26o 



A NEW APPLE TREE CANKER. 



pycnidia may sometimes be grouped together in a stroma. As 

 regards the ascus' stage, the persistent absence of a stroma., inter 

 alia, places the fungus in the genus Physalospora, which is charac- 

 terised for one thing by being non-stromatic, and having con- 

 tinuous hyaHne ascospores. He admits, however, the possibihty 

 of the occurrence of perithecia in stromata, although he has never 



Text fig. 1. 



come across them in his investigations, in which case Physalo- 

 sp^ora cydoniic would have to be put into the genus Botryo- 

 sph<p-na. 



These facts, for a time, made me wonder whether the fungus 

 T was examining was not, perhaps, a variety of Physalospora 



