356 



BACTERIAL DISEASES OF PLANTS 



when the sky is free from clouds, dust or haze, keeping one-half 

 of the plate covered). 



Effect of sodium chlorid in +15 peptonized beef bouillon 

 (begin with 5 per cent and increase to 10 per cent, comparing 

 on the one hand with Bacillus carotovorus and Bacillus coli and 

 on the other with Nos. I and V). 



a 



• 



Fig. 274. — Surface and buried colonies of Bacterium mori on agar poured 

 a. Photographed by direct transmitted Ught. h. The same by oblique 

 transmitted light, showing the internal markings. These colonies are smooth 

 on the surface and glistening white by reflected light but pale brownish by direct 

 transmitted light. X is a thin colony on the bottom of the plate. Time, 5 days. 

 Photographed February 10, 1919. X 10. 



Growth in test tubes of unshaken bouillon over chloroform 

 (Compare with No. II). 



Nothing is known respecting the action of germicides. 

 Can't you make some tests? 



For the disease. Signs. — Period of incubation in young 

 stems and leaves. Time from appearance of water-soaked 



