MUCEDINES.—Here, on the other hand, the threads, if coloured at all, are still delicate, more flexuous, with much thinner walls, and never invested with an external cortical layer. One of the most important and highly developed genera is Peronospora, the members of which are parasitic upon and destructive of living vegetables. It is to this genus that the mould of the too famous potato disease belongs. Professor De Bary has done more than any other mycologist in the investigation and elucidation of this genus; and his monograph is a masterpiece in its way.[o] He was, however, preceded by Mr. Berkeley, and more especially by Dr. Montagne, by many years in elucidation of the structure of the flocci and conidia in a number of species.[p] In this genus, there is a delicate mycelium, which penetrates the intercellular passages of living plants, giving rise to erect branched threads, which bear at the tips of their ultimate ramuli, sub-globose, ovate, or elliptic spores, or, as De Bary terms them—conidia. Deeply seated on the mycelium, within the substance of the foster plant, other reproductive bodies, called oogonia, originate. These are spherical, more or less warted and brownish, the contents of which become differentiated into vivacious zoospores, capable, when expelled, of moving in water by the aid of vibratile cilia. A similar structure has already been indicated in Cystopus, otherwise it is rare in fungi, if the Saprolegniei be excluded. In Botrytis and in Polyactis, the flocci and spores are similar, but the branches of the threads are shorter and more compact, and the septa are more common and numerous; the oogonia also are absent. De Bary has selected Polyactis cinerea, as it occurs on dead vine leaves, to illustrate his views of the dualism which he believes himself to have discovered in this species. "It spreads its mycelium in the tissue which is becoming brown," he writes, "and this shows at first essentially the same construction and growth as that of the mycelium filaments of Aspergillus." On the mycelium soon appear, besides those which are spread over the tissue of the leaves, strong, thick, mostly fasciculate branches, which stand close to one another, breaking forth from the leaf and rising up perpendicularly, the conidia-bearers. They grow about 1 mm. long, divide themselves, by successively rising partitions, into some prominent cylindrical linked cells, and then their growth is ended, and the upper cell produces near its point three to six branches almost standing rectangularly. Of these the under ones are the longest, and they again shoot forth from under their ends one or more still shorter little branches. The nearer they are to the top, the shorter are the branches, and less divided; the upper ones are quite branchless, and their length scarcely exceeds the breadth of the principal stem. Thus a system of branches appears, upon which, on a small scale, a bunch of grapes is represented. All the twigs soon end their growth; they all separate their inner space from the principal stem, by means of a cross partition placed close to it. All the ends, and also that of the principal stem, swell about the same time something like a bladder, and on the upper free half of each swelling appear again, simultaneously, several fine protuberances, close together, which quickly grow to little oval bladders filled with protoplasm, and resting on their bearers with a sub-sessile, pedicellate, narrow basis, and which at length separate themselves through a partition as in Aspergillus. The detached cells are the conidia of our fungus; only one is formed on each stalk. When the formation is completed in the whole of the panicle, the little branches which compose it are deprived of their protoplasm in favour of the conidia; it is the same with the under end of the principal stem, the limits of which are marked by a cross partition. The delicate wall of these parts shrinks up until it is unrecognizable; all the conidia of the panicle approach one another to form an irregular grape-like bunch, which rests loosely on the bearer, and from which it easily falls away as dust. If they be brought into water they fall off immediately; only the empty, shrivelled, delicate skins are to be found on the branch which bore them, and the places on which they are fixed to the principal stem clearly appear as round circumscribed hilums, generally rather arched towards the exterior. The development of the main stem is not ended here. It remains solid and filled with protoplasm as far as the portion which forms the end through its conidia. Its end, which is to be found among these pieces, becomes pointed after the ripening of the first panicle, pushes the end of the shrivelled member on one side, and grows to the same length as the height of one or two panicles, and then remains still, to form a second panicle similar to the first. This is later equally perfoliated as the first, then a third follows, and thus a large number of panicles are produced after and over one another on the same stem. In perfect specimens, every perfoliated panicle hangs loosely to its original place on the surface of the stem, until by shaking or the access of water to it, it falls immediately into the single conidia, or the remains of branches, and the already-mentioned oval hilums are left behind. Naturally, the stem becomes longer by every perfoliation; in luxuriant specimens the length can reach that of some lines. Its partition is already, by the ripening of the first panicle from the beginning of its foundation, strong and brown; it is only colourless at the end which is extending, and in all new formations. During all these changes the filament remains either unbranched, except as regards the transient panicles, or it sends out here and there, at the perfoliated spots, especially from the lower ones, one or two strong branches, standing opposite one another and resembling the principal stem.



The mycelium, which grows so exuberantly in the leaf, often brings forth many other productions, which are called sclerotia, and are, according to their nature, a thick bulbous tissue of mycelium filaments. Their formation begins with the profuse ramification of the mycelium threads in some place or other; generally, but not always, in the veins of the leaf; the intertwining twigs form an uninterrupted cavity, in which is often enclosed the shrivelling tissue of the leaf. The whole body swells to a greater thickness than that of the leaf, and protrudes on the surface like a thickened spot. Its form varies from circular to fusiform; its size is also very unequal, ranging between a few lines and about half a millimetre in its largest diameter. At first it is colourless, but afterwards its outer layers of cells become round, of a brown or black colour, and it is surrounded by a black rind, consisting of round cells, which separate it from the neighbouring tissue. The tissue within the rind remains colourless; it is an entangled uninterrupted tissue of fungus filaments, which gradually obtain very solid, hard, cartilaginous coats. The sclerotium, which ripens as the rind becomes black, loosens itself easily from the place of its formation, and remains preserved after the latter is decayed.



The sclerotia are, here as in many other fungi, biennial organs, designed to begin a new vegetation after a state of apparent quietude, and to send forth special fruit-bearers. They may in this respect be compared to the bulbs and perennial roots of under shrubs. The usual time for the development of the sclerotia is late in the autumn, after the fall of the vine leaves. As long as the frost does not set in, new ones continually spring up, and each one attains to ripeness in a few days. If frost appears, it can lie dry a whole year, without losing its power of development. This latter commences when the sclerotium is brought into contact with damp ground during the usual temperature of our warmer seasons. If this occur soon, at the latest some weeks after it is ripe, new vegetation grows very quickly, generally after a few days; in several parts the colourless filaments of the inner tissue begin to send out clusters of strong branches, which, breaking through the black rind, stretch themselves up perpendicularly towards the surface, separate from one another, and then take all the characteristics of the conidia-bearers. Many such clusters can be produced on one sclerotium, so that soon the greater part of the surface is covered by filamentous conidia-bearers with their panicles. The colourless tissue of the sclerotium disappears in the same degree as the conidia-bearers grow, and at last the black rind remains behind empty and shrivelled. If we bring, after many months, for the first time, the ripe sclerotium, in damp ground, in summer or autumn, after it has ripened, the further development takes place more slowly, and in an essentially different form. It is true that from the inner tissue numerous filamentous branches shoot forth at the cost of this growing fascicle, and break through the black rind, but its filaments remain strongly bound, in an almost parallel situation, to a cylindrical cord, which for a time lengthens itself and spreads out its free end to a flat plate-like disc. This is always formed of strongly united threads, ramifications of the cylindrical cord. On the free upper surface of the disc, the filaments shoot forth innumerable branches, which, growing to the same height, thick and parallel with one another, cover the before-named disc. Some remain narrow and cylindrical, are very numerous, and produce fine hairs (paraphyses); others, also very numerous, take the form of club-like ampulla cells, and each one forms in its interior eight free swimming oval spores. Those ampulla cells are sporidiiferous asci. After the spores have become ripe, the free point of the utricle bursts, and the spores are scattered to a great distance by a mechanism which we will not here further describe. New ampullas push themselves between those which are ripening and withering; a disc can, under favourable circumstances, always form new asci for weeks at a time. The number of the already described utricle-bearers is different, according to the size of the sclerotium; smaller specimens usually produce only one, larger two to four. The size is regulated by that of the sclerotia, and ranges, in full-grown specimens, between one and more millimetres for the length of the stalk, and a half to three (seldom more) millimetres for the breadth of the disc.[q] For some time the conidia form, belonging to the Mucedines, has been known as Botrytis cinerea (or Polyactis cinerea). The compact mycelium, or sclerotium, as an imperfect fungus, bore the name of Sclerotium echinatum, whilst to the perfect and cup-like form has been given the name of Peziza Fuckeliana. We have reproduced De Bary's life-history of this mould here, as an illustration of structure in the Mucedines, but hereafter we shall have to write of similar transformations when treating of polymorphism.

