. Bacteria in relation to plant diseases. Bacteria; Plant diseases. Fig. 124/ much rim. Most of the tubes were still somewhat cloudy and all became very turbid on shaking. Four of the six cultures from as many colonies produced crystals in the bouillon; two did not. Milk.—Like Bacterium solanaccarum, except that a brown rim formed on old cultures. No acid was formed, and there was no coagulation of the casein; the fluid became more and more alkaline, and after some weeks was translucent and pale brownish. (See pi. 41, fig. 3.) The milk was browner by transmitted light and so clear that print c
. Bacteria in relation to plant diseases. Bacteria; Plant diseases. Fig. 124/ much rim. Most of the tubes were still somewhat cloudy and all became very turbid on shaking. Four of the six cultures from as many colonies produced crystals in the bouillon; two did not. Milk.—Like Bacterium solanaccarum, except that a brown rim formed on old cultures. No acid was formed, and there was no coagulation of the casein; the fluid became more and more alkaline, and after some weeks was translucent and pale brownish. (See pi. 41, fig. 3.) The milk was browner by transmitted light and so clear that print could be read behind it and that a penholder could be seen very readily behind two tubes when one was placed back of the other; the brown bacterial rim was not visible until toward the close of the experiment, it having increased very noticeably during the last 2 weeks; the black rim has not been ob- served in milk cultures of the tomato and potato organism. Litmus milk.—Like Bacterium solanacearum (pi. 41, fig. 6), except that I have not seen any crystals such as shown in fig. 124. Colin s solution.—No growth. Numerous tests. Reduction of nitrate to nitrite.—Copious in bouillon. Thermal death-point.—This is above 48° C. and below 52° C. Minimum temperature.—This is above 8° C. No growth was obtained at C. in 6 tubes of +15 peptonized beef-bouillon exposed for 5 weeks. These were inoculated from as many colo- nies. Four out of 6 similar tubes finally clouded at C. Gas.—None from any medium. Aerobism.—Strictly aerobic so far as can be determined from general appearance of buried colo- nies, failure to grow in hydrogen, and behavior of stabs in agar and gelatin. ETIOLOGY. EXPERIMENTS OF 1907. On July 29, 1907, three young tobacco plants about 4 to 6 inches high, Nos. 595_597» were inoculated directly with Bacterium solanacearum from the browned bundles of tomato stems from Lanham, Maryland. The stems were squeezed until the juice came out, and this an
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