THE ANGULAR LEAF-SPOT OF COTTON: TYPE 



321 



nomenally large and interferes with the making of a crop, as now 

 seems probable; and especially, if this schizomycete generally 

 paves the way for the entrance of the destructive boll fungus, 

 Glomerella gossypii (Collet otricum gossypii Southworth), as 

 Mr. Orton believes or did believe at one time, then indeed it is a 

 very serious enemy of cotton growing. This much is certain, 



FIG. 244. Cotton leaf inoculated May 4, 1915, from a windowed colony. Photo- 

 graphed June 26, 1915. Time, 53 days. 



the anthracnose fungus and the schizomycete often occur 

 together on the bolls in such a way as to indicate that the 

 first invasion was bacterial. Further studies are necessary. 

 Weather conditions have much to to with the prevalence of 

 the disease. 



Cause. This disease is due to Bacterium malvacearum EFS. 

 This organism is a yellow, Gram-negative, non-acid-fast 



and fixed in Carnoy's fluid, April 5. Sectioned from paraffin. Amyl-Gram 

 stain. Stomatal region pushed up. X 1000. From a photomicrograph by 

 the writer. 



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