PLATE 53 
1. —Like Plate 52 but here the palisade tissue is also involved. No evidence of 
hyperplasia nor much of ingrowths of vascular tissue (X). Two rows of cells at the 
lower surface of tumor omitted. Same magnification as Plate 52 ( X160). 
2 . —Cross section of an ammonia intumescence above the level of the under surface 
of the leaf. Contrast with Plate 58, figures 1 to 4, which have the same magnification. 
Time, 9 days. X 160. 
67908°—17-9 
