Burrill investigated in 1880, and which is sometimes called "fire blight," was finally determined in 1884 to be the result of the attacks of Micrococcus amylovorus, otherwise named Bacillus amylovorus. In this species, althougli the formation of zooglaea has never been observed in the tissues of tlie tree, or upon solid media, they occur with much regularity in fluid cultures, when placed under favourable concUtions for rapid growth. They are produced to some extent throughout the fluid, but are most abundant in the thin pellicle which forms upon the surface. They often appear the more distinctly by being surrounded by a colourless layer, free of bacteria, which is an extension of the basal stratum of the zooglaea mass. This branch of the inquiry is, however, of such recent origin, and is in such elementary condition, that it would be imprudent to affirm too much, or indulge too freely in speculation. Thus much, then, for the Microbes, which are regarded generally, and spoken of, as the organisms which are instru- mental in producing putrefaction. It is remarkable wliat a voluminous literature has already accumulated, within a few years, which may be accepted as some evidence of its im- portance. The subject may not affect business interests so much as the cognate one of the Fungi of fermentation, but it is more than suspected that it has a very intimate relation to life and death. The yeast Fungi are very simple and low forms of vegetable life, although of a more imposing size than the Schizomycetes, or Microbes, to which we have given brief attention. The yeast Fungi, which are the agents of fermentation, are repre- sented in old books under the name of Torula cerevisiae, and • Gardener's Chronicle, 3rd June 1S93. SCHIZOMYCETES AND SACCHAROMYCETES 299 the generic name of Torida prevailed, in all notices of yeast plants, for very many years after it was demonstrated and known that Torulct had nothing whatever to do with them. But faith, fanatic faith, once wedded fast To some dear falsehood, hugs it to the List. The cells, in budding, give rise to similar cells, attached to each other in chains, resembling the conidia in Oidium, or, less closely, those of some species of Torida, in which latter genus the cells are dark coloured, almost black. The similarity of form led to the confusion of names ; whilst in point of fact the yeast Fungi have no affinity with Torula. The technical, or scientific, description of the yeast Fungi is " Unicellular plants, which multiply themselves by budding, and reproduce themselves by endogenous spores. They live singly or united in bud colonies, chiefly in saccharine solutions, where they excite alcoholic fermentation." For the purpose of illustration, the yeast which causes fermentation in beer may be taken as a type of these organisms. Primarily they consist of a single cell, which is round or elliptic, but occasionally becomes elongated, and parted off by transverse divisions. In order to multiply themselves, the simple cells produce an outgrowth from the periphery, which gradually enlarges, absorbs a portion of the contents of the parent cell — ■ t\> ^ i) ^Y^ which it ultimately resembles in '^ ^[V\ r\ form and size — then the con- J^ ^ cQ fV- v--, VJ uection between them is cut off ^ ^ Q by a transverse wall or partition, •x-c^^ x^-^-s^ and two cells occupy the place Fig. \2,i.—Saccharomyces ellipsoideus. ,. , 1 ,. -T71 1 p Chatto and Wiudus. 01 the lormer one. Each 01 these cells is capable, in like manner, of budding and producing daughter cells, and so the course goes on (Fig. 138). Increase by budding, or gemmation, goes on most rapidly under the influence of moisture, mostly immersed in a saccharine solution, and in this position the sugar of the fluid is decomposed, resulting in alcoholic fermentation. Spores may be developed on a moist substratum, by the contents of a cell dividing itself into two or four portions, each of which 300 INTRODUCTION TO THE STUDY OF FUNGI surrounds itself with a proper membrane, and becomes a spore, \vhicli is capable of budding, like the vegetative cells. AVhether the so-called species of Saccharomyces are autono- mous, or only stages in the development of some higher forms, need not be discussed here. " Brefeld considers that the conidia of A-arious species of Ustilagineae exactly resemble in mode of growth many of the forms of the so-called Saccharomyces. It is well known that the spores of the smuts, in germinating, protrude a thread, from which spring tufts, or clusters, of sporules ; these unite with one another by short transverse processes, and then give rise to sporules, or conidia of the third generation, and these to even a fourth kind. Brefeld's theory is that these successive generations of conidia do not merely resemble Saccharomyces, but are identical with them. He cultivated the spores of many Ustilagineae in nutrient fluids, and found that the conidia to which they gave rise were in form and dimensions similar to those of the various species of yeast Fungi — those of one being ovate, of another oblong- ovate, of another fusiform, of another cylindrical, of another small and roundish, and of another filiform, and so on. More- over, he cultivated these sporules in suitable media for numerous generations, and found that they reproduced themselves, so long as^the conditions remained unaltered, with unfailing certainty the whole year through. A pair of smut spores was in- duced to germinate, and the conidia which they produced were transported, with