1. An in vitro system for ovulation and maturation of Japanese quail oocytes is described. 2. Ovarian follicles removed from the ovary at 2, 4 or 6 h before the estimated time of ovulation may ovulate under in vitro conditions. 3. The presence of progesterone in the medium had a stimulatory effect on the process of maturation, as has been shown for Xenopus oocytes. |