The avian ovary is an open organ. A study of the lacunar system.

After an intraperitoneal injection of diluted yolk in female quails, young chicks or chick embryos (killed with minimal loss of blood), the absorption of a considerable quantity of yolk granules by the ovarian medullary lacunae can be demonstrated. This can be confirmed by the i.p. injection of killed Hela cells. From our investigation it may be concluded that the avian ovary, by the progressive expansion of its medullary lacunae, develops into a contractile sac-like structure with small openings (communicating with the peritoneal cavity) on its dorsal side. The lacunar system seems to function as an expansion room for the enlarging follicles (also the large pediculated follicles) and intervenes in follicle stalk formation. The relatively rapid uptake by means of an ovarian pumping mechanism of particles and fluid from the peritoneal cavity into the lacunae, suggests also that the latter play a role as diffusion chambers in the supply of nutritious substances to and elimination of wastes from the follicles.