UDPG-glycogen synthetase was studied in the uterus of ovariectomized and ovariectomized-hormone treated rabbits and in the tongue. Following the biochemical technic of Leloir and Goldenberg it was not possible to demonstrate the enzyme in the uterus of the ovariectomized or ovariectomized treated animals. However, in the tongue the enzyme was present. The data from this study along with previous histochemical studies indicates that the glycogen in the uterine muscle is not synthesized through the UPDG pathway, but is synthesized from G-1-P by the action of phosphorylase. Since UDPG-glycogen synthetase can be demonstrated in the tongue a difference seems to exist in glycogen synthesis between the smooth muscle of the uterus and skeletal muscle of the tongue.