4i8 Bulletin 76. 



for they remain upon the vines until fall, the green portions prob- 

 ably still acting in a normal manner. 



A dark discoloration often found between the main veins of 

 the leaves may be attributed to the same cause as that producing 

 the death of the edges. These dark portions, (sometimes they are 

 nearly black) do not necessarily indicate the death of such places 

 for the thickness of the leaf is apparently normal and the marked 

 curling of the leaf is wanting. In these respects the trouble 

 seems to differ from the browning and drying of the leaf as 

 mentioned above, and it may be due to some other cause. In- 

 quiries during one season were insufficient for the drawing of more 

 definite conclusions regarding the cause of this trouble. Below 

 (p. 420) are also given descriptions of two diseases which attack 

 vineyards in France and it is possible, although not probable, that 

 this one is of a similar nature to the European ones. 



In 1890 the grape growers of western New York suffered from 

 a disease which caused the grapes to shell in some cases very 

 severely. D. G. Fairchild, assistant in this section of Vegetable 

 Pathology in the U. S. Department of Agriculture, was directed 

 to investigate this trouble and an abstract of his report* is here 

 given. 



Definite reports of the trouble were received from Niagara, 

 Wayne, Cayuga, Seneca, Steuben and Ontario counties, but it is 

 probable that grapes were affected in other parts of the state. 



' ' Small irregular bunches of a dark color appear between the 

 veins, these enlarge rapidly, darken to a dull purplish or reddish 

 brown and coalesce so as to fill up the space between the veins 

 w^hich remain green or yellow. These changes occur so rapidly 

 that the foliage seems to change color suddenly. The contrast 

 between the green or light yellow veins and dark purplish brown 

 of the intervening tissues gives a peculiar streaked appearance to 

 the leaves. In the most serious cases they curl up, become dry 

 and brittle, and finally drop from the vine, leaving it nearly bare. 



' ' The berries borne upon diseased vines, almost without excep- 

 tion, have a flat, insipid, and often intensely sour taste, due to the 

 fact that they are only partially ripened. When the attack is severe 

 the berries drop off, and the ground beneath a diseased vine is often 



^Journal of Mycology, vi. 96. Annals Hort. 1890, 74. 



