88 



Infection by the Canker takes place through wounds, and probably 

 in the spring. These injuries are commonly those from sunscald or frost- 

 crack in winter, or when the bark is knocked off during cultivation, by 

 climbing, at broken limbs, or where gnawed by grazing stock. The infect- 

 ing spores usually come from other cankers. 



Black Rot. — Black Rot, the third form of the disease, is common 

 in New York and the Southern States, not rare in Ontario, but is scarcely 



Black Rot Canker on apple branch 