The form of the threads, and the form and disposition of the spores, vary according to the genera of which this order is composed. In Oidium the mostly simple threads break up into joints. Many of the former species are now recognized as conditions of Erysiphe. In Aspergillus, the threads are simple and erect, with a globose head, around which are clustered chains of simple spores. In Penicillium, the lower portion of the threads is simple, but they are shortly branched at the apex, the branches being terminated by necklaces of minute spores. In Dactylium, the threads are branched, but the spores are collected in clusters usually, and are moreover septate. In other genera similar distinctions prevail. These two groups of black moulds and white moulds are the noblest, and contain the largest number of genera and species amongst the Hyphomycetes. There is, however, the small group of Isariacei, in which the threads are compacted, and a semblance of such hymenomycetal forms as Clavaria and Pterula is the result, but it is doubtful if this group contains many autonomous species. In another small group, the Stilbacei, there is a composite character in the head, or receptacle,[r] and in the stem when the latter is present. Many of these, again, as Tubercularia, Volutella, Fusarium, &c., contain doubtful species. In Sepedoniei and Trichodermacei, the threads are reduced to a minimum, and the spores are such a distinctive element that through these groups the Hyphomycetes are linked with the Coniomycetes. These groups, however, are not of sufficient size or importance to demand from us, in a work of this character, anything more than the passing allusion which we have given to them.



We come now to consider the structure in the Sporidiifera, in which the fructifying corpuscles or germs, whether called spores or sporidia, are generated within certain privileged cysts, usually in definite numbers. In systematic works, these are included under two orders, the Physomycetes and the Ascomycetes. The former of these consists of cyst-bearing moulds, and from their nearest affinity to the foregoing will occupy the first place.



PHYSOMYCETES include, especially amongst the Mucorini, many most interesting and instructive species for study, which even very lately have occupied the attention of continental mycologists. Most of these phenomena are associated more or less with reproduction, and as such will have to be adverted to again, but there are points in the structure which can best be alluded to here. Again taking Professor de Bary's researches as our guide,[s] we will illustrate this by the common Mucor mucedo: If we bring quite fresh horse-dung into a damp confined atmosphere, for example, under a bell-glass, there appears on its surface, after a few days, an immense white mildew. Upright strong filaments of the breadth of a hair raise themselves over the surface, each of them soon shows at its point a round little head, which gradually becomes black, and a closer examination shows us that in all principal points it perfectly agrees with the sporangia of other species. Each of these white filaments is a sporangia-bearer. They spring from a mycelium which is spread in the dung, and appear singly upon it. Certain peculiarities in the form of the sporangium, and the little long cylindrical spores, which, when examined separately, are quite flat and colourless, are characteristic of the species. If the latter be sown in a suitable medium, for example, in a solution of sugar, they swell, and shoot forth germinating utricles, which quickly grow to mycelia, which bear sporangia. This is easily produced on the most various organic bodies, and Mucor mucedo is therefore found spontaneously on every substratum which is capable of nourishing mildew, but on the above-named the most perfect and exuberant specimens are generally to be found. The sporangia-bearers are at first always branchless and without partitions. After the sporangium is ripe, cross partitions in irregular order and number often appear in the inner space, and on the upper surface branches of different number and size, each of which forms a sporangium at its point. The sporangia which are formed later are often very similar, but sometimes very different, to those which first appeared, because their partition is very thick and does not fall to pieces when it is ripe, but irregularly breaks off, or remains entire, enclosing the spores, and at last falls to the ground, when the fungus withers. The cross partition which separates the sporangia from its bearers is in those which are first formed (which are always relatively thicker sporangia) very strongly convex, while those which follow later are often smaller, and in little weak specimens much less arched, and sometimes quite straight. After a few days, similar filaments generally show themselves on the dung between the sporangia-bearers, which appear to the naked eye to be provided with delicate white frills. Where such an one is to be found, two to four rectangular expanding little branches spring up to the same height round the filament. Each of these, after a short and simple process, branch out into a furcated form; the furcations being made in such a manner that the ends of the branch at last so stand together that their surface forms a ball. Finally, each of the ends of a branch swells to a little round sporangium, which is limited by a partition (called sporangiolum, to distinguish it from the larger ones), in which some, generally four, spores are formed in the manner already known. When the sporangiola are alone, they have such a peculiar appearance, with their richly-branched bearers, that they can be taken for something quite different to the organs of the Mucor mucedo, and were formerly not considered to belong to it. That they really belong to the Mucor is shown by the principal filament which it bears, not always, but very often, ending with a large sporangium, which is characteristic of the Mucor mucedo; it is still more evident if we sow the spores of the sporangiolum, for, as it germinates, a mycelium is developed, which, near a simple bearer, can form large sporangia, and those form sporangiola, the first always considerably preponderating in number, and very often exclusively. If we examine a large number of specimens, we find every possible middle form between the simple or less branched sporangia-bearers and the typical sporangiola frills; and we arrive at last at the conclusion simply to place the latter among the varieties of form which the sporangia-bearer of the Mucor mucedo shows, like every other typical organic form within certain limits. On the other hand, propagation organs, differing from those of the sporangia and their products, belong to Mucor mucedo, which may be termed conidia. On the dung (they are rare on any other substance) these appear at the same time, or generally somewhat later, than the sporangia-bearers, and are not unlike those to the naked eye. In a more accurate examination, they appear different; a thicker, partition-less filament rises up and divides itself, generally three-forked, at the length of one millimetre, into several series of branchlets. The forked branches of the last series bear under their points, which are mostly capillary, short erect little ramuli, and these, with which the ends of the principal branches articulate on their somewhat broad tops, several spores and conidia, near one another; about fifteen to twenty are formed at the end of each little ramulus. The peculiarities and variations which so often appear in the ramification need not be discussed here. After the articulation of the conidia, their bearers sink together by degrees, and are quite destroyed. The ripe conidia are round like a ball, their surface is scarcely coloured, and almost wholly smooth. These conidioid forms were at first described as a separate species under the name of Botrytis Jonesii. How, then, do they belong to the Mucor?[t] That they appear gregariously is as little proof of an original relation to one another, here as elsewhere. Attempts to prove that the conidia and sporangia-bearers originate on one and the same mycelium filament may possibly hereafter succeed. Till now this has not been the case, and he who has ever tried to disentangle the mass of filaments which exuberantly covers the substratum of a Mucor vegetation, which has reached so far as to form conidia, will not be surprised that all attempts have hitherto proved abortive. The suspicion of the connection founded on the gregariously springing up, and external resemblance, is fully justified, if we sow the conidia in a suitable medium, for example, in a solution of sugar. They here germinate and produce a mycelium which exactly resembles that of the Mucor mucedo, and, above all, they produce in profusion the typical sporangia of the same on its bearers. The latter are till now alone reproductions of conidia-bearers, and have never been observed on mycelia which have grown out of conidia.



These phenomena of development appear in the Mucor when it dwells on a damp substance, which must naturally contain the necessary nourishment for it, and is exposed to the atmospheric air. Its mycelium represents at first strong branched utricles without partitions; the branches are of the higher order, mostly divided into rich and very fine-pointed ramuli. In old mycelium, and also in the sporangia-bearers, the contents of which are mostly used for the formation of spores, and the substratum of which is exhausted for our fungus, short stationary pieces, filled with protoplasm, are very often formed into cells through partitions in order to produce spores, that is, grow to a new fruitful mycelium. These cells are called gemmules, brooding cells, and resemble such vegetable buds and sprouts of foliaceous plants which remain capable of development after the organs of vegetation are dead, in order to grow, under suitable circumstances, to new vegetating plants, as, for example, the bulbs of onions, &c.

If we bring a vegetating mycelium of Mucor mucedo into a medium which contains the necessary nourishment for it, but excluded from the free air, the formation of sporangia takes place very sparingly or not at all, but that of gemmules is very abundant. Single interstitial pieces of the ramuli, or even whole systems of branches, are quite filled with a rich greasy protoplasm; the short pieces and ends are bound by partitions which form particular, often tun-like or globular cells; the longer ones are changed, through the formation of cross partitions, into chains of similar cells; the latter often attain by degrees strong, thick walls, and their greasy contents often pass into innumerable drops of a very regular globular form and of equal size. Similar appearances show themselves after the sowing of spores, which are capable of germinating in the medium already described, from which the air is excluded. Either short germinating utricles shoot forth, which soon form themselves into rows of gemmules, or the spores swell to large round bladders filled with protoplasm, and shoot forth on various parts of their surface innumerable protuberances, which, fixing themselves with a narrow basis, soon become round vesiculate cells, and on which the same sprouts which caused their production are repeated, formations which remind us of the fungus of fermentation called globular yeast. Among all the known forms of gemmules we find a variety which are intermediate, all of which show, when brought into a normal condition of development, the same proportion, and the same germination, as those we first described.

