Fig. 1 . Diagram showing results of crossing a variety of pea with smooth, 
round seeds with one breeding true to wrinkled seeds. P designates the two 
parent types: Ft, F2 and Fa. the character of the successive hybrid generations. 
Fig. 2 . An ear of corn resulting from crossing a variety having white grains 
with one having yellow grains, showing the F2 ratio of three yellow to one white 
grain (after East and Hayes 1. 
