150 



BACTERIAL DISEASES OF PLANTS 



Inoculate by needle-pricks on the under surface of the fleshy 

 petiole, some petioles on one side only, some on both sides and 



B 



. i 



FIG. 88. A, B. JFlagella of Bacterium campestre. Stained by van Ermengem's 



silver nitrate method. X 1000. 



FIG. 89. A, Surface colonies of Bacterium- cnmpestre on nutrient agar. Plated 

 from B.C. rape. Time, 6 clays. Photo Feb. 6, 1919. X 10. B, The same by 

 oblique transmitted light. 



in the middle, setting the needle deep enough to enter the bun- 

 dles. Other plants should be inoculated in the upper soft stem 



