SEX RATIO OF THE ALBINO RAT 



387 



The five litters produced by the two rats that were spayed on the 

 left side contained 25 young, of which thirteen were males and 

 twelve were females. These results show that the sex ratio is not 

 affected in the slightest degree by the removal of the right or of the 

 left ovary from the breeding feniales, and that each ovary pro- 

 duces, in approximately equal numbers, eggs that are capable of 

 developing into males and eggs that can develop into females. 



Henke and von Seligson maintain that it is not possible for a 

 male to be produced when the right gonads are lacking in the 

 breeding pair, or for a female to develop when the left gonads have 

 been removed. They also state that it is impossible to fertilize 

 the eggs of an ovary with spermatozoa from the testicle on the 



10 



Table 1 



47 



4.7 



22 



opposite side of the body. To test the truth of these hypotheses 

 for the albino rat the following series of experiments was made: 



1. Female no. 2, which had been spayed on the right side, was 

 mated with a male from which the right testicle had been removed. 

 A litter containing five young was obtained; three of these indi- 

 viduals were males and two of them were females. 



2. Female no. 3, spayed on the left side, was mated with a 

 male castrated on the left side. There was one male and one 

 female in the resultant litter. 



3. Female no. 1, lacking the right ovary, was mated with a 

 male that had been castrated on the left side. This female had 

 a litter containing five young, of which three were males and two 

 were females. 



