Bui, .''I 3. Bureau of Plant Industry. U. S. Dept, of Agriculture. 



P! ATT XXV. 



Bacterium tumefaciens on culture media: (a) Daisy organism; agar plate from bouillon; 

 incubated 4 days at 22 to 25° C. (b) Daisy organism from a tumor; agar plate 8 days 

 old. (c) Gall organism from a peach gall; agar plate 14 days old. (d) Hard gall of 

 apple on agar poured plate at end of 5 days after being used for inoculations. The large 

 colony is an intruder, (e) Same as a. (f) Needle stroke of daisy organism on slant 

 agar, photographed after some days, (g) Old tube of sterile milk, (h) Similar tube 

 inoculated 2 months with daisy organism, showing the pellicle formed and slow separa- 

 tion of whey from casein which remains undigested and fluid. 



