There is a definite gradient of rhythmicity in the intact intestine of the dog. The frequency of the rhythmic movements in a loop 30 cm. below the ligament of Treitz is 15-16 per min., and in a loop 30 cm. above the cecum, 12-14 per min. Fasting, diets of carbohydrate, fat, or protein, or castor oil, did not alter the frequency of these rhythmic contractions. The most common type of movement in the small intestine of the dog is rhythmic, of which different forms exist. In the upper loop the progressive form is most common, whereas in the lower loop the mixing type predominates. Rhythmic movements tend to occur in cycles which alternate with periods of inactivity. The intestine of the fasting dog is much quieter than that of the dog which has eaten recently. Regardless of the site of the loop, the increase in movement after eating is usually prompt. The intravenous administration of a soln. of NaHCO3 has a marked stimulating action on the movements, whereas solns. of glucose have a mild stimulating action. Epinephrine given intravenously promptly stops visible intestinal activity, but has no effect on the electro-enterogram. Isolation of the loop, with section of its mesentery, causes a decided decrease in the frequency of the rhythmic contractions, although the gradient persists.