In the _Gasteromycetes_ the spores are produced in many cases, probably in most, if not all, at the tips of sporophores; but the hymenium, instead of being exposed, as in the _Hymenomycetes_, is enclosed within an outer peridium or sac, which is sometimes double. The majority of these spores are globose in form, some of them extremely minute, variously coloured, often dark, nearly black, and either externally smooth or echinulate. In some genera, as _Enerthenema_, _Badhamia_, &c., a definite number of spores are at first enclosed in delicate cysts, but these are exceptions to the general rule: this also is the case in at least one species of _Hymenogaster_. As the spores approach maturity, it may be observed in such genera as _Stemonitis_, _Arcyria_, _Diachea_, _Dictydium_, _Cribraria_, _Trichia_, &c., that they are accompanied by a sort of reticulated skeleton of threads, which remain permanent, and served in earlier stages, doubtless, as supports for the spores; being, in fact, the skeleton of the hymenium. It has been suggested that the spiral character of the threads in _Trichia_ calls to mind the elaters in the _Hepaticæ_, and like them may, by elasticity, aid in the dispersion of the spores. There is nothing known, however, which will warrant this view. When the spores are mature, the peridium ruptures either by an external orifice, as in _Geaster_, _Lycoperdon_, &c., or by an irregular opening, and the light, minute, delicate, spores are disseminated by the slightest breath of air. Specimens of _Geaster_ and _Bovista_ are easily separated from the spot on which they grew; when rolling from place to place, the spores are deposited over a large surface. In the _Phalloidei_ the spores are involved in a slimy mucus which would prevent their diffusion in such a manner. This gelatinous substance has nevertheless a peculiar attraction for insects, and it is not altogether romantic to believe that in sucking up the fetid slime, they also imbibe the spores and transfer them from place to place, so that even amongst fungi insects aid in the dissemination of species. Whether or not the _Myxogastres_ should be included here is matter of opinion, since the mode in which the spores are developed is but little known; analogy with the _Trichogastres_ in other points alone leading to the conclusion that they may produce basidiospores. The slender, elastic stems which support the peridia in many species are undoubted aids to the dissemination of the spores.[B] [Illustration: FIG. 48.--_Diachea elegans._]