THE GONADOTROPIC HORMONES 



(follicle-stimulating) hormone. The pituitary of the adult 

 pigeon was more potent than that of the immature rat. Clark, 

 Leonard, and Bump (1937) reported that the testis of the 

 immature pheasant responds well to the administration of 

 sheep pituitary extract. A study of the changes in the testis 

 and comb of chicks receiving injections of male hormone 

 (extract of male urine, dihydroandrosterone benzoate, testos- 

 terone, or its propionate) was made by Breneman (1937). 

 In some instances testicular growth was prevented during 



Fig. II. — The effect of i6 daily injections of 2 rat-units of pituitary gonado- 

 tropic hormone on the ovary and oviduct of the English sparrow. (From Witschi 

 and Keck, Proc. Soc. Exp. Biol. Med., 32, 598-603 [1935].) Lejt: largest of con- 

 trols; right: injected bird. 



the period of injection (5-10 day after hatching) but in- 

 creased markedly during the three following weeks. Bagg 

 (1936) was interested in the production of teratomata in the 

 fowl's testis by injecting into the gland 0.3 cc. of a 5 per cent 

 aqueous solution of ZnCL. His injection schedules were most 

 varied and his results permit only the following conclusions: 

 (i) previous treatment with sheep pituitary extract made 

 possible the production of teratoma testis in 2 of 26 birds 

 (one in June, the other in August), resembling the effect of 

 zinc chloride solution alone (2 of 20 birds in the spring); (2) 



[57] 



