1. Hymenomycetes. Hymenium, or spore-bearing surface, exposed and conspicuous, as seen in the common mushroom and all Agarics and Polyporei.
2. Gasteromycetes (gaster, a belly). Hymenium, or spore-bearing surface, enclosed in a more or less spherical case, called the peridium, which ruptures and expels the spores at maturity in the form of dust, as in the puff-balls.
3. Coniomycetes, from the Greek κωνἱς, meaning dust, the entire fungus having a dust-like appearance. Mildew forms a good example of this family.
4. Hyphomycetes, from the Greek ὑφα, meaning a thread. Thread-like fungi, the filaments being more conspicuous than the spore masses, of which group blue-mould affords an illustration.
The Hymenomycetes (1) is again subdivided into six orders, the discrimination being based on the diverse character of the spore surface. The first of these orders is the Agaricini, or gill-bearing fungi, to which our present chapter will be confined.
AGARICINI
In this order the hymenium, or spore-bearing surface, is inferior, i.e., on the under side of the pileus, and is spread over lamellæ or gills, which radiate from the stem of the fungus, and each of which may be separated into two filmy flat divisions.
On the opposite page is shown an Agaric in vertical section, disclosing a full side view of the gills. A highly magnified view of this gill-surface is indicated herewith, duly indexed, the sporophore being shown in the act of shedding its spores from their points of attachment to the four stigmata at the summit. These fruitful four-pointed sporophores or basidia are intermingled with the cystidia and sterile cells, the whole mass forming the surface of the hymenium. The dissemination of the Agaric is further considered in a later chapter on "Spore-prints."