Bui. 229, Bureau of Plant Industry, U. S. Dept. of Agriculture. PLATE IV. 



Fig. 1.— Photomicrograph of a Section of Extra-Floral Nectary of the Cowpea 

 Flower. From a Section Prepared by Dr. Albert Mann. 



^ & ^ 



<...-,- if, ■ 



Fig. 2.— Two Samples Each of Seven Varieties of Cowpeas, Showing the Dif- 

 ferent Types of Color Distribution. 



(Natural size.) 



