THE PITUITARY BODY 



the color of the bill and the size of the oviduct, were observed 

 (see Figs. lo and 1 1). 



The pituitary of birds contains gonadotropic hormone cap- 

 able of stimulating the mammalian ovary (Leonard, 1937, 

 fowl pituitary, ovulation in the rabbit, or ovarian hyper- 

 trophy in the normal or hypophysectomized rat; Witschi, 

 Stanley, and Riley, 1937, turkey pituitary, ovarian hyper- 

 trophy in the normal or hypophysectomized rat). Leonard 

 concluded that the fowl's pituitary contains luteinizing hor- 

 mone as well as the hormone stimulating the adrenal cortex. 



Fig. 10. — The effect of daily injections of 2 rat-units of pituitary gonadotropic 

 hormone on the size of the testis and the color of the bill of the English sparrow. 

 (From Witschi and Keck, Proc. Soc. Exp. Biol. Med., 32, 598-603 [1935].) 



A few other observations were made, chiefly in male birds. 

 Evans and others (1936) concluded that the apparently 

 great sensitivity of the immature pigeon's testis toward pi- 

 tuitary gonadotropic hormone depends upon the lack of ef- 

 fect of pituitary "antagonist." If the latter is first removed 

 from a pituitary extract, the ovary of the immature rat is 

 equally sensitive. Riddle and Schooley (1935), basing their 

 assays on the testicular response of the immature ring dove, 

 studied the gonadotropic potency of the pituitary of the 

 pigeon and the rat. The pituitary of pigeons or ring doves, 

 1.8-2.5 months after hatching, contained no gonadotropic 



[56] 



