Chloralose and chloralose-urethane anesthesia cause a marked secretion of very acidic gastric juice in dogs previously equipped with gastric fistulae and not subjected to any trauma at the time of anesthesia. Urethane, pentothal and to a much lesser degree nembutal anesthesia also result in the secretion of varying amts. of gastric juice of high acidity under similar conditions. The chloralose-urethane phenomenon was especially investigated. This secretion was regularly found to approach a pH of 0.9 and to possess minimal amts. of pepsin and visible mucus, thus resembling the secretion evoked by histamine. It was completely abolished by the traumatic procedure of preparing the gastric fistula at the time of the expt., and was at times completely prevented by slight mechanical manipulation of the vagi in the neck. In those instances where the phenomenon was not abolished by exposure of the cervical vagi it was immediately arrested following acute vagal section. The secretion returned to full intensity within a few days after vagal section only to almost completely disappear again as time for nerve degeneration elapsed. The secretion was not associated with a reduced blood sugar level but was regularly abolished by atropine. It was markedly reduced or unobtainable in chronically vagotomized dogs. The possible role of histamine in the nervous phase of gastric secretion and the possibility of a nervous mechanism inhibiting the secretory cell directly are discussed. Evidence is presented to suggest that the gastric glands may secrete a neutral or weakly acidic, non-mucoid juice under certain conditions.