ACCORDING to prevailing theory the physical deterioration of the hen’s egg yolk during storage is due to the movement of water by osmotic action from the albumen across the vitelline membrane into the yolk (Romanoff and Romanoff, 1949). However, Feeney et al. (1956) postulated that the degeneration of yolk quality is concomitant with albumen quality in that both appear to deteriorate under similar circumstances. These workers hypothesized that the causative mechanisms responsible for the physicochemical breakdown in the albumen and the vitelline membrane which supports the yolk are basically similar. The purpose of this investigation was to determine the extent to which water movement into the yolk from the albumen of the intact egg was responsible for the deterioration of yolk physical quality. EXPERIMENTALEggs used in this study were obtained from a flock of Single Comb White Leghorns in their initial year of production. All eggs weighed between 59 …