260 THE THEORY OF THE GENE 



ence of the blood of the male co-twin does not bring about 

 the transformation of the primordial egg cells into 

 sperm-producing cells. 



Individuals with both male and female sexual organs, 

 even including ovaries and testes, have been frequently 

 recorded in mammals, including man. These were for- 

 merly called hermaphrodites, but now are sometimes 

 called intersexes or sex intergrades. The conditions that 

 give rise to them are unknown. Crew reports twenty-five 

 cases in goats, seven in pigs.^ These, Crew believes, are 

 modified males, since testes were present in all of them. 

 Baker has recently reported that the sex intergrading 

 pigs are surprisingly common on some of the islands 

 [New Hebrides] ; "one finds them in nearly every little 

 village. ' ' This tendency to sexual abnormality is inherited 

 through the male in some cases reported by him. Baker 

 regards them as probably transformed females.^ 



2 Pick and others had earlier described such individuals, two in horses, one 

 in sheep, one in cattle. 



3 Prange has described four hermaphroditic goats with external female 

 genitalia, but with undeveloped mammae. In sex behavior and in coat they 

 were male-like. Internally both male and female ducts were present, but 

 the gonads were testes (cryptorchid). 



Miss Harman has described a " gynandromorphous " cat that had a 

 testis on the left side and an ovotestis on the right side. The reproductive 

 system of the left side is like that of a normal male, while that of the right 

 side is like that of the female, except for the size, etc., of the uterine tube. 



