GASTEROMYCETES.

Hymenium more or less permanently concealed, consisting in most cases of closely packed cells of which the fertile ones (the basidia) bear naked spores on distinct spicules, exposed only by the rupture or decay of the investing coat or peridium. Berkeley's Outlines.

This family has been subjected to numerous revisions since the days of Fries, when its structural characteristics were not so well understood as at present.

Montagne and Berkeley are credited with being the first to show the true structure of the hymenium in the puff-balls, as well as to demonstrate the presence of basidia. This important discovery led to the correlating of the Gasteromycetes with the Hymenomycetes under the common title Basidiomycetes, both having the spores borne upon basidia. The two families still remained distinct, however, not only because of the dissimilarity in their external features but principally on account of the difference in the disposition and character of the hymenium.

In the Hymenomycetes the hymenium is exposed to the light from the first, and the spores drop from the basidia as they mature; whereas in the Gasteromycetes the hymenial pulp, or gleba, consisting of the spores with the supporting basidia and the hyphæ, is enclosed within the substance of the fungus, and the spores are exposed only on the decay of the investing coat.