58 



RESEARCHES ON FUNGI 



still be able to liberate a sufficient number of spores to maintain the 

 species in existence. 



Under moist conditions, the expanded pileus of Coprinus plica- 

 tilis remains convex, whereas that of C. curtus becomes plane and 

 then more or less revolute. This is correlated with the fact that 

 in the former species the lower halves of the gills are not destroyed 

 by autodigestion from below upwards, whereas in the latter species 



they are. In C. plicatilis, since 

 the gills remain intact, the revo- 

 lution of the pileus is rendered 

 mechanically impossible. 



Coprinus plicatilis and Co- 

 prinus longipes. — In 1929 I de- 

 scribed in detail a new species 

 of Coprinus which had come up 

 many times on horse dung kept 

 for some weeks or months in 

 culture dishes in the laboratory 

 at Winnipeg, and I named it 

 Coprinus longipes because its 

 stipe is often very long in pro- 

 portion to the width of the 

 pileus. 1 This species is illus- 

 trated for the first time in Figs. 

 35-39. Fig. 35 shows three 

 young fruit-bodies on a horse-dung ball, one of which is expand- 

 ing its pileus and becoming phcate. Fig. 36 shows three fruit- 

 bodies with rather short stipes and pilei which are fully expanded. 

 The broadly convex pilei with their darker depressed discs 

 and radial pHcations greatly resemble those of C. plicatilis 

 {cf. Figs. 21 and 22, pp. 35 and 37). Fig. 37 shows a single fruit- 

 body on the side of a horse-dung ball with the pileus turned 

 so as to exhibit the dark central depressed disc. Fig. 38 shows 

 a group of four mature fruit-bodies and an isolated pileus, all 

 removed from a large culture dish which contained horse dung. 



^ G. R. Bisby, A. H. R. BuUer, and J. Dearness, The Fungi of Manitoba, 

 London, 1929, p. 118. 



Fig. 37. — Coprinus longipes. A single 

 fruit-body coming up spontaneously 

 on an old horse-dung ball in a labora- 

 tory culture at- Winnipeg. The pileus 

 has been turned so as to exhibit the 

 radial plications and dark central 

 depressed disc. Natural size. 



