I02 



Heredity and Eugenics 



such varieties are crossed together the first hybrid genera- 

 tion produces ears with red pericarp and red cob like 

 the colored variety in the previous cross. In the second 

 hybrid generation, however, we find produced i red 



Mm 



Fig. 43. — Red pericarp and red cob coupled in inheritance. (Photo by 

 Emerson.) F2 generation shown. Ears i, 2, 3 with red cob and red pericarp, 

 ear 4 with white cob and white pericarp. 



pericarp with white cob: 2 red pericarp with red cob: i 

 white pericarp with red cob. The first and third classes 

 breed true to their conditions, but the second class proves 

 to be always heterozygous and breaks up in the next gen- 

 eration as did those with similar characters of the first 

 hybrid generation. 



