RATE OF DEVELOPMENT OF INDIVIDUAL SPORES 51 



I had at my disposal, this period might be somewhat shortened. 

 Pholiota praecox, a species with brown spores, was found in an 

 uncompleted investigation to take upwards of 6 hours. Panaeolus 

 campanulatus, with black spores, has a period of about 7 hours 

 and 30 minutes. For 

 Anellaria separata 

 (Fig. 16), which also 

 has black spores, 

 where observations 

 were made in the 

 same manner as for 

 Panaeolus campanu- 

 latus, i.e. with the 

 horizontal micro- 

 scope, the period 

 was observed to be 

 between 9 and 10 

 hours. ForCoprinus 

 sterquilinus, which 

 has very black 

 spores, the period of 

 spore - development 

 was found to be 

 the longest of all, 

 namely, 32 hours. 

 For Bolbitius flavi- 

 dus, which has spores 

 with bright yellow 

 walls, the period is 

 also a very lengthy 

 one, roughly 8 hours ; but in this case the final phase of discharge 

 was not satisfactorily observed. If we compare the seven markedly 

 chromosporous species which have just been named with the 

 leucosporous and rhodosporous species already considered, it would 

 appear that the high pigmentation of the spore-walls is associated 

 with a prolonged period of spore -development. We are justified in 

 thinking of such genera as Marasmius, Collybia, and Armillaria as 



FIG. 16. Anellaria separata, a species with thick 

 black spore-walls, which develops its individual 

 spores very slowly : the interval elapsing 

 between the first formation of a spore on its 

 sterigma as a tiny rudiment and its discharge 

 is from nine to ten hours. The fruit-bodies 

 are coming up on dung covered by herbage. On 

 the extreme left is a fruit-body of Coprinus niveus 

 in the last stage of autodigestion. This species 

 also has black thick-walled spores which 

 develop relatively slowly. Photographed by 

 A. E. Peck at Scarborough, England. About 

 i natural size. 



