(Spencer and Gillen, Native Tribes of Central Australia, p. 508). ↑ In Mesopotamia cemeteries have been discovered where the sepulchral jars were set upside down, clearly by way of hindering the ghosts from escaping into the upper world. In the Dublin museum we see specimens of ancient Celtic tombs showing the same peculiarity. For a like reason perhaps the name of the dead must among the Aruntas not be uttered, nor the grave approached, by certain classes of kinsmen. The same repugnance to naming the dead exists all over the world, and leads survivors who share the dead man's name to adopt another, at least for a time. If the dead man's name was that of a plant, tree, animal or stream, that too is changed. Here is a potent cause of linguistic change, that also renders any historical tradition impossible. The survivors seem to fear that the ghost will come when he hears his name called; but it also hangs together with the taboo which hedges round the dead as it does kings, chieftains and priests. In illustration of the very different estimates that have been made, however, may be mentioned that of De Bary in 1872 of 150,000 species, and that of Cooke in 1895 of 40,000, and Massee in 1899 of over 50,000 species, the fact being that no sufficient data are as yet to hand for any accurate census. As regards their geographical distribution, fungi, like flowering plants, have no doubt their centres of origin and of dispersal; but we must not forget that every exchange of wood, wheat, fruits, plants, animals, or other commodities involves transmission of fungi from one country to another; while the migrations of birds and other animals, currents of air and water, and so forth, are particularly efficacious in transmitting these minute organisms. Against this, of course, it may be argued that parasitic forms can only go where their hosts grow, as is proved to be the case by records concerning the introduction of Puccinia malvacearum, Perono spora viticola, Hemileia vastatrix, &c. Some fungi-e.g. moulds and yeasts-appear to be distributed all over the earth. That AUTHORITIES.-B. Spencer and F. J. Gillen, The Native Tribes the north temperate regions appear richest in fungi may be due of Central Australia (London, 1899); F. B. Jevons, Introduction to only to the fact that North America and Europe have been History of Religion (London, 1896); E. S. Hartland, The Legend of much more thoroughly investigated than other countries; it is Perseus, vol. ii.; J. G. Frazer, The Golden Bough (London, 1900); certain that the tropics are the home of very numerous species! L. W. Faraday, "Custom and Belief in the Icelandic Sagas," in Folk-lore, vol. xvii. No. 4; E. B. Tylor, Primitive Culture (London, Again, the accuracy of the statement that the fleshy Agaricini, 1903); E. A. W. Budge, The Mummy (Cambridge, 1893); C. Royer, Polyporei, Pezizae, &c., are relatively rarer in the tropics may "Les Rites funéraires aux époques préhistoriques," Revue d'anthro- depend on the fact that they are more difficult to collect and pologie (1876); Forrer, Über die Totenbestattung bei den Pfahlbauern remit for identification than the abundantly recorded woody (Ausland, 1885); J. Lubbock, Origin of Civilization (London, 1875) and coriaceous forms of these regions. When we remember and Prehistoric Times (London, 1865); L. A. Muratori, "De antiquis Christianorum sepulchris," Anecd. Graeca (Padua, 1709); Onaphr. that many parts of the world are practically unexplored as Panvinius, De rilu sepeliendi mortuos apud veteres Christianos, re-regards fungi, and that new species are constantly being disprinted in Volbeding's Thesaurus (Leipzig, 1841). (F. C. C.) FUNGI (pl. of Lat. fungus, a mushroom), the botanical name covering in the broad sense all the lower cellular Cryptogams devoid of chlorophyll, which arise from spores, and the thallus of which is either unicellular or composed of branched or unbranched tubes or cell-filaments (hyphae) with apical growth, or of more or less complex wefted sheets or tissue-like masses of such (mycelium). The latter may in certain cases attain large dimensions, and even undergo cell-divisions in their interior, resulting in the development of true tissues. The spores, which may be uni- or multi-cellular, are either abstricted free from the ends of hyphae (acrogenous), or formed from segments in their course (chlamydospores) or from protoplasm in their interior (endogenous). The want of chlorophyll restricts their mode of life-which is rarely aquatic-since they are therefore unable to decompose the carbon dioxide of the atmosphere, and renders them dependent on other plants or (rarely) animals for their carbonaceous food-materials. These they obtain usually in the form of carbohydrates from the dead remains of other organisms, or in this or other forms from the living cells of their hosts; in the former case they are termed saprophytes, in the latter parasites. While some moulds (Penicillium, Aspergillus) can utilize almost any organic food-materials, other fungi are more restricted in their choice-e.g. insect-parasites, horn- and feather - destroying fungi and parasites generally. It was formerly the custom to include with the Fungi the Schizomycetes or. Bacteria, and the Myxomycetes or Mycetozoa; but the peculiar mode of growth and division, the cilia, spores and other peculiarities of the former, and the emission of naked amoeboid masses of protoplasm, which creep