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The fruit, if attacked when young or only partly grown, shows 

 first a brownish spot, and later becomes covered with the gray, downy 

 growth of the fungus. This form of the disease is sometimes called 

 "gray-rot" by vineyardists (fig. 14). When the berries escape the 

 disease until they are half grown or more it appears as a brownish 

 or brownish purple spot which spreads and soon involves the whole 

 berry. The affected fruit becomes soft and wrinkled and falls to the 

 ground when disturbed. This stage of the disease is sometimes 

 called "brown-rot." 



Fig. 12. — -A grape leaf attacked by the downy mildew (Plasmopara viticola), 

 showing the appearance of the leaf above and below. 



Besides the summer spores mentioned, there is also produced 

 within the diseased tissues another form of reproductive body, some- 

 times called a winter, or resting, spore (fig. 13, c). These spores are 

 produced in much smaller numbers than the summer spores and are 

 provided with a rather thick, dark-colored outer covering apparently 

 intended for their protection during the winter. 



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