1. Pavlov: Lectures on Conditional Reflexes, New York, 1928, p. 334, 186. See, also. Wright’s Applied Physiology, 4th ed., Oxford. 1931.
2. Fulton, Kennard and Watts:Am. J. Physiol., 109:37; 1934.
3. Carlson: The Control of Hunger in Health and Disease. Chicago, 1917.
4. Cannon: The Mechanical Factor of Digestion. London, 1911.
5. Barclay: The Digestive Tract. Cambridge, 1933.