436 



BACTERIAL DISEASES OF PLANTS 



FIG. 334. Crown-gall teratoma on Ricinus communis (castor oil plant). 

 Inoculated with hop strain of Bacterium tumefacii'ns in two places by needle- 

 pricks March 25, 1916. Photographed April 29, 1916. % nat. size. Leaves 

 reflexed and dying. Secondary tumors on petiole at X. The tumor-bearing plant 

 was of the same age and size as the check when it was inoculated. 



