The importance of the function of the sphincteric mechanism at the lower end of the common bile duct and the clinical application of knowledge concerning it in the management of disease of the biliary tract have of late been receiving a great deal of attention. Ivy and Sandblom1in this country, Schmieden and Niessen2in Germany and Pavel3in France have been in the fore in the elucidation of the types of biliary dyskinesia and of the symptoms which they produce. These men have applied knowledge gained from animal experimentation to clinical studies of cases and to operative results. We have interested ourselves in direct measurement of changes in physiologic functions of the common bile ducts of human beings who have disease of the biliary tract. With the consent of the persons concerned, we have determined changes in pressure in the common bile duct of individuals into