and fuse to streaming plasmodia, with special modes of nutrition and spore-formation of the latter, have led to their separation as groups of organisms independent of the true Fungi. On the other hand, lichens, previously regarded as autonomous plants, aré now known to be dual organisms-fungi symbiotic with algae. covered in the United States, Australia and northern Europe→→→ the best explored of all-it is clear that no very accurate census of fungi can as yet be made, and no generalizations of value as to their geographical distribution are possible.. The existence of fossil fungi is undoubted, though very few of the identifications can be relied on as regards species or genera. They extend back beyond the Carboniferous, where they occur as hyphae, &c., preserved in the fossil woods, but the best speci-' mens are probably those in amber and in siliceous petrifactions of more recent origin. Organs. Individual hyphae or their branches often exhibit specializations of form. In many Basidiomycetes minute branches arise below the septa; their tips curve over the outside of the latter, and fuse with the cell above just beyond it, forming a clamp-con nexion. Many parasitic hyphae put out minute lateral branches,' which pierce the cell-wall of the host and form a peg-like (Tricho sphaeria), sessile (Cystopus), or stalked (Hemileia), knot-like, or a B haustoria (h); 2, Erysiphe; A and B, mycelium (m), with haustoria FIG. 1.-1, Peronospora parasitica (De Bary). Mycelium with (h). (After De Bary.) The number of species in 1889 was estimated by Saccardo at about 32,000, but of these 8500 were so-called Fungi imperfecti -i.e. forms of which we only know certain stages, such as conidia, pycnidia, &c., and which there are reasons for regarding as merely the corresponding stages of higher forms. Saccardo also included about 400 species of Myxomycetes and 650 of Schizomycetes. more or less branched (Peronospora) or coiled (Prolomyces)haustorium. Allowing for these and for the cases, undoubtedly not few, In Rhizopus certain hyphae creep horizontally on the surface of the where one and the same fungus has been described under different substratum, and then anchor their tips to it by means of a tuft of names, we obtain Schroeter's estimate (in 1892) of 20,000 species.short branches (appressorium), the walls of which soften and gung themselves to it, then another branch shoots out from the tuft and many cases, and is probably deposited unectly as such, though, like repeats the process, like a strawberry-runner. Appressoria are the other substances, it may be mixed with cellulose. As in other also formed by some parasitic fungi, as a minute flattening of the tip cell-walls, so here the older membranes may be altered by deposits of a very short branch (Erysiphe), or the swollen end of any hypha of various substances, such as resin, calcium oxalate, colouring which comes in contact with the surface of the host (Piptocephalis, matters; or more profoundly altered throughout, or in definite Syncephalis), haustoria piercing in each case the cell-wall below. layers, by lignification, suberization (Trametes, Daedalea), or swelling In Botrytis the appressoria assume the form of dense tassels of short to a gelatinous mucilage (Tremella, Gymnosporangium), while cutinbranches. In Arthrobotrys side-branches of the mycelium sling them-ization of the outer layers is common. One of the most striking selves around the host (Tylenchus) much as tendrils round a support. alterations of cell-walls is that termed carbonization, in which the Many fungi (Phallus, Agaricus, Fumago, &c.) when strongly substance gradually turns black, hard and brittle, as if charredgrowing put out ribbon-like or cylindrical cords, or sheet-like e.g. Xylaria, Ustulina, some sclerotia. At the other extreme the mycelial plates of numerous parallel hyphae, all growing together cell-walls of many lichen-fungi are soft and colourless, but turn equally, and fusing by anastomoses, and in this way extend long blue in iodine, as does starch. The young cell-wall is always tenuous distances in the soil, or over the surfaces of leaves, branches, &c. and flexible, and may remain so throughout, but in many cases These mycelial strands may be white and tender, or the outer thickenings and structural differentiations, as well as the changes hyphae may be hard and black, and very often the resemblance of referred to above, alter the primary wall considerably. Such the subterranean forms to a root is so marked that they are termed thickening may be localized, and pits (e.g. Uredospores, septa of rhizomorphs. The outermost hyphae may even put forth thinner Basidiomycetes), spirals, reticulations, rings, &c. (capillitium fibres hyphae, radiating into the soil like root-hairs, and the convergent of Podaxon, Calostoma, Battarrea), occur as in the vessels of higher tips may be closely appressed and so divided by septa as to resemble plants, while sculptured networks, pittings and so forth are as the root-apex of a higher plant (Armillaria mellea). common on fungus-spores as they are on pollen grains. Sclerotia.