WILT-DISEASES OF TOBACCO. 



243 



Nicotiana rustica is not attacked, and the following varieties of N. tabacum are not 

 much subject: Ohasama, Taketadate, Mitsuke, Kentucky White, Green River Prior. 

 Inoculations succeeded on Physalis minimum, Capsicum longum, Amaranthus gangeticus, 

 and Polygonum tinctorum; they failed on Solanum mclongcna, Lycopersicum esculentum, and 



Physalis alkekengi. No 

 details are given as to 

 methods of inoculation, 

 phenomena produced, or 

 number of experiments. 



N itrogenous fertilizers 

 predispose to disease; pot- 

 ash salts do not. Early 

 planting is the best protec- 

 tion. 



Through the courtesy 

 of Dr. Uyeda, who sent 

 alcoholic material, I was 

 enabled to study his dis- 

 ease in serial sections. 



The bacteria closely 

 resemble Bact. solanacea- 

 rum in general appearance. 

 They are enormously abun- 

 dant in vessels of the wood, 

 in inner and outer phloem, 

 in the cortical parenchyma, 

 and in the pith. I also found 

 them to have made cavities 



Fig. 131.' 



resembling those due to Bact. solanacearum. They 

 stained deep red with carbol fuchsin and were quite 

 uniform in appearance. Spores were not observed. 

 (Compare figs. 131 and 132 

 with those made from stems 

 of the North Carolina to- 

 bacco, figs. 116 and 117.) 



Also, with bacteria 

 taken from this Japanese 

 tobacco stem I made several 

 attempts to stain the flagella. 

 At first I got no indications 

 of peritrichiate rods and 



many faint indications of Fl * IJ2 -t Fl *- 



polar flagella; nevertheless no well-stained ones, such as could be relied on for demonstration. 



*Fic. 131. Cross-section of a tobacco-stem received from Uyeda, showing character of the bacterial occupation 

 in the Japanese tobacco wilt (compare with fig. 1 17). The section is taken from the wood midway between pith and 

 bark, the cambium being in the direction of the arrow. The vessels next beyond V, V, V, V, Fare also occupied by the 

 bacteria, as well as many others. Middle section of slide 482, stained with carbol fuchsin. The contrast is greater 

 than here indicated. At X are a few bodies which look like fungus spores. (For an enlarged drawing of the bacteria 

 see fig. 132.) 



fFic. 132. Schizomycetes from the Japanese tobacco-stem shown in fig. 131. 



JFio. 133. Flagella on bacteria taken directly from the interior of a tobacco-stem attacked by the bacterial wilt of 

 Japan (Uyeda's disease). Out of alcoholic material received from Uyeda. Pitfield's stain. 



