INTERSEXUALITY 407 



Scheme B. This is easy to understand, if we take into con- 

 sideration the fact that a quaUtatively uniform change in the 

 activity of male or female sexual hormones will cause very 

 different changes in the somatic and psychical sex characters, 

 according to the time at which the activation of the hormones of 

 the other sex takes place, and according to the quantity of 

 the heterologous sexual hormone which enters into play. 

 This is why it is very difficult to limit different groups 

 or types of intersexuality in a classification based on sex 

 characters. 



By "complete" intersexuality we do not mean that there 

 are cases where the male and female modifications of every 

 sex character are simultaneously present in the same individual, 

 but only that there are cases where besides different somatic 

 and psychical characters of both sexes generative characters 

 of both sexes are also present. Complete intersexuality, which 

 is the rule in some invertebrates and in many plants, is a very 

 rare phenomenon in vertebrates, and especially in man. As 

 Blair Bell says, very few cases would pass the test if the 

 described condition of complete intersexuality is considered 

 critically. Most of the cases belong to partial intersexuality. 

 There are cases where only somatic characters of both sexes 

 are present, and other cases w^here there is only a psychical 

 bisexuality. Further, a combination of somatic characters 

 of one sex with psychical characters of the other sex is possible 

 as in ordinary homosexuality. 



The somatic and psychical sex characters in intersexual 

 individuals are as a rule incompletely developed or rudi- 

 mentary; this can be explained on the assumption that these 

 characters are derived from an antagonistic, simultaneous or 

 successive action on the part of the hormones of both sexes. 

 But sometimes one or more somatic, psychical or generative 

 sex characters may be completely developed. Underdevelop- 

 ment of heterologous sex characters in the intersexual individual 

 will be all the more marked the later the heterologous hormones 

 enter into action. Since the reaction of the different sex 

 characters to the sexual hormones will be very different accord- 

 ing to time, it follows that variations in time and variations in 

 the quantity of the hormones of both sexes will cause an extra- 

 ordinary variability of intersexual types. One may say without 

 any exaggeration that there are no two intersexual individuals 