-Fungi, like other plants, are often found to store up large quantities of reserve materials (oil, glycogen, carbohydrates, &c.) in special parts of their vegetative tissues, where they lie accumulated between a period of active assimilation and one of renewed activity, forming reserves to be consumed particularly during the formation of large fructifications. These reserve stores may be packed away in single hyphae or in swollen cells, but the hyphae containing them are often gathered into thick cords or mycelial strands (Phallus, mushroom, &c.), or flattened and anasto-microscope, but rendered visible by reagents, are glycogen, Mucor, mosing ribbons and plates, often containing several kinds of hyphae (Merulius lacrymans). In other cases the strands undergo differentiation into an outer layer with blackened, hardened cell-walls and a core of ordinary hyphae, and are then termed rhizomorphs (Armillaria mellea), capable not only of extending the fungus in the soil, like roots, but also of lying dormant, protected by the outer casing. Such aggregations of hyphae frequently become knotted up into dense masses of interwoven and closely packed hyphae, varying in size from that of a pin's head or a pea (Peziza, Coprinus) to that of a man's fist or head, and weighing 10 to 25 lb or more (Polyporus Mylittae, P. tumulosus, Lentinus Woermanni, P. Sapurema, &c.). The interwoven hyphae fuse and branch copiously, filling up all interstices. They also undergo cutting up by numerous septa into short cells, and these often divide again in all planes, so that a pseudoparenchyma results, the walls of which may be thickened and swollen internally, or hardened and black on the exterior. In many cases the swollen cell-walls serve as reserves, and sometimes the substance is so thickly deposited in strata as to obliterate the lumen, and the hyphae become nodular (Polyporus sacer, P. rhinoceros, Lentinus Woermanni). The various sclerotia, if kept moist, give rise to the fructifications of the fungi concerned, much as a potato tuber does to a potato plant, and in the same way the reserve materials are consumed. They are principally Polyporei, Agaricini, Pezizae; none are known among the Phycomycetes, Uredineae or Ustilagineae. The functions of mycelial strands, rhizomorphs and sclerotia are not only to collect and store materials, but also to extend the fungus, and in many cases similar strands act as organs of attack. The same functions of storage in advance of fructification are also exercised by the stromata so common in Ascomycetes. Tissue Differentiations.-The simpler mycelia consist of hyphae all alike and thin-walled, or merely differing in the diameter of the branches of various orders, or in their relations to the environment, some plunging into the substratum like roots, others remaining on its surface, and others (aerial hyphae) rising into the air. Such hyphae may be multicellular, or they may consist of simple tubes with numerous nuclei and no septa (Phycomycetes), and are then non-cellular. In the more complex tissue-bodies of higher fungi, however, we find considerable differences in the various layers or strands of hyphae. An epidermis-like or cortical protective outer layer is very common, and is usually characterized by the close septation of the densely interwoven hyphae and the thickening and dark colour of their outer walls (sclerotia, Xylaria, &c.). Fibre-like hyphae with the lumen almost obliterated by the thick walls occur in mycelial cords (Merulius). Latex-tubes abound in the tissues of Lactarius, Stereum, Mycena, Fistulina, filled with white or coloured milky fluids, and Istvanffvi has shown that similar tubes with fluid or oily contents are widely spread in other Hymenomycetes. Sometimes fatty oil or watery sap is found in swollen hyphal ends, or such tubes contain coloured sap. Cystidia and paraphyses may be also classed here. In Merulius lacrymans Hartig has observed thin-walled hyphae with large lumina, the septa of which are perforated like those of sieve-tubes. As regards its composition, the cell-wall of fungi exhibits variations of the same kind as those met with in higher plants. While the fundamental constituent is a cellulose in many Mucorini and other Phycomycetes, in others bodies like pectose, callose, &c., commonly occur, and Wisselingh's researches show that chitin, a gluco-proteid common in animals, forms the main constituent in Cell-Contents.-The cells of fungi, in addition to protoplasm, nuclei and sap-vacuoles, like other vegetable cells, contain formed and amorphous bodies of various kinds. Among those directly visible to the microscope are oil drops, often coloured (Uredineae) crystals of calcium oxalate (Phallus, Russula), proteid crystals (Mucor, Pilobolus, &c.) and resin (Polyporei). The oidia of Erysipheae contain fibrosin bodies and the hyphae of Saprolegnieae cellulin bodies, but starch apparently never occurs. Invisible to the Ascomycetes, yeast, &c. In addition to these cell-contents we have good indirect evidence of the existence of large series of other bodies, such as proteids, carbohydrates, organic acids, alkaloids, enzymes, &c. These must not be confounded with the numerous substances obtained by chemical analysis of masses of the fungus, as there is often no proof of the manner of occurrence of such bodies, though we may conclude with a good show of probability that some of them also exist preformed in the living cell. Such are sugars (glucose, mannite, &c.), acids (acetic, citric and a whole series of lichen-acids), ethereal oils and resinous bodies, often combined with the intense colours of fungi and lichens, and a number of powerful alkaloid poisons, such as muscarin (Amanita), ergotin (Claviceps), &c. Among the enzymes already extracted