Fes. 
. . 
a 
New York AGRICULTURAL EXPERIMENT STATION. 207 
were rare while the cane knots were plentiful, and it was plain 
that no relation existed between the two kinds of knots. 
On August 16 we again visited the plantation for the purpose 
of studying the disease on the new canes. ‘The knots were already 
abundant on the new canes and in all stages of'development. It 
was at once observed that the knots were intimately associated 
with anthracnose. Some of the canes were considerably 
spotted'with anthracnose and such canes were badly knotted. 
Where anthracnose was most abundant, the knots were most 
abundant; and where there was no anthracnose, there were no 
knots. One apparent exception to this rule was found. A cane 
bearing a single incipient knot appeared to be entirely free from 
anthracnose. This cane was placed over night in a moist cham- 
ber, and the following morning a typical anthracnose spot was 
seated on the very summit of the forming knot. Upon micro- 
scopic examination the spot was found to be fruiting profusely 
and was undoubtedly anthracnose. The knots were most abun- 
dant near the base of the cane and the anthracnose, also, was 
most abundant on that part of the cane. Occasionally canes 
were. found bearing many anthracnose spots, but no knots. All 
the anthracnose spots did not produce knots by any means. 
Each knot seemed to start in an anthracnose spot. At first a 
longitudinal] crack appears across the anthracnose spot: this 
crack elongates, becomes brown, and as the knot increases in 
size the outer bark is gradually thrown off, exposing masses of 
rough spongy tissue, which takes forms very suggestive of pop- 
corn. 
We have seen the same kind of knots, also, on the variety 
Thompson on the Station grounds; and there existed the same 
intimate relation between the knots and anthracnose as in the 
ease of the Cuthberts. It is plain that this cane knot of rasp- 
berries is caused by the anthracnose fungus. Possibly Bailey’s 
blackberry cane knot® may have the same origin. 
Rust (Puccinia peckiana Howe. Syn. Cwoma nitens Schw.).— 
Rust is a common and destructive disease of black raspberries 
 &Qornell Univ. Agr. Exp. Sta. Bul, 99 ; 427-428, 
