522 



BACTERIAL DISEASES OF PLANTS 



FIG. 392. Block of raw potato showing experimental production of small 

 tumors like the accidental ones of Fig. 390. The pared sterile potato flesh, resting 

 in wet cotton, was sealed into a test tube February 7, 1919, kept in the dark 

 at room temperature, 22 to 25C.. and photographed April 17. X 5. Small 

 shoots were torn away at A", which was the bottom of the block bedded in the 

 wet cotton. 



