36 
THE LARGER FUNGI 
Further a microscopic feature often of importance is the occurrence of special 
colls, known as cystidia, met with in certain species and usually found projecting 
from the surface of the gills between the basidia. The colour, shape, and size of 
the mature spores are, within limits, constant for each species. 
In the case of the pore-bearing fungi, the description outlined above will require 
some modifications, but its general principles still apply. Here tubes take the 
place of gills and are lined by the hymenium bearing the spores. We have 
therefore to consider the size and depth of the tubes, to note whether some extend 
deeper than others or not, to see whether they form a layer readily separable 
from the rest of the hymenophore or seem merely imbedded in this, to ascertain 
whether there are layers or strata of tubes (representing periods of growth) or 
only one layer, to note the colour and so on. The size, shape, and colour of the 
orifices of the pores must be ascertained and the number of such orifices in one 
millimetre of surface. Some of the pore-bearing fungi are fleshy and readily 
decay, such as the Buleti. A large number, however, are leathery, corky, or 
woody. Some have a cap and stem, but many are laterally attached, forming 
brackets, or may even be spread out over the surface (as in Poria). It must 
be pointed out that in some genera we see transitional conditions between gills 
and pores. Thus cross-partitions or anastomoses may convert gills into chambers 
and in other species these pass into elongated pores. In some genera, such as 
Merulius, the hymenial surface is represented by wrinkles enclosing spaces which 
represent the pores. 
In the Hydnaceae, spines, granules, knobs, or their representatives bear the 
hymenium. In the Tlielephoraeeae it is borne on a more or less smooth surface, 
in the Cyphellaceae in a cup-shaped receptacle and in the Clavariaceae on clubs 
or coral-shaped sporophores. The principles of description already outlined can 
be readily modified to meet the requirements of these various groups. 
The Gasteromycetales include the various puff-balls as well as the remarkable 
phalloids, some of which latter are called “stink horns.” Many of the fungi 
in the Auriculariales, Tremellales, Tulasnellales, and Calocerales are gelatinous 
or horny-gelatinous. The points of importance in the descriptions of these, as 
well as of the few genera of the larger fleshy Ascomycetes that will be con- 
sidered, can be readily gathered from the systematic part of this work dealing 
with them and need not be considered here. 
