SEX BIOLOGY AND SEX PSYCHOLOGY 149 



characters begin to develop, including male instincts; 

 and dissection reveals the presence of a double set 

 of ducts — the female uterus and vagina, the male 

 epididymis and vas deferens, but only a single uni- 

 form reproductive 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, has been physiologically in a neutral 

 state, which permits the growth of the internal ap- 

 paratus proper to both sexes. Externally, the ''neu- 

 tral" condition approximates 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 in- 

 stincts. 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 activa- 

 tion 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 