due precautions, into a drop of nutrient fluid, in which they continued to bud till the nutri- ment was exhausted. A few of these were then removed to another drop of the same fluid, and the process was continued for nearly thirty times, extending over a space of twelve months. The author considers that he has thus proved that these conidia can propagate themselves indefinitely by budding, just like the cells of Saccharomyces, and he asks — If we had commenced this series of cultivations, not with the smut spores, but with the conidia which arise from them, should we have been able to distinguish their mode of growth from that of the yeast of beer ? " ^ ^ Syncqisis of the Bacteria ami Yeast Fungi, by W. B. Grove. B.A. (1884), p. 81. SCHIZOMYCETES AND SACCHAROMYCETES 301 All saccharine fluids which contain glucose, or grape sugar, or a sugar which can be changed into glucose, and also all nitrogenous substances, phosphates, and ammoniacal salts, produce alcohol at a given temperature. The process of con- version is by fermentation. Pasteur states that every fermentation has its specific ferment ; in all fermentations in which the presence of an organised ferment has been ascer- tained that ferment is necessary. This minute being produces the transformation which constitutes fermentation, by breath- ing the oxygen of the substance to be fermented, or by appropriating for an instant the whole _Q q^^ ^ ^V) substance, then de- C5 © @^ ^ Q-^y rp stroying it, by what ^<||) © ^ cC^p^^^ ^>' ^b may be termed the ^ ^J O secretion of the fer- ^ ,„„ ,,„. , ,„ ,,, ^, , ,„. , Fig. 139. — ' High yeast. Chatto and Wmdus. mented products. Three things are necessary for the development of the ferment — nitrogen in a soluble condition, phosphoric acid, and a hydrocarbon capable of fermentation, such as grape sugar. The common ferment of wine has elliptical cells, but there are other forms, or species, which are capable of pro- ducing fermentation in wine. The yeast of beer has round or oval cells,^ and so on, through the range of species, of which Saccardo enumerates thirty-one (Fig. 139). It was contended at one time that these ferments were derived from moulds and Mucors, which under favourable conditions continued to increase themselves by budding — viz. simple vegetation — but, if deprived of nutrition, produced the fructification of a mould. De Bary, whilst controverting this, suggests that some yeast cells have probably been mixed with the spores sown in a nutritive fluid. He thus describes the development of yeast, beyond the ordinary vegetation in a fermentable solution : " If we bring living cells of yeast out of the fluid, on the moist surface of a succulent part of a plant — for example, a piece of carrot — the sprouting goes on slowly for some time, and entirely ceases after some days. About the sixth day, we remark how some of the cells wither and others 1 Microbes, Ferments, ami Moulds, by E. L. Trouessart, London, 1889. 302 INTRODUCTION TO THE STUDY OF FUNGI become larger ; the greater part of the latter form spores in their inner space through the free formation of cells, like those of an asciis, and then becoming thicker at the cost of the protoplasm, at last entirely fill the membrane of the utricle. We can produce the same phenomenon if we thoroughly wash fresh yeast, and, mixing a little clear water with it, let it stand. The formation of the spores here follows, by a sufficient supply of water, at the cost of the organic substance, which has assimilated during the fermentation ; we must seek it in the yeast which is used technically when, after its fermentation is complete, it is laid aside clear and wet. The spores begin, when they are brought into a suitable liquid, to sprout like the vegetating cells, in order to produce new repeated genera- tions of the latter. No other forms of development are known for the Fungus which is found in yeast." ^ The yeast Fungus is the principal promoter of the alcoholic fermentation which appears in practical life, especi- ally the greater part of beer and spirit fermentation. That which is distinguished by the name of harm, and the yeast deposited at the bottom of the cask, are in many cases — not in all — the same Fungi, which in a lower temperature remains at the bottom, and collects as under-yeast ; by higher temperature it accumulates in the froth on the surface of the fluid, and is called harm. There is a slight difference in the form of the yeasts, but the one form can be transferred to the other, by changing the temperature of the fermentation. Further details will have to be sought in some work dealing specially with the subject, as we are only interested in furnishing an outline of the organisms concerned in the processes of putre- faction and fermentation. BIBLIOGRAPHY Saccardo, p. a. " Saccharomycetaceae," by J. B. de Toui, and "' Scliizoniy- cetaceae," by De Toni et V. Trevisan, in Syllogc Fungurum, vol. viii. Padua, 1889. TiiouEssAiiT, E. L. Microbes, Ferments, and Moulds. Cuts. Sni. Svo. London, 1889. Grove, W. B. A Synopsis of Bacteria and Yeast Fungi. Sm. Svo. Cuts. London, 1884. 