Notes on Certain Diseases of Plants 235 



a paste composed of copper sulphate and lime, but as a rule it 

 will be found more satisfactory to destroy diseased trees and to 

 guard against a fresh importation of the trouble from the 

 nursery. 



Foot -Rot of Peach. — Occasionally the student of plant dis- 

 eases is confronted with what appears to be a hitherto undis- 

 covered disease. It may be actually new. or it may be merely 



Fig. 2. CROWN-GALL OF PEACH 



a peculiar phase of an old trouble. Such is the disease of 

 peach trees which I have called foot-rot, and which is illus- 

 trated in Plate 3. It made its appearance very suddenly a 

 year or two ago, and since that time has spread with alarm- 

 ing rapidity. The diseased trees show, above ground, symptoms 

 similar to those accompanying the crown-gall; that is, a gradual 

 decrease in vigor. But these symptoms are much more pro- 

 nounced than in the case of crown -gall, and the disease runs 

 its course much more rapidly. Thus, the tree in the illustra- 

 tion referred to appeared normal and healthy one season; the 

 next spring it put out leaves, but the latter failed to develop 



