This book is a pioneering study of the physiology of digestion, based on the research of Ivan Pavlov, the Nobel Prize-winning Russian scientist. In a series of lectures, Pavlov presents his findings on the secretion of digestive juices by the salivary glands, stomach, pancreas, and liver, and their role in the process of digestion. He also explores the reflexes and conditioning that influence the digestive system, and considers the implications of his research for medicine and psychology. Thompson's translation and notes provide a clear and accessible introduction to Pavlov's work. This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.