1 De Bary On Mildew and Fermentation, Berlin (1872), p. 61. SCHIZOMYCETES AND SACCHAROMYCETES 303 WooDHEAD, G. S. Bacteria and their Prod^ids. Sm. 8vo. Cuts. London, 1891. and Hare, A. W. Pathological My cologie. Roy. Svo. Cuts. Edinburgh, 1885. De Bary, a. Morphologic iiiid Physiologic der Pilze, etc. 8vo. Leipzig, 1866. Lectures on Bacteria, translated into English. Svo. London, 1887. Pasteur, iltudcs sur le Vin (1866). £tudcs sur Ic Vinaigre (1868). Etudes sur la Biere (1876). Paris. Schutzenberger, Pruf. Fermentation. Sm. Svo. Cuts. London. Bastian, C. H. The modes of Origin of Lowest Organisms. Svo. London, 1871. The Beginnings of Life. 2 vols. Post Svo. London, 1872. CiENKOWSKi, L. " Zur Morphologie der Bacterien." Monoirs Acad., x's.y. St. Petersburg, 1877. Reess, M. Bot. Untersuch ii. d. Alkuholgahrungsinlzc. Leipzig, 1870. MoRiNi, F. Gli Schizomiceti. Milan, 1883. Alcune Considcrazioni sugli Schizomiceti. Milan, 1882. Crookshank, E. M. Manual of Bacteriology. Svo. Col. plates. London, 1886. ScHENK, S. L. Elements of Bacteriology. English Translation. Roy. Svo. London, 1893. CHAPTEE XXV SLIME FUNGI :\rYXOMYCETES The Myxomycetes, or Myxogasters, are an extraordinary group, which have been the subject of much discussion, on account of some peculiar features which characterise them, and separate them from Fungi generally, and all other of the Cryptogamia. On this account some have advocated their exclusion from the vegetable kingdom altogether, whilst zoologists have been in no hurry to accept them. The common error of accepting analogy for affinity is one which even scientific minds are occasionally betrayed into committing, and yet, apparently, unconscious of their own failing. We liave, during a period of half a century, seen several hypotheses started on similar unstable bases, flourish awhile, and then come to nought. For a long time, and up to a very recent date, the Myxogasters were classed with the Trichogasters, as two groups of the order of Gasteromycetes. Without a knowledge of their life-history, and but little of their microscopical structure, this assumed alliance was a natural one, but it has come to be renounced. It was only in 1864 that the position was assailed by De Bary, who changed the name to Mycetozoa, and claimed for them a position as nearly related to the animal as the vegetable world. " I have," he says, " placed the Myxomycetes, under the name of Mycetozoa, outside the limits of the vegetable kingdom, and I still consider this to be their true position." Strangely enough, however, in all his subsequent botanical works, he continues to include the Mycetozoa, as if he lacked the courage of his opinions; and other botanical writers and compilers of text-books have continued the same course. In this group the two stages or phases of life, the vegetative and the reproductive. SLIME FUNGI— MYXOMYCETES 305 are sharply defined and distinct. It is in the vegetative stage that all the supposed affinities with the animal world are encountered, and in the reproductive everything is suggestive of Fungi, even to the terminology which is borrowed from, and represents identical structure with what is familiar in Gas- tromycetes. The outer wall is either a sporangium or peridium, the threads of the interior still compose a capillitium, the con- tinuation of the stem into the interior is a columella, and the reproductive units are not ova, but the spores. This is accounted for by De Bary from the " close agreement in structure and in biological characters between their organs of reproduction and the spores of Fungi." As Mr. Massee has lately pointed out, it is clear that De Bary derived all his reasons and his evidence against the vegetable nature of the Myxomycetes from the early, or vegetative, phase. On the other hand, it seems to have been suggested that in the later, or reproductive, phase the disparity is so great between the structure and biological characters of the Mycetozoa and those of any of the lower animals, that he was compelled to use the terms, in describing them, which belong also to the Gastromycetes. Here, then, we are supposed to come face to face with a problem — certain organisms in their early, or vegetative, stage belonging to the animal kingdom, and subsequently in their final, or reproductive, stage undoubtedly vegetable, — a worse example of a dual-hypothesis than that which combines an Alga with a Fungus to produce a Lichen. Taking away all expletives, and reducing the indictment to its simplest form, it remains as a specific reason that " the characteristic mark of separation lies in the formation of Plas- modia, or aggregation of swarm-cells." In his recent monograph of this group,^ Mr. Massee has faced and combated the position occupied by De Bary, step by step. " In the Myxomycetes," he says, " the spores on germination give origin to one, two, or more naked cells, which possess the power of movement, due to the protrusion of pseudopodia, or the presence of a cilium ; these cells are known as swarm-cells. The swarm-cells possess a nucleus, multiply by bi-partition, and eventually coalesce to form a plasmodium in the following manner. After the pro- duction of numerous swarm-spores by repeated bi-partition, little ^ Massee, Monograph of the Myxogastres, London (1892), p. 5. 