120 RESEARCHES ON FUNGI 



(4) Every part of the hymenium on any gill in a normally 



oriented fruit-body looks more or less downwards. 



(5) The spores do not ripen in succession from below upwards 



on each gill but more or less uniformly all over the gill- 

 surfaces. 



(6) The spores are not discharged in succession from below 



upwards on each gill but more or less uniformly all over 

 the gill-surfaces. 



(7) Autodigestion does not proceed from below upwards on 



each gill or involve any part of a gill during the period 



of spore-discharge. 

 With the help of the seven criteria enumerated above one can 

 readily determine whether or not any particular fungus should be 

 included in the genus Coprinus, i.e. in the Inaequi-hymeniiferae. 



Other Characters. — With the chief characters of the Coprinus 

 Type are associated and correlated others of less fundamental 

 importance but of no little interest, which are concerned with the 

 colour of the gills, the nature of the elements making up the 

 hymenium, the sub-zones of the zones of spore-development and 

 spore-discharge, the general structure of the pileus-flesh and of the 

 stipe, the length of the spore-discharge period, and the ephemeral 

 nature of the Coprinus Type taken as a whole. Of these we shall 

 now treat. 



(1) The gills are neither mottled nor perfectly even in colour 

 texture, for during development they blacken from below upwards. 

 This blackening of the gills from below upwards is a well-known 

 field character for the larger Coprini, such as Coprinus comatus and 

 C. atramentarius, but it also occurs in the smaller Coprini, such as 

 Copririus ephemerus and C. stercorarius^. It is due to the fact that 

 the spores, whilst ripening, develop a deep brown pigment in their 

 walls and also to the fact that the spores on a single gill ripen in 

 succession from below upwards. 



(2) The number of generations of basidia, as a rule, is Umited to 

 two. These two generations overlap so that the younger one is 

 only slightly behind the older one in beginning and ending its 

 development. Finally the spores of neighbouring basidia of both 

 generations come to be ripe and ready for discharge at approxi- 



