Page:Popular Science Monthly Volume 7.djvu/147

Rh and moisture to burst into independent life. Myriads of the minute germs of moulds fasten upon various domestic articles, or dance about in the air-currents of our apartments, moving rapidly up and down and in every direction. The microscopist and the chemist have demonstrated the existence of these germs in greater or less quantity in the air of both country and town, out-of-doors as well as in-doors; and Prof. Tyndall by calling in the aid of optical analysis has, on this point, made assurance doubly sure. If we venture for a moment to imagine the overwhelming number of seeds which the different species of fungi must disseminate in the course of a single year—if we consider that each individual of the common puff-ball contains upward of ten million seeds, and these so small as to form a mere cloud when puffed into the air; and that a single filament of the mould which infests our bread and preserves will produce as many germs as an oak will acorns, so that a piece of decaying matter, not two inches square, will scatter upon the air, at the slightest breath of the summer breeze or the gentlest touch of an insect's wing, as many seeds, quick with life, as all the oaks of the country will produce acorns in a twelve-month—if we take these things into consideration, it is not too much to suppose that the seeds of fungi must be ubiquitous, and from their excessively minute size penetrate into every place, even into the stomachs and other parts of animals. Indeed, the difficulty seems to be to imagine a spot without them."

But, in looking up the relatives of the mushroom, we have been led too far away from the study of its structure. Recurring to the species with which we began our study, and a cluster of which, at different stages of growth, is represented in Fig. 3, let us inspect it once more, and make sure that we have a clear notion of all its parts. Observe the mycelium at the base, the stem, the unbroken volva in the young ones, the beginning of its rupture in a more advanced stage, and, finally, at the end of growth, the fully-developed cap, with its gills, and the ring left by the volva upon the stem. After this account of its structure, its specific description should be quite intelligible to anybody, and ought to suffice for the ready recognition of the living plant. It is as follows:

Cup fleshy, either smooth or scaly; its color is white, or tawny, or smoke-colored, or brown; gills free, when first formed pale, then changing to flesh-color, then to pink, next to purple, and, at length, tawny-black; stem white, full, firm, varying in shape, with a white persistent ring. Spores brown-black; volva quickly disappearing. In his recent work an "Fungi and their Uses," Coooke says of this plant that the color of the spores and gills, and the presence of the ring, are characters that never vary, but the color and scaliness of the cap, and other minor features, are variable; and, furthermore, he enjoins that it must not be sought in the woods. Its proper season is September and October.