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

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

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

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

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

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

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

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

[K] "Gardener's Chronicle," March 26, 1864.

[L] Gray, G., "Notices of Insects that are Known to Form the Bases of Fungoid Parasites." London, 1858.

[M] Halsey, "Ann. Lyceum," New York, 1824, p. 125.

[N] Tulasne, "Selecta Fung. Carp." vol. iii. p. 17.

[O] "Berlin Entom. Zeitung," 1858, p. 178.

[P] "Smithsonian Contributions to Knowledge," v. p. 53.

[Q] "Wiegmann Archiv." 1835, ii. p. 354; "Ann. Nat. Hist." 1841, 405.

[R] Leidy, "Proc. Acad. Nat. Sci. Phil." 1851, p. 204.

[S] "Gardener's Chronicle," November 21, 1868.

[T] Corda, "Prachtflora," pl. ix.

[U] Leidy, "Fauna and Flora within Living Animals," in "Smithsonian Contributions to Knowledge."

[V] Murie, in "Monthly Microscopical Journal" (1872), vii. p. 149.

[W] See genus Mycetophagus, "Stephen's Manual Brit. Coleopt." p. 132.

[X] Sowerby's "Fungi," plates 289 and 387, fig. 6.

[Y] Schacht, "Fungous Threads in the Cells of Plants," in Pringsheim's "Jahrbuch." Berlin, 1863.

[Z] "Proceedings of the Agri. Hort. Soc. of India" (1871), p. 85.

[a] "Gardener's Chronicle" (1852), p. 643, with fig.

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

[c] De Bary, "Die gegenwartig herrschende Kartoffelkrankheit."

[d] De Bary, "Memoir on Peronospora," in "Annales des Sci. Nat."

[e] "Reports of H. M. Secretaries of Embassy and Legation on the Effects of the Vine Disease on Commerce, 1859;" "Reports of H. M. Secretaries of Embassy, &c., on Manufactures and Commerce, Vine Disease in Bavaria and Switzerland, 1859," pp. 54 and 62.

[f] C. H. Peek, "On the Black Knot," in "Quekett Microscopical Journal," vol. iii. p. 82.

[g] Cooke, "Microscopic Fungi," p. 177.

[h] "Grevillea," i. p. 90.

[i] "Gardener's Chronicle," 1873.

[j] "Gardener's Chronicle," 1852, p. 627, with fig.

[k] "Podisoma Macropus," Hook, "Journ. Bot." vol. iv. plate xii. fig. 6.

[l] Berkeley, in "Gardener's Chronicle," 1862, p. 308.

[m] "Gardener's Chronicle," August 22, 1874, p. 243.



XI.

HABITATS.

It commonly happens that one of the first inquiries which the student seeks to have answered, after an interest is excited in fungi, is—Where, and under what circumstances, are they to be found? The inexperienced, indeed, require some guide, or much labour will be expended and patience lost in seeking microscopic forms in just such places as they are least likely to inhabit. Nor is it wholly unprofitable or uninteresting for others, who do not claim to be students, to summarize the habitats of these organisms, and learn how much the circumstances of their immediate surrounding elements influence production. For reasons which will at once be recognized by the mycologist, the most satisfactory method of study will be somewhat that of the natural groups into which fungi are divided.

AGARICINI.—There is such a close affinity between all the genera of this group that it will be a manifest advantage to take together all those fleshy pileate fungi, the fruit of which is borne on folded plates or gills. It must be premised of this group that, for the majority, shade, a moderate amount of moisture, and steady warmth, but not too great heat, are required. A stroll through a wood in autumn will afford good evidence of the predilection of Agaricini, as well as some smaller groups, for such spots. A larger proportion will be found in woods, where shade is afforded, than on open heaths or pastures. These wood-loving forms will consist, again, of those which appear on the soil, and those which are found on rotten stumps and decaying trees. Many of those which grow on trees have a lateral stem, or scarcely any stem at all. It may be remarked, that some species which spring from the soil delight most in the shelter of particular trees. The Agarics of a beech wood will materially differ largely from those in an oak wood, and both will differ from those which spring up beneath coniferous trees.

It may be accepted as true of the largest proportion of terrestrial species, that if they do not spring directly from rotten leaves, and vegetable debris in the last stage of decay, the soil will be rich in vegetable humus. A few only occur on sandy spots. The genus Marasmius is much addicted to dead leaves; Russula, to open places in woods, springing immediately from the soil. Lactarius prefers trees, and when found in exposed situations, occurs mostly under the shadow of trees.[A] Cantharellus, again, is a woodland genus, many of the species loving to grow amongst grass or moss, and some as parasites on the latter. Coprinus is not a genus much addicted to woods, but is rather peculiar in its attachment to man—if such expression, or one even implying domesticity, might be employed—farmyards, gardens, dunghills, the base of old gateposts and railings, in cellars, on plaster walls, and even on old damp carpets. Hygrophorus loves "the open," whether pastures, lawns, heaths, commons, or up the slopes of mountains, nearly to the top of the highest found in Great Britain. Cortinarius seems to have a preference for woods, whilst Bolbitius affects dung, or a rich soil. Lentinus, Panus, Lenzites, and Schizophyllum all grow on wood. Coming to the subgenera of Agaricus, we find Pleurotus, Crepidotus, Pluteus, Collybia, Pholiota, Flammula, Hypholoma, and some species of Psathyra growing on wood, old stumps, or charcoal; Amanita, Tricholoma, and Hebeloma most attached to woods; Clitocybe and Mycena chiefly amongst leaves; Nolanea amongst grass; Omphalia and Galera chiefly in swampy places; Lepiota, Leptonia, Psalliota, Stropharia, Psilocybe, and Psathyrella mostly in open places and pastures; Deconica and Panaeolus mostly on dung; Entoloma and Clitopilus chiefly terrestrial, and the rest variable.

Of special habitats, we may allude to Nyctalis, of which the species are parasitic on dead fungi belonging to the genus Russula. One or two species of Agaricus, such as Agaricus tuberosus and Agaricus racemosus, P., grow on decaying Agarics, whilst Agaricus Loveianus flourishes on Agaricus nebularis even before it is thoroughly decayed. A few species grow on dead fir cones, others on old ferns, &c. Agaricus cepoestipes, Sow., probably of exotic origin, grows on old tan in hothouses. Agaricus caulicinalis, Bull, flourishes on old thatch, as well as twigs, &c. Agaricus juncicola, Fr., affects dead rushes in boggy places, whilst Agaricus affricatus, Fr., and Agaricus sphagnicola, B., are attached to bog moss in similar localities. Some few species are almost confined to the stems of herbaceous plants. Agaricus petasatus, Fr., Agaricus cucumis, P., and Paxillus panuoides, F., have a preference for sawdust. Agaricus carpophilus, Fr., and Agaricus balaninus, P., have a predilection for beech mast. Agaricus urticoecola, B. and Br., seems to confine itself to nettle roots. Coprinus radians, Fr., makes its appearance on plaster walls, Coprinus domesticus, Fr., on damp carpets. The only epizoic species, according to M. Fries, is Agaricus cerussatus v. nauseosus, which has been met with in Russia on the carcase of a wolf; this, however, might have been accidental. Persoon described Agaricus Neapolitanus, which was found growing on coffee-grounds at Naples; and more recently Viviani has described another species, Agaricus Coffeae, with rose-coloured spores, found on old fermenting coffee-grounds at Genoa.[B] Tratinnick figures a species named Agaricus Markii, which was found in wine casks in Austria. A Coprinus has, both in this country and on the Continent, been found, after a very short time, on the dressing of wounds, where there has been no neglect. A curious case of this kind, which at the time excited great interest, occurred some fifty years since at St. George's Hospital. Some species appear to confine themselves to particular trees, some to come up by preference on soil in garden pots. Certain species have a solitary, others a gregarious habit, and, of the latter, Agaricus grammopodius, Bull, Agaricus gambosus, Fr., Marasmius oreades, Fr., and some others grow in rings. Hence it will be seen that, within certain limits, there is considerable variation in the habitats of the Agaricini.

Boleti do not differ much from Agaricini in their localization. They seem to prefer woods or borders of woods to pastures, seldom being found in the latter. One species, B. parasiticus, Bull, grows on old specimens of Scleroderma, otherwise they are for the most part terrestrial.

Polypori also have no wide range of habitat, except in choice of trees on which to grow, for the majority of them are corticolous. The section Mesopus, which has a distinct central stem, has some species which prefer the ground. Polyporus tuberaster, P., in Italy springs from the Pietra funghaia,[C] and is cultivated for food as well as Polyporus avellanus, which is reared from charred blocks of cob-nut trees.

