THE GONADOTROPIC HORMONES 



or hypertrophy of the gonads in other fishes. Usually changes 

 in the gonads or secondary sexual organs of fishes, including 

 spawning, can be produced by fish pituitary but not by 

 mammalian pituitary or by extract of the mammalian pitui- 

 tary. However, dosage may not have been adequate. De- 

 scriptions of experiments and references to other work can 

 be found in the reports of Gerbilsky and Kashchenko (1937) 

 and of von Ihering and de Azevedo (1937). ArtemofF (1936) 

 successfully used the pituitary of the frog. 



Amphibia. — The majority of the reports previously re- 

 viewed indicated that the amphibian pituitary has an im- 

 portance in the maintenance of the gonads corresponding to 

 that in mammals. The most that will be attempted here is 

 to bring the references up to date by citing the work of recent 

 authors. 



I. Anuran amphibia. — Several aspects of the biology of 

 gonadotropic hormones have been studied in six species of 

 frogs {Bombinator igneus^ Hyla arborea^ Pelobates Juscus^^ 

 Rana esculenta^ R. pipiens^ and R. tempot^aria^'"^). Several 

 authors have studied ovulation or oviposition or both. Ros- 

 tand administered the extract of 6-20 pituitary glands of the 

 same species to R. esculenta^ R. temporaria., or Bujo vulgaris. 

 He found that ovulation could be produced 5 months before 

 the normal time. It was more difficult to induce ovulation 

 earlier; moreover, the ova then were often not mature and 

 could not be fertilized. Similar results were reported by Gal- 

 lien who used R. temporaria. The number of eggs extruded 

 appeared to be proportional to the dose of frog pituitary 

 (6-9 glands as a saline extract) or beef anterior lobe (1.6-3 

 gm. as an alkaline extract). The very low potency of the 

 pituitary of the ox was previously reported by others (e.g., 

 Rostand using H. arborea). Gallien observed no effect from 

 the injection of urine of spayed women (3-8 cc.) or urine of 

 pregnancy (7-9 cc). According to Rostand, extract of the 

 pituitary of R. esculeyjta or Bujo vulgaris can readily induce 



' Rostand (1934-35). ' Rugh (1937). 3 Gallien (1937). " Shapiro (1937). 



[49] 



