Induction of Ovulation in Frogs and Toads.

Abstract

Experiments on the induction of ovulation in frogs and toads by means of pituitary inoculations and injections of extracts were carried on during the fall of 1930. The results obtained are in essential agreement with those of Houssay, Giusti, and Lascano-Gonzalez 1 and of Kehl 2 on different species of toads and frogs. At the same time it appears possible to explain the seemingly contradictory results in the work of these authors and in the present work without employing the idea of a “zoological specificity” of anterior lobe hormones suggested by Houssay et al.

Mature toads (Bufo vulgaris) and frogs (Rana vulgaris) were inoculated with anterior lobes of pituitaries or injected with extracts† of mammalian pituitary, human placenta, pregnant urine, or with 0.7% NaCl solution. The pituitaries were placed in the dorsal lymph sacs of the animals, while extracts were injected into the dorsal lymph sac, or the muscles of the hind leg, or (rarely) into the body cavity.

Inoculations of pituitaries into toads and frogs. I. The first series of experiments consisted of toads inoculated with toad pituitaries (Table 1).