INTERSEXUALITY 383 



the male sexual behaviour as due to the highly developed 

 interstitial tissue. Since no other male sex characters were 

 present, and since the mammary gland was developed rather 

 after the manner of a female, Loeb assumes that the effect 

 of the hormonic influence on the soma depends not only upon 

 a specific action of the interstitial cells, but primarily upon 

 the system on which the hormones act. The somatic system 

 will have in one case the tendency to react rather to the male 

 side, in another case rather to the female side. In an indi- 

 vidual with a tendency towards a female reaction even a strong 

 male hormonic influence will not be able to prevent develop- 

 ment of certain female sex characters ; the case described might 

 have been such a one. I do not think that it is necessary to 

 explain this case as Loeb does. The animal perhaps began 

 its development rather as a female, but afterwards changed 

 to a male without the male sex gland at the beginning being in 

 a very active condition; when greater hormonic activity dis- 

 played itself, only the more variable sexual behaviour reacted, 

 the other characters being already in a fixed condition. 

 So Loeb's case might possibly be understood as due to the 

 successive influence of hormones of both sexes. 



{b) The case of the freemartin. 



The observations made independently of one another by 

 Keller and Tandler (1916) in Austria and by Lillie (1916, 1917, 

 1923) in America, on the freemartin, are of the greatest import- 

 ance for a true understanding of intersexuality in mammals, 

 giving support to the assumption that intersexuality may be 

 caused during embryonic life by the simultaneous or successive 

 influence of hormones of both sexes on the soma. 



It has long been known that sometimes female twins in 

 cattle show abnormalities in sex characters. These abnormal 

 animals are generally called freemartins. They are sterile even 

 when the external genital organs seem to be well developed; 

 sometimes there are abnormalities also in the external 

 genital organs, the clitoris being enlarged and transformed 

 into a penis-like organ. A more detailed examination 

 reveals a marked abnormality of the internal genital organs, 

 whereas externally the animals resemble "castrates." There 

 is a great variability in the condition of the internal genital 

 organs. The ovaries are in general rudimentary, resembling 



2B 



