THE PITUITARY BODY 



gonadectomy; so far as the removal of the pituitary was con- 

 cerned, they beheved that parts of the gland other than the 

 pars glandularis also were factors in the regulation of the con- 

 centration of the blood calcium. 



The effects of hypophysectomy in r^/)///^j,^Schaefer (1933) 

 has hypophysectomized garter snakes {Thamnophis sirtalis 

 and T. radix). He reported that the operated snakes shed 

 repeatedly at irregular intervals apparently because of a hy- 

 pofunction of the thyroid. Hypophysectomy was also fol- 

 lowed by an atrophy and a degeneration of the testes as well 

 as a reduction in the size of the adrenal cortex. 



THE EFFECTS OF HYPOPHYSECTOMY IN BIRDS 



The pituitary body or the pars glandularis has been re- 

 moved from the fowl, duck, pigeon, and turkey (Mitchell, 

 1929; Martins, 1933; Hill and Parkes, 1934). Hill and Parkes 

 concluded that a severe metabolic disturbance, not the result 

 of anesthesia or operative trauma^ accounted for the death of 

 their hypophysectomized fowls (80 per cent) about 48 hours 

 after operation. Martins, on the other hand, mentioned that 

 pigeons may survive the operation at least 60 days. 



In surviving fowls or in those kept alive by the temporary 

 injection of extracts of the pars glandularis or the adrenal cor- 

 tex (Hill and Parkes), atrophic changes were found in the 

 gonads and thyroid. Secondary sexual characters, such as 

 the comb and wattles, regressed so that their appearance re- 

 sembled thatof gonadectomized fowls. According to Hill and 

 Parkes, the changes in the plumage were those one would ex- 

 pect in fowls suffering from a deficiency of the internal secre- 

 tions of both the thyroid and the gonads. 



Hill, Corkill, and Parkes (1934) believed that a hypogly- 

 cemia following hypophysectomy (normal blood sugar, 200 

 mg. per cent; in hypophysectomized fowl, as low as 119 mg. 

 per cent) was at most a contributory cause of death. Fowls 

 surviving because of treatment only during the critical period 



[42] 



