236 BOTANICAL GAZETTE. [Sept. 
in nature this Roestelia has developed very slowly, and it is highly 
probable that the excidia will ripen as, when growing wild, the 
tubercles appear in July and August, but the ripe peridia are not 
found until some time in Se tember, in Massachusetts. This 
My second supposition has been proved by Mr. Thaxter’s 
cultures to be incorrect. The spores of Gymn. clavipes growing 
nae m 
peared principally on the leaves while the wcidia were on the 
