i86 



Bulletin 236. 



Fig. 56. — Pit canker. Rapidly 

 forming callus closing the 

 wound and forcing ont the 

 diseased bark. 



Fig. 58. — Typical pit cankers in the 

 body of a tree from which the diseased 

 bark has dropped out. The upper one 

 is exuding sap, — " bleeding." 



Fig. 57. — The ivoiind Iwaling beneath the 

 cankered bark, xvhich still clings to the 

 tree as a sort of scab. This canker was 

 more or less superficial. 



