Bui. 213, Bureau of Plant Industry, U. S. Dept. of Agriculture, 



Plate XXIX. 



Cross section of outer part of a tobacco stem. The lower half of the plate shows normal 

 cortical parenchyma; the upper (outer) half, rapidly proliferating small-celled tumor 

 tissue resulting from an inoculation. In the upper right-hand corner (in cross section) 

 is a recently developed vascular bundle. 



