PLATE 23. 



Bacterial wilt of the cucumber. 



(Introduced to illustrate transmission of the disease by insects). The central plant (variety Long green) wai inoculated on June 17 with Bacillus 

 tracheiphilus by the striped cucumber-beetle (Diabrotica vittata). As a result the gnawed leaves first wilted and then the whole upper part of 

 the plant, the vascular bundles being occluded by the sticky white slime of this bacillus. Photographed July 1 , 1 905. About 1-14 natura 

 ze. The entire plant was dead about two weeks later. 



