COPRINUS LAGOPUS 315 



rise only to partially or comi^letely sterile fruit-bodies enables us 

 to infer w ith confidence that the normal fully fertile fruit-bodies of 

 this species, which we see coming up on unsterilised horse dung in 

 fields or in the laboratory, have all been produced on secondary 

 mycelia, i.e. on mycelia which have resulted from the fusion of two 

 mycelia of opposite sex. 



(5) Vertical sections through fruit-hodies. In Fig. 138 is shown 

 a series of drawings which illustrate not only how the fruit-bodies 

 of Coprinus lagopus vary in size but also the appearance of the 

 fruit-bodies in vertical section. 



In Fig. 138, the fruit-bodies shown at A, B, C, and D were 

 found upon unsterilised horse dung at Winnipeg, and they range in 

 size from the tiniest dwarfs (A) to a fruit-body of medium size (D). 

 All the other fruit-bodies, E-P, were raised in pure polysporous 

 cultures on horse dung in the laboratory. E-N came up in the 

 light, and and P in total darkness, the latter exhibiting a strone 

 tendency to form attenuated stipe-bases or pseudorhizae (p). Suc- 

 cessive stages in development are shown in the series of drawings : 

 K, L, E and F, M, N or 0, G, H, I, J, P. The gills are at first white 

 (K, L), then blacken from below upwards owing to the ripening 

 of the spores from below upwards (M), and finally become black 

 all over (N) ; so that the pileus, at the time the stipe begins to 

 elongate, appears from without to be cinereous grey. After the 

 stipe has elongated considerably, the pileus expands rapidly (G, H), 

 flattens, and commences to shed spores (I), finally becoming more 

 or less revolute and torn into rays (J). Autodigestion of the gills 

 from below upwards causes the gills to become gradually reduced 

 in area (J) until, finally, when spore-discharge has ceased, the 

 remains of the gills and the pileus-disc are left at the top of 

 the stipe as a watery remnant of the originally much larger 

 pileus (P). 



In Fig. 138 are also shown some variations in the relative width 

 of the gills. The fruit-bodies M and N, raised in pure cultures on 

 sterilised horse dung, were unusually vigorous and have extremely 

 wide gills ; while the fruit-bodies G, H and I, raised in a similar 

 manner, have normal narrower gills. The fruit-body 0, also raised 

 in pure culture on sterilised horse dung, but in total darkness 