from fungi are invertases (yeasts, moulds, &c.), which split cane-sugar and other complex sugars with hydrolysis into simpler sugars such as dextrose and levulose; diastases, which convert starches into sugars (Aspergillus, &c.); cytases, which dissolve cellulose similarly (Botrytis, &c.); peptases, using the term as a general one for all enzymes which convert proteids into peptones and other bodies (Penicillium, &c.); lipases, which break up fatty oils (Empusa, Phycomyces, &c.); oxydases, which bring about the oxidations and changes of colour observed in Boletus, and zymase, extracted by Buchner from yeast, which brings about the conversion of sugar into alcohol and carbondioxide. That such enzymes are formed in the protoplasm is evident from the behaviour of hyphae, which have been observed to pierce cell-membranes, the chitinous coats of insects, artificial collodion films and layers of wax, &c. That a fungus can secrete more than one enzyme, according to the materials its hyphae have to attack, has been shown by the extraction of diastase, inulase, trehalase, invertase, maltase, raffinase, malizitase, emulsin, trypsin and lipase from Aspergillus by Bourquelot, and similar events occur in other fungi. The same fact is indicated by the wide range of organic substances which can be utilized by Penicillium and other moulds, and by the behaviour of parasitic fungi which destroy various cell-contents and tissues. Many of the coloured pigments of fungi are fixed in the cell-walls or excreted to the outside (Peziza aeruginosa). Matruchot has used them for staining the living protoplasm of other fungi by growing the two together. Striking instances of coloured mycelia are afforded by Corticium sanguineum, blood-red; Elaphomyces Leveillei, yellow-green; Chloros plenium aeruginosum, verdigris green; and the Dematei, brown or black. Nuclei. Although many fungi have been regarded as devoid of nuclei, and all have not as yet been proved to contain them, the numerous investigations of recent years have revealed them in the cells of all forms thoroughly examined, and we are justified in concluding that the nucleus is as essential to the cell of a fungus as to that of other organisms. The hyphae of many contain numerous, even hundreds of nuclei (Phycomycetes); those of others have several (Aspergillus) in each segment, or only two (Exoascus) or one (Erysiphe) in each cell. Even the isolated cells of the yeast plant have each one nucleus. As a rule the nuclei of the mycelium are very minute (1.5-2 in Phycomyces), but those of many asci and spores are large and easily rendered visible. As with other plants, so in fungi the essential process of fertilization consists in the fusion of two nuclei, but owing to the absence of well-marked sexual organs from many fungi, a peculiar interest attaches to certain nuclear fusions in the vegetative cells or in young spores of many forms. Thus in Ustilagineae the chlamydospores, and in Uredineae the teleutospores, each contain two nuclei when young, which fuse as the spores mature. In young asci a similar fusion of two nuclei occurs, and also in basidia, in each case the nucleus of the ascus or of the basidium resulting from the fusion subsequently giving rise by division to the nuclei of the ascospores and basidiospores respectively. The significance of these fusions will be discussed under the various groups. Nuclear division is usually accompanied by all the essential features of karyokinesis. Spores.-No agreement has ever been arrived at regarding the consistent use of the term spore. This is apparently owing to the facts that too much has been attempted in the definition, and that differences arise according as we aim at a morphological or a physiological definition. Physiologically, any cell or group of cells separated off from a hypha or unicellular fungus, and capable of itself growing out-germinating-to reproduce the fungus, is a spore: but it is evident that so wide a definition does not exclude the ordinary vegetative cells of sprouting fungi, such as yeasts, or small sclerotium like cell-aggregates of forms like Coniothecium. Morphologically considered, spores are marked by peculiarities of form, size, colour, place of origin, definiteness in number, mode of preparation, and so forth, such that they can be distinguished more or less sharply from the hyphae which produce them. The only physiological peculiarity exhibited in common by all spores is that they germinate and initiate the production of a new fungus-plant. Whether a spore results from the sexual union of two similar gametes (zygospore) or from the fertilization of an egg-cell by the protoplasm of a male organ (oospore); or is developed asexually as a motile (zoospore) or a quiescent body cut off from a hypha (conidium) or developed along its course (oidium or chlamydospore), or in its protoplasm (endospore), are matters of importance which have their uses in the classification and terminology of spores, though in many respects they are largely of academic interest. Klebs has attempted to divide spores into three categories as follows: (1) kinospores, arising by relatively simple cell-divisions and subserving rapid dissemination and propagation, e.g. zoospores, conidia, endogonidia, stylospores, &c.; (2) paulospores, due to simple rearrangement of cell-contents, and subserving the persistence of the fungus through periods of