In other genera of the Polyporei similar habitats prevail. Merulius lacrymans, Fr., one form of dry rot, occurs in cellars, and too often on worked timber; whilst Merulius himantoides, Fr., is much more delicate, sometimes running over plants in conservatories.

HYDNEI.—There is nothing calling for special note on the habitats of these fungi. The stipitate species of Hydnum are some of them found in woods, others on heaths, one on fir-cones, while the rest have similar habitats to the species of Polyporus.

AURICULARINI.—The genera Hymenochoete, Stereum, and Corticium, with some species of Thelephora, run over corticated or decorticated wood; other species of Thelephora grow on the ground. The Pezizoid forms of Cyphella and Solenia, like species of Peziza, sometimes occur on bark, and of the former genus some on grasses and others on moss.

CLAVARIEI.—The interesting, often brightly-coloured, tufts of Clavaria are usually found amongst grass, growing directly from the ground. Only in rare instances do they occur on dead leaves or herbaceous stems. Calocera probably should be classed with the Tremellini, to which its structure seems more closely allied. The species are developed on wood. The species of Typhula and Pistillaria are small, growing chiefly on dead herbaceous plants. One or two are developed from a kind of Sclerotium, which is in fact a compact perennial mycelium.

TREMELLINI.—These curious gelatinous fungi are, with rare exceptions, developed on branches or naked wood; Tremella versicolor, B. and Br., one of the exceptions, being parasitic on a species of Corticium, and Tremella epigaea, B. and Br., spreading over the naked soil. This completes our rapid survey of the habitats of the Hymenomycetes. Very few of them are really destructive to vegetation, for the Agarics and Polypori found on growing trees are seldom to be seen on vigorous, but rather on dead branches or partly-decayed trunks.

The GASTEROMYCETES are far less numerous in species, and also in individuals, but their habitats are probably more variable. The Hypogaei, or subterranean species, are found either near the surface or buried in the soil, usually in the neighbourhood of trees.

PHALLOIDEI.—In most cases the species prefer woody places. They are mostly terrestrial, and have the faculty of making their presence known, even when not seen, by the fetid odour which many of them exhale. Some of them occur in sandy spots.

PODAXINEI.—These resemble in their localities the Trichogastres. Species of Podaxon affect the nests of Termites in tropical countries.[D] Others are found growing amongst grass.

TRICHOGASTRES.—These are chiefly terrestrial. The rare but curious Batarrea phalloides, P., has been found on sand-hills, and in hollow trees. Tulostoma mammosum, Fr., occurs on old stone walls, growing amongst moss. Geaster striatus, D. C., was at one time usually found on the sand of the Denes at Great Yarmouth. Although Lycoperdon giganteum, Batsch, occurs most frequently in pastures, or on hedge banks in fields, we have known it to occur annually for some consecutive years in a garden near London. The species of Scleroderma seem to prefer a sandy soil. Agloeocystis is rather an anomalous genus, occurring on the fruit heads of Cyperus, in India. Broomeia occurs at the Cape on rotten wood.

MYXOGASTRES.—Rotten wood is one of the most favoured of matrices on which these fungi develop themselves; some of them, however, are terrestrial. AEthalium will grow on spent tan and other substances. Species of Diderma flourish on mosses, jungermanniae, grass, dead leaves, ferns, &c. Angioridium sinuosum, Grev., will run over growing plants of different kinds, and Spumaria, in like manner, encrusts living grasses. Badhamia not only flourishes on dead wood, but one species is found on the fading leaves of coltsfoot which are still green. Craterium runs over almost any substance which lies in its way. Licea perreptans was found in a cucumber frame heated with spent hops. One or two Myxogastres have been found on lead, or even on iron which had been recently heated. Sowerby found one on cinders, in one of the galleries of St. Paul's Cathedral.

NIDULARIACEI grow on the ground, or on sticks, twigs, chips, and other vegetable substances, such as sawdust, dung, and rotten wood.

The CONIOMYCETES consist of two sections, which are based on their habitats. In one section the species are developed on dead or dying plants, in the other they are parasitic on living plants. The former includes the Sphaeronemei, which are variable in their proclivities, although mostly preferring dead herbaceous plants and the twigs of trees. The exceptions are in favour of Sphaeronema, some of which are developed upon decaying fungi. In the large genera, Septoria, Ascochyta, Phyllosticta, Asteroma, &c., the favourite habitat is fading and dying leaves of plants of all kinds. In the majority of cases these fungi are not autonomous, but are merely the stylosporous conditions of Sphaeria. They are mostly minute, and the stylospores are of the simplest kind. The Melanconiei have a preference for the twigs of trees, bursting through the bark, and expelling the spores in a gelatinous mass. A few of them are foliicolous, but the exceptions are comparatively rare, and are represented chiefly in Gloeosporium, species of which are found also on apples, peaches, nectarines, and other fruits. The Torulacei are superficial, having much of the external appearance of the black moulds, and like them are found on decaying vegetable substances, old stems of herbaceous plants, dead twigs, wood, stumps of trees, &c. The exceptions are in favour of such species as Torula sporendonema, which is the red mould of cheese, and also occurs on rats' dung, old glue, &c., and Sporendonema Muscae, which is only the conidia of a species of Achlya. One species of Bactridium is parasitic on the hymenium of Peziza, and Echinobotryum atrum, on the flocci of black moulds.

In the other section of Coniomycetes the species are parasitic upon, and destructive to, living plants, very seldom being found on really dead substances, and even in such rare cases undoubtedly developed during the life of the tissues. Mostly the ultimate stage of these parasites is exhibited in the ruptured cuticle, and the dispersion of the dust-like spores; but in Tilletia caries, Thecaphora hyalina, and Puccinia incarcerata, they remain enclosed within the fruit of the foster-plant. The different genera exhibit in some instances a liking for plants of certain orders on which to develop themselves. Peridermium attacks the Coniferae; Gymnosporangium and Podisoma the different species of Juniper; Melampsora chiefly the leaves of deciduous trees; Roestelia attaches itself to pomaceous trees, whilst Graphiola affects the Palmaceae, and Endophyllum the succulent leaves of houseleek. In AEcidium a few orders seem to be more liable to attack than others, as the Compositae, Ranunculaceae, Leguminosae, Labiatae, &c., whilst others, as the Graminaceae, Ericaceae, Malvaceae, Cruciferae, are exempt. There are, nevertheless, very few natural orders of phanerogamous plants in which some one or more species, belonging to this section of the Coniomycetes, may not be found; and the same foster-plant will occasionally nurture several forms. Recent investigations tend to confirm the distinct specific characters of the species found on different plants, and to prove that the parasite of one host will not vegetate upon another, however closely allied. This admission must not, however, be accepted as universally applicable, and therefore it should not be assumed, because a certain parasite is found developed on a special host, that it is distinct, unless distinctive characters, apart from habitat, can be detected. AEcidium compositarum and AEcidium ranunculacearum, for instance, are found on various composite and ranunculaceous plants, and as yet no sufficient evidence has been adduced to prove that the different forms are other than varieties of one of the two species. On the other hand, it is not improbable that two species of AEcidium are developed on the common berberry, as De Bary has indicated that two species of mildew, Puccinia graminis, and Puccinia straminis, are found on wheat.

HYPHOMYCETES.—The moulds are much more universal in their habitats, especially the Mucedines. The Isariacei have a predilection for animal substances, though not exclusively. Some species occur on dead insects, others on decaying fungi, and the rest on sticks, stems, and rotten wood. The Stilbacei have also similar habitats, except that the species of Illosporium seem to be confined to parasitism on lichens. The black moulds, Dematiei, are widely diffused, appearing on herbaceous stems, twigs, bark, and wood in most cases, but also on old linen, paper, millboard, dung, rotting fruit, &c., whilst forms of Cladosporium and Macrosporium are met with on almost every kind of vegetable substance in which the process of decay has commenced.

