BROWN ROT OF SOLANACEAE. 



197 



The organism is not sticky, or only slightly so occasionally on agar, and diffuses out of 

 the vessels of the host-plants readily in 75 per cent alcohol, but not, according to Hunger, 

 when i per cent nitric acid is added to the alcohol. It possesses a decided odor when grow- 

 ing on potato, i. e. t a smell like that of some rotting potatoes, and likened by one person to 

 the odor of sour bran. The starch of steamed potatoes is not destroyed to any great extent, 

 but a little of it is converted into amylodextrine, 

 i. e., yields a red reaction with iodine. There 

 was no growth, or very slight, in Cohn's solution; 

 very little growth appeared on silicate jelly (with 

 Fermi's solution) at the end of 6 days. The 



Rg. 107.* 



Fig. I08.f 



*Fic. 107. Portsmouth. Virginia, potato tuber. A detail from fig. 83 at A, showing more extensive bacterial 

 occupation than in fig. 83 at /*. and complete absence of starch on the periphery. A few starch-grains occur inside of 

 cells at 5/. (center). Only four cells containing crystal-sand are present. Cavities have begun to form and additional 

 ones are present beyond C (right margin), where also are a few cells containing starch-grains (see fig. 106). In various 

 places, as at X (use lens), some change has taken place in the walls of the cells and they are made out with difficulty. 

 In other places, as on the left side, cells which appear to have unbroken walls are occupied by the bacteria. The walls 

 of the cells destitute of starch seem to take the stain somewhat heavier than those of cells in which it is present. 

 Camera drawn, but slightly diagrammatic. Slide 349(15. 



fFlo. 108. A detail from fig. 83 at B, showing character of the tissues and absence of the starch in the vicinity of 

 the bacterial foci (at the center). Tissues fixed in Carnoy's solution. Camera drawn, but slightly diagrammatic 

 t. r., it is probable if the slide were taken and compared cell by cell with the drawing, some omissions and some errone- 

 ous lines would be detected. 



