COPRINUS MICACEUS 335 



earliest stages of development so that he might study the origin of 

 the gills, does not tell us what kind of organic matter the soil con- 

 tained. So far as I know, Coprinus micaceus has never been found 

 upon horse dung ; and corn-meal agar is a laboratory product. 

 Levine's experiments upon the culture of Coprinus micaceus, there- 

 fore, although interesting in themselves, do not throw much light 

 upon the manner in which the fungus carries on its vegetative 

 existence under natural conditions. 



General Description of the Fruit-bodies. — Some fruit-bodies in 

 various stages of development are shown in Figs. 149 and 150. 

 They grew beneath a large dead Poplar tree {Populus serotina) and 

 were photographed in the open immediately after they had been 

 dug up. They were therefore unspoiled by handling and exhibit 

 their natural forms. 



The pileus at maturity is from about 3 to 6 cm. in diameter and 

 the mature plants are from 8 to 11 cm. (3-4-3 inches) high. 



The pileus is submembranaceous, elliptical, then campanulate, 

 then under moist conditions helmet-shaped, the sdges becoming 

 revolute and torn into rays (Fig. 150). When young, the pileus is 

 ochraceous-tan in colour, the disc being darker, and covered with 

 delicate scales composed of globular cells which glisten somewhat 

 in the light (Fig. 151, p. 339). The scales tend to occur in radial 

 lines (c/. the youngest fruit-bodies in Fig. 149) and are so loosely 

 attached that they are removed from the pileus by the slightest 

 touch or by a shower of rain. Older pilei are therefore often quite 

 naked. The unexpanded pileus exhibits prominent striations 

 which pass radially from the pileus-periphery to the disc. These 

 striations mark the positions of furrows in the flesh and are situated 

 above the lines of attachment of the longer gills (c/. Figs. 149, p. 334, 

 and 152, p. 341). As the pileus expands, the furrows open out and 

 the top of the pileus becomes radially rimoso-sulcate (Fig. 150). As 

 it grows older and spore-discharge takes place, the pileus turns to 

 a darker hue. 



The gills are 2-3 cm. long and 0*4-0 -8 cm. broad, somewhat 

 rigid owing to their being about 0*3 mm. thick in their halves 

 nearest to the pileus-fiesh, becoming lanceolate during autodigestion 

 so that in the middle stage of spore-discharge they are sharply 



