26 



BACTERIAL DISEASES OF PLANTS 





* 



T^^K** 



FIG. 17. Black chaff of wheat. Agar plate poured (June 2, 1917) from a leaf 

 stripe of No. 20, McKinney, Texas. Photographed June 11. X 4. Colonies yel- 

 low and smooth on surface (as photographed), and also by direct transmitted 

 light; but by oblique transmitted light they are like Figs. 18, 19. 



