sae all ea Le Nat 
New York AGRICULTURAL EXPERIMENT STATION. 319 
- until the entire erape is uniformly discolored, imparting to it the 
_ appearance of rottenness, although its original contour and firm- 
ness are retained. Hven before the completion of this change it 
usually happens that the part first affected becomes darker in 
color, and minute black pimples or pustules are developed, 
imparting aroughness to the surface. At the same point the berry 
now begins to lose its fulness, an irregular depression appears, 
which soon extends into a general withering of the berry, the 
- pimples meanwhile having multiplied so rapidly as to cover its 
entire surface. The destruction of the berry is complete ; it is 
hard, dry, shriveled to one-half or one-fourth its original size, the 
folds of the skin being closely pressed upon the seeds and raised 
into strong, prominent and irregular ridges. These last, and the 
little pimples which are easily seen with the naked eye, are char- 
acteristic of this form of rot. The rotted berries remain firmly 
attached to the supports for a long time, sometimes even till the 
following spring. 
The disease does not extend from one berry to another by con- 
tact, nor through the tissues of the pedicels and common peduncle, 
but there is a distinct infection for every berry diseased. 
The manifestations of the black rot do not always appear as 
detailed above, for not infrequently the first evidence of the dis- 
ease is the sudden appearance of one or more circular, slightly 
depressed spots of a bluish-black color, in the center of which 
there soon appear a few of the little pimples or pustules above 
referred to. These spots increase in-size, the pimples in number, 
and ere long the berry exhibits the black and shriveled appearance 
already described. 
These changes are effected in from one to five days, varying 
with the atmospheric conditions. Some authors assert that the 
same fungus which produces the rot in the berry also attacks the 
young shoots and leaves, but I am not yet convinced that this is 
so. (I. Lamson Scribner, Report on the Fungus Diseases of the 
Grape-vine, Dept. Ag. Bulletin, No. 11, 1886.) But as to the last 
sentence of the foregoing, see Dept. Ag. Report, 1887, page 326, 
by the same author, as follows: 
In Bulletin 2 of the Botanical Division, page 40, grape-leaf spot 
disease was treated as distinct from black rot, for the writer at 
that time was not convinced of their identity although the close 
similarity of the pyenidial spores of Phyllosticta labruscoe with 
those of Phoma wvicola was, of course, observed. 