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

ASCOMYCETES.—Passing now to the Ascomycetes, which are especially rich in genera and species, we must first, and but superficially, allude to Tuberacei, an order of sporidiiferous fungi of subterranean habit, and rather peculiar structure.[u] In this order an external stratum of cells forms a kind of perithecium, which is more or less developed in different genera. This encloses the hymenium, which is sinuous, contorted, and twisted, often forming lacunae. The hymenium in some genera consists of elongated, nearly cylindrical asci, enclosing a definite number of sporidia; in the true truffles and their immediate allies, the asci are broad sacs, containing very large and beautiful, often coloured, sporidia. These latter have either a smooth, warted, spinulose, or lacunose epispore, and, as will be seen from the figures in Tulasne's Monograph,[v] or those in the last volume of Corda's great work,[w] are attractive microscopical objects. In some cases, it is not difficult to detect paraphyses, but in others they would seem to be entirely absent. A comparatively large number have been discovered and recorded in Great Britain,[x] but of those none are more suitable for study of general structure than the ordinary truffle of the markets.

The structure of the remaining Ascomycetes can be studied under two groups, i.e., the fleshy Ascomycetes, or, as they have been termed, the Discomycetes, and the hard, or carbonaceous Ascomycetes, sometimes called the Pyrenomycetes. Neither of these names gives an accurate idea of the distinctions between the two groups, in the former of which the discoid form is not universal, and the latter contains somewhat fleshy forms. But in the Discomycetes the hymenium soon becomes more or less exposed, and in the latter it is enclosed in a perithecium. The Discomycetes are of two kinds, the pileate and the cup-shaped. Of the pileate such a genus as Gyromitra or Helvella is, in a certain sense, analogous to the Agarics amongst Hymenomycetes, with a superior instead of an inferior hymenium, and enclosed, not naked, spores. Again, Geoglossum is somewhat analogous to Clavaria. Amongst the cup-shaped, Peziza is an Ascomycetous Cyphella. But these are perhaps more fanciful than real analogies.

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



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

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

The paraphyses, which are formed at the first commencement of the receptacle, are at first very short, but soon elongate, and become wholly developed before the appearance of the asci. They are linear, sometimes branched and sometimes simple, often more or less thickened at their tips; almost always they contain within them some oleaginous granules, either coloured or colourless. Their special function seems still somewhat obscure, and Boudier suggests that they may be excitatory organs for the dehiscence of the asci. However this may be, some mycologists are of opinion that, at least in some of the Ascomycetes, the paraphyses are abortive asci, or, at any rate, that abortive asci mixed with the paraphyses cannot be distinguished from them.

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

The asci appear first at the base of the paraphyses, under the form of oblong cells, filled with colourless protoplasm. By rapid growth, they soon attain a considerable size and fulness, the protoplasm being gradually absorbed by the sporidia, the first indication of which is always the central nucleus. The mucilage also partly disappears, and the asci, attaining their maturity, become quite distinct, each enclosing its sporidia. But before they take their complete growth they detach themselves from the subhymenial tissue, and being attenuated towards their base, are forced upwards by pressure of the younger asci, to, and in some instances beyond, the upper surface of the disc. This phenomenon commences during the night, and continues during the night and all the morning. It attains its height at mid-day, and it is then that the slightest breath of air, the slightest movement, suffices to cause dehiscence, which is generally followed by a scarcely perceptible contractile motion of the receptacle.



There is manifestly a succession in formation and maturity of the asci in a receptacle. In the true Ascobolei, in which the sporidia are coloured, this may be more distinctly seen. At first some thin projecting points appear upon the disc, the next day they are more numerous, and become more and more so on following days, so as to render the disc almost covered with raised black or crystalline points;[z] these afterwards diminish day by day, until they ultimately cease. The asci, after separation from the subhymenial tissue, continue to lengthen, or it may be that their elasticity permits of extension, during expulsion. Boudier considers that an amount of elasticity is certain, because he has seen an ascus arrive at maturity, eject its spores, and then make a sharp and considerable movement of retraction, then the ascus returned again, immediately towards its previous limits, always with a reduction in the number of its contained sporidia.

The dehiscence of the asci takes place in the Ascobolei, in some species of Peziza, Morchella, Helvella, and Verpa, by means of an apical operculum, and in other Pezizae, Helotium, Geoglossum, Leotia, Mitrula, &c., by a fissure of the ascus. This operculum may be the more readily seen when the ascus is coloured by a drop of tincture of iodine.

The sporidia are usually four or eight, or some multiple of that number, in each ascus, rarely four, most commonly eight. At a fixed time the protoplasm, which at first filled the asci, disappears or is absorbed in a mucilaginous matter, which occupies its place, in the midst of which is a small nucleus, which is the rudiment of the first spore; other spores are formed consecutively, and then the substance separates into as many sections as there are sporidia. From this period each sporidium seems to have a separate existence. All have a nucleus, which is scarcely visible, often slightly granular, but which is quite distinct from the oleaginous sporidioles so frequent amongst the Discomycetes, and which are sometimes called by the same name. The sporidia are at first a little smaller than when mature, and are surrounded by mucilage. After this period the sporidia lose their nebulous granulations, whilst still preserving their nucleus; their outlines are distinct, and, amongst the true Ascobolei, commence acquiring a rosy colour, the first intimation of maturity. This colour manifests itself rapidly, accumulating exclusively upon the epispore, which becomes of a deep rose, then violet, and finally violet blue, so deep as sometimes to appear quite black. There are some modifications in this coloration, since, in some species, it passes from a vinous red to grey, then to black, or from rose-violet to brown.

The epispore acquires a waxy consistence by this pigmentation, so that it may be detached in granules. It is to this particular consistency of the epispore that the cracks so frequent in the coloured sporidia of Ascobolus are due, through contraction of the epispore. As they approach maturity, the sporidia accumulate towards the apex of the asci, and finally escape in the manner already indicated.

In all essential particulars there is a great similarity in the structure of the other Discomycetes, especially in their reproductive system. In most of them coloured sporidia are rare. In some the receptacle is pileate, clavate, or inflated, whilst in Stictis it is very much reduced, and in the lowest form of all, Ascomyces, it is entirely absent. In the Phacidiacei, the structure is very similar to that of the Elvellacei, whilst the Hysteriacei, with greater affinities with the latter, still tend towards the Pyrenomycetes by the more horny nature of the receptacle, and the greater tendency of the hymenium to remain closed, at least when dry. In some species of Hysterium, the sporidia are remarkably fine. M. Duby[AA] has subjected this group to examination, and M. Tulasne partly so.[AB]

SPHAERIACEI.—In this group there is considerable variation, within certain limits. It contains an immense number of species, and these are daily being augmented. The general feature in all is the presence of a perithecium, which contains and encloses the hymenium, and at length opening by a pore or ostiolum at the apex. In some the perithecia are simple, in others compound; in some immersed in a stroma, in others free; in some fleshy or waxy, in others carbonaceous, and in others membranaceous. But in all there is this important difference from the Ascomycetes we have already had under consideration, that the hymenium is never exposed. The perithecium consists usually of an external layer of cellular structure, which is either smooth or hairy, usually blackish, and an internal stratum of less compact cells, which give rise to the hymenium.



As in the Discomycetes, the hymenium consists of asci, paraphyses, and mucilage, but the whole forms a less compact and more gelatinous mass within the perithecium. The formation and growth of the asci and sporidia differ little from what we have described, and when mature the asci dehisce, and the sporidia alone are ejected from the ostiolum. We are not aware that operculate asci have yet been detected. It has been shown in some instances, and suspected in others, that certain moulds, formerly classed with Mucedines and Dematiei, especially in the genus Helminthosporium, bear the conidia of species of Sphaeria, so that this may be regarded as one form of fruit.

Perithecia, very similar externally to those of Sphaeria, but containing spores borne on slender pedicels and not enclosed in asci, have had their relations to certain species of Sphaeria indicated, and these are no longer regarded so much as species of Hendersonia or Diplodia as the pycnidia of Sphaeria. Other and more minute perithecia, containing minute, slender stylospores in great numbers, formerly classed with Aposphaeria, Phoma, &c., but are now recognized as spermogonia containing the spermatia of Sphaeriae. How these influence each other, when and under what circumstances the spermatia are instrumental in impregnation of the sporidia, is still matter of mystery. It is clear, however, that in all these conidia, macrospores, microspores, and some spermatia, or by whatever names they may be called, there exists a power of germination. Tulasne has indicated in some instances five or six forms of fruit as belonging to one fungus, of which the highest and most perfect condition is a species of Sphaeria.



