THE rAKASITIO EXOASCEAE. 



165 



Exoascus deformans (]')erk.) causes the " curl disease " of tli 

 peach {Persica vvlrjaris), and may inflict great injury. Th 



Cuil disease of Cherry. 



mycelium hibernates in bark, pith, and medullary rays of 

 so that it reappears each year. An B.ax/scn^, which 



twigs, 

 (jccurs 



Fig. {il.~-£j:oascus dejormans. Comparison of normal section of leaf of P,vnu> 

 Persica with a hypertrophied one, B; in the latter the mycelial hyphae liave 

 been slightly shaded. The sections are from different parts of tlie same leaf, and 

 are drawn with the same magnification. (After W. G. Smith.) 



Oil the almond {Amijgdalus communis), resembles Ej^. deformans 

 so closely that they are now regarded as the same species. 



