Chapter 8

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

TABULAR ARRANGEMENT OF FAMILIES AND ORDERS.

DIVISION I. SPORIFERA. _Spores naked._

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

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