PERISPORIACEI.—Except in the perithecia rupturing irregularly, and not dehiscing by a pore, some of the genera in this group differ little in structure from the Sphaeriacei. On the other hand, the Erysiphei present important and very interesting features. They occur chiefly on the green parts of growing plants. At first there is a more or less profuse white mycelium.[AC] This gives rise to chains of conidia (Oidium), and afterwards small sphaeroid projections appear at certain points on the mycelium. These enlarge, take an orange colour, ultimately passing into brown, and then nearly black. Externally these perithecia are usually furnished with long, spreading, intertwined, or branching appendages, sometimes beautifully branched or hooked at their tips. In the interior of the receptacles, pear-shaped or ovate asci are formed in clusters, attached together at the base, and containing two or more hyaline sporidia. Other forms of fruit have also been observed on the same mycelium. In an exotic genus, Meliola, the fulcra, or appendages, as well as the mycelium, are black, otherwise it is very analogous to such a genus of Erysiphei as Microsphaeria. In Chaetomium, the perithecia bristle with rigid, dark-coloured hairs, and the sporidia are coloured. Our limits, however, will not permit of further elucidation of the complex and varied structure to be found amongst fungi.[AD]

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

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

[C] In Paxillus involutus the hymenium may be readily torn off and unfolded.

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

[E] A. de Bary, "Morphologie und Physiologie der Pilze," in "Hofmeister's Handbuch," vol. ii. cap. 5, 1866, translated in "Grevillea," vol. i. p. 181.

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

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

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

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

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

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

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

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

[N] Tulasne, L. R. and C., "Observations on the Organization of the Tremellini," in "Ann. des Sci. Nat." 3^me ser. xix. (1853), pp. 193, &c.

[O] M. Leveille, in "Ann. des Sci. Nat." 2^me ser. viii. p. 328; 3^me ser. ix. p. 127; also Bonorden, "Handbuch der Mycologie," p. 151.

[P] Tulasne, in "Ann. des Sci. Nat." (loc. cit.) xix. pl. x. fig. 29. Tulasne, "New Notes upon Tremellinous Fungi," in "Journ. Linn. Soc." vol. xiii. (1871), p. 31.

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

[R] Tulasne, L. R. and C., "Fungi Hypogaei." Paris. Berkeley and Broome, "British Hypogaeous Fungi," in "Ann. Nat. Hist." 1846, xviii. p. 74. Corda, "Icones Fungorum," vol. vi. pl. vii. viii.

[S] Tulasne, "Sur le Genre Secotium," in "Ann. des Sci. Nat." (1845), 3^me ser. vol. iv. p. 169, plate 9.

[T] Tulasne, L. R. and C., "De la Fructification des Scleroderma comparee a celle des Lycoperdon et des Borista," in "Ann. des Sci. Nat." 1842, xvii. p. 5. Tulasne, L. R. and C., "Sur les Genres Polysaccum et Geaster," in "Ann. des Sci. Nat." 1842, xviii. p. 129, pl. 5 and 6.

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

[V] Wigand, "Morphologie des Genres Trichia et Arcyria," in "Ann. des Sci. Nat." 4^me ser. xvi. p. 223.

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

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

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

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

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

[b] In the Caeomacei and Pucciniaei the term "pseudospore" would be much more accurate.

[c] Leveille, "Sur la Disposition Methodique des Uredinees," in "Ann. des Sci. Nat." (1847), vol. viii. p. 369.

[d] De Bary, "Champignons Parasites," in "Ann. des Sci. Nat." 4^me ser. vol. xx.

[e] Tulasne, "Memoire sur les Uredinees, &c.," in "Ann. des Sci. Nat." (1854), vol. ii. p. 78.

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

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

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

[i] Tulasne, "Memoire sur les Ustilaginees," in "Ann. des Sci. Nat." (1847), vii. pp. 12 and 73.

[j] Corda, "Icones Fungorum," vol. iii. fig. 45.

[k] Cooke, "On Podisoma," in "Quekett Journal," vol. ii. p. 255.

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

[m] Cooke, "On Microscopic Moulds," in "Quekett Journal," vol. ii. plate 7.

[n] See "Dendryphium Fumosum," in "Quekett Journal," vol. ii. plate 8; or, "Corda Prachtflora," plate 22.

[o] De Bary, "Champignons Parasites," in "Ann. des Sci. Nat." 4^me ser. vol. xx.

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

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

[r] Cooke, "Handbook of British Fungi," vol. ii. p. 552.

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

[t] We are quite aware that Von Tieghem and Le Monnier, in "Ann. des Sci. Nat." 1873, p. 335, dispute that this belongs to Mucor mucedo, and assert that Chaetocladium Jonesii is itself a true Mucor, with monosporous sporangia.

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

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

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

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

[y] Boudier (E.), "Memoire sur les Ascoboles," in "Ann. des Sci. Nat." 5^me ser. vol. x. (1869).

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

[AA] Duby, "Memoire sur la Tribu des Hysterinees," 1861.

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

[AC] Tulasne, "Selecta Fungorum Carpologia," vol. i. Leveille, "Organisation, &c., sur l'Erysiphe," in "Ann. des Sci. Nat." (1851), vol. xv. p. 109.

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

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

Hoffmann, "Icones Analyticae Fungorum."

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

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

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

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

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

De Bary, "Ueber der Brandpilze." 1853.

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

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

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

Cornu, M., "Sur les Saprolegniees," in "Ann. des Sci. Nat." 5^me ser. xv. p. 5.

Janczenski, "Sur l'Ascobolus furfuraceus," in "Ann. des Sci. Nat." 5^me ser. xv. p. 200.

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

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

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



III

CLASSIFICATION

A work of this kind could not be considered complete without some account of the systematic arrangement or classification which these plants receive at the hands of botanists. It would hardly avail to enter too minutely into details, yet sufficient should be attempted to enable the reader to comprehend the value and relations of the different groups into which fungi are divided. The arrangement generally adopted is based upon the "Systema Mycologicum" of Fries, as modified to meet the requirements of more recent microscopical researches by Berkeley in his "Introduction,"[A] and adopted in Lindley's "Vegetable Kingdom." Another arrangement was proposed by Professor de Bary,[B] but it has never met with general acceptance.

In the arrangement to which we have alluded, all fungi are divided into two primary sections, having reference to the mode in which the fructification is produced. In one section, the spores (which occupy nearly the same position, and perform similar functions, to the seeds of higher plants) are naked; that is, they are produced on spicules, and are not enclosed in cysts or capsules. This section is called SPORIFERA, or spore-bearing, because, by general consent, the term spore is limited in fungi to such germ-cells as are not produced in cysts. The second section is termed SPORIDIIFERA, or sporidia-bearing, because in like manner the term sporidia is limited to such germ-cells as are produced in cells or cysts. These cysts are respectively known as sporangia, and asci or thecae. The true meaning and value of these divisions will be better comprehended when we have detailed the characters of the families composing these two divisions.

First, then, the section SPORIFERA contains four families, in two of which a hymenium is present, and in two there is no proper hymenium. The term hymenium is employed to represent a more or less expanded surface, on which the fructification is produced, and is, in fact, the fruit-bearing surface. When no such surface is present, the fruit is borne on threads, proceeding direct from the root-like filaments of the mycelium, or an intermediate kind of cushion or stroma. The two families in which an hymenium is present are called Hymenomycetes and Gasteromycetes. In the former, the hymenium is exposed; in the latter, it is at first enclosed. We must examine each of these separately.

