The Vegetable World: Being a History of Plants, with Their Botanical Descriptions and Peculiar Properties

this at length separates, having a double membrane, the cell of the spore itself, and the covering or sporangium arising from the parent cell in Penicillium and Botrytis. In others, the threadlike cells form a spherical swelling at the extremity, from which project a number of such prolongations, each of which contains a spore, which forms a divided sporangium, as in Mucor and Penicillium.

“In others, as in Gasteromycetes, the ventricular Fungi, the thread-like cells, combine into pointed and non-pointed, variously-shaped sporocarps, in or upon which are spores of the development of which we know nothing. After the scattering of the spores the thread-like cells often remain as tender wool, as in the Trichiacea, or as delicate net-work (capillitum), as in Stemonitis Cribrarea, and the external capsule, generally composed of fine filamentous cells, 18 then dissolved or ruptured in a regular manner, as in Arcyria and Geastrum. “In the most highly developed species, the Hymenomycetes, or membraneous fungi, elongated pouch-like cells combine so closely side by side as to form a membrane or hymenium. Some of these enlarge and become sporangia, sending out from one to six points at their free extremity, on each of which a spore is developed. Thus the filiform cells either form round masses closed in all round,

called Sporocarps, with cavities in their interior, or they form definitely arranged columns in Merisma tubes in Polyporns, or lamellee in Dedalea and Agaricus, or clothed on the hymenium, as = the Hymeniumeetes. In A garicus the law of their development ‘8 pretty well understood. At definite points of the flocculent mycelium, small hollow heads (volve) are formed, at the bottom of the cavity of which there grows a corpuscle, pedunculated below, and enlarged into a sperical form at the top. In the lower part of this protuberance a circular horizontal cavity is formed, to the upper surface of which are attached the tubes, lamella, &c., which bear the hymenium. The bottom of the cavity is only formed by oe (indusium), separated from the pedicel on its further Ce ammepde or loosening itself at once from it and the upper part The *same time, it remains as a membraneous ring upon the stalk. ailaupper part, which supports the hymenium on its lower surface, tes subsequently, and appears as an umbrella-like expansion,

called the cap (pileus). The whole then breaks through the volvæ, which is very soon dissolved.”

A most formidable array of Fungales (Entophyta), which are parasites on man and living animals, can be produced. Still more numerous are those which infest fruits and vegetables. Smut in wheat, and other cereals, is produced by Uredo segetum; rust, red gum, red rag, is produced by Uredo rubigo; mildew is caused by Puccinia graminis enlarging the stomato of the plant. The potato disease, which caused such distress in many quarters of the globe a few years ago, is due to the attack Botrytis infestans; the spores of which, according to Berkeley, are supposed to enter the stomato of the leaves, causing disease in them, which afterwards extends to the tubers. The dry-rot in timber is another form of Fungi.

Fries, whose great work is the foundation of most of the modern arrangements of this immense family, separates them into four great divisions, which he calls Cohorts, and each of these he again divides into four sub-orders, distinguished by the following characteristics:—

IV. Concomycetes.—Spores naked; texture between filamentous and cellular; the thallus often imperceptible.

Musurooms (AGARICS).

The Mushrooms, then, are leafless, stemless, and rootless; they respire, thereby producing carbonic acid, like flowers and animals. e organs of vegetation and those of reproduction are quite distinet in the mushrooms. The first are composed of a sort of pack- _ filaments, which are ing, consisting of very thin intercrossing termed Mycelium. This mycelium is subterranean, not very apparent, and often doomed to immediate destruction. It is upon the mycelium that the apparatus of reproduction, so closely connected with the organs of vegetation, develops itself. i multiplicity of reproductive organs is recognised in certain species of which we shall have occasion to speak. The Erysiphe, which attack the Pea, and the Oidium Tuckheri, which attacks the Vine, is supposed to be a particular state of Erysephes, in which are noted

three distinct kinds of reproductive apparatus, which develop themselves in succession. Mushrooms exist under the most opposite conditions, and in every kind of locality. Some appear on the surface of the earth, as the cultivated Mushroom, the edible Boletus, the Morel, the Puff-ball, c. Some grow upon the trunks of trees, upon branches, and upon leaves; others, as the Truffle, are found buried in the earth . a considerable depth. Thousands of small species live as parasites upon other plants; the Oidiwm Tuckeri on the Vine, Botrytis infestans on the potato. Others attack animals. No one is ‘gnorant that the malady which destroyed so many silkworms in ’ € nurseries in the south of France was produced by a Fungi which developed itself in the interior of the living larve. Jn short, these microscopic and encroaching objects attack even the skin

and mucous membrane of man and animals, producing new and dangerous diseases. | f Mushrooms in many countries are a source of nourishment to the poor, who look for their return as a providential manna. But others conceal a mortal poison. Animals, such as worms, insects, and snails, feed upon them. It is not, therefore, without reason that beneficent nature has scattered them with so much profusion over the globe. It would be out of place to enter here upon a” elaborate consideration of Fungales in general. We must there-

