520 



BACTERIAL DISEASES OF PLANTS 







 . 



B 



FIG. 390. Photographs showing small tumors developing under the cut surface 

 (cork -layer) of a raw potato which was sealed into a \ery limited air space: (A) 

 Front view; (B) upper surface of A; (C) lower surface of A. The cork -layer is 

 ruptured in places. Block enclosed in a test tube May 2, 1917, and sealed in with 

 sealing wax. At X one of the tumors has developed a bud. Photo. Sept. 25, 1917 