Mucedines, in some instances, have not been known to appear on more than one kind of matrix, but in the far greater number of cases they nourish on different substances. Aspergillus glaucus and Penicillium crustaceum are examples of these universal Mucedines. It would be far more difficult to mention substances on which these moulds are never developed than to indicate where they have been found. With the species of Peronospora it is different, for these are truly parasitic on living plants, and, as far as already known, the species are confined to certain special plants, and cannot be made to vegetate on any other. The species which causes the potato murrain, although liable to attack the tomato, and other species of Solanaceae, does not extend its ravages beyond that natural order, whilst Peronospora parasitica confines itself to cruciferous plants. One species is restricted to the Umbelliferae, another, or perhaps two, to the Leguminosae, another to Rubiaceae, two or three to Ranunculaceae, and two or three to Caryophyllaceae. All the experiments made by De Bary seem to prove that the species of Peronospora will only flourish on certain favoured plants, to the exclusion of all others. The non-parasitic moulds are scarcely exclusive. In Oidium some species are parasitic, but probably all the parasitic forms are states of Erysiphe, the non-parasitic alone being autonomous; of these one occurs on Porrigo lupinosa, others on putrefying oranges, pears, apples, plums, &c., and one on honeycomb. Acrospeira grows in the interior of sweet chestnuts, and we have seen a species growing within the hard testa of the seeds of Guilandina Bondue, from India, to which there was no external opening visible, and which was broken with considerable difficulty. Several Mucedines are developed on the dung of various animals, and seldom on anything else.

The Physomycetes consist of two orders, Antennariei and Mucorini, which differ from each other almost as much in habitat as in external appearance. The former, if represented by Antennaria, runs over the green and fading leaves of plants, forming a dense black stratum, like a congested layer of soot; or in Zasmidium, the common cellar fungus, runs over the walls, bottles, corks, and other substances, like a thick sooty felt. In the Mucorini, as in the Mucedines, there is usually less restriction to any special substance. Mucor mucedo occurs on bread, paste, preserves, and various substances; other species of Mucor seem to have a preference for dung, and some for decaying fungi, but rotting fruits are nearly sure to support one or other of the species. The two known species of the curious genus Pilobolus, as well as Hydrophora, are confined to dung. Sporodinia, Syzygites, &c., nourish on rotten Agarics, where they pass through their somewhat complicated existence.

The Ascomycetes contain an immense number of species, and in general terms we might say that they are found everywhere. The Tuberacei are subterraneous, with a preference for calcareous districts. The Perisporiacei are partly parasitical and partly not. The Erysiphei include those of the former which flourish at the expense of the green parts of roses, hops, maples, poplars, peas, and many other plants, both in Europe and in North America, whilst in warmer latitudes the genus Meliola appears to take their place.

The Elvellacei are fleshy fungi, of which the larger forms are terrestrial; Morchella, Gyromitra, and Helvella mostly growing in woods, Mitrula, Spathularia, and Leotia in swampy places, and Geoglossum amongst grass. The very large genus Peziza is divided into groups, of which Aleuriae are mostly terrestrial. This group includes nearly all the large-sized species, although a few belong to the next. Lachneae are partly terrestrial and partly epiphytal, the most minute species being found on twigs and leaves of dead plants. In Phialea the species are nearly entirely epiphytal, as is also the case in Helotium and allied genera. Some species of Peziza are developed from the curious masses of compact mycelium called Sclerotia. A few are rather eccentric in their habitats. P. viridaria, P. domestica, and P. hoemastigma, grow on damp walls; P. granulata and some others on dung. Peziza Bullii was found growing on a cistern. P. theleboloides appears in profusion on spent hops. P. episphaeria, P. clavariarum, P. vulgaris, Helotium pruinosum, and others are parasitic on old fungi. One or two species of Helotium grow on submerged sticks, so as to be almost aquatic, a circumstance of rare occurrence in fungi. Other Discomycetes are similar in their habitats to the Elvellacei. The group to which the old genus Ascobolus belongs is in a great measure confined to the dung of various animals, although there are two or three lignicolous species; and Ascophanus saccharinus was first found on old leather, Ascophanus testaceus on old sacking, &c. Ascomyces is, perhaps, the lowest form which ascomycetous fungi assume, and the species are parasitic on growing plants, distorting the leaves and fruit, constituting themselves pests to the cultivators of peach, pear, and plum trees.

The Sphaeriacei include a very large number of species which grow on rotten wood, bark, sticks, and twigs; another group is developed on dead herbaceous stems; yet another is confined to dead or dying leaves. One genus, Torrubia, grows chiefly on insects; Hypomyces is parasitic on dead fungi; Claviceps is developed from ergot, Poronia on dung, Polystigma on living leaves, as well as some species of Stigmatea and Dothidea. Of the genus Sphaeria, a considerable number are found on dung, now included by some authors under Sordaria and Sporormia, genera founded, as we think, on insufficient characters. A limited number of species are parasitic on lichens, and one species only is known to be aquatic.



We have thus rapidly, briefly, and casually indicated the habitats to which the majority of the larger groups of fungi are attached, regarding them from a systematic point of view. There is, however, another aspect from which we might approach the subject, taking the host or matrix, or in fact the habitat, as the basis, and endeavouring to ascertain what species of fungi are to be found in such positions. This has partly been done by M. Westendorp;[E] but every year adds considerably to the number of species, and what might have been moderately accurate twelve years since can scarcely be so now. To carry this out fully a special work would be necessary, so that we shall be content to indicate or suggest, by means of a few illustrations, the forms of fungi, often widely distinct in structure and character, to be found in the same locality.

The stems of herbaceous plants are favourite habitats for minute fungi. The old stems of the common nettle, for example, perform the office of host to about thirty species.[F] Of these about nine are Pezizae, and there are as many sphaeriaceous fungi, whilst three species of Dendryphium, besides other moulds, select this plant. Some of these have not hitherto been detected growing on any other stems, such as Sphaeria urticae and Lophiostoma sex-nucleatum, to which we might add Peziza fusarioides and Dendryphium griseum. These do not, however, include the whole of the fungi found on the nettle, since others are parasitic upon its living green parts. Of these may be named AEcidium urticae and Peronospora urticae, as well as two species described by Desmazieres as Fusisporium urticae and Septoria urticae. Hence it will be seen how large a number of fungi may attach themselves to one herbaceous plant, sometimes whilst living, but most extensively when dead. This is by no means a solitary instance, but a type of what takes place in many others. If, on the other hand, we select such a tree as the common lime, we shall find that the leaves, twigs, branches, and wood bear, according to M. Westendorp,[G] no less than seventy-four species of fungi, and of these eleven occur on the leaves. The spruce fir, according to the same authority, nourishes one hundred and fourteen species, and the oak not less than two hundred.

It is curious to note how fungi are parasitic upon each other in some instances, as in that of Hypomyces, characteristic of the genus, in which sphaeriaceous fungi make hosts of dead Lactarii, &c. We have already alluded to Nyctalis, growing on decayed Russulae, to Boletus parasiticus, flourishing on old Scleroderma, and to Agaricus Loveianus, on the pileus of Agaricus nebularis. To these we may add Torrubia ophioglossoides and T. capitata, which flourish on decaying Elaphomyces, Stilbum tomentosum on old Trichia, Peziza Clavariarum on dead Clavaria, and many others, the mere enumeration of which would scarcely prove interesting. A very curious little parasite was found by Messrs. Berkeley and Broome, and named by them Hypocrea inclusa, which makes itself a home in the interior of truffles. Mucors and moulds flourish on dead and decaying Agarics, and other fleshy forms, in great luxuriance and profusion. Mucor ramosus is common on Boletus luridus, and Syzygites megalocarpus on Agarics, as well as Acrostalagmus cinnabarinus. A very curious little parasite, Echinobotryum atrum, occurs like minute nodules on the flocci of black moulds. Bactridium Helvellae usurps the fructifying disc of species of Peziza. A small Sphinctrina is found both in Britain and the United States on old Polypori. In Sphaeria nigerrima, Nectria episphaeria, and two or three others, we have examples of one sphaeriaceous fungus growing upon another.

