Bui. 108, Bureau of Chemistry, U. S. Dept. of Agriculture. 



PLATE 



F. 1. SEED COAT OF CHARLOCK. 

 (X 150.) 



FIG. 2. CROSS CELLS OF SEED COAT OF RYE. 

 (X 150.) 



FIG. 3. CROSS CELLS OF SEED COAT OF WHEAT. 

 (X 150.) 



FIG. 4. ALEURON LAYER OF WHEAT. 

 (X 150.) 



FIG. 5. EPIDERMAL LAYER OF SEED COAT OF 

 COMMON PIGWEED. (X 150.) 



FIG. 6. EPIDERMAL LAYER OF SEED COAT OF 

 ROUGH PIGWEED. (X 150.) 