20 3o6 INTRODUCTION TO THE STUDY OF FUNGI groups are formed by the close approach of two or more of these bodies ; these groups often disperse again, but eventually the components of a group coalesce, and lose their individuality ; this coalescence and loss of individuality results in the forma- tion of a small plasmodium, which, in some unknown way, possesses the power of attracting surrounding free swarm-cells ; these at once coalesce and add to the bulk of the plasmodium. The nuclei of the component swarm -cells retain their in- dividuality in the plasmodium, the latter retaining the power of motion originally possessed by its components, and represent the vegetative phase of a Myxogaster. Under certain con- ditions, unfavourable for active vegetative work, plasmodia possess the power of passing into a temporary sclerotioid, or resting stage ; the preliminaries for this condition are the breaking up of the protoplasm into innumerable roundish or polyhedric cells. In some species the cells become surrounded by a distinct, colourless membrane, which shows the reaction of cellulose." From the above account we learn that the coalescence of naked motile cells, or even the aggregation of naked motile cells without loss of individuality, is, from De Bary's standpoint, the proof that the Myxogasters are not plants. After comparison of these phenomena with similar analogous instances in the Phycomycetes and other Fungi, the following reasons are adduced in support of the vegetable, rather than animal, nature of these organisms : — (1) Frequent presence of cellulose in the general membrane protecting plasmodia, cell-walls of spores, sporangia, and walls enclosing the protoplasm in the sclerotioid, or resting stage of plasmodia. (2) Presence of germ -pores in the cell- walls of the spores, of some species. (3) The frequent separation of lime from the protoplasm at the commencement of the reproductive phase. (4) The frequent separation of a substance from the protoplasm during the period of spore -formation, homologous with the substance separated during the same period in the Ascomycetes, etc. This substance in the Myxogasters forms the capillitium. (5) The agreement with many Fungi in the contrivance for spore dissemination. (6) The production by free cell-formation of spores protected in the early stage with SLIME FUNGI— MYXOMYCETES 307 a wall of cellulose, which eventually becomes differentiated, and, as stated by De Bary, " behaves towards reagents in a similar manner to cuticularised plant cell-membranes, and to spore- membranes as in the Fungi. (7) Presenting analogy with undoubted members of the vegetable kingdom, as Hydrodictyon, where the naked motile swarm-cells coalesce to form a caenobium, which eventually becomes invested with a membrane. (8) In the close affinity with Ceratium (but, as Ceratium has been included by some with Myxogasters, this will not carry so much weight). (9) In the coalescence of the naked cells to form a Plasmodium, being the result of conjugation between the com- ponent cells, thus presenting features in common with the primitive forms included in the group Zygosporeae." It may be added that, in this country, Mr. Saville Kent, as a zoologist, espoused De Bary's views, and even went beyond him, in his Manual of Infusoria, for he included the Mycetozoa, and suggested their affinity with sponges. These views were contested at the time,^ but really no fresh evidence was produced in support of the views of De Bary, who was the great authority cited. The only addition necessary to quote, or allude to, in support of the animal nature of the Myxomycetes, in the vegetative stage, is the evidence of Mr. Lister ; but these obser- vations extend no further than the vegetative stage, and do not furnish any convincing proof that the phenomena are in- compatible with a condition of vegetable organisms, any more than the amoeboid forms in such Algae as the Volvocineae. " I have repeatedly seen bacteria taken by swarm-cells of Chondrioderma difforme in the manner described, and it would appear that bacteria form their principal food. On one occasion I had a favourable opportunity for observing the digestion of bacilli on account of the quiescent state assumed by a swarm-cell, which remained with little active movement for an hour and a half On the previous evening I had placed some spores of Chondrioderma difforme in water, under a thin cover -slip; on the following morning swarm-cells were in great abundance in the pure water. I introduced a drop con- taining multitudes of bacilli from a glass in which a piece of ^ "Animal Nature of Myxomycetes," in Grcvillca, vol, ix. (Dec. ISSO), p. 41. 3oS INTRODUCTION TO THE STUDY OF FUNGI Stereum hirsutum had been soaking for several days. In a short time a number of the swarm-cells were seen, attended by bacilli, some of which were attached to their pseudopodia, and some were already enclosed in vacuoles. The swarm-cell in question had taken an amoeboid form, occasionally producing and again withdrawing the cilium, while from time to time thin pseudopodia were extended from the opposite end, but more frequently the posterior region expanded into a somewhat funnel-shaped mouth. Into such an expansion a stout bacillus was seen to enter ; in the course of a few seconds it was enclosed with a noticeable amount of water, by the folding over of the lips of the funnel, and conveyed into the body -substance ; a few minutes after, another bacillus was taken in, much in the same manner, but no globule of water was introduced. Ten minutes later a large bacillus was caught by a prolongation of one side of the funnel, and in the course of half a minute a tube-like extension of protoplasmic substance invested the bacillus, and it was drawn in. It remained for a short time in direct contact with the granular matter of the body, but was soon surrounded by an oval vacuole. The swarm -cell continued inactive for nearly an hour, when it assumed an extended form, and shortly after swam away with rapid jogging movement. Constant observation was maintained during this hour, and the bacilli