56 RESEARCHES ON FUNGI 



Development of Individual Spores of Stropharia semiglobata. 



The Table shows that each spore, on the average, took an hour 

 and ten minutes to attain full size and that, after this, the spores 

 remained colourless for an hour. Then the process of pigmentation 

 of the walls began and the spore-walls continued to deepen in 

 colour for two and a half hours. After pigmentation had been 

 completed, the spores remained on their sterigmata for one hour 

 more, at the end of which time one spore on each basidium was 

 discharged. The other three spores on each basidium were dis- 

 charged within about ten more minutes. After another ten minutes 

 a new set of basidia was observed to be developing a new set of 

 spores, so that at the end of six hours a hymenial picture was 

 presented almost precisely similar to that with which the 

 observations began. 



The process of pigmentation of the spore-walls is evidently a 

 long one. Jn Stropharia semiglobata, as we have seen, it takes 

 some two and a half hours. In Panaeolus campanulatus it was 

 observed to take fully an hour and a half, and in Coprinus sterquilinus 

 several hours. 



Effect of Temperature. The development of a spore is due to 

 processes of growth. Now, since growth in general is dependent 

 on temperature, there can be but little doubt that the spores of 

 agarics develop relatively slowly in cold weather and relatively 

 fast in warm weather. A systematic study of the effect of tem- 

 perature on spore-development would yield interesting results ; but, 

 unfortunately, up to the present, the writer has not found time 

 to undertake it. 



For Collybia radicata, evidence that the rate of spore-develop- 



