THE BLACK ROT OF CRUCIFERS I TECHNIC 151 



i 



b # 



Fig. 90. — Surface and buried colonies of Bacterium campestre (New York iso- 

 lation of 1908) at end of 10 days in +14 beef peptone agar. Crystal at x. Colo- 

 nies coming to the surface at a, b. Photographed February 11, 1919, by direct 

 transmitted light. X 10. Tested on Crucifers Feb. 9, 1919. 



