1. The stomach and intestine of the dog isolated half an hour after a hypodermic injection of 1 mg. atropine per kilo only contract weakly and with diminishing strength. The tone falls rapidly. The same is true for the stomach. These effects persist as a general rule for five or six hours or longer, at any rate in the intestine.
2. The same depressant action may be obtained after 0.1 mg. or 0.005 mg., while after 0.001 mg. the movement is normal though the tone falls rapidly.
3. The production of the substance which excites movement and the reaction of the intestine to this substance did not seem to be influenced by the previous injection of atropine.
4. The extract of the stomach or of the intestine has no influence on the contraction or tonus of the isolated stomach.