Mr. Phillips has recently indicated the species of fungi found by him on charcoal beds in Shropshire,[H] but, useful as it is, that only refers to one locality. A complete list of all the fungi which have been found growing on charcoal beds, burnt soil, or charred wood, would be rather extensive. The fungi found in hothouses and stoves are also numerous, and often of considerable interest from the fact that they have many of them never been found elsewhere. Those found in Britain,[I] for instance, are excluded from the British Flora as doubtful, because, growing upon or with exotic plants, they are deemed to be of exotic origin, yet in very few cases are they known to be inhabitants of any foreign country. Some species found in such localities are not confined to them, as Agaricus coepestipes, Agaricus cristatus, AEthalium vaporarium, &c. It is somewhat singular that certain species have a predilection for growing in proximity with other plants with which they do not appear to have any more intimate relation. Truffles, for instance, in association with oaks, Peziza lanuginosa under cedar-trees, Hydnangium carneum about the roots of Eucalypti, and numerous species of Agaricini, which are only found under trees of a particular kind. As might be anticipated, there is no more fertile habitat for fungi than the dung of animals, and yet the kinds found in such locations belong to but a few groups. Amongst the Discomycetes, a limited number of the genus Peziza are fimicolous, but the allied genus Ascobolus, and its own immediate allies, include amongst its species a large majority that are found on dung. If we take the number of species at sixty-four, there are only seven or eight which do not occur on dung, whilst fifty-six are fimicolous. The species of Sphaeria which are found on the same substances are also closely allied, and some Continental authors have grouped them under the two proposed genera Sporormia and Sordaria, whilst Fuckel[J] proposes a distinct group of Sphaeriacei, under the name of Fimicoli, in which he includes as genera Coprolepa, Hypocopra, Delitschia, Sporormia, Pleophragmia, Malinvernia, Sordaria, and Cercophora. The two species of Pilobolus, and some of Mucor, are also found on dung, Isaria felina on that of cats, Stilbum fimetarium and a few other moulds, and amongst Agarics some species of Coprinus. Animal substances are not, as a rule, prolific in the production of fungi. Ascobolus saccharinus and one or two others have been found upon old leather. Onygena of two or three species occurs on old horn, hoofs, &c. Cheese, milk, &c., afford a few forms, but the largest number infest dead insects, either under the mouldy form of Isaria or the more perfect condition of Torrubia, and occasionally under other forms.

Robin[K] has recorded that three species of Brachinus, of the order Coleoptera, have been found infected, whilst living, with a minute yellow fungus which he calls Laboulbenia Rougeti, and the same species has been noted on other beetles. Torrubia Melolonthae[L] has been described by Tulasne as occurring on the maybug or cockchafer, which is allied to, if not identical with, Cordyceps Ravenelii, B. and C., and also that described and figured by M. Fougeroux de Bondaroy.[M] Torrubia curculionum, Tul., occurs on several species of beetles, and seems to be by no means uncommon in Brazil and Central America. Torrubia coespitosa, Tul., which may be the same as Cordyceps Sinclairi, B.,[N] is found on the larvae of Orthoptera in New Zealand, Torrubia Miquelii on the larvae of Cicada in Brazil, and Torrubia sobolifera on the pupae of Cicada in the West Indies. A romantic account is given of this in an extract cited by Dr. Watson in his communication to the Royal Society.[O] "The vegetable fly is found in the island Dominica, and (excepting that it has no wings) resembles the drone, both in size and colour, more than any other English insect. In the month of May it buries itself in the earth and begins to vegetate. By the latter end of July, the tree is arrived at its full growth, and resembles a coral branch, and is about three inches high, and bears several little pods, which, dropping off, become worms, and from thence flies, like the English caterpillar." Torrubia Taylori, which grows from the caterpillar of a large moth in Australia, is one of the finest examples of the genus. Torrubia Robertsii, from New Zealand, has long been known as attacking the larva of Hepialus virescens. There are several other species on larvae of different insects, on spiders, ants, wasps, &c., and one or two on mature Lepidoptera, but the latter seem to be rare.

That fungi should make their appearance and flourish in localities and conditions generally considered inimical to vegetable life is no less strange than true. We have already alluded to the occurrence of some species on spent tan, and some others have been found in locations as strange. We have seen a yellow mould resembling Sporotrichum in the heart of a ball of opium, also a white mould appears on the same substance, and more than one species is troublesome in the opium factories of India. A mould made its appearance some years since in a copper solution employed for electrotyping in the Survey Department of the United States,[P] decomposing the salt, and precipitating the copper. Other organisms have appeared from time to time in various inorganic solutions, some of which were considered destructive to vegetable life, and it is not improbable that some of these organisms were low conditions of mould. It may well occasion some surprise that fungi should be found growing within cavities wholly excluded from the external air, as in the hollow of filberts, and the harder shelled nuts of Guilandina, in the cavities of the fruit of tomato, or in the interior of an egg. It is scarcely less extraordinary that Hypocrea inclusa should flourish in the interior of a kind of truffle.

From the above it will be concluded that the habitats of fungi are exceedingly variable, that they may be regarded as almost universal wherever decaying vegetable matter is found, and that under some conditions animal substances, especially of vegetable feeders, such as insects, furnish a pabulum for their development.

A very curious and interesting inquiry presents itself to our minds, which is intimately related to this subject of the habitats of fungi. It shapes itself into a sort of "puzzle for the curious," but at the same time one not unprofitable to think about. How is the occurrence of new and before unknown forms to be accounted for in a case like the following?[Q]

It was our fortune—good fortune as far as this investigation was concerned—to have a portion of wall in our dwelling persistently damp for some months. It was close to a cistern which had become leaky. The wall was papered with "marbled" paper, and varnished. At first there was for some time nothing worthy of observation, except a damp wall—decidedly damp, discoloured, but not by any means mouldy. At length, and rather suddenly, patches of mould, sometimes two or three inches in diameter, made their appearance. These were at first of a snowy whiteness, cottony and dense, just like large tufts of cotton wool, of considerable expansion, but of miniature elevation. They projected from the paper scarcely a quarter of an inch. In the course of a few weeks the colour of the tufts became less pure, tinged with an ochraceous hue, and resembling wool rather than cotton, less beautiful to the naked eye, or under a lens, and more entangled. Soon after this darker patches made their appearance, smaller, dark olive, and mixed with, or close to, the woolly tufts; and ultimately similar spots of a dendritic character either succeeded the olive patches, or were independently formed. Finally, little black balls, like small pin heads, or grains of gunpowder, were found scattered about the damp spots. All this mouldy forest was more than six months under constant observation, and during that period was held sacred from the disturbing influences of the housemaid's broom and duster.

Curiosity prompted us from the first to submit the mouldy denizens of the wall to the microscope, and this curiosity was increased week by week, on finding that none of the forms found vegetating on nearly two square yards of damp wall could be recognized as agreeing specifically with any described moulds with which we were acquainted. Here was a problem to be solved under the most favourable conditions, a forest of mould indoors, within a few yards of the fireside, growing quite naturally, and all strangers. Whence could these new forms proceed?

The cottony tufts of white mould, which were the first to appear, had an abundant mycelium, but the erect threads which sprang from this were for a long time sterile, and closely interlaced. At length fertile threads were developed in tufts, mixed with the sterile threads. These fruit-bearers were shorter and stouter, more sparingly branched, but beset throughout nearly their whole length with short patent, alternate branchlets. These latter were broadest towards the apex, so as to be almost clavate, and the extremity was beset with two or three short spicules. Each spicule was normally surmounted by an obovate spore. The presence of fertile threads imparted the ochraceous tint above alluded to. This tint was slight, and perhaps would not have been noticed, but from the close proximity of the snow-white tufts of barren threads. The fertile flocci were decumbent, probably from the weight of the spores, and the tufts were a little elevated above the surface of the matrix. This mould belonged clearly to the Mucedines, but it hardly accorded well with any known genus, although most intimately related to Rhinotrichum, in which it was placed as Rhinotrichum lanosum.[R]

The white mould having become established for a week or two, small blackish spots made their appearance on the paper, sometimes amongst thin patches of the mould, and sometimes outside them. These spots, at first cloudy and indefinite, varied in size, but were usually less than a quarter of an inch in diameter. The varnish of the paper was afterwards pushed off in little translucent flakes or scales, an erect olivaceous mould appeared, and the patches extended to nearly an inch in diameter, maintaining an almost universal circular form. This new mould sometimes possessed a dirty reddish tint, but was commonly dark olive. There could be no mistake about the genus to which this mould belonged; it had all the essential characters of Penicillium. Erect jointed threads, branched in the upper portion in a fasciculate manner, and bearing long beaded threads of spores, which formed a tassel-like head, at the apex of each fertile thread. Although at first reminded of Penicillium olivaceum, of Corda, by the colour of this species, it was found to differ in the spores being oblong instead of globose, and the ramifications of the flocci were different. Unable again to find a described species of Penicillium with which this new mould would agree, it was described under the name of Penicillium chartarum.[S]

Almost simultaneously, or but shortly after the perfection of the spores of Penicillium, other and very similar patches appeared, distinguished by the naked eye more particularly by their dendritic form. This peculiarity seemed to result from the dwarfed habit of the third fungus, since the varnish, though cracked and raised, was not cast off, but remained in small angular fragments, giving to the spots their dendritic appearance, the dark spores of the fungus protruding through the fissures. This same mould was also found in many cases growing in the same spots amongst Penicillium chartarum, but whether from the same mycelium could not be determined.

