352 RESEARCHES ON FUNGI 



outwards from the gill-surfaces (c/. Fig. 146, p. 325), When the gills 

 have been pulled apart in the manner just indicated, spore-discharge 

 begins along the base of each gill, and there comes into existence a 

 zone of spore-discharge which proceeds upwards on both sides of 

 each gill, as in other Coprini. 



The zone of spore-discharge in Coprinus micaceus is more com- 

 plex than in any other species of Coprinus, for it consists of four 

 sub-zones. The highest sub-zone of spore-discharge belongs to the 

 basidia of the first generation, the next highest sub-zone to the 

 basidia of the second generation, and so on for the third and fourth 

 sub-zones. The zone of spore-discharge, owing to its including four 

 sub-zones instead of two, is unusually wide, its actual width being 

 0-15 mm. The relations of the four sub-zones of spore-discharge 

 to one another in Coprinus micaceus are of the same nature as those 

 of the two sub-zones of Coprinus sterquilinus, and it will therefore be 

 unnecessary to describe them and illustrate them in detail. It may 

 simply be remarked that, in any narrow band of the hymenium 

 (say 0- 15 mm. wide) which is parallel to the free gill-edge, the 

 basidia of the first generation shed their spores first, the basidia of 

 the second generation their spores next, the basidia of the third 

 generation their spores next, and the basidia of the fourth genera- 

 tion their spores last of all, i.e. the basidia shed their spores in suc- 

 cession according to their length, beginning with the longest. This 

 permits of all the basidia, which as we have seen are crowded 

 together on the hymenium, getting rid of their spores safely without 

 any collision. 



It was noticed that, when seen from above on a living gill, the 

 four spores of each basidium are more divergent from the basidial 

 axis in the zone of spore-discharge than above this zone higher up 

 the gill. It thus appears that the divergence of the four spores of 

 each basidium increases just before spore-discharge takes place. 

 The significance of this fact remains to be investigated. 



The spores are discharged from their basidia in the same manner 

 as in other Hymenomycetes. The drop of water excreted at the 

 hilum of each spore takes from five to ten seconds to attain full 

 size. The spore and its drop always disappear from the end of the 

 sterigma at the same moment, and it is therefore reasonable to 



