PART I 



MORPHOLOGICAL PHYSIOLOGICAL AND 

 PSYCHOLOGICAL CONSIDERATIONS 



AT the commencement it is essential that we consider 

 how far the internal secretions are concerned in pro- 

 ducing and maintaining the feminine characteristics, 

 and in ensuring the full development of the genital 

 organs. Afterwards I shall support with experimental 

 evidence the view that the internal secretions of the 

 ovary alone are not the sole factors in the preservation 

 of the integrity of the genital functions, once these have 

 been fully established. 



Origin of 



Determina- 

 tionofsex. 



SEX-CHARACTERISTICS 

 PRIMARY SEX-CHARACTERISTICS 



It has always been considered that the primary sex- 

 characteristics in the human subject are those peculiar 

 to the genital organs, and especially to the gonads. I 

 shall show later, however, that the primary sex-charac- 

 teristics cannot be limited in this way. 



If we wish to seek for the origin of the primary 

 characteristics, we are, of course, called upon to examine 

 carefully the primary causes in the determination of sex. 

 This question has been the subject of far more theorizing 

 than of scientific investigation. I propose, therefore, 

 but briefly to review some of the evidence at oui 

 disposal concerning the causation of sex. 



It is stated by Geddes and Thomson 1 and by others 

 sexua j dimorphism is found in protozoa that 



1 Geddes, P., and J. A. Thomson, The Evolution of Sex, 1901, 

 Revised ed. 



