THE MULBERRY BLIGHT: CA1SK 



347 



the American species, believing the French organism could not 

 be different from our own. In this belief I was entirely right, 

 as subsequent observations and experiments have proved (1913). 

 With these introductory comments we may proceed to a 

 statement of the characters of Bacterium mori B. and L., drawn 

 entirely from studies made in my laboratory, using cultures de- 

 rived both from American and French sources. 



FIG. 268. Cross-section of young stem of mulberry showing the inner cortex 

 honeycombed by cavities due to Bacterium mori. A. natural infection from 

 Arkansas. 1908. Medium magnification. 



Bacterium mori B. and L. emend. EFS., is a white, non-viscid 

 or slightly viscid (potato), slow-growing, non-sporiferous, non- 

 capsulate, actively motile (1-7 polar flagella, usually 1-4), 

 Gram-negative, non-gas-forming, strongly aerobic, non-lique- 

 fying (gelatin and Lo frier's solidified blood serum), non-nitrate- 

 reducing, acid-sensitive (Cohn's solution), sunlight-sensitive, 



