8o RESEARCHES ON FUNGI 



(4) Usually the hymenium on one side of a gill at maturity 



looks slightly downwards, and that on the other side 

 slightly upwards. 



(5) The spores ripen in succession from below upwards on each 



gill. 



(6) The spores are discharged in succession from below upwards 



on each gill. 



(7) Autodigestion proceeds from below upwards on each gill and 



removes those parts of the gills which have become spore- 

 free and which, if they continued in existence, would become 

 mechanical hindrances to the fall of the remaining spores. 



All the facts just given are correlated with one another. In 

 the genus Coprinus the ripening and discharge of the spores from 

 below upwards on each gill, and the autodigestion from below 

 upwards on each gill, are special arrangements which permit of 

 successful spore-discharge from parallel-sided, non-geotropic gills. 



After the fruit-body mechanism of Coprinus had been elucidated, 

 it seemed to me advisable to investigate the fruit-bodies of a Bol- 

 bitius with a view to finding out whether or not their arrangements 

 for producing and liberating spores were the same as in Coprinus. 

 I therefore examined the living fruit-bodies of Bolbitius flavidus 

 Bolt, with the results already recorded in this Chapter. 



In the fruit-bodies of the Bolbitius : 



(1) The gills are very thin. 



(2) The gills are not parallel-sided but are acutely wedge-shaped 



in cross-section. 



(3) The gills are positively geotropic. 



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



oriented fruit-bodv looks more or less downwards. 



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



on each gill. 



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



upwards on each gill. 



(7) Autodigestion does not proceed from below upwards on 



each gill ; it does not have any relation to spore-discharge, 

 but is a post-mortem change. 

 It is clear that the special mode of spore-production and spore- 



