AND WINE MAKING. 69 



ripening of the wood, and in consequence, the hardiness 

 of the vine in winter. His experience will be more fully 

 given in his own words in Part II of this work. 



Prof. R. N. Price, of the Texas Agricultural and Me- 

 chanical College, has given the subject of black rot 

 much attention. He propagated the fungus from spores, 

 and published its life history in an illustrated bulletin, 

 which is the most complete treatise on the subject I 

 have yet seen. I regret that want of space forbids its 

 reproduction entire, in this volume, but some of his 

 experience will be given at the end of this chapter, as it 

 relates to nearly all fungous diseases of the grape, and 

 about the same remedies are applicable to all. 



DOWNY MILDEW (Peronospora viticola). This is also 

 called "gray rot," as the young berries, when first 

 attacked, show marbling or veins of gray. This soon 

 changes to a uniform gray, entirely over the affected 

 berry, which shrinks and drops. It attacks all the green 

 parts of the vine, showing like a gray down on the under- 

 side of the leaves, and appearing as rusty blotches on 

 the upper side. It usually appears in warm, sultry 

 weather, after the berries are nearly grown, and as the 

 fungus spreads very rapidly it is one of the most destruc- 

 tive if left unchecked. The spores are produced on the 

 extremity of minute, threadlike stems, which protrude 

 through the underside of the leaf. They are contained 

 in small spherical sacs, which are blown about by the 

 wind, and alighting upon the soft green surface of the 

 leaves, soon burst and the liberated spores germinate, 

 spreading the disease to all parts of the vine. As gen- 

 eration follows generation with great rapidity, the spores 

 continue to spread through the entire vineyard until 

 autumn, when the hardy winter spores are formed in 

 small sacs with tough leathery coats which live through 

 the winter, and renew the work of infection in the 

 spring. The disease spreads very rapidly during cold, 



