SCHIZOMYCETES. BACTERIA 



121 



Pseudomonas malvacearum Erw. Smith. This parasite produces, 

 through stomatal infections, water-soaked, angular areas (Fig. 30), 

 known as angular leaf spot of cotton (Gossypium). Later these 



^sr^C: 



Fig. 30. Angular Leaf Spot of Cotton. (Photograph by Erwin F. Smith) 



spots turn purple and finally become dry and brown. The disease 

 is apparently widely distributed in the southern states, but the 

 organism has not yet been fully described. 1 



X. PEAR BLIGHT 

 Bacillus amylovorus (Burrill) De Toni 



Arthur, J. C. Diseases of the Pear. N. Y. Agl. Exp. Sta. Rept. 3 : 357-367. 



1884. 

 Arthur, J. C. History and Biology of Pear Blight. Proc. Phil. Acad. Nat. 



Sci. (1886): 322-341. pi. 3. 

 Burrill, T. J. Trans. 111. State Hort. Soc. (1877): 114; ibid. (1878): 80. 

 Burrill, T. J. Proc. Am. Assn. Adv. Sci. 29 : 583. 1880. 



1 Smith, Erw. F. Bacteria in Relation to Plant Diseases 1 : 95, 126. 