exigency, e.g. gemmae, chlamydospores, resting-cells, cysts, &c.; (3) carpospores, produced by a more or less complex formative process, often in special fructifications, and subserving either or both multiplication and persistence, e.g. zygospores, oospores, brand-spores, accidiospores, ascospores, basidiospores, &c. Little or nothing is gained by these definitions, however, which are especially physiological. In practice these various kinds of spores of fungi receive further special names in the separate groups, and names, moreover, which will appear, to those unacquainted with the history, to have been given without any consistency or regard to general principles; nevertheless, for ordinary purposes these names are far more useful in most cases, owing to their descriptive character, than the proposed new names, which have been only partially accepted. Sporophores.-In some of the simpler fungi the spores are not borne on or in hyphae which can be distinguished from the vegetative parts or mycelium, but in the vast majority of cases the sporogenous hyphae either ascend free into the air or radiate into the surrounding water as distinct branches, or are grouped into special columns, cushions, layers or complex masses obviously different in colour, consistency, shape and other characters from the parts which gather up and assimilate the food-materials. The term receptacle" sometimes applied to these spore-bearing hyphae is better replaced by sporophore. The sporophore is obsolete when the spore-bearing hyphae are not sharply distinct from the mycelium, simple when the constituent hyphae are isolated, and compound when the latter are conjoined. The chief distinctive characters of the sporogenous hyphae are their orientation, usually vertical; their limited apical growth; their peculiar branching, form, colour, contents, consistency; and their spore-production. According to the characters of the last, we might theoretically divide them into conidiophores, sporangiophores, gametophores, oidiophores, &c.; but since the two latter rarely occur, and more than one kind of spore or spore-case may occur on a sporophore, it is impossible to carry such a scheme fully into practice. FIG. 2.-Peronospora para sitica (De Bary). Conidiophore with conidia. A simple sporophore may be merely a single short hypha, the end of which stops growing and becomes cut off as a conidium by the formation of a septum, which then splits and allows the conidium to fall. More generally the hypha below the septum grows forwards again, and repeats this process several times before the terminal conidium falls, and so a chain of conidia results, the oldest of which terminates the series (Erysiphe); when the primary branch has thus formed a basipetal series, branches may arise from below and again repeat this process, thus forming a tuft (Penicillium). Or the primary hypha may first swell at its apex, and put forth a series of short peg-like branches (sterigmata) from the increased surface thus provided, each of which develops a similar basipetal chain of conidia (Aspergillus), and various combinations of these processes result in the development of numerous varieties of exquisitely branched sporophores of this type (Botrytis, Botryosporium, Verticillium, &c.). A second type is developed as follows: the primary hypha forms a septum below its apex as before, and the terminal conidium, thus abstricted, puts out a branch at its apex, which starts as a mere point and rapidly swells to a second conidium; this repeats the process, and so on, so that we now have a chain of conidia developed in acropetal succession, the oldest being below, and, as in Penicillium, &c., branches put forth lower down may repeat the process (Hormodendron). In all these cases we may speak of simple conidiophores. The simple sporophore does not necessarily terminate in conidia, however. In Mucor, for example, the end of the primary hypha swells into a spheroidal head (sporangium), the protoplasm of which C undergoes segmentation into more or less numerous globular masses, each of which secretes an enveloping cell-wall and becomes a spore (endospore), and branched systems of sporangia may arise as before (Thamnidium). Such may be termed sporangiophores. In Sporodinia the branches give rise also to short branches, which meet and fuse their contents to form zygospores. In Peronospora, Saprolegnia, &c., the ends of the branches swell up into sporangia, which develop zoospores in their interior (zoosporangia), or their contents become oospheres, which may be fertilized by the contents of other branches (antheridia) and so form egg-cases (oogonia). Since in such cases the sporophore bears sexual cells, they may be conveniently termed gametophores. Compound sporophores arise when any of the branched or unbranched types of spore-bearing hyphae described above ascend into the air in consort, and are more or less crowded into definite layers, cushions, columns or other complex masses. The same laws apply to the individual hyphae and their branches as to simple sporophores, and as long as the conidia, sporangia, gametes, &c., are borne on their external surfaces, it is quite consistent to speak of these as compound sporophores, &c., in the sense described, however complex they may become. Among the simplest cases are the sheet-like aggregates of sporogenous hyphae in Puccinia, Uromyces, &c., or of basidia in Exobasidium, Corticium, &c., or of asci in