222 



FUNGOUS DISEASES OF PLANTS 



upon the leaves and stems, but particularly upon the berries of 

 the host, and it may sometimes cause injury to currant bushes. 

 The mycelium is more persistent than that of most Erysiphaceae. 

 It is one of the few forms the mycelium of which becomes buff 



FIG. 87. GOOSEBERRY MILDEW. (After Close) 



or brown and thick-walled with age. The mycelium forms dense 

 circular or effuse patches, sometimes completely covering a berry 

 and the adjacent twig. 



The perithecia are imbedded in the dense mycelium. They 

 average about 8o-ioo/-i in diameter and are beset with a few 

 light brown, tortuous appendages. A single subglobose ascus 



