OBSERVATIONS ON THE CALIFORNIA VINE DISEASE 145 
“As the season of ripening approaches, certain berries of the 
affected clusters fall to the ground on account of the inability 
of the main fibers and other connecting tissue of the fruit-stems 
to sustain their weight. . . . The portions of the clusters first 
affected are, so far as my observations go, invariably either the 
lower extremity of the cluster as it hangs from the cane, or, in 
the case of heavily shouldered clusters, the outer extremity of 
the stem forming the shoulder. . . . Sometimes only one or two 
berries may fall, but in other cases the drying and shriveling of 
the stem gradually extends upwards, the affected portion being 
plainly marked by the absence of the berries. . . . It often occurs 
that not a berry remains hanging upon the bunch. .. . Some 
clusters upon a vine seem to be more free from shelling than 
others upon the same plant.’ 
The development of shelling is sporadic. Тһе disease affects 
vines at the height of summer and is as selective as Folletage or 
Rougeot. One, several, or all the shoots may be affected. 
“It very commonly occurs that plants in certain portions of a 
vineyard shell, while the large majority of them do not. | Тһе 
line is sometimes so sharply drawn,” our authority continues, 
“that the affected plant may be entirely surrounded by healthy 
vines; and it is not uncommon to find a healthy vine in the midst 
of those which shell. . . . Some clusters upon a vine seem to be 
more free from shelling than others upon the same plant. This 
seems to be due, in many cases, to its location upon the cane, but 
there are so many exceptions that no definite rule can be laid 
Wn. ... Another peculiarity which may sometimes be seen, 
although cases of it are very rare, is the shelling of the berries 
upon only one portion of the vine, as for instance those borne 
upon the canes which spring from an arm, the difficulty thus 
affecting only one half of the plant. One case was noticed in 
which the clusters found upon one cane were the only ones which 
suffered, amongst all those borne by the vine.” 
The cause of Shelling is not definitely known, though the 
Weight of the evidence points to defective nutrition. 
Tetranychosis?—Young vigorously growing leaves become 
convex and paler than normal; they may even become somewhat 
maturity and the Viniferae are not entirely free from the trouble. Certain 
Franco Х Americans behave similarly. 
*Lodeman, E. С. Loc. cit., 413-415. 
*Lodeman, Е. С. Loc. сй., 415. 
* Maladie rouge. 
