Gemis C opr inns. 125 
The flesh of the pileus is very thin in all the species of 
Coprmus , and in many kinds is reduced to such a delicate 
membrane that Fries considered it to be entirely wanting, 
and in his latest work 1 divides the genus into two tribes, 
founded respectively on the supposed presence or absence 
of a cuticle or layer of flesh covering the gills. The species 
included in the first tribe — Pelliculosi— have a pellicle, and 
when the pileus becomes upturned and split at maturity, the 
splitting takes place through the pellicle, between the gills. 
In the second tribe — Veliformes — the pellicle is supposed by 
Fries to be absent, but this view will be shown to be a mis- 
taken one ; the radiating grooves which appear as the pileus 
expands are due to the splitting of the gills themselves, 
commencing at the back and continuing towards the free 
edge of each gill, owing to the trama offering least resistance, 
and consequently giving way first during the expansion of 
the pileus. The hyphae of the trama do not deliquesce 
during the splitting of the gill, but are torn apart. As 
already stated, a very thin but continuous layer of flesh is 
present, covering the surface of the pileus in the members of 
the tribe Veliformes ; the portion nearest the gills consisting 
of slender septate interwoven hyphae, the free ends of which 
give origin to a layer of piriform or subglobose cells, closely 
packed side by side like the palisade-tissue of a leaf, and 
forming the free surface of the pileus. During expansion the 
large cells forming the surface of the pileus are torn apart, 
but persist in a dry condition, and produce the scurfy or 
furfuraceous appearance presented by the pileus of all the 
species of the tribe Veliformes during expansion. Fig. 25 
is a section through a portion of the pileus of Coprinus 
plicatilis , Fries, and shows the splitting of the gills, also the 
scurfy appearance of the pileus, due to the separated large 
external cells of the pellicle. 
There is no trace of a secondary veil present in any known 
species of Coprinus : hence a true ring or annulus is never 
1 Hym. Eur., p. 320 (1874). 
K 
