[Ultrastructure function and regulation of the oviduct of the Rana ridibunda (author's transl)]

An investigation has been carried out into the structure, ultrastructure, function and of the oviduct on the adult female of Rana ridibunda. The most important part of the oviduct comprises tubulary glands and a luminal epithelium which is composed of ciliated cells and vesicular cells. The discharge processes of secretory substances were studied. Injection of the mature females with estrogens and progesterone have show that progesterone was the most effective in provoking jelly release. It is probably that in Rana ridibunda the pituitary hormones act on the follicle cells of ripe oocytes, causing them to secrete a progesterone-like hormone which provodes the maturation of the oocytel and jelly release from the oviducal glands.