Abstract
Shell glands of the uterus of the hen oviduct secrete fluid which contains a high percentage of calcium1). The secretion rate of the fluid is higher during the time when normally ovulated ovum (ovum)2) or an artificial yolk-containing egg-like mass2) is present in the uterus comparing with other times2). However, whether the higher secretion rate during that time is caused by a certain stimulus associated with the presence of an egg or an egg-like mass has not been completely determined, since there remains a possibility that the higher secretion rate is due to a diurnal rhythm of the secretory activity of the uterus. The present experiments were performed to demonstrate that the presence of the egg in the uterus stimulates the secretion of the shell gland fluid. For this purpose, the volume of the shell gland fluid and its calcium concentration were measured at definite of a day in hens of which ovulated ovum was artificially retained at various regions of the oviduct by a surgical ligation.