The common mushroom may be accepted, by way of illustration, as a type of the family Hymenomycetes, in which the hymenium is exposed, and is, in fact, the most noticeable feature in the family from which its name is derived. The pileus or cap bears on its under surface radiating plates or gills, consisting of the hymenium, over which are thickly scattered the basidia, each surmounted by four spicules, and on each spicule a spore. When mature, these spores fall freely upon the ground beneath, imparting to it the general colour of the spores. But it must be observed that the hymenium takes the form of gill-plates in only one order of Hymenomycetes, namely, the Agaricini; and here, as in Cantharellus, the hymenium is sometimes spread over prominent veins rather than gills. Still further divergence is manifest in the Polyporei, in which order the hymenium lines the inner surface of pores or tubes, which are normally on the under side of the pileus. Both these orders include an immense number of species, the former more or less fleshy, the latter more or less tough and leathery. There are still other forms and orders in this family, as the Hydnei, in which the hymenium clothes the surface of prickles or spines, and the Auricularini, in which the hymenium is entirely or almost even. In the two remaining orders, there is a still further divergence from the mushroom form. In the one called Clavariei, the entire fungus is either simply cylindrical or club-shaped, or it is very much branched and ramified. Whatever form the fungus assumes, the hymenium covers the whole exposed surface. In the Tremellini, a peculiar structure prevails, which at first seems to agree but little with the preceding. The whole plant is gelatinous when fresh, lobed and convolute, often brain-like, and varying in size, according to species, from that of a pin's head to that of a man's head. Threads and sporophores are imbedded in the gelatinous substance,[C] so that the fertile threads are in reality not compacted into a true hymenium. With this introduction we may state that the technical characters of the family are thus expressed:—

Hymenium free, mostly naked, or, if enclosed at first, soon exposed; spores naked, mostly quaternate, on distinct spicules = HYMENOMYCETES.



In this family some mycologists believe that fungi attain the highest form of development of which they are capable, whilst others contend that the fructification of the Ascomycetes is more perfect, and that some of the noblest species, such as the pileate forms, are entitled to the first rank. The morel is a familiar example. Whatever may be said on this point, it is incontrovertible that the noblest and most attractive, as well as the largest, forms are classed under the Hymenomycetes.

In Gasteromycetes, the second family, a true hymenium is also present, but instead of being exposed it is for a long time enclosed in an outer peridium or sac, until the spores are fully matured, or the fungus is beginning to decay. The common puff-ball (Lycoperdon) is well known, and will illustrate the principal feature of the family. Externally there is a tough coat or peridium, which is at first pale, but ultimately becomes brown. Internally is at first a cream-coloured, then greenish, cellular mass, consisting of the sinuated hymenium and young spores, which at length, and when the spores are fully matured become brownish and dusty, the hymenium being broken up into threads, and the spores become free. In earlier stages, and before the hymenium is ruptured, the spores have been found to harmonize with those of Hymenomycetes in their mode of production, since basidia are present surmounted each by four spicules, and each spicule normally surmounted by a spore.[D] Here is, therefore, a cellular hymenium bearing quaternary spores, but, instead of being exposed, this hymenium is wholly enclosed within an external sac or peridium, which is not ruptured until the spores are fully matured, and the hymenium is resolved into threads, together forming a pulverulent mass. It must, however, be borne in mind, that in only some of the orders composing this family is the hymenium thus evanescent, in others being more or less permanent, and this has led naturally enough to the recognition of two sub-families, in one of which the hymenium is more or less permanent, thus following the Hymenomycetous type; and in the other, the hymenium is evanescent, and the dusty mass of spores tends more towards the Coniomycetes, this being characterized as the coniospermous (or dusty-spored) sub-family.

The first sub-family includes, first of all, the Hypogaei, or subterranean species. And here again it becomes necessary to remind the reader that all subterranean fungi are not included in this order, inasmuch as some, of which the truffle is an example, are sporidiiferous, developing their sporidia in asci. To these allusion must hereafter be made. In the Hypogaei, the hymenium is permanent and convoluted, leaving numerous minute irregular cavities, in which the spores are produced on sporophores. When specimens are very old and decaying, the interior may become pulverulent or deliquescent. The structure of subterranean fungi attracted the attention of Messrs. Tulasne, and led to the production of a splendid monograph on the subject.[E] Another order belonging to this sub-family is the Phalloidei, in which the volva or peridium is ruptured whilst the plant is still immature, and the hymenium when mature becomes deliquescent. Not only are some members of this order most singular in appearance, but they possess an odour so foetid as to be unapproached in this property by any other vegetable production.[F] In this order, the inner stratum of the investing volva is gelatinous. When still young, and previous to the rupture of the volva, the hymenium presents sinuous cavities in which the spores are produced on spicules, after the manner of Hymenomycetes.[G] Nidulariacei is a somewhat aberrant order, presenting a peculiar structure. The peridium consists of two or three coats, and bursts at the apex, either irregularly or in a stellate manner, or by the separation of a little lid. Within the cavity are contained one or more secondary receptacles, which are either free or attached by elastic threads to the common receptacle. Ultimately the secondary receptacles are hollow, and spores are produced in the interior, borne on spicules.[H] The appearance in some genera as of a little bird's-nest containing eggs has furnished the name to the order.

The second sub-family contains the coniospermous puff-balls, and includes two orders, in which the most readily distinguishable feature is the cellular condition of the entire plant, in its earlier stages, in the Trichogastres, and the gelatinous condition of the early state of the Myxogastres. Both are ultimately resolved internally into a dusty mass of threads and spores. In the former, the peridium is either single or double, occasionally borne on a stem, but usually sessile. In Geaster, the "starry puff-balls," the outer peridium divides into several lobes, which fall back in a stellate manner, and expose the inner peridium, like a ball in the centre. In Polysaccum, the interior is divided into numerous cells, filled with secondary peridia. The mode of spore-production has already been alluded to in our remarks on Lycoperdon. All the species are large, as compared with those of the following sub-family, and one species of Lycoperdon attains an enormous size. One specimen recorded in the "Gardener's Chronicle" was three feet four inches in circumference, and weighed nearly ten pounds. In the Myxogastres, the early stage has been the subject of much controversy. The gelatinous condition presents phenomena so unlike anything previously recorded in plants, that one learned professor[I] did not hesitate to propose their exclusion from the vegetable, and recognition in the animal, kingdom as associates of the Gregarines. When mature, the spores and threads so much resemble those of the Trichogastres, and the little plants themselves are so veritably miniature puff-balls, that the theory of their animal nature did not meet with a ready acceptance, and is now virtually abandoned. The characters of the family we have thus briefly reviewed are tersely stated, as—

Hymenium more or less permanently concealed, consisting in most cases of closely-packed cells, of which the fertile ones bear naked spores on distinct spicules, exposed only by the rupture or decay of the investing coat or peridium = GASTEROMYCETES.



We come now to the second section of the Sporifera, in which no definite hymenium is present. And here we find also two families, in one of which the dusty spores are the prominent feature, and hence termed Coniomycetes; the other, in which the threads are most noticeable, is Hyphomycetes. In the former of these, the reproductive system seems to preponderate so much over the vegetative, that the fungus appears to be all spores. The mycelium is often nearly obsolete, and the short pedicels so evanescent, that a rusty or sooty powder represents the mature fungus, infesting the green parts of living plants. This is more especially true of one or two orders. It will be most convenient to recognize two artificial sub-families for the purpose of illustration, in one of which the species are developed on living, and in the other on dead, plants. We will commence with the latter, recognizing first those which are developed beneath the cuticle, and then those which are superficial. Of the sub-cuticular, two orders may be named as the representatives of this group in Britain, these are the Sphaeronemei, in which the spores are contained in a more or less perfect perithecium, and the Melanconiei, in which there is manifestly none. The first of these is analogous to the Sphaeriacei of Ascomycetous fungi, and probably consists largely of spermogonia of known species of Sphaeria, the relations of which have not hitherto been traced. The spores are produced on slender threads springing from the inner wall of the perithecium, and, when mature, are expelled from an orifice at the apex. This is the normal condition, to which there are some exceptions. In the Melanconiei, there is no true perithecium, but the spores are produced in like manner upon a kind of stroma or cushion formed from the mycelium, and, when mature, are expelled through a rupture of the cuticle beneath which they are generated, often issuing in long gelatinous tendrils. Here, again, the majority of what were formerly regarded as distinct species have been found, or suspected, to be forms of higher fungi. The Torulacei represent the superficial fungi of this family, and these consist of a more or less developed mycelium, which gives rise to fertile threads, which, by constriction and division, mature into moniliform chains of spores. The species mostly appear as blackish velvety patches or stains on the stems of herbaceous plants and on old weathered wood.

