COPRINUS STERQUILINUS 193 



view, one usually perceives that the flanged edge of each gill is not 

 straight but wavy (c/. Fig. 80, B, iv). The same phenomenon can 

 be observed in Cojwinus comatus. This waviness is evidence of 

 the fact that the gills are more or less corrugated toward their 

 flanged edges from 

 below upwards. 

 The lamellae ap- 

 pear to grow faster 

 in length along 

 their flanged edges 

 than where they 

 adjoin the pileus- 

 flesh. Hence the 

 production of trans- 

 verse corrugations. 

 These corrugations 

 can also be seen 

 when the fruit-body 

 is expanding but, 

 as a rule, they are 

 then less marked. 

 Some of them are 

 shown, particularly 

 toward the upper 

 ends of the gills, 

 in Fig. 81, which 

 represents a pileus 



Fig. 81. — Coprinus slerquilinus. Under side of the 

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

 just after the beginning of .spore-discharge. In 

 the dark peripheral zone, where the spores are 

 being shot out from the gill-edges, the interlamellar 

 spaces ai-e well-developed ; but in the lighter 

 central zone, where the white flanges of the gill- 

 edges are still intact, spore-discharge has not 

 yet begun. Natural size. 



which has become 

 helmet-shaped but is not yet flattened. As the pileus gradually 

 expands and flattens out so as to become plane, the lower free 

 margins of the gills are necessarily stretched more than the upper 

 parts attached to the pileus-flesh. The result of this is that 

 the corrugations in the gflls, during the flattening of the pileus, 

 become gradually eliminated. The development of the corrugations 

 seems to show that provision for the rapid stretching of the gills 

 in length durmg the flattenmg out of the pfleus is made in advance. 

 If the gills were not corrugated but simply extended their area 



VOL. IT I. 



