TABOO AND GENETICS 49 



or double in that material, though he favoured 

 the latter explanation. 



Dr Bell, the English gynecologist, using 

 human surgical cases as a basis, commits 

 himself strongly to the dual basis. (2, p. 13.) 

 " Every fertilized ovum," he says, " is poten- 

 tially bisexual," but has " a predominating 

 tendency . . . toward mascuhnity or femin- 

 inity." But " at the same time," he remarks, 

 "it is equalty obvious that latent traits of the 

 opposite sex are always present." After dis- 

 cussing mental traits observed in each sex which 

 normally belong to the other, he concludes as 

 follows : " If further evidence of this bisexuality, 

 which exists in everyone, were required, it is 

 to be found in the embryological remains of the 

 latent sex, which always exist in the genital 

 ducts." 



In some lower forms, dual sexuality is apparent 

 until the animal is fairly well developed. In 

 frogs, for example, the sex glands of both sexes 

 contain eggs in early life, and it is not possible 

 to tell them apart with certainty, until they are 

 about four months old. (12, p. 125.) Then the 

 eggs gradually disappear in the male. 



However, we need not depend upon non- 

 mammalian evidence for either the secretory 

 explanation or the dual basis. An ideal case 

 would be to observe the effects of circulating 

 the blood of one sex in a developing embryo of 



E 