Much interest attaches to the other sub-family of Coniomycetes, in which the species are produced for the most part on living plants. So much has been discovered during recent years of the polymorphism which subsists amongst the species in this section, that any detailed classification can only be regarded as provisional. Hence we shall proceed here upon the supposition that we are dealing with autonomous species. In the first place, we must recognize a small section in which a kind of cellular peridium is present. This is the AEcidiacei, or order of "cluster cups." The majority of species are very beautiful objects under the microscope; the peridia are distinctly cellular, and white or pallid, produced beneath the cuticle, through which they burst, and, rupturing at the apex, in one genus in a stellate manner, so that the teeth, becoming reflexed, resemble delicate fringed cups, with the orange, golden, brown, or whitish spores or pseudospores nestling in the interior.[J] These pseudospores are at first produced in chains, but ultimately separate. In many cases these cups are either accompanied or preceded by spermogonia. In two other orders there is no peridium. In the Caeomacei, the pseudospores are more or less globose or ovate, sometimes laterally compressed and simple; and in Pucciniaei, they are elongated, often subfusiform and septate. In both, the pseudospores are produced in tufts or clusters direct from the mycelium. The Caeomacei might again be subdivided into Ustilagines[K] and Uredines.[L] In the former, the pseudospores are mostly dingy brown or blackish, and in the latter more brightly coloured, often yellowish. The Ustilagines include the smuts and bunt of corn-plants, the Uredines include the red rusts of wheat and grasses. In some of the species included in the latter, two forms of fruit are found. In Melampsora, the summer pseudospores are yellow, globose, and were formerly classed as a species of Lecythea, whilst the winter pseudospores are brownish, elongated, wedge-shaped by compression, and compact. The Pucciniaei[M] differ primarily in the septate pseudospores, which in one genus (Puccinia) are uniseptate; in Triphragmium, they are biseptate; in Phragmidium, multiseptate; and in Xenodochus, moniliform, breaking up into distinct articulations. It is probable that, in all of these, as is known to be the case in most, the septate pseudospores are preceded or accompanied by simple pseudospores, to which they are mysteriously related. There is still another, somewhat singular, group usually associated with the Pucciniaei, in which the septate pseudospores are immersed in gelatin, so that in many features the species seem to approach the Tremellini. This group includes two or three genera, the type of which will be found in Podisoma.[N] These fungi are parasitic on living junipers in Britain and North America, appearing year after year upon the same gouty swellings of the branches, in clavate or horn-shaped gelatinous processes of a yellowish or orange colour. Anomalous as it may at first sight appear to include these tremelloid forms with the dust-like fungi, their relations will on closer examination be more fully appreciated, when the form of pseudospores, mode of germination, and other features are taken into consideration, especially when compared with Podisoma Ellisii, already alluded to. This family is technically characterized as,—

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

The last family of the sporifera is Hyphomycetes, in which the threads are conspicuously developed. These are what are more commonly called "moulds," including some of the most elegant and delicate of microscopic forms. It is true of many of these, as well as of the Coniomycetes, that they are only conidial forms of higher fungi; but there will remain a very large number of species which, as far as present knowledge extends, must be accepted as autonomous. In this family, we may again recognize three subdivisions, in one of which the threads are more or less compacted into a common stem, in another the threads are free, and in the third the threads can scarcely be distinguished from the mycelium. It is this latter group which unites the Hyphomycetes with the Coniomycetes, the affinities being increased by the great profusion with which the spores are developed. The first group, in which the fertile threads are united so as to form a compound stem, consists of two small orders, the Isariacei and the Stilbacei, in the former of which the spores are dry, and in the latter somewhat gelatinous. Many of the species closely imitate forms met with in the Hymenomycetes, such as Clavaria; and, in the genus Isaria, it is almost beyond doubt that the species found on dead insects, moths, spiders, flies, ants, &c., are merely the conidiophores of species of Torrubia.[O]

The second group is by far the largest, most typical, and attractive in this family. It contains the black moulds and white moulds, technically known as the Dematiei and the Mucedines. In the first, the threads are more or less corticated, that is, the stem has a distinct investing membrane, which peels off like a bark; and the threads, often also the spores, are dark-coloured, as if charred or scorched. In many cases, the spores are highly developed, large, multiseptate, and nucleate, and seldom are spores and threads colourless or of bright tints. In the Mucedines, on the contrary, the threads are never coated, seldom dingy, mostly white or of pure colours, and the spores have less a tendency to extra development or multiplex septation. In some genera, as in Peronospora for instance,[P] a secondary fruit is produced in the form of resting spores from the mycelium; and these generate zoospores as well as the primary spores, similar to those common in Algae. This latter genus is very destructive to growing plants, one species being the chief agent in the potato disease, and another no less destructive to crops of onions. The vine disease is produced by a species of Oidium, which is also classed with Mucedines, but which is really the conidiiferous form of Erysiphe. In other genera, the majority of species are developed on decaying plants, so that, with the exception of the two genera mentioned, the Hyphomycetes exert a much less baneful influence on vegetation than the Coniomycetes. The last section, including the Sepedoniei, has been already cited as remarkable for the suppression of the threads, which are scarcely to be distinguished from the mycelium; the spores are profuse, nestling on the floccose mycelium; whilst in the Trichodermacei, the spores are invested by the threads, as if enclosed in a sort of false peridium. A summary of the characters of the family may therefore be thus briefly expressed:—

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



Having thus disposed of the Sporifera, we must advert to the two families of Sporidiifera. As more closely related to the Hyphomycetes, the first of these to be noticed is the Physomycetes, in which there is no proper hymenium, and the threads proceeding from the mycelium bear vesicles containing an indefinite number of sporidia. The fertile threads are either free or only slightly felted. In the order Antennariei, the threads are black and moniliform, more or less felted, bearing irregular sporangia. A common fungus named Zasmidium cellare, found in cellars, and incrusting old wine bottles, as with a blackened felt, belongs to this order. The larger and more highly-developed order, Mucorini, differs in the threads, which are simple or branched, being free, erect, and bearing the sporangia at the tips of the thread, or branches. Some of the species bear great external resemblance to Mucedines until the fruit is examined, when the fructifying heads, commonly globose or ovate, are found to be delicate transparent vesicles, enclosing a large number of minute sporidia; when mature, the sporangia burst and the sporidia are set free. In some species, it has long been known that a sort of conjugation takes place between opposite threads, which results in the formation of a sporangium.[Q] None of these species are destructive to vegetation, appearing only upon decaying, and not upon living, plants. A state approaching putrescence seems to be essential to their vigorous development. The following characters may be compared with those of the family preceding it:—

Filamentous, threads free or only slightly felted, bearing vesicles, which contain indefinite sporidia = PHYSOMYCETES.



In the last family, the Ascomycetes, we shall meet with a very great variety of forms, all agreeing in producing sporidia contained in certain cells called asci, which are produced from the hymenium. In some of these, the asci are evanescent, but in the greater number are permanent. In Onygenei, the receptacle is either club-shaped or somewhat globose, and the peridium is filled with branched threads, which produce asci of a very evanescent character, leaving the pulverulent sporidia to fill the central cavity. The species are all small, and singular for their habit of affecting animal substances, otherwise they are of little importance. The Perisporiacei, on the other hand, are very destructive of vegetation, being produced, in the majority of cases, on the green parts of growing plants. To this order the hop mildew, rose mildew, and pea mildew belong. The mycelium is often very much developed, and in the case of the maple, pea, hop, and some others, it covers the parts attacked with a thick white coating, so that from a distance the leaves appear to have been whitewashed. Seated on the mycelium, at the first as little orange points, are the perithecia, which enlarge and become nearly black. In some species, very elegant whitish appendages radiate from the sides of the perithecia, the variations in which aid in the discrimination of species. The perithecia contain pear-shaped asci, which spring from the base and enclose a definite number of sporidia.[R] The asci themselves are soon dissolved. Simultaneously with the development of sporidia, other reproductive bodies are produced direct from the mycelium, and in some species as many as five different kinds of reproductive bodies have been traced. The features to be remembered in Perisporiacei, as forming the basis of their classification, are, that the asci are saccate, springing from the base of the perithecia, and are soon absorbed. Also that the perithecia themselves are not perforated at the apex.

The four remaining orders, though large, can be easily characterized. In Tuberacei, all the species are subterranean, and the hymenium is mostly sinuated. In Elvellacei, the substance is more or less fleshy, and the hymenium is exposed. In Phacidiacei, the substance is hard or leathery, and the hymenium is soon exposed. And in Sphaeriacei, although the substance is variable, the hymenium is never exposed, being enclosed in perithecia with a distinct opening at the apex, through which the mature spores escape. Each of these four orders must be examined more in detail. The Tuberacei, or subterranean Ascomycetes, are analogous to the Hypogaei of the Gasteromycetes. The truffle is a familiar and highly prized example. There is a kind of outer peridium, and the interior consists of a fleshy hymenium, more or less convoluted, sometimes sinuous and confluent, so as to leave only minute elongated and irregular cavities, and sometimes none at all, the two opposing faces of the hymenium meeting and coalescing.[S] Certain privileged cells of the hymenium swell, and ultimately become asci, enclosing a definite number of sporidia. The sporidia in many cases are large, reticulated, echinulate or verrucose, and mostly somewhat globose. In the genus Elaphomyces, the asci are more than commonly diffluent.

