THE BEAN BLIGHT! TECHNIC 



291 



let, and Red Valentine are susceptible varieties, also many others 

 including Early Refugee, reported as resistant. 



Infections appear sooner and the disease progresses faster 

 in warm weather than in cool weather. If there are facilities, 

 two sets of spray inoculations may be identical in all respects 

 except as to temperature, i.e'., one in a greenhouse at 30 to 

 35C., the other in a house at 18 to 20C. 



Determine 



FOR THE ORGANISM. Morphology. Size in microns. Con- 

 ditions under which chains and filaments occur. Absence of 



FIG. 225. Bacterial invasion in outer tissues of a bean pod. Epidermis lifted 

 by bacterial pressure in the stomatal region. Intercellular spaces occupied. A 

 stomatal infection obtained by spraying. Time, 12 days. 1914. 



endospores. Number and attachment of flagella. Conditions 

 leading to the formation of clumped masses (pseudozoogloeae). 

 Do involution forms occur? Are the rods ever curved or larger 

 at one end than at the other (see No. II)? Do capsules occur? 

 Cultural Characters. Determine appearance of colonies on 

 thin-sown agar plates (figs. 229, 230) ; behavior in agar stabs and 



