PLATE 64 
1. —Paraffin-embedded stained section of cauliflower leaf exposed to secondary 
methylamin showing hypertrophy of interior cells, absence of chlorophyll, and en¬ 
largement of the nuclei. At the left, cross section of a normal leaf rib, and at the right 
a longitudinal section of a smaller group of vascular bundles. Same material as 
Plate 46 , figure 3. X160. 
2. —Cross section of cauliflower leaf (PI. 63, fig. 2) exposed to primary ethylamin 
showing general thickening to double the normal thickness and absence of palisade 
tissue (upper surface of leaf at top.) X160, 
3. —Same leaf and section as figure 2, but from a normal portion. Palisade tissue 
above. X160. 