The distinguishing features of this fungus consist in an extensive mycelium of delicate threads, from which arise numerous erect branches, bearing at the apex dark brown opaque spores. Sometimes the branches were again shortly branched, but in the majority of instances were single. The septate spores had from two to four divisions, many of them divided again by cross septa in the longitudinal direction of the spore, so as to impart a muriform appearance. As far as the structure and appearance of the spores are concerned, they resembled those of Sporidesmium polymorphum, under which name specimens were at first published,[T] but this determination was not satisfactory. The mycelium and erect threads are much too highly developed for a good species of Sporidesmium, although the name of Sporidesmium alternaria was afterwards adopted. In fresh specimens of this fungus, when seen in situ by a half-inch objective, the spores appear to be moniliform, but if so, all attempts to see them so connected, when separated from the matrix, failed. On one occasion, a very immature condition was examined, containing simple beaded, hyaline bodies, attached to each other by a short neck. The same appearance of beaded spores, when seen in situ, was recognized by a mycological friend, to whom specimens were submitted for confirmation.[U]

The last production which made its appearance on our wall-paper burst through the varnish as little black spheres, like grains of gunpowder. At first the varnish was elevated by pressure from beneath, then the film was broken, and the little blackish spheres appeared. These were, in the majority of cases, gregarious, but occasionally a few of the spheres appeared singly, or only two or three together. As the whole surface of the damp paper was covered by these different fungi, it was scarcely possible to regard any of them as isolated, or to declare that one was not connected with the mycelium of the others. The little spheres, when the paper was torn from the wall, were also growing from the under surface, flattened considerably by the pressure. The spherical bodies, or perithecia, were seated on a plentiful hyaline mycelium. The walls of the perithecia, rather more carbonaceous than membranaceous, are reticulated, reminding one of the conceptacles of Erysiphe, to which the perithecia bear considerable resemblance. The ostiolum is so obscure that we doubt its existence, and hence the closer affinity of the plant to the Perisporiacei than to the Sphaeriacei. The interior of the perithecium is occupied by a gelatinous nucleus, consisting of elongated cylindrical asci, each enclosing eight globose hyaline sporidia, with slender branched paraphyses. A new genus has been proposed for this and another similar form, and the present species bears the name of Orbicula cyclospora.[V]

The most singular circumstance connected with this narrative is the presence together of four distinctly different species of fungi, all of them previously unknown and undescribed, and no trace amongst them of the presence of any one of the very common species, which would be supposed to develop themselves under such circumstances. It is not at all unusual for Sporocybe alternata, B., to appear in broad black patches on damp papered walls, but in this instance not a trace was to be found. What were the peculiar conditions present in this instance which led to the manifestation of four new forms, and none of the old ones? We confess that we are unable to account satisfactorily for the mystery, but, at the same time, feel equally unwilling to invent hypotheses in order to conceal our own ignorance.

[A] These predilections must be accepted as general, to which there will be exceptions.

[B] Viviani, "I Funghi d'Italia."

[C] Badham's "Esculent Funguses," Ed. i. pp. 42, 116.

[D] An excellent white Agaric occurs on ant nests in the Neilgherries, and a curious species is found in a similar position in Ceylon.

[E] Westendorp, "Les Cryptogams apres leurs stations naturelles."

[F] Cooke, "On Nettle Stems and their Micro-Fungi," in "Journ. Quekett Micro. Club," iii. p. 69.

[G] Westendorp, "Les Cryptogams apres leurs stations naturelles," 1865.

[H] "Gardener's Chronicle," 1874.

[I] W. G. Smith, in "Journ. Botany," March, 1873; Berkeley, in "Grevillea," vol. i. p. 88.

[J] Fuckel, "Symbolae Mycologicae," p. 240.

[K] Robin, "Veget. Parasites," p. 622, t. viii. f. 1, 2.

[L] Tulasne, "Selecta Fung. Carp." iii. p. 12.

[M] "Hist. de l'Acad. des Sciences," 1769. Paris, 1772.

[N] Berkeley, "Crypt. Bot." p. 73; Hooker, "New Zealand Flora," ii. 338.

[O] "Philosophical Transactions," liii. (1763), p. 271.

[P] Berkeley's "Outlines," p. 30.

[Q] "Popular Science Review," vol. x. (1871), p. 25.

[R] Specimens of this mould were distributed in Cooke's "Fungi Britannici Exsiccati," No. 356, under the name of Clinotrichum lanosum.

[S] Cooke's "Handbook of British Fungi," p. 602.

[T] Cooke's "Fungi Britannici Exsiccati," No. 329, under the name of Sporidesmium polymorphum var. chartarum.

[U] This reminds one of Preuss's Alternaria, figured in Sturm's "Flora;" it has been suggested that the mould, as seen when examined under a power of 320 diam., is very much like a Macrosporium. Again arises the question of the strings of spores attached end to end.

[V] "Handbook of British Fungi," vol. ii. p. 926, No. 2,788.



XII.

CULTIVATION.

The cultivation of fungi in this country for esculent purposes is confined to a single species, and yet there is no reason why, by a series of well-conducted experiments, means should not be devised for the cultivation of others, for instance, Marasmius orcades, and the morel. Efforts have been made on the Continent for the cultivation of truffles, but the success has hitherto been somewhat doubtful. For the growth of the common mushroom, very little trouble and care is required, and moderate success is certain. A friend of ours some years since was fortunate enough to have one or two specimens of the large puff-ball, Lycoperdon giganteum, growing in his garden. Knowing its value, and being particularly fond of it when fried for breakfast, he was anxious to secure its permanence. The spot on which the specimens appeared was marked off and guarded, so that it was never desecrated by the spade, and the soil remained consequently undisturbed. Year after year, so long as he resided on the premises, he counted upon and gathered several specimens of the puff-ball, the mycelium continuing to produce them year after year. All parings, fragments, &c., not utilized of the specimens eaten were cast on this spot to rot, so that some of the elements might be returned to the soil. This was not true cultivation perhaps, as the fungus had first established itself, but it was preservation, and had its reward. It must be admitted, however, that the size and number of specimens diminished gradually, probably from exhaustion of the soil. This fungus, though strong, is much approved by many palates, and its cultivation might be attempted. Burying a ripe specimen in similar soil, and watering ground with the spores, has been tried without success.[A]

As to the methods adopted for cultivation of the common mushroom, it is unnecessary to detail them here, as there are several special treatises devoted to the subject, in which the particulars are more fully given than the limits of this chapter will permit.[B] Recently, M. Chevreul exhibited at the French Academy some splendid mushrooms, said to have been produced by the following method: he first develops the mushrooms by sowing spores on a pane of glass, covered with wet sand; then he selects the most vigorous individuals from among them, and sows, or plants their mycelium in a cellar in a damp soil, consisting of gardener's mould, covered with a layer of sand and gravel two inches thick, and another layer of rubbish from demolitions, about an inch deep. The bed is watered with a diluted solution of nitrate of potash, and in about six days the mushrooms grow to an enormous size.[C] The cultivation of mushrooms for the market, even in this country, is so profitable, that curious revelations sometimes crop up, as at a recent trial at the Sheriffs' Court for compensation by the Metropolitan Railway Company for premises and business of a nurseryman at Kensington. The Railway had taken possession of a mushroom-ground, and the claim for compensation was L716. It was stated in evidence that the profits on mushrooms amounted to 100 or 150 per cent. One witness said if L50 were expended, in twelve months, or perhaps in six months, the sum realized would be L200.

Immense quantities of mushrooms are produced in Paris, as is well known, in caves, and interesting accounts have been written of visits to these subterranean mushroom-vaults of the gay city. In one of these caves, at Montrouge, the proprietor gathers largely every day, occasionally sending more than 400 pounds weight per day to market, the average being about 300 pounds. There are six or seven miles' run of mushroom-beds in this cave, and the owner is only one of a large class who devote themselves to the culture of mushrooms. Large quantities of preserved mushrooms are exported, one house sending to England not less than 14,000 boxes in a year. Another cave near Frepillon was in full force in 1867, sending as many as 3,000 pounds of mushrooms to the Parisian markets daily. In 1867, M. Renaudot had over twenty-one miles of mushroom-beds in one great cave at Mery, and in 1869 there were sixteen miles of beds in a cave at Frepillon. The temperature of these caves is so equal that the cultivation of the mushroom is possible at all seasons of the year, but the best crops are gathered in the winter.

Mr. Robinson gives an excellent account, not only of the subterranean, but also of the open-air culture of mushrooms about Paris. The open-air culture is never pursued in Paris during the summer, and rarely so in this country.[D] What might be termed the domestic cultivation of mushrooms is easy, that is, the growth by inexperienced persons, for family consumption, of a bed of mushrooms in cellars, wood-houses, old tubs, boxes, or other unconsidered places. Even in towns and cities it is not impracticable, as horse-dung can always be obtained from mews and stables. Certainly fungi are never so harmless, or seldom so delicious, as when collected from the bed, and cooked at once, before the slightest chemical change or deterioration could possibly take place.

