12 



HELEN DEAN KING 



TABLE 5 



Shoiring the sexratios in the inbred and in the half-inbred litters produced in each of 

 the first twenty-five generations of the B series of inbred 



100 9 , and that the 106 half-inbred htters had an even higher 

 proportion of males (IM.OcT : 100 9 ). For the total of 250 

 litters the sex ratio was 113.2cf : 100 9 . 



Until the seventh generation, as already stated, there was no 

 selection of breeding animals iir either series. As the sex ratio 

 among the animals in the early generations of the A series was 



