PHYSIOLOGICAL PROPERTIES OF THE GONADS. 299 



but mention a correlation between the sex glands and the hypophy- 

 sis first mentioned by Hatai and approved by Livingston. Hatai 

 called attention to an apparent reciprocal relationship between 

 these two glands, of such a nature that different effects can be 

 noted in subsequent growth. He noted that castrated animals 

 showing an hypophyseal hypertrophy did not show an overgrowth 

 in body weight, and conversely if the hypophysis had not increased 

 in weight, relative to the normal, the animal did show an over- 

 growth in body weight. ' Thus if a compensatory growth of the 

 hypophysis does not follow, as is the case after spaying, the product 

 of the unaltered gland must be employed for two purposes : one, 

 to replace the ovarian hormone, and, two, for the normal uses, 

 whatever they may be." 



Later experiments led Hatai to believe that his assumptions were 

 correct, as further observations substantiated the idea. Living- 

 ston ('16) agrees with the assumption of Hatai inasmuch as the 

 results of his series of gonadectomized rabbits could be interpreted 

 on this basis. He states that when the body responds by an 

 increase in weight, even though slight, the pituitary does not show 

 a compensatory hypertrophy. 



My own observations on the guinea pig, however, do not accord 

 with the idea that in the absence of hypophyseal hypertrophy an 

 overgrowth of body proportions follow. The average weight of 

 the normal male hypophysis was 14 per cent, greater than that of 

 the castrated male, whereas the average body weight of the cas- 

 trated males was less than that of the normal animals ; and simi- 

 larly the average weight of the normal female hypophysis was 12 

 per cent, greater than that of the spayed females; and, again, the 

 average total body weight of the spayed female was below, or 

 almost identical with, that of the normal female. And in each of 

 the above cases, to substantiate the hypothesis, there should have 

 been a relative increase in the body weight of the gonadectomized 

 animals, since the hypophyseal weight was less. It remains, there- 

 fore, for subsequent investigation to prove that there is this gen- 

 eral relationship that has been indicated by the rat and .rabbit 

 material. 