Mr. Cuthill's advice may be repeated here. He says:—"I must not forget to remind the cottager that it would be a shilling or two a week saved to him during the winter, if he had a good little bed of mushrooms, even for his own family, to say nothing about a shilling or two that he might gain by selling to his neighbours. I can assure him mushrooms grow faster than pigs, and the mushrooms do not eat anything; they only want a little attention. Addressing myself to the working classes, I advise them, in the first place, to employ their children or others collecting horse-droppings along the highway, and if mixed with a little road-sand, so much the better. They must be deposited in a heap during summer, and trodden firmly. They will heat a little, but the harder they are pressed the less they will heat. Over-heating must be guarded against; if the watch or trial stick which is inserted into them gets too hot for the hand to bear, the heat is too great, and will destroy the spawn. In that case artificial spawn must be used when the bed is made up, but this expedient is to be avoided on account of the expense. The easiest way for a cottager to save his own spawn would be to do so when he destroys his old bed; he will find all round the edges or driest parts of the dung one mass of superior spawn; let him keep this carefully in a very dry place, and when he makes up his next bed it can then be mixed with his summer droppings, and will insure a continuance and excellent crop. These little collections of horse-droppings and road-sand, if kept dry in shed, hole, or corner, under cover, will in a short time generate plenty of spawn, and will be ready to be spread on the surface of the bed in early autumn, say by the middle of September or sooner. The droppings during the winter must be put into a heap, and allowed to heat gently, say up to eighty or ninety degrees; then they must be turned over twice daily to let off the heat and steam; if this is neglected the natural spawn of the droppings is destroyed. The cottager should provide himself with a few barrowfuls of strawy dung to form the foundation of his bed, so that the depth, when all is finished, be not less than a foot. Let the temperature be up to milk heat. He will then, when quite sure that the bed will not overheat, put on his summer droppings. By this time these will be one mass of natural spawn, having a grey mouldy and thready appearance, and a smell like that of mushrooms. Let all be pressed very hard; then let mould, unsifted, be put on, to the thickness of four inches, and trodden down hard with the feet and watered all over; and the back of a spade may now be used to make it still harder, as well as to plaster the surface all over."[E] Mushrooms are cultivated very extensively by Mr. Ingram, at Belvoir, without artificial spawn. There is a great riding-house there, in which the litter is ground down by the horses' feet into very small shreds. These are placed in a heap and turned over once or twice during the season, when a large quantity of excellent spawn is developed which, placed in asparagus beds or laid under thin turf, produces admirable mushrooms, in the latter case as clean as in our best pastures.[F]

Other species will sometimes be seen growing on mushroom-beds besides the genuine mushroom, the spawn in such cases being probably introduced with the materials employed. We have seen a pretty crisped variety of Agaricus dealbatus growing in profusion in such a place, and devoured it accordingly. Sometimes the mushrooms will, when in an unhealthy condition, be subject to the ravages of parasitic species of mould, or perhaps of Hypomyces. Xylaria vaporaria has, in more than one instance, usurped the place of mushrooms. Mr. Berkeley has received abundant specimens in the Sclerotioid state, which he succeeded in developing in sand under a bell glass. Of course under such conditions there is much loss. The little fairy-ring champignon is an excellent and useful species, and it is a great pity that some effort should not be made to procure it by cultivation. In Italy a kind of Polyporus, unknown in this country, is obtained by watering the Pietra funghaia, or fungus stone, a sort of tufa impregnated with mycelium. The Polypori, it is said, take seven days to come to perfection, and may be obtained from the foster mass, if properly moistened, six times a year. There are specimens which were fully developed in Mr. Lee's nursery at Kensington many years since. Another fungus is obtained from the pollard head of the black poplar. Dr. Badham says that it is usual to remove these heads at the latter end of autumn, as soon as the vintage is over, and their marriage with the vine is annulled; hundreds of such heads are then cut and transported to different parts; they are abundantly watered during the first month, and in a short time produce that truly delicious fungus Agaricus caudicinus, which, during the autumn of the year, makes the greatest show in the Italian market-places. These pollard blocks continue to bear for from twelve to fourteen years.

Another fungus, which Dr. Badham himself reared (Polyporus avellanus), is procured by singeing, over a handful of straw, a block of the cob-nut tree, which is then watered and put by. In about a month the fungi make their appearance, and are quite white, of from two to three inches in diameter, and excellent to eat, while their profusion is sometimes so great as entirely to hide the wood from whence they spring.[G] It has been said that Boletus edulis may be propagated by watering the ground with a watery infusion of the plants, but we have no knowledge of this method having been pursued with success.

The culture of truffles has been partially attempted, on the principle that, in some occult manner, certain trees produced truffles beneath their shade. It is true that truffles are found under trees of special kinds, for Mr. Broome remarks that some trees appear more favourable to the production of truffles than others. Oak and hornbeam are specially mentioned; but, besides these, chestnut, birch, box, and hazel are alluded to. He generally found Tuber oestivum under beech-trees, but also under hazel, Tuber macrosporum under oaks, and Tuber brumale under oaks and abele. The men who collect truffles for Covent Garden Market obtain them chiefly under beech, and in mixed plantations of fir and beech.[H]

Some notion may be obtained of the extent to which the trade of truffles is carried in France, when we learn that in the market of Apt alone about 3,500 pounds of truffles are exposed for sale every week during the height of the season, and the quantity sold during the winter reaches upwards of 60,000 pounds, whilst the Department of Vaucluse yields annually upwards of 60,000 pounds. It may be interesting here to state that the value of truffles is so great in Italy that precautions are taken against truffle poachers, much in the same way as against game poachers in England. They train their dogs so skilfully that, while they stand on the outside of the truffle grounds, the dogs go in and dig for the fungi. Though there are multitudes of species, they bring out those only which are of market value. Some dogs, however, are employed by botanists, which will hunt for any especial species that may be shown to them. The great difficulty is to prevent them devouring the truffles, of which they are very fond. The best dogs, indeed, are true retrievers.

The Count de Borch and M. de Bornholz give the chief accounts of the efforts that have been made towards the cultivation of these fungi. They state that a compost is prepared of pure mould and vegetable soil mixed with dry leaves and sawdust, in which, when properly moistened, mature truffles are placed in winter, either whole or in fragments, and that after the lapse of some time small truffles are found in the compost.[I] The most successful plan consists in sowing acorns over a considerable extent of land of a calcareous nature; and when the young oaks have attained the age of ten or twelve years, truffles are found in the intervals between the trees. This process was carried on in the neighbourhood of Loudun, where truffle-beds had formerly existed, but where they had long ceased to be productive—a fact indicating the aptitude of the soil for the purpose. In this case no attempt was made to produce truffles by placing ripe specimens in the earth, but they sprang up themselves from spores probably contained in the soil. The young trees were left rather wide apart, and were cut, for the first time, about the twelfth year after sowing, and afterwards at intervals of from seven to nine years. Truffles were thus obtained for a period of from twenty-five to thirty years, after which the plantations ceased to be productive, owing, it was said, to the ground being too much shaded by the branches of the young trees. It is the opinion of the Messrs. Tulasne that the regular cultivation of the truffle in gardens can never be so successful as this so-called indirect culture at Loudun, but they think that a satisfactory result might be obtained in suitable soils by planting fragments of mature truffles in wooded localities, taking care that the other conditions of the spots selected should be analogous to those of the regular truffle-grounds, and they recommend a judicious thinning of the trees and clearing the surface from brushwood, etc., which prevents at once the beneficial effects of rain and of the direct sun's rays. A truffle collector stated to Mr. Broome that whenever a plantation of beech, or beech and fir, is made on the chalk districts of Salisbury Plain, after the lapse of a few years truffles are produced, and that these plantations continue productive for a period of from ten to fifteen years, after which they cease to be so.

