PLANT BACTERIA-VOL 3. 







TOBACCO WILT. 

 Behavior of Sumatran Bad. solanaeearum (Medan III) at 25C. in centrifuged !itmus-milk to which cream was added. (1) Control 

 in cream-free litmus-milk, inoculated and kept 31 days (compare with pis. 23, fig. 7, and 41. fig. 6): no reduction, .scanty bacterial 

 precipitate at X; (2) the same with addition of cream: tube inoculated 8 days, acid production beginning in cream layer; (3) another 

 tube of same inoculated milk plus cream, after 31 days: distinct reduction, and copious bacterial precipitate at X; t4) another tube of 

 the same after 55 days. Tubes 5, 7, 8, are cultures of other organisms in same creamy medium introduced for comparison: (5) 

 Aplanobaeter michiganensi i N. Y. strain, colony 5), after 12 days: cream not reddened (compare with pi. 11, fig. 6); (6) uninoculated 

 tube for comparison with 7 and 8, the white mass at the top is cream; (7) Bacterium campestre after 28 days: milk slightly reddened 

 and translucent, cream unchanged; (8) Bacterium mori (isolated from French mulberry) after 28 days: milk blued, cream not reddened. 



