24 



HELEN DEAN KING 



TABLE 10 

 Showing the sex ratios in litters produced by the mating of outbred stock females with 



inbred males 



examined was too small to warrant any general conclusion from 

 the results obtained. 



The second section of table 10 shows the sex ratios in the vari- 

 ous groups of litters obtained from the matings of stock females 

 with males from the ninth to the eighteenth generations of the A 

 series of inbreds. There was considerable variation in these sex 

 ratios, as was to be expected considering the number of animals 

 involved. The total of 107 litters in this group gave a sex ratio 

 of 102.3 cf : 100 9 . This ratio, it will be noted, was below the 

 norm, although the sires of the litters were males that, paired 

 with their sister, had fathered litters in which there was, as a rule, 

 a preponderance of male young. 



