GONADS AND THE PITUITARY BODY 



the pituitary of Leptodactylus ocellatus and implanted, in 

 some cases, nine pituitaries in a period of 3 days. The frogs 

 which he used as donors, unHke those of Lipschiitz and Paez, 

 were l<;illed during the stage of sexual activity. 



Houssay, Giusti, and Lascano-Gonzalez (1929) showed 

 that homo-implants of the pituitary produced ovulation and 

 oviposition in female toads [Bufo arenarum). In male toads 

 of the same species, implants caused an increase in the size 

 of the testes as well as the appearance of the clasping reflex. 

 They were unable to produce such changes by the adminis- 

 tration of hetero-implants obtained not only from various 

 mammals but also from the fowl, the frog, and the snake. 

 Although others^ also have been unable to cause ovulation in 

 toads (5. vulgaris and B. americanus) by implanting frog 

 pituitary, but could do so by means of homo-implants. Wills, 

 Riley, and Stubbs (1933) caused ovulation in B. americanus 

 by implanting the pituitary of the frog {R. pipiens and R. 

 sphenocephala) or of fish (garpikes, two varieties of Lepidos- 

 teus). Even extracts of mammalian anterior pituitary bring 

 about ovulation and oviposition in the South African toad, 

 Xenopus laevis^ and in Fowler's toad, B. fowleri (Hogben, 

 Charles, and Slome, 1931; Bellerby, 1933; Rugh, 1935). It is 

 therefore not possible to generalize on the "zoological speci- 

 ficity" of the response of the toad's ovary as some have done. 



In hypophysectomized toads {B. arenarum and B. mari- 

 nus)j homo-implants of the pituitary restore to normal the 

 atrophied gonads of both male and female hypophysecto- 

 mized toads (Houssay and others, 1929). As a result of castra- 

 tion in mammals, the pituitary enlarges and produces an in- 

 creased gonadotropic effect; however, the pituitary of the 

 toad {B. arenarum)^ even 90 days after castration, is neither 

 enlarged nor more potent in causing ovulation in female toads 

 (Novelli, 1929). Bellerby (1933), using extracts of the an- 

 terior pituitary of the ox, studied the effects of environ- 



'' Adams (1931), and Bardeen (1932). 



[121I 



