SEXUAL DIMORPHISM 3 



also possible to any degree at all in the absence of the sexual 

 glands ? 



It will be our task in the following chapters of this book to 

 supply answers to all these questions, basing our statements 

 on the known data, and only after this has been done shall 

 we have the material necessary for a genetic system. Until 

 these questions have been answered, there can be no object 

 gained in discussing whether or in what way we should 

 distinguish between "secondary" and ''primary" sexual 

 characters. 



Nevertheless it is desirable at the outset that we should have 

 a clear idea as to what we mean by a "sexual character." In 

 the present work we propose to use the term so as to include 

 all morphological, physiological and psychological features b}^ 

 which the individuals of one sex of a given species differ from 

 the individuals of the other sex of the same species. It will 

 not matter whether these distinguishing features are related to 

 the sexual function or not. That certain features are different 

 in the two sexes suffices to designate them as sexual characters. 

 For us the generative cells will be sexual characters in the same 

 sense as the penis, the clitoris, the uterus and the prostate, 

 as the hairiness, size and proportions of the body, as voice, 

 temperament and sexual behaviour. The problem we have to 

 solve is the genetic systematization of the sexual characters. 



From what has just been said it follows that at the base of 

 our attempt to erect a genetic system of the sexual characters 

 we shall put the sexual glands. The justification for doing so 

 will be apparent when we have dealt with the facts described 

 in the following pages. These will show to how great an extent 

 the sexual characters depend upon the sexual glands. But one 

 realizes also at the outset, as has been clearly show^n, that the 

 sexual glands themselves depend in their development and 

 function upon other internal factors. The thyroid gland, the 

 adrenals, the hypophysis, the pineal body, are in functional 

 relation with the sexual glands and consequently with the 

 sexual characters also. These relationships must be taken into 

 consideration, if we are to understand the formation and 

 persistence of the sexual characters. Now, before we are in a 

 position to erect a scientific superstructure we require a 

 relatively fixed point or basis on which we may start to build. 

 This relatively quiescent basis is afforded by the sexual gland. 



