ACTION OF SEX HORMONES IN FOETAL LIFE 417 



male factors in different varieties as in the intersexual hybrids of 

 Lymantria. 



The case of the free-martin shows that a gonad with a primary 

 female determination may form a structure which is morphologi- 

 cally a testis (Chapin '17), through suppression of the cortex and 

 overdevelopment of the medullary cords and urinogenital union 

 under the influence of male sex-hormones. Lesser degrees of 

 transformation are of course possible, so that it is certain that the 

 gonad of a mammalian female zygote is capable of most, at least, 

 of the series of transformations that may exist between an ovary 

 and a testis. Whether the transformation in the male direction 

 may proceed under such conditions to the production of true sper- 

 matocytes and spermatozoa is at least doubtful. Such elements 

 have not hitherto been described for free-martins, if we except D. 

 Berry Hart's statement concerning the gonads of Hunter free- 

 martins, that "in only one are spermatozoa present." More than 

 six words seem necessary to establish so important an exception. 



Pick's investigation of ^true hermaphroditism' in man and 

 mammals shows that in all bilateral cases the gonad is part 

 ovary and part testis; but that whereas normal germ cells may 

 arise in the ovarian part, there is no trace of spermatocytes or 

 spermatozoa in the testicular part. Four such cases are de- 

 scribed for the hog, and it would seem that the theoretical' possi- 

 bility exists of explaining them as due to embryonic foetal anasto- 

 mosis of blood-vessels between opposite sexes, by making the 

 farther assumption that such anastomosis was only temporary 

 and ceased after the transformation of part of the genital ridge. 

 The interpretation of 'hermaphroditism''' in mammals is in any 



* The term 'hermaphroditism' has so many and various connotations that it 

 seems better to drop it from our vocabulary, so far as mammals are concerned, 

 and to describe the conditions hitherto gathered under this head simply as inter- 

 sexual. Some conception of the confusion that results from present methods of 

 classification of these cases may be felt by stating that our case 44 (fig. 28), 

 would be classified as Hermaphroditismus spurius masculinus externus (Neu- 

 gebauer '08): 'spurius' because both kinds of gonads are not present; 'mascu- 

 linus' because the gonads are apparently testes; 'externus' because the external 

 organs are female. But the animal is female, not male, and it represents merely 

 a certain stage in a series. The animal is not a sex-mosaic, e.g., male in front 

 of a certain transverse level and female behind ('transverse hermaphroditism'); 

 it is a step in a series of sex intergrades. 



