MORE RECENT INVESTIGATIONS OF MENDELISM 553 



resented by A, B, C, and D. Since the tall variety is pure for 

 its height, its extra height over the small variety is due to the 

 presence of AABBCCDD, and the corresponding constitution of 

 the small variety is aabbccdd, in which the small letters represent 

 the absence of the extra factors for size. If the tall variety is 

 32 inches taller than the small variety, each of the factors A, B, 



FIG. 482. Inheritance of size and beards in Wheat. Parent types 

 (Turkey X Bluestem at the left and a hybrid No. 143 at the right) and be- 

 tween the parent types the FI generation of the Cross. In the FI generation 

 the heads are somewhat intermediate in size and have short beards. After 

 Gaines. 



C, and D represents 4 inches in height. Now the gametes of 

 the tall variety have A BCD in them, while the corresponding 

 constitution of the gametes of the small variety is abed, and 

 the fertilized eggs and first generation of hybrids resulting 

 from the cross between these two varieties have the formula 

 AaBbCcDd. Now since each factor for height represented by 

 the large letters is responsible for 4 inches of height, the individ- 