The Elvellacei are fleshy in substance, or somewhat waxy, sometimes tremelloid. There is no peridium, but the hymenium is always exposed. There is a great variety of forms, some being pileate, and others cup-shaped, as there is also a great variation in size, from the minute Peziza, small as a grain of sand, to the large Helvella gigas, which equals in dimensions the head of a child. In the pileate forms, the stroma is fleshy and highly developed; in the cup-shaped, it is reduced to the external cells of the cup which enclose the hymenium. The hymenium itself consists of elongated fertile cells, or asci, mixed with linear thread-like barren cells, called paraphyses, which are regarded by some authors as barren asci. These are placed side by side in juxtaposition with the apex outwards. Each ascus contains a definite number of sporidia, which are sometimes coloured. When mature, the asci explode above, and the sporidia may be seen escaping like a miniature cloud of smoke in the light of the mid-day sun. The disc or surface of the hymenium is often brightly coloured in the genus Peziza; tints of orange, red, and brown having the predominance.

In Phacidiacei, the substance is hard and leathery, intermediate between the fleshy Elvellacei and the more horny of the Sphaeriacei. The perithecia are either orbicular or elongated, and the hymenium soon becomes exposed. In some instances, there is a close affinity with the Elvellacei, the exposed hymenium being similar in structure, but in all the disc is at first closed. In orbicular forms, the fissure takes place in a stellate manner from the centre, and the teeth are reflexed. In the Hysteriacei, where the perithecia are elongated, the fissure takes place throughout their length. As a rule, the sporidia are more elongated, more commonly septate, and more usually coloured, than in Elvellacei. Only a few solitary instances occur of individual species that are parasitic on living plants.



In the Sphaeriacei, the substance of the stroma (when present) and of the perithecia is variable, being between fleshy and waxy in Nectriei, and tough, horny, sometimes brittle, in Hypoxylon. A perithecium, or cell excavated in the stroma which fulfils the functions of a perithecium, is always present. The hymenium lines the inner walls of the perithecium, and forms a gelatinous nucleus, consisting of asci and paraphyses. When fully mature, the asci are ruptured and the sporidia escape by a pore which occupies the apex of the perithecium. Sometimes the perithecia are solitary or scattered, and sometimes gregarious, whilst in other instances they are closely aggregated and immersed in a stroma of variable size and form. Conidia, spermatia, pycnidia, &c., have been traced to and associated with some species, but the history of others is still obscure. Many of the coniomycetous forms grouped under the Sphaeronemei are probably conditions of the Sphaeriacei, as are also the Melanconiei, and some of the Hyphomycetes. A very common fungus, for instance, which is abundant on sticks and twigs, forming rosy or reddish pustules the size of a millet seed, formerly named Tubercularia vulgaris, is known to be the conidia-bearing stroma of the sphaeriaceous fungus, Nectria cinnabarina;[T] and so with many others. The following are the technical characters of the family:—

Fruit consisting of sporidia, mostly definite, contained in asci, springing from a naked or enclosed stratum of fructifying cells and forming a hymenium or nucleus = ASCOMYCETES.

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

To assist in this we have given on the following page an analytical arrangement of the families and orders, according to the system recognized and adopted in the present volume. It is, in all essential particulars, the method adopted in our "Handbook," based on that of Berkeley's "Introduction" and "Outlines."

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

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

[C] Tulasne, L. and C. R., "Observations sur l'Organisation des Tremellinees," "Ann. des Sci. Nat." 1853, xix. p. 193.

[D] Berkeley, M. J., "On the Fructification of Lycoperdon, Phallus, and their Allied Genera," in "Ann. of Nat. Hist." (1840), vol. iv. p. 155; "Ann. des Sci. Nat." (1839), xii. p. 163. Tulasne, L. R. and C., "De la Fructification des Scleroderma comparee a celle des Lycoperdon et des Bovista," in "Ann. des Sci. Nat." 2^me ser. xvii. p. 5.

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

[F] Stapeliae in this respect approach most closely to the Phalloidei.

[G] Berkeley, in "Ann. Nat. Hist." vol. iv. p. 155.

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

[I] De Bary, A., "Des Myxomycetes," in "Ann. des Sci. Nat." 4^me ser. xi. p. 153; "Bot. Zeit." xvi. p. 357.

[J] Corda, "Icones Fungorum," vol. iii. fig. 45.

[K] Tulasne, "Memoire sur les Ustilaginees," "Ann. des Sci. Nat." (1847), vii. 12-73.

[L] Tulasne, "Memoire sur les Uredinees," "Ann. des Sci. Nat." (1854), ii. 78.

[M] Tulasne, "Sur les Uredinees," "Ann. des Sci. Nat." 1854, ii. pl. 9.

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

[O] Tulasne, L. R. and C., "Selecta Fungorum Carpologia," vol. iii. pp. 4-19.

[P] De Bary, A., "Recherches sur les Champignons Parasites," in "Ann. des Sci. Nat." 4^me ser. xx. p. 5; "Grevillea," vol. i. p. 150.

[Q] A. de Bary, translated in "Grevillea," vol. i. p. 167; Tulasne, "Ann. des Sci. Nat." 5^me ser. (1866), p. 211.

[R] Leveille, J. H., "Organisation, &c., de l'Erysiphe," in "Ann. des Sci. Nat." (1851), xv. p. 109.

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

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

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

TABULAR ARRANGEMENT OF FAMILIES AND ORDERS.

DIVISION I. SPORIFERA. Spores naked.

I. Hymenium free, mostly naked, or soon exposed HYMENOMYCETES. Hymenium normally inferior— Fruit-bearing surface lamellose Agaricini. Fruit-bearing surface porous or tubular Polyporei. Fruit-bearing surface clothed with prickles Hydnei. Fruit-bearing surface even or rugose Auricularini. Hymenium superior or encircling— Clavate, or branched, rarely lobed Clavariei. Lobed, convolute, or disc-like, gelatinous Tremellini.

II. Hymenium enclosed in a peridium, ruptured when mature GASTEROMYCETES. Hymenomycetous— Subterranean, naked or enclosed Hypogaei. Terrestrial, hymenium deliquescent Phalloidei. Peridium enclosing sporangia, containing spores Nidulariacei. Coniospermous— Stipitate, hymenium convolute, drying into a dusty mass, enclosed in a volva Podaxinei. Cellular at first, hymenium drying up into a dusty mass of threads and spores Trichogastres. Gelatinous at first, peridium containing at length a dusty mass of threads and spores Myxogastres.

III. Spores naked, mostly terminal, on inconspicuous threads, free or enclosed in a perithecium CONIOMYCETES. Growing on dead or dying plants— Subcutaneous— Perithecium more or less distinct Sphaeronemei. Perithecium obsolete or wanting Melanconiei. Superficial— Fructifying surface naked. Spores compound or tomiparous Torulacei. Parasitic on living plants— Peridium distinctly cellular AEcidiacei. Peridium none— Spores sub-globose, simple or deciduous Caeomacei. Spores mostly oblong, usually septate Pucciniaei.

IV. Spores naked, on conspicuous threads, rarely compacted, small HYPHOMYCETES. Fertile threads compacted, sometimes cellular— Stem or stroma compound— Spores dry, volatile Isariacei. Mass of spores moist, diffluent Stilbacei. Fertile threads, free or anastomosing— Fertile threads dark, carbonized— Spores mostly compound Dematiei. Fertile threads not carbonized— Very distinct— Spores mostly simple Mucedines. Scarcely distinct from mycelium— Spores profuse Sepedoniei.

DIVISION II. SPORIDIIFERA. Sporidia in Asci.

V. Fertile cells seated on threads, not compacted into a hymenium PHYSOMYCETES. Threads felted, moniliform— Sporangia irregular Antennariei. Threads free— Sporangia terminal or lateral Mucorini. Aquatic Saprolegniei.

VI. Asci formed from the fertile cells of a hymenium ASCOMYCETES. Asci often evanescent— Receptacle clavaeform— Asci springing from threads Onygenei. Perithecia free— Asci springing from the base Perisporiacei. Asci persistent— Perithecia opening by a distinct ostiolum Sphaeriacei. Hard or coriaceous, hymenium at length exposed Phacidiacei. Hypogaeous; hymenium complicated Tuberacei. Fleshy, waxy, or tremelloid; hymenium mostly exposed Elvellacei.



IV.

USES.

