PLATE 3 
Photomicrographs of crowngall tissue from tomato stem 
A. —Six days after inoculation. The darkly stained region (a) which contains 
the bacteria is surrounded by a more or less circular hyperplastic area (b), and this is 
bordered by a region of hypertrophy (c). Paraffin section, stained with Flemming’s 
triple stain. X167. 
B. —A darkly stained region on the same slide as section A, but a few sections re¬ 
moved, is shown at a higher magnification. In this preparation the bacteria (a) are 
masked by the increased intensity of staining in the wall (b) and the substance in the 
intercellular space. X600. 
C. —Forty-eight hours after inoculation. The large clear space (a) shows where the 
needle passed. This is surrounded by masses of bacteria which appear also in the 
injured cells (b) and intercellular spaces (c). The region at x is enlarged in figure D. 
Paraffin section stained with dilute carbol-fuchsin and light green. X134. 
D. —An enlargement of the region marked x in figure C. Ruptured cells appear so 
crowded with bacteria that their continued activity seems unlikely. X400. 
