THE PITUITARY BODY 



ovulation in H. arborea but not in Bombinator igneus^ unless 

 the ovary contains ripe ova. He found P.fuscus, even when 

 the ovaries contained ripe ova, very insensitive toward either 

 type of pituitary extract. ^ 



Rugh concluded that the anterior pituitary of the male frog 

 {R. pipiens)^ although somewhat heavier than that of the 

 female, contains little more than half the amount of ovula- 

 tion-inducing hormone. He stated that usually within 24 

 hours oviposition in mature frogs followed the intraperitoneal 

 administration of the pars glandularis of two adult females or 

 four adult males. In the hibernating male frog of the same 

 species, Rugh found that about 16 hours after the administra- 

 tion of anterior pituitary gonadotropic hormone, amplexus 

 (with an ovulating female of the same species only) and the 

 release of all mature spermatozoa could take place. Sperma- 

 tozoa were found in the lumen of seminiferous tubules, in 

 Bowman's capsule, the renal tubules, and the ureter. In an- 

 other article, Rugh reported on seasonal changes in ovarian 

 and pituitary weight and the relationship of such changes to 

 alterations in pituitary gonadotropic effects. Shapiro (1936- 

 37) has particularly studied the clasping reflex in R. tempo- 

 raria and Xenopus laevis (a toad). He decided that secretions 

 of both the pars glandularis and the testis or ovary are neces- 

 sary for the initiation of the reflex. The reflex, followed by 

 ovulation, oviposition, and fertilization, could be produced 

 in Xenopus by the injection of pregnancy-urine extract or an 

 acid extract of the pars glandularis of the sheep or goat. In 

 B. arenarum the removal of the pars glandularis a few days 

 after subtotal extirpation of testis tissue prevents the marked 

 compensatory growth of the latter (Houssay and Lascano- 

 Gonzalez, 1935). 



The implantation of pituitary tissue of the frog or toad can 

 cause ovarian stimulation in the immature mouse (Benazzi, 

 1937; and Zwarenstein, 1937). However, the potency of am- 

 phibian pituitary is much less than that of mouse pituitary. 



5 See also Osima (1937). 



[50] 



