388 GAEL R. MOORE 



SUMMARY AND CONCLUSIONS 



1. Pieces of ovaries implanted in a young castrated male 

 guinea-pig will grow and retain the characteristic ovarian tissue 

 for a period of several months. 



2. The presence of ovarian grafts in the male leads to an hyper- 

 trophy of the teats of the mammary glands to such an extent 

 that they resemble the conditions of a pregnant female (somatic 

 modification). The psychical characteristics of the male, how- 

 ever, were unmodified; such animals gave no indication of 

 acquired feminine instincts in reference to young animals: they 

 not only avoid the attempts of young to suckle, but fight them 

 away. 



3. Testicular transplantation into young spayed females, 

 thoiigh successful in a less number of cases than ovarian grafting, 

 is possible. The testicle tissue remained in a typical condition 

 for nine months after transplantation, except that spermatozoa 

 are absent from the tubules. 



4. The effect of the testicle tissue in both somatic and psychical 

 modification was pronounced. The clitoris of the female under- 

 went hypertrophy resulting in a condition resembling the male 

 more than the female (somatic modification). Such animals 

 behaved as typical males toward each other and toward females 

 (psychical modification). 



5. The writer considers that there is an entire lack of evidence 

 of an active antagonistic effect between the secretions of the two 

 opposite sex glands. 



Hull Zoological Laboratories 

 The University of Chicago 



