382 HELEN DEAN KING 



were mated are very remarkable. In every instance a litter was 

 composed of males when the left ovary and the left testicle of 

 the parents were lacking, and entirely of females when the oper- 

 ation had removed the gonad from the right side of each parent. 

 In one of his experiments Henke mated a bitch that had been 

 sprayed on the right side with a dog that had been castrated on 

 the left side, but no litter was produced. From the results said 

 to have been obtained in these experiments Henke concludes that 

 in all mammals each ovary and each testicle has its own kind of 

 ^germ. ' Eggs from the left ovary can only be fertilized with 

 'samen' from the left testicle, the resultant individual always 

 being a female; conversely, male eggs from the right ovary can 

 only be fertilized with 'samen' from the right testicle. Most 

 modern zoologists would not consider these conclusions warranted, 

 since Henke made but a small number of experiments and appar- 

 ently had no controls of any kind. 



Ignoring the manner in which Henke carried out his experi- 

 ments, von Seligson ('95a, '95b) uses the results to support his 

 own theory, which is that of Henke expressed in more modern 

 terms. Von Seligson himself operated upon four female rabbits, 

 removing the left ovary from two of them and the right ovary 

 from the remaining two : each of these rabbits was subsequently 

 mated twice with normal males. Von Seligson states that the 

 two females that were spayed on the left side produced males 

 only, and that the other two rabbits had litters containing only 

 females. The results of these experiments can hardly be con- 

 sidered to afford conclusive evidence in support of von Seligson's 

 claims, since all details are wanting regarding the manner in 

 which the experiments were conducted. Von Seligson does not 

 mention what precautions, if any, were taken to safeguard the 

 experiments ; and in no case, apparently, did he make an autopsy 

 to ascertain whether or not the operation had been successful. 



The publication of von Seligson's theory caused a considerable 

 amount of discussion among physicians, particularly in Germany, 

 and a number of papers soon appeared in various medical journ- 

 als giving birth records, after one-sided ovariotomy, which were 

 not explicable according to the theory of Henke and von Selig- 