Exoascus, Ascocorticium, &c. In the former, where the layer is small, it is often termed a sorus, but where, as in the latter, the sporogenous layer is extensive, and spread out more or less sheet-like on the supporting tissues, it is more frequently termed a hymenium. Another simple case is that of the columnar aggregates of sporogenous hyphae in forms like Stilbum, Coremium, &c. These lead FUNGI us to cases where the main mass of the sporophore forms a supporting | endospores of Mucor, conidia of Empusa, &c., serves to gum the spore tissue of closely crowded or interwoven hyphae, the sporogenous terminal parts of the hyphae being found at the periphery or apical absorbing water, swell and carry out the spores in long tendrils, regions only. Here we have the cushion-like type (stroma) of which emerge for days and dry as they reach the air, the glued spores to animals. Such gums are formed abundantly in pycnidia, and, Nectria and many Pyrenomycetes, the clavate Clavaria, &c., passing into the complex forms met with in Sparassis, tinia) a minute double wedge of wall-substance arises in the middle receptacle Xylaria, Polyporei, and Agaricini, &c. In these cases the compound lamella between each pair of contiguous oidia, and by its enlargement of gradually being set free by rain, wind, &c. In oidial chains (Sclerosporophore is often termed the hymenophore, and its various parts splits the separating lamella. demand special names (pileus, stipes, gills, pores, &c.) to denote application for the elastic push of the swelling spore-ends, and as peculiarities of distribution of the hymenium over the surface. These disjunctors serve as points of Other series of modifications arise in which the tissues correspond- spores are jerked asunder. In many cases the slimy masses of ing to the stroma invest the sporogenous hyphal ends, and thus spermatia (Uredineae), conidia (Claviceps), basidiospores (Phallus, the connecting outer lamella of cell-wall suddenly gives way, the enclose the spores, asci, basidia, &c., in a cavity. In the simplest Coprinus), &c., emit more or less powerful odours, which attract case the stroma, after bearing its crop of conidia or oidia, develops flies or other insects, and it has been shown that bees carry the ascogenous branches in the loosened meshes of its interior (e.g. fragrant oidia of Sclerotinia to the stigma of Vaccinium and infect Onygena). Another simple case is where the plane or slightly convexit, and that flies carry away the foetid spores of Phallus, just as surface of the stroma rises at its margins and overgrows the sporo- pollen is dispersed by such insects. genous hyphal ends, so that the spores, asci, &c., come to lie in the trimethylamine evolved by the spores of Tillelia attracts insects is depression of a cavity-e.g. Solenia, Cyphella-and even simpler not known. Whether the strong odour of cases are met with in Mortierella, where the zygospore is invested by the overgrowth of a dense mat of closely branching hyphae, and in Falck have shown that the sporophores of the BasidiomycetesGymnoascus, where a loose mat of similarly barren hyphae covers especially the large sporophores of such forms as Boletus, PolyporusThe recent observations and exceedingly ingenious experiments of in the tufts of asci as they develop. up by the active metabolism occurring when the fruit-body is ripe. By this means the temperature of the sporophore is raised and the contain quantities of reserve combustible material which are burnt difference between it and the surrounding air may be one of several degrees. As a result convection currents are produced in the air which are sufficient to catch the basidiospores in their fall and carry them, away from the regions of comparative atmospheric stillness near the ground, to the upper air where more powerful air-currents can bring about their wide distribution. results. In " In such examples as the above we may regard the hymenium (Solenia, Cyphella), zygospores, or asci as truly invested by later growth, but in the vast majority of cases the processes which result in the enclosure of the spores, asci, &c., in a "fructification" are much more involved, inasmuch as the latter is developed in the interior of hyphal tissues, which are by no means obviously homologous with a stroma. &c., hyphal ends which are the initials of ascogenous branches, are Thus in Penicillium, Eurolium, Erysiphe, invested by closely packed branches at an early stage of development, and the asci develop inside what has by that time become a complete investment. Whether a true sexual process precedes these processes or not does not affect the present question, the point being that the resulting spheroidal "fructification carp, perithecium) has a definite wall of its own not directly comparable with a stroma. In other cases (Hypomyces, Nectria) the (cleistoperithecia arise on an already mature stroma, while yet more numerous examples can be given (Poronia, Hypoxylon, Claviceps, &c.) where the perithecia originate below the surface of a stroma formed long before. Similarly with the various types of conidial or oidial fructifications," termed pycnidia, spermogonia, accidia, &c. the simplest of these cases-e.g. Fumago a single mycelial cell divides by septa in all three planes until a more or less solid clump Then a hollow appears in the centre owing to the more Japid extension of the outer parts, and into this hollow the cells Jining it put