SEX BIOLOGY AND PSYCHOLOGY 149 



and vas deferens, but only a single uniform repro- 

 ductive organ, and that always a testis. The simplest 

 explanation (although it is admittedly tentative) 

 appears to be that the testis has not been activated 

 during embryonic and juvenile life, and that therefore 

 until puberty the animal, though really male, his 

 been physiologically in a neutral state, which permits 

 the growth of the internal apparatus proper to both 

 sexes. Externally, the * neutral ' condition approxi- 

 mates more closely to the female type, and the animal 

 is thus first classed as a female. Some other gland is 

 then responsible for the second activation at puberty, 

 and this occurs in a normal manner. 



This is of considerable interest, since it appears 

 that in man too the largest class of sexually abnormal 

 individuals are those whose external appearance is 

 almost or quite feminine, but who possess male instincts. 

 It is at least probable that examination will show that 

 they, too, or many of them, will be of the type described 

 above — males with delayed activation of testis, a 

 consequent classification as female at birth, and a 

 girl's upbringing, with male instincts arising in the 

 unhappy creature at puberty. 



It is the fashion nowadays to write down abnormal 

 sexual psychology wholly to the account of the mind, 

 to an abnormal development with causes entirely 

 psychological. It is clear, however, that if some 

 abnormal individuals can be cured by implantation, 

 and others are abnormal owing to an early failure of 



