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 

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



Fig. 56. 

 Types of F2 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 