Fig. 319.—Agaricus Campestris. e best know? fore limit our remarks to some types selected from th Ss from their in their scientific connections, or which interest u. utility, or from the dangerous maladies to which they give birth. The Cuttivatep MusHroom (Agaricus Campestris). This species; commonly raised for the table (Fig. 319), consists of footstalk oF stipe, ranging from an inch and a half to two inches and a half ™ height. When young, they resemble little snow-balls, usually a Button Mushrooms. Afterwards, when the stalk appea?®, the c@P

separates, and it becomes convex, or slightly conical, of a white or palish yellow, with rose-coloured gills, and a thick white fleshy cap. At a more advanced age the cap becomes concave, the colour grey, and the gills nearly black. A whitish membrane, like a species of veil, entirely covers the young gills, forming afterwards a sort of collar, more or less perfect, round the stalk. The field mushroom grows naturally upon the grass sward, where it is exposed to the sun. It is also obtained by culture in dark places where there is heat and moisture, as in caves and quarries. But it is necessary to guard against its being confounded with other species which are dangerous poisons; such are the Fly

mushroom, A. muscarius and A. virosus, and a species of Amanita, which somewhat resembles it, although it is distinguished by the footstalk being bulbous at the base, enveloped as by a purse (volva), and by the colour of its gills, which are not rose-coloured, as in A. campestris, but of a pale whitish colour. That we may have some exact idea of the structure of the mushrooms in general, let us consider the structure of the comestible species.

Let us detach one of the lamin or gills which occupy the lower face of the cap. We shall readily observe, by looking at it through a lens, that the two surfaces are of a velvety texture; but it is only through the microscope that their true organisation can be appreciated. Ifa transverse incision is made in the thinner parts of these lamin, which shall be perpendicular to their surface, we may assure ourselves ocularly that each plate presents three very distinct beds. A middle bed in connection with the substance

of the cap—a sort of layer, upon which the perpendicular elements of the two other beds rest. These elements consist of cells of three distinct kinds. (Fig. 319, 4). The first are shorter than the others, carrying nothing at their free extremity: the next are a little longer, terminating in four points, which each bear 4 small spherical sac at their summit (Fig. 319, 5). The third are much larger, but have neither point nor sac at their extremity.

We are assured by experiment that the little sacs, disposed in fours at the summit of the centre cells, are the reproductive organs which germinate and reproduce the mother plant. We call them “Pores;the cellules which support them are called dasides. The

result of the germination of these spores is that mycelium of which we have already spoken as being the reproductive apparatus of — the fungi, which are seen in the form of filaments at the foot of the mushroom in Fig. 319, 1. Fragments of this mycelium can multiply the plant much as a fragment of rhizome of a phanerogamous vegetable does. It is on this principle that gardeners sow the mycelium, which they term mushroom spawn, and which may be preserved for many years without losing its germinating properties. In cultivating mushrooms a hotbed is prepared, consisting of horse-dung, covered with a bed of earth of about three feet thick, in which the mycelium is planted, watering it from time to time in order to maintain a certain degree of humidity. In a short time small tubercles will appear, which at a later period become young mushrooms.

The Trurrix, belonging to the sub-order of Gasteromycetes, asserts its fungale characteristics by its membraneous sporang™ which are scattered on a serpentine vein-like hymenium, and enclosed in a concrete uterus. The sporidie are at first pulpy: There are two genera: Tuder, the common truffle, and Rhazo-pogan, the white truffle, the species being very generally dt over the temperate parts of the globe, growing ten or twelve inches beneath the surface of the soil. The R/izopogans have a sessile uterus, bursting irregularly, and marbled internally with anasto-mosing veins and sessile sporangia; the Tubers a closed uterus, marbled internally with veins. The sporangia are pedicillate and confined to the veins. The Common Truffle (7. cibarium) is of irregular form, nearly black in colour, and warty in appearance. It seems to affect the soil covered with woods, especially oak and beech woods, but there is no reason to suppose that there is anything approaching a parem bond between the truffle and the roots of trees among which it grows by preference. It develops itself as others of the mushroom ttt; planth in the matureddo, by spores, which make their appearance They are singularly small, something less than the three-hundred When the trufile is left after mlpart of an inch in diameter. to decompose in the sun, these spores produce whitish mage: analogous to the mycelium of the Agaracese. This mycelium, W buried in the soil, in due time reproduces the trufile.