GONADS AS CONTROLLERS OF CHARACTERISTICS 467 



female and the male a more apparent male are due to the 

 presence of the specific gonads, and these differences, in many 

 cases, have proved themselves capable of being controlled to a 

 certain extent. 



CONCLUSIONS 



After early removal of sex glands the growth curve of the 

 determined male is (without exception in these experiments) 

 higher than that of the determined female. There is, there- 

 fore, a real difference (of metabolism?) in the two sexes, which 

 may represent an inherited difference from the original ova, but 

 this difference may be accentuated by the presence of the ovary 

 in the female. 



Hull Zoological Laboratories, 



The University of Chicago, 



February 17, 1919. 



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