52 RESEARCHES ON FUNGI 



appears at the pileus-periphery and, as spore-discharge continues, the 

 white zone increases in width centripetally, thus gradually diminishing 

 the central grey zone. Finally, when all the spores have been shed, 

 the white zone extends to the disc and the grey zone has disappeared. 

 If one gathers the fruit-body at the end of the spore-discharge 

 period, one finds the gills whitened owing to the loss of their spores 

 but completely intact, owing to the fact that they have not been 

 subjected to the process of autodigestion (Fig. 34, E). 



At Kew Gardens on a wet lawn, early in September, 1925, at 

 midday, there were many fruit-bodies with expanded pilei among 

 the grass ; and, by looking down on them and observing their 

 white and grey zones, I was able to assure myself that, at one and 

 the same moment, in some of the fruit-bodies the process of spore- 

 discharge had not yet begun, in others it was from one-quarter to 

 one-half completed, and in yet others it was nearly complete. Then 

 I gathered the fruit-bodies and examined their pilei from below. 

 The white and grey zones seen directly on each gill were found to 

 correspond exactly with the white and grey zones which had been 

 seen by looking down on the pilei from above. 



The spores of Coprinus plicatilis, in England, in the month of 

 September, are shed from shortly before noon to late in the after- 

 noon. The spore-discharge period is a brief one and, other things 

 being equal, is determined by the size of the pileus. The longer 

 the gills, the longer the distance the zone of spore-discharge has to 

 travel before all the spores are discharged and the longer the time 

 occupied by the journey. Therefore here, as in Coprinus curtus 

 and indeed all other Coprini, the larger the pileus, the longer is the 

 spore-discharge period, and the smaller the pileus, the shorter is 

 the spore-discharge period. The actual length of the spore-discharge 

 period, which has not yet been determined by precise observations 

 on particular fruit-bodies, was estimated to be from about one to 

 four hours according to the size of the pilei concerned. 



The four spores of each basidium of Coprinus plicatilis are dis- 

 charged from their sterigmata in succession in the course of a few 

 seconds or minutes, and each discharge is accompanied by drop- 

 excretion at the spore-hilum, just as in all other Hymenomycetes. 

 I gathered some fruit-bodies from a lawn at Kew Gardens, took 

 them to the Herbarium, removed the pilei, turned the pilei upside 



