PLANT BACTERIA-VOL. 3. 



PLATE 41. 



TOBACCO WILT. DISEASE OF ORCHARD GRASS. 



CI. 2. 7) The Japanese tobacco disease. After Uyeda. (3) Tube of milk inoculated on August 23, 1905. with N. C. tobacco 

 organism (colony B), painted October 11, by reflected light. (4) Old potato culture of the N. C. tobacco organism. Inoculated 

 July 17, 1905, painted August 27, bacterial growth dark brown, substratum and fluid browned. This will answer equally well for the 

 potato and tomato organism. (5) Check tube of litmus-milk. (6) Tube of litmus-milk inoculated with the N. C. tobacco organism 

 September 25, 1905, and painted October 20, i. e., after 25 days at about 25C. Bacterial precipitate at bottom. No acid formed; 

 gradually increasing alkalinity without separation of casein. Illustrates equally well cultures of potato and tomato organism of same age. 

 (8) Agar poured-plate colony of the Granville tobacco wilt organism after 22 days at about 23C. x 4, painted April 22, 1909. Plated from 

 stem of wilting tobacco-plant (root infection). Central part of the colony darker than the periphery. The brown stain in the agar is 

 somewhat exaggerated. (9, 10) Spikelets of orchard grass showing early and late stage of Rathay's disease. 



