A study has been made of the movements of surviving strips from the different regions of the gastric musculature of the cat and dog. The action of pilocarpine, adrenaline, and atropine on the rhythmic movements and “tonus” of the strips has been investigated.Each region has a characteristic type of contraction which resembles closely the movements described in the intact stomach.The power of “postural adaptation” is most clearly shown in the fundic region, and decreases progressively to the pylorus. This function is demonstrated by the changes produced by drugs in the baseline from which rhythmic contractions take origin.The motor power of the stomach varies inversely with the possession of this capability of postural adaptation: thus, from the pyloric region, which exhibits the most powerful contractions, postural changes cannot be elicited.Pilocarpine imitates only the motor action of the vagus, causing a change of the base‐line in the fundic region with no augmentation of contractions; and in the pyloric region, augmentation of rhythmic movements without alteration of the base‐line.Adrenaline imitates the inhibitory effects of splanchnic stimulation in all regions of the stomach except the cardia, in which it causes contraction. It produces in all other regions of the stomach a cessation of rhythmic movements, which in the fundus is associated with relaxation: strips from intermediate parts relax slightly, while in the vicinity of the pylorus the length of the muscle fibre is unaltered.Atropine antagonises the action of pilocarpine and produces effects similar to those observed after adrenaline.The cardiac and pyloric sphincters are not alike in their response to drugs. In the cardia pilocarpine and adrenaline cause a rise of the lever from the base‐line, while atropine has little effect. The cardia appears to exhibit “tonus” changes, to the exclusion of rhythmic movements. The pyloric sphincter resembles in all respects the adjacent musculature of the pyloric antrum, addition of drugs causing alteration of the rhythmic movements without changing the constancy of the base‐line.The sling of Forssell combines both the property of postural adaptation and considerable motor power, drugs causing alterations in the length of the muscle fibre in addition to changes in the amplitude of rhythmic movements.The expenses of the investigation have been defrayed by a grant from the Government Grants Committee of the Royal Society.