DETERMINATION OF SEX 13 



It may, therefore, at once be stated emphatically Ovaries alone 

 that the ovaries are not alone responsible either for 

 the primary or the secondary female characteristics. 

 We have very pertinent evidence on this point, to beistics. 

 considered later, in the human monstrosities known as 

 'Hermaphrodites'. In certain of the invertebrates 

 hermaphroditism to the fullest extent that is with the 

 power of fertilizing and of being fertilized is well 

 known, but generally speaking the higher we go in 

 a consideration of the evolution of reproduction the 

 greater do we find the differentiation of sex-character- 

 istics and functions. 



It is probable, then and I shall adduce much 

 evidence on the point later that many if not all the 

 organs of internal secretion influence the primary 

 genital characteristics ; and that all the hormonopoietic 

 organs, as well as the gonads, have normally a primary 

 tendency to produce either masculine characteristics 

 and functions, or feminine. 



It has been stated that there is no evidence that the Differences in 

 organs of internal secretion, other than the gonads, differ 



histologically in the two sexes 1 , although Kolmer 2 claims secretion in 



J . the two sexes. 



to have noted differences between the male and female 

 suprarenals in rabbits, and Erdheim and Stumme 3 have 

 demonstrated the effect of pregnancy on the pituitary. 

 But we need not be surprised at these differences of 

 opinion, when we remember that although the special 

 sex-elements ova and spermatozoa must necessarily 

 be differentiated, the interstitial cells of the gonads, 

 as we shall see in dealing with hermaphroditism, do 

 not show any special tendency to produce either male or 

 female secondary characteristics, as has been universally 

 presumed hitherto. But since all persons are bi- 

 sexual in varying degrees, one would expect to find in 



1 Mcllroy, Louise, Discussion. Proc. Roy. Soc, Med., (Obstet. and 

 Oyncecol. Sect.) 1913, vol. vii, p. 76. 



2 Kolmer, W.,Pfl'uger's Archiv. f. Pkysiol., 1912, vol. cxliv, p. 361. 



3 Erdheim, J., and E. Stumme, Beitr. z. Pathol. Anat. und z. Attg. 

 PathoL, 1909, vol. xlv, p. 1. 



