14 



THE SEX-COMPLEX 



the two sexes. 



Differences in the hormonopoietic organs other than the generative 

 internal* portions of the gonads functional, even if there were 

 secretion in no obvious structural, differences. This is an important 

 point that has, strangely enough, been entirely over- 

 looked, in spite of all the evidence from the pathology 

 of the organs of internal secretion, to which I shall call 

 attention later. 



SECONDARY SEX-CHARACTERISTICS 



Nature of 

 secondary 

 character- 

 istics. 



Importance 

 of secondary 

 character- 

 istics. 



At birth we distinguish the sex of the child by the 

 character of the external genitalia, which in normal 

 circumstances correspond with the internal genitalia. 

 These genital features are generally held to constitute 

 the primary characteristics. At the same time, as 

 already indicated, were we able to recognize the differ- 

 ences, we could claim primary sex-characterization, 

 male or female, in regard to probably all the ductless 

 glands. 



The secondary characteristics, however, constitute 

 the sexe-ensemble seen not only with respect to the general 

 conformation of the body and the details connected 

 therewith, but also in connexion with the specialized 

 functions peculiar to the sex, both physical and 

 psychical. 



No doubt the secondary characteristics appeared 

 after the differentiation of sex was evolved, to assist 

 sexual selection and adapt the different species to their 

 environment and conditions of reproduction. 



The secondary sex-differentiations vary considerably 

 in different classes of animal life. In some, such as the 

 rodents among the mammalian orders, the differences in 

 the secondary characteristics of the two sexes are slight. 

 In others, such as the birds, they are often most pro- 

 nounced. 



The secondary sex-characteristics are to be noted not 

 only in the various forms of external adornment, in the 