The rigid utilitarian will hardly be satisfied with the short catalogue which can be furnished of the uses of fungi. Excepting those which are employed more or less for human food, very few are of any practical value in arts or medicine. It is true that imperfect conditions of fungi exert a very important influence on fermentation, and thus become useful; but, unfortunately, fungi have the reputation of being more destructive and offensive than valuable or useful. Notwithstanding that a large number of species have from time to time been enumerated as edible, yet those commonly employed and recognized are very few in number, prejudice in many cases, and fear in others, militating strongly against additions to the number. In Great Britain this is especially the case, and however advisable it may be to exercise great care and caution in experimenting on untried or doubtful species, it can only be regarded as prejudice which prevents good, in fact, excellent, esculent species being more extensively used, instead of allowing them to rot by thousands on the spots where they have grown. Poisonous species are also plentiful, and no golden rule can be established by means of which any one may detect at a glance good from bad, without that kind of knowledge which is applied to the discrimination of species. Yet, after all, the characters of half a dozen good esculent fungi are acquired as easily as the distinctions between half a dozen birds such as any ploughboy can discriminate.

The common mushroom (Agaricus campestris) is the best known esculent, whether in its uncultivated or in a cultivated state. In Britain many thousands of people, notably the lower classes, will not recognize any other as fit for food, whilst in Italy the same classes have a strong prejudice against this very species.[A] In Vienna, we found by personal experience that, although many others are eaten, it is this which has the most universal preference, yet it appears but sparingly in the markets as compared with others. In Hungary it does not enjoy by any means so good a reputation. In France and in Germany it is a common article of consumption. The different varieties found, as the results of cultivation, present some variation in colour, scaliness of pileus, and other minor features, whilst remaining true to the constituent characters of the species. Although it is not our intention to enumerate here the botanical distinctions of the species to which we may call attention, yet, as mistakes (sometimes fatal) are often being recorded, in which other fungi are confounded with this, we may be permitted a hint or two which should be remembered. The spores are purple, the gills are at first delicate pink, afterwards purple; there is a permanent ring or collar round the stem, and it must not be sought in woods. Many accidents might have been spared had these facts been remembered.

The meadow mushroom (Agaricus arvensis) is common in meadows and lowland pastures, and is usually of a larger size than the preceding, with which it agrees in many particulars, and is sent in enormous quantities to Covent Garden, where it frequently predominates over Agaricus campestris. Some persons prefer this, which has a stronger flavour, to the ordinary mushroom, and it is the species most commonly sold in the autumn in the streets of London and provincial towns. According to Persoon, it is preferred in France; and, in Hungary, it is considered as a special gift from St. George. It has acquired in England the name of horse mushroom, from the enormous size it sometimes attains. Withering mentions a specimen that weighed fourteen pounds.[B]

One of the commonest (in our experience the most common) of all edible fungi in the public markets of Vienna is the Hallimasche (Agaricus melleus), which in England enjoys no good reputation for flavour or quality; indeed, Dr. Badham calls it "nauseous and disagreeable," and adds that "not to be poisonous is its only recommendation." In Vienna it is employed chiefly for making sauce; but we must confess that even in this way, and with a prejudice in favour of Viennese cookery, our experience of it was not satisfactory. It is at best a sorry substitute for the mushroom. In the summer and autumn this is a very common species in large tufts on old stumps. In similar localities, and also in tufts, but neither so large, nor so common, Agaricus fusipes is found. It is preferable to the foregoing as an esculent, and is easily recognized by the spindle-shaped stem.

Agaricus rubescens, P., belongs to a very suspicious group of fungi, in which the cap or pileus is commonly studded or sprinkled with paler warts, the remains of an investing volva. To this group the poisonous but splendid fly-agaric (Agaricus muscarius) belongs. Notwithstanding its bad company, this agaric has a good reputation, especially for making ketchup; and Cordier reports it as one of the most delicate mushrooms of the Lorraine.[C] Its name is derived from its tendency to become red when bruised.

The white variety of an allied species (Agaricus vaginatus) has been commended, and Dr. Badham says that it will be found inferior to but few agarics in flavour.

A scaly-capped fungus (Agaricus procerus), with a slender stem, called sometimes the parasol mushroom, from its habit, is an esteemed esculent. In Italy and France it is in high request, and is included in the majority of continental works on the edible fungi.[D] In Austria, Germany, and Spain, it has special "vulgar" names, and is eaten in all these countries. It is much more collected in England than formerly, but deserves to be still better known. When once seen it can scarcely be confounded with any other British species, save one of its nearest allies, which partakes of its own good qualities (Agaricus rachodes), though not quite so good.

Agaricus prunulus, Scop., and Agaricus orcella, Badh., if they be not forms of the same species (which Dr. Bull contends that they are not[E]), have also a good reputation as esculents. They are both neat, white agarics, with a mealy odour, growing respectively in woods and open glades. Agaricus nebularis, Batsch, is a much larger species, found in woods, often in large gregarious patches amongst dead leaves, with a smoky mouse-coloured pileus, and profuse white spores. It is sometimes as much as five or six inches in diameter, with rather a faint odour and mild taste. On the continent, as well as in Britain, this is included amongst edible fungi. Still larger and more imposing is the magnificent white species, Agaricus maximus, Fr.,[F] which is figured by Sowerby,[G] under the name of Agaricus giganteus. It will attain a diameter of fourteen inches, with a stem, two inches thick, and rather a strong odour.

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

The closely allied species, Agaricus albellus,[I] D.C., has also the reputation of being edible, but it is so rare in England that this quality cannot be put to the test. The curious short-stemmed Agaricus brevipes, Bull,[J] has a similar reputation.

Two singularly fragrant species are also included amongst the esculent. These are Agaricus fragrans, Sow., and Agaricus odorus, Bull. Both have a sweet anise-like odour, which is persistent for a long time. The former is pale tawny-coloured, nearly white, the latter of a dirty pale green. Both are white-spored, and although somewhat local, sufficient specimens of Ag. odorus may be collected in the autumn for domestic use. We have the assurance of one who has often proved them that they constitute an exquisite dish.

A clear ivory-white fungus, Agaricus dealbatus, of which a crisped variety is occasionally found in great numbers, springing up on old mushroom beds in dense clusters, is very good eating, but rather deficient in the delicate aroma of some other species. The typical form is not uncommon on the ground in fir plantations. A more robust and larger species, Agaricus geotrupes, Bull, found on the borders of woods, often forming rings, both in this country and in the United States, as well as on the continent of Europe, is recognized as esculent.

We may add to these three or four other species, in which the stem is lateral, and sometimes nearly obsolete. The largest and most common is the oyster mushroom (Agaricus ostreatus, Jacq.[K]), so universally eaten, that it is included in almost every list and book on edible fungi; it is the most common species in Transylvania, tons of it sometimes appearing in the markets. It does not possess that delicate flavour which is found in many species, and although extolled by some beyond its merits, it is nevertheless perfectly wholesome, and, when young and carefully cooked, not to be despised. It must not be confounded with a very similar species (Agaricus euosmus, B.), with rosy spores, which is unpleasant. Agaricus tessellatus, Bull, Agaricus pometi, Fr., Agaricus glandulosus, Bull, are all allies of the foregoing, and recorded as edible in the United States, although not one of the three has hitherto been recorded as occurring in Great Britain. To these may also be added the following:—Agaricus salignus,[L] Fr., which is rare in England, but not uncommon abroad and in the United States. In Austria it is commonly eaten. Agaricus ulmarius,[M] Bull, is common on elm trunks, not only in Britain but also in North America, and is by some preferred to the oyster mushroom. An allied species, Agaricus fossulatus, Cooke,[N] is found on the Cabul Hills, where it is collected, dried, and forms an article of commerce with the plains. Another, but smaller species, is dried in the air on strings passed through a hole in the short stem (Agaricus subocreatus, Cooke), and sent, it is believed, from China to Singapore.

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

Before quitting the group of true agarics, to which all hitherto enumerated belong, we must mention a few others of less importance, but which are included amongst those good for food. Foremost of these is a really splendid orange species (Agaricus caesarius, Scop.[P]), which belongs to the same subgenus as the very deleterious fly-agaric, and the scarcely less fatal Agaricus vernus, Bull. It is universally eaten on the continent, but has hitherto never been found in Great Britain. In the same subgenus, Agaricus strobiliformis,[Q] Fr., which is rare in this country, and probably also Agaricus Ceciliae, B. & Br.[R] Besides these, Agaricus excoriatus, Schaeff., Agaricus mastoideus, Fr., Agaricus gracilentus, Kromb., and Agaricus holosericeus, Fr.,[S] all belonging to the same subgenus as the parasol mushroom, more or less uncommon in England.