SPORES OR SEEDS.

All funguses have not seeds,—at least, seeds apparent to us;[106] but if we reflect that these, even where visible, can do no more than present to our senses the visible tabernacle of that life which is still invisible, and which, not being material, must ever elude our search,[107] then it will not appear so difficult to conceive that the apparently seedless threads of some particular moulds should include, in their interior, vital germs of some sort, which, being homogeneous with, or of the same colour as, the parenchyma of the mould itself, are invisible—just as we know them to be for a season in puff-balls, in the veins of truffles, or in the Agyrium, the receptacle of which last breaks up, when ripe, into sporidia, which then and not till then become manifest. The seeds of funguses are called spores: in the great majority of cases, the microscope, which brings their shapes under observation (for to the naked eye they appear as dust), presents them to us as round, oval, oblong, or even angular corpuscules, and, more rarely still, echinulate or with a tail. They are as various in size as in shape, the first bearing no proportion whatever to the dimensions of the future plant. They vary, too, greatly in colour, being sometimes of a pure white, and continuing so throughout the whole of their seminal existence; at other times, the white acquires a yellow tinge on drying. Some are brown, some yellow, some pink, some purple, some purple-black, and some pass successively from pink to purple, and from purple to purple-black.[108] These seeds or spores are sometimes naked, but are much more commonly shut up in little pouches or receptacles, either of a regular or of an irregular shape; the first are called thecæ, the latter sporanges; thecæ (which are in shape similar to the cases of the same name that used to receive the ancient εἱλίγματα, or scrolls) are small, cylindrical bodies, in which the seeds lie one over the other, as in a rouleau; they are themselves let into a receptacle (or that part of the fungus the office of which is to receive and support the reproductive organs) in a regular and symmetrical manner, and at length occupy it completely. Not all are prolific; for some, pressing upon others, cause them to abort, leaving wherever this happens, sterile thecæ, or paraphyses, between those that are fertile. Sporanges are little globose or turbinated receptacles, frequently furnished with a pedicle, in which the seeds lie without order, as they are themselves inserted symmetrically, or without order, into the receptacle. Sometimes these seeds are packed in series of fours, as in the fimetary Agarics; in other genera, as in the Helvellæ and Morels, they are stored away in series of eights. The spores, so soon as they are ripe, either drop out of the sporiferous membrane (hymenium), or, as more frequently happens, are projected from it with an elastic jerk, or else, as is the case of Agarics of a deliquescent kind, return to the earth mixed up with the black liquid into which these ultimately resolve themselves. Sometimes the whole external surface of the fungus is dusted with seed; but much more frequently they are restricted to some particular part, and either lie on the upper side, as in the Pezizæ, or on that which is beneath, as in the mushroom. The spores generally lie on the outside of the fungus, but in the puff-ball, as every one knows, they are internal, and in such prodigious quantity as sometimes entirely to fill its cavity. It is a speculation from Germany, that spores are capable of altering their forms, and that according to the accidents of climate or soil, they assume this or that type, and give rise at different times to different kinds of funguses; on which it is sufficient to remark, that while there is not the least foundation for such an hypothesis, there is in fact much evidence against it; nature acts by immutable laws and has no changelings. To appeal to experience, when did mushrooms ever spawn toadstools? When was the Pietra funghaia ever seen to bring forth anything but its own Polyporus? or the fig, the poplar, or the hazel (when singed and watered to render them prolific) exhibit any but their own particular mushroom? Spores are endowed, like other seeds, with an extraordinary vitality, which may lie dormant in them for an indefinite period; but unlike most other seeds, they seem capable of resisting the prolonged heat of boiling water, infused in which, and poured upon the ground, they are still capable of producing each after its kind. The specific gravity of spores is greater than that of water, as may be seen by placing a mushroom over a glass which contains it, when, falling upon the surface, they presently subside to the bottom. These spores sometimes merely multiply without any further progress in development; sometimes they proceed a certain way only, and then, the conditions necessary for their further advance failing, this is arrested; sometimes, as in the Sistotrema, the plant appears twice under a perfect form, being for part of its existence a Hydnum, and during the other half a Boletus; but, generally speaking, these minute corpuscular bodies are destined to receive an infinite variety of protean and imperfect forms, and to pass stage by stage, and step by step, to the full attainment of that ultimate one which they assume when their growth has reached its natural limits. Sometimes the spore expands outright into a puff-ball; sometimes it shoots up straight into a club, as in some of the Clavarias; or lies like a bowl, resupinate on the ground and stalkless, as in the Peziza; in other cases, it assumes the more perfect but much less simple forms of Chanterelle, Boletus, Dædalea, Morel, or Mushroom.