were seen gradually to dissolve in the vacuoles in which they lay, until at length all trace of them had disappeared, together with their containing vacuoles, and only the contracting vacuole remained in the homogeneous granular substance of the swarm-cell. " At the commencement of the observation this granular protoplasm was much more turbid than at the close, when it was remarkably hyaline ; the swarm-cell appeared also to have increased in size, though it was difficult to determine by measurement in consequence of its changing form, No re- jection of refuse matter took place while the observation lasted. " In the same preparation I watched a swarm-cell creeping in a straight line, with the strange snail-like movement so difficult to understand. In its course it came to a small group of motionless bacilli lying against the glass ; immediately it changed its linear form and spread itself out, covering four of SLIME FUNGI— MYXOMVCETES 309 the bacilli. In about two minutes it resumed its former shape and movement, and crept away, carrying off two of the bacilli in vacuoles. " These observations seem to confirm the opinion of De Bary that the organisms under consideration should be classed among the animal rather than the vegetable kingdom. When a creeping swarm-cell is watched, with the projecting cilium placed immediately in advance of the nucleus, which never shifts its position, and when we note the manner in which the vibrating extremity of the cilium appeared to detect the presence of the bacilli, before the swarm-cell spread itself over them ; again, when we observe the creeping action suddenly change, and raising itself from the decum- bent attitude, with a few lashing strokes of the cilium the swarm-cell releases its foothold and swims Fig. 140.— Cluster of TubuUna away ; and when to these remarkable cyimdnca. movements is added the process of ingestion, we cannot but feel the force of the conclusion at which De Bary arrived, if indeed a distinct line of demarcation between the two kingdoms can be said to exist." ^ Nearly all the species in this grc^^p are minute, and when not so are composite, several individuals being united in a cluster (Fig. 140). Most of them are more or less gregarious, and sometimes covered with a shiny envelope, of which portions extend to the matrix, and resemble when dry a sort of mem- branaceous thallus. The tendency is certainly towards the globose in form, now and then attenuated into the cylindrical. If we were to attempt a kind of typical description, we should say that they are small globose or pear-shaped bodies, with or without a stem, scarcely exceeding a millimetre in diameter, variable in colour, sometimes shining and sometimes covered with white chalky granules ; at first pulpy, then dry and fragile, filled within with a mass of pulverulent spores, often mixed with threads of a capillitium. Into this interior the stem is continued as a columella, which is connected with the 1 " Xotes on Chondrioderma difforme," etc., by A. Lister, in Annals of Botany, iv. (May 1890), p. 281. 3IO INTRODUCTION TO THE STUDY OF FUNGI walls of the sporaugiiuii Ly the radiating threads uf the capillitium. It will be observed how closely these details accord with those of the Lyco'perdaceae amongst puS-balls, so that we would seem to be describing very microscopical puff- balls. To a certain extent this is correct, but with the ex- ception that the early condition is slimy, there is often when mature a thin film of dried mucilage derived from the envelope, and the capillitium is sometimes very highly developed. We must, however, guard against the inference that there is any true affinity between Myxomycetes and Gastromycetes, as old authors believed. They are mostly developed upon dead leaves, or very rotten wood, in damp places ; and though probably most common in temperate regions, a few species extend into the tropics. The total number of recorded species, included in the most recent work on the subject, is 425 ; but no extended analysis of their geographical distribution has been attempted, as it is not clear that species recorded from distant stations twenty or thirty years ago were determined with sufficient accuracy. It is unnecessary to allude at any length to the classifica- tion adopted for the arrangement of this group. Previous to the Monograph by Eostafinski ^ all the species were arranged according to external characters, determined by the aid of a pocket lens. Although it must be admitted that Fries exhibited a remarkable insight into the relations and affinities of the various groups of Fungi, yet his method was insufficient for the minute species, and the Myxogasters, amongst others, received only inadequate treatment at his hands, so that a revision, with the aid of the microscope, became an absolute necessity. De Bary evidently intended to do this, but never accomplished it, although subsequently one of his pupils, who had the benefit of becoming acquainted with his views, pro- duced, in Polish, the Monograph above alluded to. Ptostafinski accepted, in name, the Mycetozoa of De Bary, but with a more restricted application, and his classification proceeded on a botanical basis, since it was the reproductive phase, or completed condition, which he recognised as the individual. ■ Sluzowce, a Monograj^h of the Ilycdozoa, by Dr. Joseph Eostafinski (in Polish), 1875. SLIME FUNGI— MYXOMYCETES 311 Hence we find that the primary division into two sub- divisions was based upon spore characters. In