408 MANUAL OF FRUIT DISEASES 
if formed at all, never reaches full maturity, but ripens pre- 
maturely or dries up. 
The petioles of the oldest leaves are attacked soon after the 
canes are affected. Purplish spots as described for the canes 
Fig. 119. — Anthracnose on canes of 
black raspberry. 
above are developed. The 
affected tissue enlarges 
along the petiole, finally 
reaching the leaf proper. 
On the leaf whitish, blister- 
like lesions appear. The 
leaves then become dis- 
torted, their edges rolling 
in toward the midrib. 
Spots on the leaf-blade 
are similar to those on 
the canes, although smaller ; 
they are one-twenty-fifth 
of an inch or less in diam- 
eter. They are closely dis- 
tributed, but rarely coa- 
lesce. Frequently — the 
diseased area, in which 
most of the tissue is dead, 
becomes separated from 
the surrounding healthy 
tissue and the leaf shows 
a shot-hole effect. Leaves 
on the laterals of new canes 
do not ordinarily become 
diseased. 
Anthracnose shows on 
the fruit. The upper drupels are more commonly attacked. 
Many fruits are affected while still green in color and 
sometimes before they are larger than a pea. A small brown 
