GONADS AND THE PITUITARY BODY 



affect the results. Only infrequently have studies been made 

 in animals after the removal of the pituitary body; it would 

 be desirable to have all conclusions confirmed by means of 

 experiments in hypophysectomized animals. 



THE EFFECTS OF IMPLANTS OF THE PARS GLANDULARIS 

 ON THE GONADS OF THE MOUSE AND THE RAT 



Smith and Engle, and Zondek and Aschheim published in 

 1927 a detailed description of the effects of implanting the 

 pituitary into immature mice and rats. They were able to 

 show that the growth and maturation of the gonads were tre- 

 mendously accelerated. Not only was the germinal epitheli- 

 um stimulated (follicle-epithelium and epithelium of the 

 seminiferous tubules)/ but there also followed an increased 

 secretion of the hormones of the gonads as demonstrated by 

 changes in the secondary sex organs. Gonadectomy prevent- 

 ed any effect on the secondary sex organs; so they concluded 

 that such effects were indirect and depended upon the stimu- 

 lation of the primary sex organ (ovary or testis). The anteri- 

 or-pituitary implants produced the same general effects al- 

 though obtained from animals of different sexes and although 

 they were frequently heteroplastic (from the cat, guinea pig, 

 man, mouse, ox, rabbit, and rat). All the control tissues 

 which they implanted were without effect (skeletal muscle, 

 adrenal, epiphysis, pars tuberalis, posterior pituitary, testis, 

 thymus, and thyroid). 



In this section only the general effects of implanted an- 

 terior-pituitary tissue will be considered. 



The efects in female animals. — The first external evidence 

 of ovarian stimulation in immature mice and rats is the open- 

 ing of the vaginal orifice and the appearance of nucleated or 

 cornified epithelial cells, without leucocytes, in smears of the 

 vaginal contents. There are therefore present all the external 



' In the hypophysectomized but not the normal immature male. 

 [Ill] 