M. Gasparin reported to the jurors of the Paris Exhibition of 1855, concerning the operations of M. Rousseau, of Carpentras, on the production of oak truffles in France. The acorns of evergreen and of common oaks were sown about five yards apart. In the fourth year of the plantation three truffles were found; at the date of the report the trees were nine years old, and over a yard in height. Sows were employed to search for the truffles. Although these plantations consist both of the evergreen and common oak, truffles cannot be gathered at the base of the latter species, it so happening that it arrives later at a state of production. The common oak, however, produces truffles like the evergreen oak, this report states, for a great number of the natural truffle-grounds at Vaucluse are planted with common oaks. It is remarked that the truffles produced from these are larger but less regular than those of the evergreen oak, which are smaller, but nearly always spherical. The truffles are gathered at two periods of the year; in May only white truffles are to be found, which never blacken and have no odour; they are dried and sold for seasoning. The black truffles (Tuber melanosporum) commence forming in June, enlarging towards the frosty season; then they become hard, and acquire all their perfume. They are dug a month before and a month after Christmas. It is also asserted that truffles are produced about the vine, or at any rate that the association of the vine is favourable to the production of truffles, because truffle-plots near vines are very productive. The observation of this decided M. Rousseau to plant a row of vines between the oaks. The result of this experiment altogether does not appear to have been by any means flattering, for at the end of eight years only little more than fifteen pounds were obtained from a hectare of land, which, if valued at 45 francs, would leave very little profit. M. Rousseau also called attention to a meadow manured (sic) with parings of truffles, which was said to have given prodigious results.

The cultivation of minute fungi for scientific purposes has been incidentally alluded to and illustrated in foregoing chapters, and consequently will not require such full and particular details here. Somewhat intermediately, we might allude to the species of Sclerotium, which are usually compact, externally blackish, rounded or amorphous bodies, consisting of a cellular mass of the nature of a concentrated mycelium. Placed in favourable conditions, these forms of Sclerotium will develop the peculiar species of fungus belonging to them, but in certain cases the production is more rapid and easy than in others. In this country, Mr. F. Currey has been the most successful in the cultivation of Sclerotia. The method adopted is to keep them in a moist, somewhat warm, but equable atmosphere, and with patience await the results. The well-known ergot of rye, wheat, and other grasses may be so cultivated, and Mr. Currey has developed the ergot of the common reed by keeping the stem immersed in water. The final conditions are small clavate bodies of the order Sphaeriacei, belonging to the genus Claviceps. The Sclerotium of the Eleocharis has been found in this country, but we are not aware that the Claviceps developed from it has been met with or induced by cultivation. One method recommended for this sort of experiment is to fill a garden-pot half full of crocks, over which to place sphagnum broken up until the pot is nearly full, on this to place the Sclerotia, and cover with silver sand; if the pot is kept standing in a pan of water in a warm room, it is stated that production will ensue. Ergot of the grasses will not always develop under these conditions, but perseverance may ultimately ensure success.

A species of Sclerotium on the gills of dead Agarics originates Agaricus tuberosus, another Agaricus cirrhatus,[J] but this should be kept in situ when cultivated artificially, and induced to develop whilst still attached to the rotten Agarics. Peziza tuberosa, in like manner, is developed from Sclerotia, usually found buried in the ground in company with the roots of Anemone nemorosa. At one time it was supposed that some relationship existed between the roots of the anemone and the Sclerotia. From another Sclerotium, found in the stems of bulrushes, Mr. Currey has developed a species of Peziza, which has been named P. Curreyana.[K] This Peziza has been found growing naturally from the Sclerotia imbedded in the tissue of common rushes. De Bary has recorded the development of Peziza Fuckeliana from a Sclerotium of which the conidia take the form of a species of Polyactis. Peziza ciborioides is developed from a Sclerotium found amongst dead leaves; and recently we have received from the United States an allied Peziza which originated from the Sclerotia found on the petals of Magnolia, and which has been named Peziza gracilipes, Cooke, from its very slender, thread-like stem. Other species of Peziza are also known to be developed from similar bases, and these Fuckel has associated together under a proposed new genus with the name of Sclerotinia. Two or three species of Typhula, in like manner, spring from forms of Sclerotium, long known as Sclerotium complanatum and Sclerotium scutellatum. Other forms of Sclerotium are known, from one of which, found in a mushroom-bed, Mr. Currey developed Xylaria vaporaria, B., by placing it on damp sand covered with a bell glass.[L] Others, again, are only known in the sclerotioid state, such as the Sclerotium stipitatum found in the nests of white ants in South India.[M] From what is already known, however, we feel justified in the conclusion that the so-called species of Sclerotium are a sort of compact mycelium, from which, under favourable conditions, perfect fungi may be developed. Mr. Berkeley succeeded in raising from the minute Sclerotium of onions, which looks like grains of coarse gunpowder, a species of Mucor. This was accomplished by placing a thin slice of the Sclerotium in a drop of water under a glass slide, surrounded by a pellicle of air, and luted to prevent evaporation and external influences.[N]

As to the cultivation of moulds and Mucors, one great difficulty has to be encountered in the presence or introduction of foreign spores to the matrix employed for their development. Bearing this in mind, extensive cultivations may be made, but the conditions must influence the decision upon the results. Rice paste has been used with advantage for sowing the spores of moulds, afterwards keeping them covered from external influences. In cultivation on rice paste of rare species, the experimenter is often perplexed by the more rapid growth of the common species of Mucor and Penicillium. Mr. Berkeley succeeded in developing up to a certain point the fungus of the Madura Foot, but though perfect sporangia were produced, the further development was masked by the outgrowth of other species. In like manner, orange juice, cut surfaces of fruits, slices of potato tubers, etc., have been employed. Fresh, horse-dung, placed under a bell glass and kept in a humid atmosphere, will soon be covered with Mucor, and in like manner the growth of common moulds upon decayed fruit may be watched; but this can hardly be termed cultivation unless the spores of some individual species are sown. Different solutions have been proposed for the growth of such conditions as the cells which induce fermentation, to which yeast plants belong. A fly attacked by Empusa muscae, if immersed in water, will develop one of the Saprolegniae.

The Uredines and other epiphyllous Coniomycetes will readily germinate by placing the leaf which bears them on damp sand, or keeping them in a humid atmosphere. Messrs. Tulasne and De Bary have, in their numerous memoirs, detailed the methods adopted by them for different species, both for germination of the pseudospores and for impregnating healthy foster plants. The germination of the pseudospores of the species of Podisoma may easily be induced, and secondary fruits obtained. The germination of the spores of Tilletia is more difficult to accomplish, but this may be achieved. Mr. Berkeley found no difficulty, and had the stem impregnated as well as the germen. On the other hand, the pseudospores of Cystopus, when sown in water on a slip of glass, will soon produce the curious little zoospores in the manner already described.

The sporidia of the Discomycetes, and some of the Sphaeriacei, germinate readily in a drop of water on a slip of glass, although not proceeding further than the protrusion of germ-tubes. A form of slide has been devised for growing purposes, in which the large covering glass is held in position, and one end of the slip being kept immersed in a vessel of water, capillary attraction keeps up the supply for an indefinite period, so that there is no fear of a check from the evaporation of the fluid. Even when saccharine solutions are employed this method may be adopted.

The special cultivation of the Peronosporei occupied the attention of Professor De Bary for a long time, and his experiences are detailed in his memoir on that group,[O] but which are too long for quotation here, except his observations on the development of the threads of Peronospora infestans on the cut surface of the tubers of diseased potatoes. When a diseased potato is cut and sheltered from dessication, the surface of the slice covers itself with the mycelium and conidiiferous branches of Peronospora, and it can easily be proved that these organs originate from the intercellulary tubes of the brown tissue. The mycelium that is developed upon these slices is ordinarily very vigorous; it often constitutes a cottony mass of a thickness of many millimetres, and it gives out conidiiferous branches, often partitioned, and larger and more branched than those observed on the leaves. The appearance of these fertile branches ordinarily takes place at the end of from twenty-four to forty-eight hours; sometimes, nevertheless, one must wait for many days. These phenomena are observed in all the diseased tubercles without exception, so long as they have not succumbed to putrefaction, which arrests the development of the parasite and kills it.

Young plants of the species liable to attack may be inoculated with the conidia of the species of Peronospora usually developed on that particular host, in the same manner that young cruciferous plants, watered with an infusion of the spores of Cystopus candidus, will soon exhibit evidence of attack from the white rust.

It is to the cultivation and close investigation of the growth and metamorphoses of the minute fungi that we must look for the most important additions which have yet to be made to our knowledge of the life-history of these most complex and interesting organisms.

[A] Experiments were made at Belvoir, by Mr. Ingram, in the cultivation of several species of Agaricini, but without success, and a similar fate attended some spawn of a very superior kind from the Swan River, which was submitted to the late Mr. J. Henderson. No result was obtained at Chiswick, either from the cultivation of truffles or from the inoculation of grass-plots with excellent spawn. Mr. Disney's experiments at the Hyde, near Ingatestone, were made with dried truffles, and were not likely to succeed. The Viscomte Noe succeeded in obtaining abundant truffles, in an enclosed portion of a wood fenced from wild boars, by watering the ground with an infusion of fresh specimens; but it is possible that as this took place in a truffle country, there might have been a crop without any manipulation. Similar trials, and it is said successfully, have been made with Boletus edulis. Specimens of prepared truffle-spawn were sent many years since to the "Gardener's Chronicle," but they proved useless, if indeed they really contained any reliable spawn.

