CHERRY DISEASES 183 
for several years. Finally an affected branch or trunk may be 
girdled, as a result of which the foliage becomes yellow, then 
brown, and finally withers and dies. Such foliage hangs on the 
tree for some time. Below a girdled trunk, suckers may spring 
up from the healthy part. 
In addition to the cankers just described another phase of 
bacterial-gummosis is found in a blighting of the spurs and 
buds. The first indication of this is usually not noticed until 
Fic. 50.— Cherry twigs affected with bacterial-gummosis; cankers 
about the base of blighted spurs. Gum-flow evident. 
spring, when some of the buds fail to swell and open when others 
unfold. A drop of gum often exudes from such buds. Some- 
times affected buds do unfold in the spring in an apparently 
normal fashion, but before the blossoms open, these buds wilt 
and become dry. 
Cause. 
The bacterial-gummosis of cherry is caused by Bacterium 
Cerasi. Before proceeding with a discussion of this particular 
disease, brief reference will be made to the causal nature of 
gummosis in general. As already indicated, the trouble may be 
