It is not my intention in the time at my disposal to review the diagnosis and treatment of the known and well-understood lesions of the gall bladder and bile ducts. On the contrary, it is my desire to call your attention to some of the controversial points in the diagnosis and therapy of lesions in this region. There is probably no more fascinating field of medicine than the biliary tract and the various aspects of lesions which may affect it. The reason for this is the fact that a lesion in the biliary tract is hardly ever entirely localized, since portions of the tract are present within the liver and the lower portion of the common bile duct is surrounded by the head of the pancreas in two of three cases. It is apparent that inflammation in the wall of the gall bladder or the bile ducts is likely to