CANKER OF TOMATO I CULTURAL CHARACTERS 



213 



Cultural Characters. Growth on thick vs. thin-sown agar 

 and gelatin plates. Behavior in agar and gelatin streaks and 

 stabs. Can you find two types of colony: a round, b spreading? 

 On which agar do you get the best results (a) + 15, (6) +6, or (c) 

 +0? Will the organism grow on 10 agar? 20 agar? Appearance 

 on steamed potato; behavior in bouillon, and in nitrate bouillon; 



FIG. 156. Stomatal infection on sprayed tomato leaf due to 

 michiganense. The stoma is at X. Under it the cells are destroyed and the 

 bacteria are abundant in the bundle. Time, 21 days. 



behavior in milk and litmus milk; streaks on litmus-lactose agar; 

 growth in peptone water in fermentation tubes with various sugars 

 and alcohols. Relative rapidity of growth in diluted tomato 

 and potato juices, as compared with Dunham's solution and pep- 

 tone bouillon (Titrate each to determine acidity and inoculate 

 sparingly with a 1-mm. loop from a fluid culture) ; behavior in 



