PLATE 24. 



Brown rot of the potato. 



Potato-tuber from Hastings, Florida, crop of 1905. sound externally, but brown-rotted in the vascular system, the bacteria having entered 

 through the vessels of the underground stem. Bacterium solanacearum was plated out and subculture* were used to infect potted potato- 

 plants. The plant shown was inoculated on June 27, by delicate needle- pricks. Disease more advanced on one inoculated hoot than on 

 the other; later this also shriveled. Tuber natural size; photographed May 29. Plant about one-fifth natural size; photographed 

 July 15. 1905. 



