Studies on the Egg Shell Formation in the Fowl Oviduct I. The Calcium Mobilization at the Each Location of Egg in the Oviduct Segments of the Laying Hens

Using ten hens of white Leghorn 150 days after hatching, samplings were carried out from their oviducts at various stages of laying or non-laying hens, which were defined in the previous study (7). Histochemical observation of the mucosubstances in the luminal epithelia and gland cells in the lamina propria were performed.The infundibulum has been known as the chalaziferous gland. However, the present study revealed that the secretion materials from the luminal epithelium were sulfomucins (chondroitin sulfate C) and sialo- or hyaluromucins which constituted the chalaza in the lumen together with those from the magnum. PAS-positive mucins in the chalaza were the secretives from the basal cells of the magnum epithelium at stage 2 and 3, where egg was coated with albumen.PAS-positive granules of the luminal epithelium in the isthmus are thought to be a cementing substance in the formation of shell membrane. PAS-positive large granules from the isthmian glands appeared just prior to the egg transportation to the uterus (stage 5) and it served to construct the shell membrane. These large granules contained sulfomucin and sialo- or hyaluromucin, which may be necessary for calcium precipitating sites on the shell membrane.The basal and the ciliated cells of the uterine epithelia secreted two types of granules. The one contained sialomucin and the other protein richly. They were surmized to be components of the organic matrix in the shell.