EVOLUTION OF THE COPRINI 259 



if it remained in existence, would prevent the escape of the spores 

 from the pileus. Thus the production and liberation of the spores 

 on each gill from below upwards, together with the autodigestion 

 of each gill from below upwards, made it possible for the spores to 

 be successfidly liberated from the pilei even although the gills were 

 more or less parallel-sided and ageotropic. This mechanism for 

 the production and liberation of spores, on account of its success, 

 has persisted in the Coprini until the present day, and it is beauti- 

 fully exemplified in Coprinus sterquilinns. 



