Abstract
SUMMARY: Physical and chemical observations were made on the loss of strength and substance by the vitelline membrane of the hen's egg during changes in ambient pH. It was found that the vitelline membrane of the freshly laid egg contains a network of fibers on its surface which tends to dissipate as the pH of the albumen rises. In conjunction with the physical deterioration of the fibrous structure on the vitelline membrane, there are significant changes in weight, protein, and hexosamine content of this membrane. Hypotheses are presented concerning the mode of action of the physiochemical changes in the vitelline membrane.