70 



HEREDITY AND SEX 



bers. Again, the resemblance of the reciprocal cross 

 to one of the combinations for eye color is apparent. 

 In fact, this case can be explained on the same prin- 

 ciple as that used for the flies, except that in birds it is 



FIG. 40. Sex-linked inheritance in fowls. Upper line black Laugshan 

 hen and barred Plymouth Rock cock. Second line, F lt barred cock and 

 hen. Third line, F 2 , three barred (cock, hen, cock) and one black (hen). 

 (Cuts from " Reliable Poultry Journal.") F\ and F 2 for color only. 



