The importance of the initial psychic secretion of saliva for further digestion is indicated when, in estimating the function of taste for the pleasures of appetite, we realize that materials can be tasted only when dissolved in the mouth and thereby brought into relation with the taste organs. The saliva which “waters” the mouth assures the dissolving of dry but soluble food even when it is taken in large amount. The importance of the initial psychic secretion of gastric juice is made clear by the fact that continuance of the flow of this juice during digestion is provided by the action of its acid or its digestive products on the mucous membrane of the pyloric end of the stomach, and that secretion of the pancreatic juice and bile are called forth by the action of this same acid on the mucous membrane of the duodenum. The proper starting of the digestive process, therefore, is conditioned by the satisfactions of the palate, and the consequent flow of the first digestive fluids. The facts brought out experimentally in studies on lower animals are doubtless true also of man. Not very infrequently, because of the accidental swallowing of corrosive substances, the esophagus is so injured that, when it heals, the sides grow together and the tube is closed. Under these circumstances an opening has to be made into the stomach through the side of the body and then the individual chews his food in the usual manner, but ejects it from his mouth into a tube which is passed through the gastric opening. The food thus goes from mouth to stomach through a tube outside the chest instead of inside the chest. As long ago as 1878, Richet,[3] who had occasion to study a girl whose esophagus was closed and who was fed through a gastric fistula, reported that whenever the girl chewed or tasted a highly sapid substance, such as sugar or lemon juice, while the stomach was empty, there flowed from the fistula a considerable quantity of gastric juice. A number of later observers[4] have had similar cases in human beings, especially in children, and have reported in detail results which correspond remarkably with those obtained in the laboratory. Hornborg[4] found that when the little boy whom he studied chewed agreeable food a more or less active secretion of gastric juice invariably started, whereas the chewing of an indifferent substance, as gutta-percha, was followed by no secretion. All these observations clearly demonstrate that the normal flow of the first digestive fluids, the saliva and the gastric juice, is favored by the pleasurable feelings which accompany the taste and smell of food during mastication, or which are roused in anticipation of eating when choice morsels are seen or smelled.