112 BENJAMIN H. WILLIER 



underlie these asymmetrical disturbances. The blood supply 

 may be greater to the left gonad than to the right, yet this can- 

 not be regarded as the primary factor. 



The interrelation between the reproductive glands and other 

 glands of internal secretion is supported by the observations of 

 many, yet none of these observations furnish any definite clue 

 as to the nature of the correlation. The whole developmental 

 history of the free-martin reproductive system is certainly com- 

 plicated by such correlations as these. 



If the intersexual condition in the free-martin gonads is com- 

 pared with the condition of intersexuality in the gonads of other 

 animals, definite similarities in structure and origin are recog- 

 nized. Goldschmidt ('12, '14, '16) has shown that both the male 

 and female individuals of Lymantria contain the primordia for 

 each sex. Which sex is to appear depends upon the quantitative 

 relations of both male and female sex factors of the gametes. 

 If the crosses between two species are made in such a way that 

 the male factors have dominance over the female factors, an 

 ovary transforms into a testis. Thus with a variable quantity 

 of the male factors all degrees of transformations are possible. 

 On this point Goldschmidt ('16, p. 713) states: ''This is a body 

 [sex gland] looking externally like a testis, but showing in sec- 

 tions every single step between an ovary with nothing but 

 immature eggs through a mixture of ovarial and testis tissue to a 

 real testis." The reverse changes, that is, the transformation 

 of a testis into an ovary, are also possible. It has been shown 

 that the free-martin gonad is primarily an ovary, which would 

 be due, according to the conceptions of Goldschmidt, to the 

 dominance of the female factors over the male. Lillie ('17) 

 pointed out that the intersexual condition in the free-martin 

 gonad may be explained "as due to an acceleration or intensi- 

 fication of the male factors of the female zygote by the male 

 hormones." The degree of transformation would be dependent 

 on the quantity of the hormone. Obviously, in the free-martin 

 gonad the male-sex expression is the result of a variable quantity 

 of internal secretions, instead of a variable quantity of male-sex 

 factors as in the gonads of the intersexual hybrids of the gypsy- 