[B] Robinson, "On Mushroom Culture," London, 1870. Cuthill, "On the Cultivation of the Mushroom," 1861. Abercrombie, "The Garden Mushroom; its Culture, &c." 1802.

[C] This has, however, not been confirmed, and is considered (how justly we cannot say) a "canard."

[D] This method is pursued with great success by Mr. Ingram, at Belvoir, and by Mr. Gilbert, at Burleigh.

[E] Cuthill, "Treatise on the Cultivation of the Mushroom," p. 9.

[F] Mr. Berkeley lately recommended, at one of the meetings of the Horticultural Society at South Kensington, that the railway arches should be utilized for the cultivation of mushrooms.

[G] Badham, "Esculent Funguses," 1st ed. p. 43.

[H] Broome, "On Truffle Culture," in "Journ. Hort. Soc." i. p. 15 (1866).

[I] No faith, however, is, in general, placed on these treatises, as they were merely conjectural.

[J] Dr. Bull has been very successful in developing the Sclerotium of Agaricus cirrhatus.

[K] Currey, "On Development of Sclerotium roseum," in "Journ. Linn. Soc." vol. i. p. 148.

[L] Currey, in "Linn. Trans." xxiv. pl. 25, figs. 17, 26.

[M] Berkeley, "On Two Tuberiform Veg. Productions from Travancore," in "Trans. Linn. Soc." vol. xxiii. p. 91.

[N] Berkeley, "On a Peculiar Form of Mildew in Onions," "Journ. Hort. Soc." vol. iii p. 91.

[O] De Bary, "Ann. des Sci. Nat." 4th series, vol. xx.



XIII.

GEOGRAPHICAL DISTRIBUTION.

Unfortunately no complete or satisfactory account can be given of the geographical distribution of fungi. The younger Fries,[A] with all the facilities at his disposal which the lengthened experience and large collections of his father afforded, could only give a very imperfect outline, and now we can add very little to what he has given. The cause of this difficulty lies in the fact that the Mycologic Flora of so large a portion of the world remains unexplored, not only in remote regions, but even in civilized countries where the Phanerogamic Flora is well known. Europe, England, Scotland, and Wales are as well explored as any other country, but Ireland is comparatively unknown, no complete collection having ever been made, or any at least published. Scandinavia has also been well examined, and the northern portions of France, with Belgium, some parts of Germany and Austria, in Russia the neighbourhood of St. Petersburg, and parts of Italy and Switzerland. Turkey in Europe, nearly all Russia, Spain, and Portugal are almost unknown. As to North America, considerable advances have been made since Schweinitz by Messrs. Curtis and Ravenel, but their collections in Carolina cannot be supposed to represent the whole of the United States; the small collections made in Texas, Mexico, etc., only serve to show the richness of the country, not yet half exhausted. It is to be hoped that the young race of botanists in the United States will apply themselves to the task of investigating the Mycologic Flora of this rich and fertile region. In Central America very small and incomplete collections have as yet been made, and the same may be said of South America and Canada. Of the whole extent of the New World, only the Carolina States of North America can really be said to be satisfactorily known. Asia is still less known, the whole of our vast Indian Empire being represented by the collections made by Dr. Hooker in the Sikkim Himalayas, and a few isolated specimens from other parts. Ceylon has recently been removed from the category of the unknown by the publication of its Mycologic Flora.[B] All that is known of Java is supplied by the researches of Junghuhn; whilst all the rest is completely unknown, including China, Japan, Siam, the Malayan Peninsula, Burmah, and the whole of the countries in the north and west of India. A little is known of the Philippines, and the Indian Archipelago, but this knowledge is too fragmentary to be of much service. In Africa no part has been properly explored, with the exception of Algeria, although something is known of the Cape of Good Hope and Natal. The Australasian Islands are better represented in the Floras published of those regions. Cuba and the West Indies generally are moderately well known from the collections of Mr. C. Wright, which have been recorded in the journal of the Linnaean Society, and in the same journal Mr. Berkeley has described many Australian species.

It will be seen from the above summary how unsatisfactory it must be to give anything like a general view of the geographical distribution of fungi, or to estimate at all approximately the number of species on the globe. Any attempt, therefore, must be made and accepted subject to the limitations we have expressed.

The conditions which determine the distribution of fungi are not precisely those which determine the distribution of the higher plants. In the case of the parasitic species they may be said to follow the distribution of their foster-plants, as in the case of the rust, smut, and mildew of the cultivated cereals, which have followed those grains wherever they have been distributed, and the potato disease, which is said to have been known in the native region of the potato plant before it made its appearance in Europe. We might also allude to Puccinia malvacearum, Ca., which was first made known as a South American species; it then travelled to Australia, and at length to Europe, reaching England the next year after it was recorded on the Continent. In the same manner, so far as we have the means of knowing, Puccinia Apii, Ca., was known on the Continent of Europe for some time before it was detected on the celery plants in this country. Experience seems to warrant the conclusion that if a parasite affects a certain plant within a definite area, it will extend in time beyond that area to other countries where the foster-plant is found. This view accounts in some part for the discovery of species in this country, year after year, which had not been recorded before; some allowance being made for the fact that an increased number of observers and collectors may cause the search to be more complete, yet it must be conceded that the migration of Continental species must to some extent be going on, or how can it be accounted for that such large and attractive fungi as Sparassis crispa, Helvellas gigas, and Morchella crassipes had never been recorded till recently, or amongst parasitic species such as the two species of Puccinia above named? In the same manner it is undoubtedly true that species which at one time were common gradually become somewhat rare, and at length nearly extinct. We have observed this to apply to the larger species as well as to the microscopic in definite localities. For instance, Craterellus cornucopioides some ten years ago appeared in one wood, at a certain spot, by hundreds, whereas during the past three or four years we have failed to find a single specimen. As many years since, and in two places, where the goat's-beard was abundant, as it is now, we found nearly half the flowering heads infested with Ustilago receptaculorum, but for the past two or three years, although we have sought it industriously, not a single specimen could be found. It is certain that plants found by Dickson, Bolton, and Sowerby, have not been detected since, whilst it is not improbable that species common with us may be very rare fifty years hence. In this manner it would really appear that fungi are much more liable than flowering plants to shift their localities, or increase and diminish in number.

The fleshy fungi, Agaricini and Boleti especially, are largely dependent upon the character of woods and forests. When the undergrowth of a wood is cleared away, as it often is every few years, it is easy to observe a considerable difference in the fungi. Species seem to change places, common ones amongst a dense undergrowth are rare or disappear with the copsewood, and others not observed before take their place. Some species, too, are peculiar to certain woods, such as beech woods and fir woods, and their distribution will consequently depend very much on the presence or absence of such woods. Epiphytal species, such as Agaricus ulmarius, Agaricus mucidus, and a host of others, depend on circumstances which do not influence the distribution of flowering plants. It may be assumed that such species as flourish in pastures and open places are subject to fewer adverse conditions than those which affect woods and forests.

Any one who has observed any locality with reference to its Mycologic Flora over a period of years will have been struck with the difference in number and variety caused by what may be termed a "favourable season," that is, plenty of moisture in August with warm weather afterwards. Although we know but little of the conditions of germination in Agarics, it is but reasonable to suppose that a succession of dry seasons will considerably influence the flora of any locality. Heat and humidity, therefore, are intimately concerned in the mycologic vegetation of a country. Fries has noted in his essay the features to which we have alluded. "The fact," he says, "must not be lost sight of that some species of fungi which have formerly been common in certain localities may become, within our lifetime, more and more scarce, and even altogether cease to grow there. The cause of this, doubtless, is the occurrence of some change in the physical constitution of a locality, such as that resulting from the destruction of a forest, or from the drainage, by ditches and cuttings, of more or less extensive swamps, or from the cultivation of the soil—all of them circumstances which cause the destruction of the primitive fungaceous vegetation and the production of a new one. If we compare the fungal flora of America with that of European countries, we observe that the former equals, in its richness and the variety of its forms, that of the phanerogamous flora; it is probable, however, that, in the lapse of more or fewer years, this richness will decrease, in consequence of the extension of cultivation—as is illustrated, indeed, in what has already taken place in the more thickly peopled districts, as, for example, in the vicinity of New York."