forth short sporogenous branches, from the tips of which the spores (stylospores, conidia, spermatia) are abstricted. In a similar way are developed the pycnidia of Cicinnobolus, Pleospora, Cucurbitaria, Leptosphaeria and others. In other cases (Diplodia, Accidium, &c.) conidial or oidial "fructifications "arise by a number of hyphae interweaving themselves into a knot, as if they were forming a sclerotium. The outer parts of the mass then differentiate as a wall or investment, and the interior becomes a hollow, into which hyphal ends grow and abstrict the spores. complicated are the processes in a large series of "fructifications,' Much more where the mycelium first develops a densely packed mass of hyphae, all alike, in which labyrinths of cavities subsequently form by separation of hyphae in the previously homogeneous mass, and the hymenium covers the walls of these cavities and passages as with a lining layer. Meanwhile differences in consistency appear in various strata, and a dense outer protective layer (peridium), soft gelatinous layers, and so on are formed, the whole eventually attaining great complexity-c.g. puff-balls, earth-stars and various Phalloideae. Spore-Distribution.-Ordinary conidia and similarly abstricted dry spores are so minute, light and numerous that their dispersal is ensured by any current of air or water, and we also know that rats and other burrowing animals often carry them on their fur; similarly with birds, insects, slugs, worms, &c., on claws, feathers, proboscides, &c., or merely adherent to the slimy body. In addition to these accidental modes of dispersal, however, there is a series of interesting adaptations on the part of the fungus itself. Passing over the locomotor activity of zoospores (Pythium, Peronospora, Saprolegnia) we often find spores held under tension in sporangia (Pilobolus) or in asci (Peziza) until ripe, and then forcibly shot out by the sudden rupture of the sporangial wall under the pressure of liquid behind-mechanism comparable to that of a pop-gun, if we suppose air replaced by watery sap. tense to the last moment by the elastic cell-wall, may be thus shot Even a single conidium, held forward by a spurt of liquid under pressure in the hypha abstricting it (e.g. Empusa), and similarly with basidiospores (Coprinus, Agaricus, &c.). A more complicated case is illustrated by Sphaerobolus, where the entire mass of spores, enclosed in its own peridium, is suddenly shot up into the air like a bomb from a mortar by the elastic retroversion of a peculiar layer which, up to the last moment, surrounded the bomb, and then suddenly splits above, turns inside out, and drives the former as a projectile from a gun. Gelatinous or mucilaginous degenerations of cell-walls, are frequently employed in the interests of spore dispersal. The mucilage surrounding the majority of the fungi proper fall into three main groups, Classification. It has been accepted for some time now that the Phycomycetes, Ascomycetes and Basidiomycetes, the Schizomycetes and Myxomycetes (Mycetozoa) being considered as independent groups not coming under the true fungi. been those of P. A. Saccardo (1882-1892), of Oskar Brefeld and The chief schemes of classification put forward in detail have Schroeter (1892). The scheme of Brefeld, which was based on Von Tavel (1892), of P. E. L. Van Tieghem (1893) and of J. pletely, asexual and that these two groups had been derived the view that the Ascomycetes and Basidiomycetes were comfrom one division (Zygomycetes) of the Phycomycetes, has been very widely accepted. The recent work of the last twelve years distinct sexuality, of either a normal or reduced type, and has has shown, however, that the two higher groups of fungi exhibit also rendered very doubtful the view of the origin of these two groups from the Phycomycetes. The real difficulty of classificaThere is very little doubt that the primitive fungi have been tion of the fungi lies in the polyphyletic nature of the group. in evolution but on several occasions, so that we have in the derived by degradation from the lower algae. It appears, however, that such a degradation has occurred not only once Phycomycetes not a series of naturally related forms, but groups various groups of the algae. It is also possible in the absence of satisfactory intermediate forms that the Ascomycetes and which have arisen perfectly independently of one another from Basidiomycetes have also been derived from the algae independently of the Phycomycetes, and perhaps of one another. complicated, so that in the present state of our knowledge it A natural classification on these lines would obviously be very will be best to retain the three main groups mentioned above, bearing in mind that the Phycomycetes especially are far from being a natural group. The following gives a tabular survey of the scheme adopted in the present article: A. PHYCOMYCETES. Alga-like fungi with unicellular, thallus and well-marked sexual organs. CLASS 1-Oomycetes. Mycelium usually well developed, but 2. Peronosporineae. Mycelium present; antheridia but no 3. Chytridineae. Mycelium poorly developed or absent; oogonia and antheridia (without antherozoids) known in some cases; zoospores common: Chytridiaceae. Any cylistaceae. CLASS II.