CLASSIFICATION, 65 
are produced in cells or cysts. These cysts are respectively 
known as sporangia, and ascz or thece. The true meaning and 
value of these divisions will be better comprehended when we 
have detailed the characters of the families composing these two 
divisions. 
First, then, the section Seorirera contains four families, in two 
of which a hymenium is present, and in two there is no proper 
hymenium. The term hymenium is employed to represent a 
more or less expanded surface, on which the fructification is 
produced, and is, in fact, the fruit-bearing surface. When no 
such surface is present, the fruit is borne on threads, proceeding 
direct from the root-like filaments of the mycelium, or an intcr- 
mediate kind of cushion or stroma. The two families in which 
an hymenium is present are called Hymenomycetes and Gastero- 
mycetes. Inthe former, the hymenium is exposed ; in the latter, it 
is at first enclosed. We must examine each of these separately. 
The common mushroom may be accepted, by way of illustra- 
tion, as a type of the family Hymenomycetes, in which the 
hymenium is exposed, and is, in fact, the most noticeable 
feature in the family from which its name is derived. The 
pileus or cap bears on its under surface radiating plates or gills, 
consisting of the hymenium, over which are thickly scattered 
the basidia, each surmounted by four spicules, and on each 
spicule a spore. When mature, these spores fall freely upon the 
ground beneath, imparting to it the general colour of the spores. 
But it must be observed that the hymenium takes the form of 
gill-plates in only one order of Hymenomycetes, namely, the 
Agaricini; and here, as in Cantharellus, the hymenium is some- 
times spread over prominent veins rather than gills. Still 
further divergence is manifest in the Polyporei, in which order 
the hymenium lines the inner surface of pores or tubes, which 
are normally on the under side of the pileus. Both these orders 
include an immense nuraber of species, the former more or less 
fleshy, the latter more or less tough and leathery. There are 
still other forms and orders in this family, as the Hydnei, in 
which the hymenium clothes the surface of prickles or spines, 
and the 4Auricularini, in which the bymenium is entirely or 