the first section, the Amaurosporeae, the spores were violet, or brownish violet ; and in the second subdivision, the LamjjrosjJoreae, the spores were variously coloured, but never of any tinge of violet. The next feature which seemed to him most im- portant, or at least most fitting for the purpose of classifica- tion, was the presence or absence of a capillitium. Sub- sidiary to these two features, the presence or absence of lime in the sporangium or capillitium, the production or suppression of a columella, and the perforation of the walls, were employed in the delimitation of families ; after which followed the genera, with their varied predominant characteristics. Subsequent writers, having Eostafinski's work as a basis, have proposed alterations and emendations, whilst the majority of mycologists have felt that, although it did much to direct inquiry into a new channel, and classify on sounder principles, the Monograph did not exhaust the subject, but left many occasions for improvement. As we are writing this chapter, the latest attempt at a revised classification has issued from the press.^ In this arrangement the primary subdivision, as to spore coloration, is abolished, and another central idea established, which is thus explained : — " The most pronounced feature in the evolution of the Myxogastres is in connection with spore dissemination, and the following arrangement is based on the relative development of the capillitium, which is seen in its most perfect form in the genera Trichia and Arcyria." The entire group is subdivided into four orders, in the following sequence: — (1) Wall of sporangium without lime; capillitium absent, or formed from the wall of the sporangium. (2) Wall of sporangium still without lime ; capillitium originating from a central columella. (3) Wall of sporangium with an external deposit of lime ; capillitium present. (4) Wall of sporangium without external deposit of lime ; capil- litium present, but not springing from a columella. In the introduction the above is the sequence of orders, but in the 1 A Monograph of the Myxogastres, by G. Massee, Loudon, 1892 : and subsequently that by A. Lister in 1895. 312 INTRODUCTION TO THE STUDY OF FUNGI subsequent elaboration tbe last two orders are transposed. For the most part the genera are the same as in Eostafinski, with the exception of two or three instances in which con- tiguous genera are amalgamated. It must be expected that an evolutionist, such as Mr. Massee confesses himself to be, would have decided ideas as to the evolution of this group. " I consider," he says, " the Myxogastres as illustrating one of the earliest known attempts at differentiation in the direction that has eventually resulted in the mass of organisms constituting the vegetable kingdom ; but having originated from the Flarjellatae, a group more in touch with the animal side of life, the work of developing individuality has been slow, as illustrated by the tardy appearance of cellulose cell-walls, which, as would be expected, is most complete in the newly evolved reproductive phase, itself to a great extent the outcome of a gradual change of environment from aquatic to aerial ; but the radical mistake, after having adopted the plant line of development, consisted in the non-development of chromatophores, and retention of the animal mode of nutrition, which in the plant world means parasite, or sapr ophite. The fungi, a later group, differentiated from ancestors that had already evolved the leading plant characteristics, including cell-walls, chlorophyll, starch, hence in this respect are more typical plants than the Myxogastres ; but in the fungi, the check to progress was due to the degeneration of the chromatophores, already evolved by their ancestors, whereas, in the Myxogastres, the check was due to their inability to differentiate these essentials." As for ourselves, we are by no means disposed to dogmatise on any speculations of this kind, which seem to have such a slight basis of solid fact, and permit such a free scope to inference. Neither are we content to exclude Myxomycetes from Fungi, as the above quotation suggests, since their strongest affinities when mature appear to be with Fungi ; but we confess to a predilection for regarding them as a peculiar and aberrant group, which, by reason of their vegetative phase, do not fall well into place with our present arrangement of Fungi. It is incumbent upon us to append a brief synopsis of the SLIME FUNGI— M YXOM YCE TES ;i3 classification which has been adoi^tecl for these singular organisms, the characters for which are derived from the final and reproductive condition. The first of the four orders, into which the entire group is subdivided, is the Peritrichiaceae, in which the wall of the sporangium is not encrusted with lime, and the capillitium is either absent or formed from the wall of the sporangium. This order is again subdivided into two suborders — that of the Tululinae, in which the wall of the sporangium is not perforated ; and the Crihrariae, in which the wall of the sporangium is perforated. The principal genus in the Tubulinae is that of Tuhulina, in which the sporangia are crowded together so as to form an aethalium, which term is applied to an ag- glomeration of sporangia. The Crih- rariae includes the genera Enteridium, Clathroptychium, Cribraria, and Dic- tydium, in all of which the perforated sporangia are very elegant objects. The subsidiary characteristics of the several genera have reference chiefly to the manner of the perforations. In Cribraria the permanent upper portion of the sporangium forms a Fig. 141. — Cribraria intricata. kind of network (Fig. 141), and in Dictydium the permanent radiating ribs are united by transverse bars (Fig. 142). The second order, ColumelUferae, with the walls of the sporangium not containing lime, has for its chief character a central columella, from which the capillitium originates. The two suborders into which this group is divided are the Stemoniteae, in which the capillitium springs from every part of an elongated columella, and the Zamprodermeae, in which the capillitium springs from Fig. 142. — Dictydium. natural size and magnified. 