-Zygomycetes. Mycelium well developed; sexual reproduction by zygospores; asexual reproduction by sporangia and conidia. In Cystopus Blili the oosphere contains numerous nuclei, and all 1. Mucorineae. Sexual reproduction as above, asexual by sporangia or conidia or both: Mucoraceae. MortierelTolaceae, Chaetocladiaccae, Piptocephalidaceae. Bord 2. Entomophthorineae. Sexual reproduction typical but head with sometimes inequality of the fusing gametes (game-ings (ana mungo tangia ?): Entomophthoraceae. B. HIGHER FUNGI. Fungi with segmental thallus; sexual reproduction sometimes with typical antheridia and oogonia (ascogonia) but usually much reduced. 10. CLASS I.--Ustilaginales. Forms with septate thallus, and reproduction by chlamydospores which on germination produce sporidia; sexuality doubtful. CLASS II.-Ascomycetes. Thallus septate: spores developed in special type of sporangium, the ascus, the number of spores being usually eight. Sexual reproduction sometimes typical, usually reduced. Exoascineae, Saccharomycetineae, Perisporinea, Discomycetes, Pyrenomycetes, Tuberineae, Laboulbeniincae. CLASS III.-Basidiales. Thallus septate. Conidia (basidiospores) borne in fours on a special conidiophore, the basidium. Sexual reproduction always much reduced. I. Uredineae. Life-history in some cases very complex and with well-marked sexual process and alternation of generations, in others much reduced; basidium (promycelium) derived usually from a thick-walled spore (teleutospore). Basidiomycetes. Life-history always very simple, no wellmarked alternation of generations; basidium borne directly on the mycelium. M (A) Protobasidiomycetes. Basidia septate. A. PHYCOMYCETES.-Most of the recent work of importance pak moju „mutanta olqinis neda 3d 29350ymo✪ ni bobalni blow yoqadɔ sztrgan mod? bine as poos staifioinu vlleurų From Strasburger's Lehrbuch der Botanik, by permission of Gustav Fischer, tyliauj FIG. 4-Fertilization of the Peronosporeae. After Wager.ood Peronospora parasitica. Young at tube (a) of the antheridium multinucleate oogonium (eg) which introduces the male gai and antheridium (an), do allɔ ɔd nucleus,ammeln dimisiqojong 2, Albugo candida. Oogonium 43. The same. Fertilized eggwith the central uninucleated cell (o) surrounded by the oosphere and the fertilizing periplasm (p). H number of undifferentiated gametes and has been termed a cocno- -phim” y no signɛnfos on seh's bat บ E E Peronosporaceae are a group of endophytic parasites-about 100 species of great importance as comprising the agents of "damping off" disease (Pythium), vine-mildew (Plasmopara), potato disease (Phytophthora), onion-mildew (Peronospora). Pythium is a semiaquatic form attacking seedlings which are too plentifully supplied with water; its hyphae penetrate the cell-walls and rapidly destroy the watery tissues of the living plant; then the fungus lives in the dead remains. When the free ends of the hyphae emerge again into the air they swell up into spherical bodies which may either fall off and behave as conidia, each putting out a germ-tube and infecting the host; or the germ-tube itself swells up into a zoosporangium which develops a number of zoospores. In the rotting tissues branches of the older mycelium similarly swell up and form antheridia and oogonia (fig. 4). The contents of the antheridium are not set free, but that organ penetrates the oogonium by means of a narrow outgrowth, the fertilizing tube, and a male nucleus then passes over into the single oosphere, which at first multinucleate becomes uninucleate before fertilization. Pythium is of interest as illustrating the dependence of zoospore-formation on conditions and the indeterminate nature of conidia. The other genera are more purely parasitic; the mycelium usually sends haustoria into the cells of the host and puts out branched, aerial conidiophores through the asyncAo lo anivde volisdie bas s 10′′ charger hissyä bas„muihinoɔ a stomata, the branches of which abstrict numerous conidia "FIG. 5. Phytophthora infestans. Fungus of Potato Disease. these either germinate directly or their contents break up into A, B, Section of Leaf of Potato G, H. J. Further development หารA zoospores (fig. 5). The development of the "conidia " as true conidial spores or as zoosporangia may occur in one and the same with sporangiophores of Phy of the sporangia. species (Cystopus candidus, Phytophthora infestans) as in Pythium tophthora infestans passing K, Germination of the zoospores described above; in other cases the direct conidial germination is through the stomata D. on formed in the sporangia. characteristic of genera-e.g. Peronospora; while others emit the under surface of the leaf. L, M, N, Fertilization of the zoospores-e.g. Plasmopara, &c. In Cystopus (Albugo) the "conidia E, Sporangia. to shore (stancia)ogonium and development of are abstricted in basipetal chain-like series from the ends of hyphae yoga-pno 143, idishni tabing the oospore in Peronospora. which come to the surface in tufts and break through the epidermis to a zoosporangium, but may form directly a germ tube which infects as white pustules. Each "conidium contains numerous nuclei the host. about wode injosul smoa pri banatan and is really a zoosporangium, as after dispersal it breaks up into a Saprolegniaceae are aquatic forms found growing usually on dead number of zoospores. The Peronosporaceae reproduce themselves insects lying in water but occasionally on living fish (e.g. the salmon sexually by means of antheridia and oogonia as described in Pythium, disease associated with Saprolegnia ferax). The chief genera are |