COPRINUS STERQUILINUS 235 



one-half of each gill has disappeared, in G about three-quarters, and 

 in H nearly the whole. In the drawings E, F, G, and H, the spores 

 have been represented diagrammatically as falling from the gill- 

 edges and being carried away by a gentle current of air. In the 

 drawings, B, C, D, E, F, G, and H, one may follow the gradual 

 expansion of the pileus just before and during the discharge of the 

 spores : one perceives that the pileus, which is at first barrel-shaped 

 (B), becomes campanulate (C, D), then helmet-shaped (E, F), then 

 flattened (G), and finally revolute (H). The revolution of the rim 

 of the pileus serves to remove the exhausted and therefore now 

 functionless peripheral parts of the gills out of the way of the 

 stream of spores which is being carried off by the wind. The spore- 

 stream of the revolute pileus shown at H is coming from the 

 edges of the much reduced but still active parts of the gills which 

 stand in a ring around the top of the stipe immediately beneath 

 the disc. 



The relation of certain photographs of pilei to the vertical 

 sections of Fig. 97 may now be considered. The photograph repro- 

 duced in Fig. 77 (p. 188) shows a pileus which had just begun to shed 

 its spores and which therefore is very slightly in advance of the 

 pileus shown at D in Fig. 97 (p. 232) which is just about to begin 

 to shed its spores. The photograph reproduced in Fig. 98 (p. 234) 

 shows a pileus at a stage corresponding to the stage F in Fig. 97, 

 i.e. a middle stage in spore-discharge and autodigestion ; whilst 

 the photograph reproduced in Fig. 99 (p. 234) shows a pileus at a 

 stage corresponding to the stage H in Fig. 97, i.e. a stage in which 

 the spore-discharge period is almost ended and in which the process 

 of autodigestion has almost destroyed the gills. The photograph 

 reproduced in Fig. 100 shows, two-thirds the natural size, the whole 

 of the fruit-body from which the pileus of Fig. 99 was taken. The 

 exposed upper part of the stipe and the ragged, revolute, dripping, 

 almost exhausted pileus of Fig. 100 contrast strikingly with the 

 half-concealed upper part of the stipe and the intact campanulate 

 pileus of the younger fruit-body shown in Fig. 77 (p. 188). In 

 the latter fruit-body, as already pointed out, the liberation of the 

 spores and the gradual destruction of the gills by autodigestion 

 bad only just begun. 