314 INTRODUCTION TO THE STUDY OF FUNGI the upper portion Fig. 143.— ,Srotoplasm, exhibiting amoeboid motion. Pleomorphism — when more than one independent form in the life-cycle of a species occurs it is called pleo- morphy. Pleicroblastic — in Peronosporeae, those forms which produce vesicular lateral outgrowths that serve as haustoria. Pore — in Pyrenomycetes it is the ostio- lum ; in Polyporei the mouth of the tube which encloses the hymenium. Promycelium — the product of tube germination of a spore which con- stricts off a number of spores, unlike the mother spore, and then dies. Psrudoperidium — the cup, or recep- tacle, in Aecidium. Pscitdopodium — in Myxomycetes, the protruded and I'etracted protoplasm of amoeboid forms, imparting motion. Pycnidium — in Ascomycetes, a cavity resembling a perithecium containing gonidia, which are termed pycno- gonidia. Receptacle — general term for hol- lowed -out body, containing otlier bodies. 356 INTRODUCTION TO THE STUDY OF FUNGI Jlcsti/nj-sjJorc^VL .sjiore which lies dor- mant or rests lor a period before germination. A hibernating spore. nesting stage, resting 'period — stage or period of quiescence or dormancy. Eesupinatc — attached to the matrix by the back. niiizoid, or Bhizine — thread-like deli- cate organs of attachment. SAPROPnYTE — a plant living and thriving on dead organic matter. Sclerotium — hard tuber-like body tilled with reserve material, of the nature of a compact mycelium, which re- mains dormant tor a time, and then develops sporophores. Scokcitc — peculiar rudimentary bodies in Discomycetes which are jirobably the first distinction of fertile from sterile hypha, doubtfully described as sexual. Sorus — a heap, or aggregation, chiefly of reproductive bodies. Spcrmatiuni — male gamete cell which conjugates with a trichogyne. Spermatozoid — thread-like bodies, pos- sessed of motion, and supposed to be fecundative. Sporangiole — small sporangium, pro- duced in some genera of Mucors, supplementary to large sporangium. Sjmrangiophorc — the sperojihore of a sporangium. Sporangium — envelope or sac in which spores are produced. Spore — in a general sense it is a repro- ductive cell, which becomes free, and is capable of developing into a new plant ; in a special sense, restricted to the Hymen omycetes. Sporidesm — multicellular spore-body, becoming free, of which each cell is an independent spore. Sporidiolum — diminutive of sporidium — applied to promycelial spores in the Uredines. Sporidium — in Ascomycetes, a spore developed in an ascus. In Uredines a. spore abjointed on a promycelium. Sporifcrous — bearing spores. Sporocarp — multicellular body, de- veloped sexiially from an archicarp, unlike the body which produced the archicarp, and serving to form spores. Sporogcnous — producing spores. Sporophore — branch which bears spores, or mother-cells. Sjiorule — designation for spore, en- closed in a perithecium, in imperfect Fungi, such as Sphaeropsideae, with- out asci. Sterigma, Sjncule — slender stalk-like branch of basidium bearing a spore. Stipe — general term for the stalk of a sporophore, usually applied to the stem of Agarics. Stroma — Fungus body with the form of a cushion, crust, club, or branched exjiansion ; usually supporting cora- ]iound fructitication. Stglospore — sjiore borne on a filament. Suspcnsor — in Mucors ; club-shaped or conical portion of hypha, adjoining a gamete cell after its differentiation. Sivarm-cell — naked motile protoplasmic body. Symbion — an organism living in a state of symbiosis. Symbiosis — the living together of dis- similar organisms. Televtospore — in Uredines, the ulti- mate spore of the cycle which is cai>able of germinating and producing a promycelium. Tliallopkytes — cellular Cryptogamia. Includes Algae and Fungi, where there is no ditferentiation into stem and leaf. Thallus — the vegetative body of a Thallo])hyte. Theca — the same as ascus. Tliccaspore — synonymous with asco- spore. Trama — in Basidiomycetes, the middle tissue of the gill plates, or other projections of the receptacle which bears the hymenium. Trichogyne — female receptive portion of an archicarj) to which the sper- matia become attached. Tubulus, Tube — in Hymenomycetes, the tube lined with the hymenium, as in Polyporei. Uredo — hymenium producing uredo- spores. Uredospore Urcdogoniditim — in Ure- dineae, spore formed upon a sporo- phore from which it separates at maturity, and on germination pro- duces a mycelium bearing uredospores or teleutospores, or both. Uterus — same as peridium in Gastro- mycetes. Veil, Velum — in Hvmenomycetes, special envelope in which the growth GLOSSAJ^y 357 of the whole or part of the sporo- phore takes place. Volva, Velum universale — in Hymeiio- mycetes, sac enclosing the whole of a sporophore at first, but ultimately ruptured at the apex