98 



THE THEORY OF THE GENE 



character reappeared in almost one-quarter of the indi- 

 viduals in the second generation. 



Baur crossed two species of snapdragon, Antirrhinum 

 majus and A. molle (Fig. 54). He used at least five 



Fig. 56. 



Types of F 2 flowers from the cross shown in Fig. 55. (After 



Baur.) 



mutant types of A. majus and recovered them in the sec- 

 ond generation in the expected number of individuals 

 (Fig. 55 and 56). 



Detlefsen crossed two species of guinea pigs, Cavia 

 porcellus and C. rufescens. The hybrid females (the hy- 

 brid males are sterile) were mated to C. porcellus males 