by the expand- ing pileus. Veast fungus — species of Saccharo- myces. ZooGLAEA — in Schizomycetes, a colony imbedded in a gelatinous stratum. Zoogonidium — active gonidium. See Zoospore. Zoosporangium — sporangium contain- ing zoospores. Zoospore — motile spore. Zygote, Zygospore — spore resulting from the conjugation of two similar gametes. INDEX Aecidium, 243 Agaric, parts of, 32 Agaricus, section of, 127 Alternation of generations, 70 Anthrax, 295 Appendix on collecting, 345 Archicarps, 229 Arthrospore, 292 Artificial cultures, 249 Asci and parapliyses, 104, 166 Ascomycetes, 164 Ascus and sporidia, 45 Aseptate mycelium, 16 Atrophied basidia, 121 Bacteria, 291 Basidia, 41, 120 Basidiomycetes, 115, 119 Beech Morels, 186 Bird's-nest Fungus, 153 Black moulds, 278, 283 Bunt spores, 255 Calostoma, development of, 156 Capillitium, 43, 309 Capsular Fungi, 197 Carpophore, 22 Car})ophores agglomerated, 28 Census of Fungi, 319 Clamp-connections, 11, 150 Classification, 93 Clavate carpophore, 29 Clinospore, 45 Cluster-cups, 48, 242 Collecting, instructions, 345 Coloration of pileus, 34 Colouring matters, 85 Columella, 36, 313 Compound carpophore, 23 Sphaeriaceae, 213 Conidiojihore, 51 Conidium, 45 Coniomycetes, 259 Conjugating Fungi, 227 hyphae, 62 Conjugation in Peziza, 58 Constituents of Fungi, 84 Crested sporules, 275 Cup-shaped receptacle, 37 Cuticle of pileus, 33 Cystidia, 41, 121 Cyttaria, 186 Definition of Fungi, 1 Dematiaei, 278, 281 Destructiveness, 107 Development in Erysiphe, 55 of Eurotium, 56 Diatrype and Valsa, 211 Dichocarpism, 64, 286 Dimorphic Fungi, 64, 286 Discoid Fungi, 172 Discomycetes, 173 Disintegration by mycelium, 21 Distribution, 317, 324 Dothideaceae, 207 Dust Fungi, 259 Elaphomyces, 195 Empusa, development, 236 Endopliytal parasites, 75 Entomophthoraceae, 235 Entyloma, germination, 256 Epiphytal parasites, 74 Ergot and Claviceps, 202 of grains, 1 4 Erysipheae, 199 Evolution of Fungi, 111 Excipulum, 37 Fertilisation, 53 Fish-moulds, 232 Flies and Fungi, 152 Formation of zygospore, 17, 59 Fructification, 41 Fungi, census of, 319 and Lichens, 109 in general, 95 the Great Destroyer, 109 Fungus poisons, 86 INDEX 359 Gaping Fungi, 222 Gastromycetal carpophore, 26 Gastromycetes, 149 Geographical distribution, 32 -i Germination of zoospores, 76 Gleba, 43 Globose carpophore, 29 Gloeosporiura, 272 Glossary, 353 Glycogen in Fungi, 87 Growth of Bacteria, 291 Haplophyllae, 132 Hereditary transmission, 81 Heteroecism, 245 Hymenium, 42, 102, 124 of Peziza, 44 Hymenomycetes, 126 Hypertrophied basidia, 122 Hyphal bodies, 18, 235 Hyphomycetes, 277 Hypocreaceae, 202 Hypodermeae, 78, 242 Hysteriaceae, 222 analogues, 268 Imperfect capsular Fungi, 259 Imperfect Fungi, 103 Introduction, 1 Lactiferous vessels, 25, 33 Lichens and Fungi, 3, 109 Lycoperdaceae, 154 Macrocysts, 58 Macronemeae, 280 Melanoonieae, 260, 271 ]\Ielanconis and conidia, 67 Melasmia and Rhytisma, 65 Mesomycetes, 113 Metuloids, 42, 143 Microbes, 290 Micronemeae, 280 Microthyriaceae, 219 Microzyma, 297 Milky juice, 25, 33, 89 Morels, 178 Moulds and their conidia, 50, 277 Mucedines, 278 Mucor, development, 229 Mucoraceae, 228 Mushroom spawn, 9, 97 Mycelium, 9, 97 Mycomycetes, 113 Mycorhiza, 20 Myxomycetes, 304 Myxomycetes not animal, 19, 304 Nakkd hymenium, 41 Naked-spored Fungi, 102, 119 Nidulariaceae, 153 OiDiuM and Uncinula, 66 Old definitions, 96 Oocyst, 56 Oogonia, or female cells, 60 Oogonium and oosphere, 232 Organography, 7 Ostiolum, or mouth, 38 Paracysts, 58 Paraphyses, 42, 121, 168 Pathogenous microbes, 296 Perennial mycelium, 20 Peridiola, 46, 153 Peridium, 36 Perisporiaceae, 198 Perithecium, 38, 48, 198 Peronospora, development, 231 reproduction of, 77 Peronosporaceae, 230 Peziza sclerotia, 15, 180 Phalloideae, 151 Phosphorescence, 89 Phyeomycetes, 113, 227 Pileate receptacle, 31 Plasmodia, 305 Podaxis, structure of, 160 Polymorphism, 220 Polyphagus, development, 237 Polyporei, 135 Promycelial spores, 246, 254 Pseudoperidia, 48 Puccinia, life-history, 78 Puff-ball Fungi, 149 Pyrenomycetes, 197 Receptacle, 31 Resin in Pol3-porei, 88 Rhizomorpha, 12, 99 Root Fungi, 20 Rust Fungi, 242 Saccharomycetes, 290, 298 Saprolegnia, development, 233 Saprolegniaceae, 232 Saprophytes and parasites, 73 Schizomycetes, 290, 293 Schizophyllae, 130 Sclerotium, 14 Scolecite, 46, 57, 175 Section of Agaric, 32 Sessile pilei, 35 Sexuality, 54 in Achlya, 60 in Peronospora, 61 in Peziza, 176 Sexual reproduction, 229, 234 Simple Sphaeriaceae, 214 Slime Fungi, 304 36o INTRODUCTION TO THE STUDY OF FUNGI Smut Fungi, 251 Spermatia, 45 Sphaeriaceae, 205 analogues, 261 Sphaeiopsiiieae, 259 Sponuigiuiu, 50 Siiorc, naked, 45 division of Agaricus, 130 forms, 45 value, 345 Sporidium, 45 Sporule, 45 Stinkhorn Fungi, 151 Stipe, or stem, 25 Stylospore, 45 Stylosporous fructification, 49 Subterranean Fungi, 189 Suspensor and gamete, 229 Swarm-cells, 305 Table of groups, 117 Teleutospores, 242 Thallogens, 2 Thallophytes, 3 Tilletia, germination, 63, 255 Touchwood, 99 Trama, 32, 128 Tremelloid Fungi, 145 Truffles, 191 TuT)eraceae, 190 Tubercularia and Nectria, 204 Two forms of fruit, 69 Uredineae, 242 Ustilagines, 251 Varnished pilei, 88 Vegetative system, 11 Vinegar plant, 100 White moulds, 278 Xylaria and stroma, 206 Yeast Fungi, 298 Zoosi'OiiEs, ^ogonidia, 227 Zygomycetes, 229 Zygospore formation, 17, 59 Zygospores, 227 THE END D. H. HILL i_^:rr?4RT Printed by H. & R. Clark, Limited, Edbihurgh. North Carolina State University Libraries QK603 .C63 INTRODUCTION TO THE STUDY OF FUNGI THEIR ORGA