In recent years great strides have been made in the study of the chemistry and physiology of the biliary tract. This increase in knowledge, however, has not altered the position pathologic conditions of the biliary tract hold as formidable opponents of the surgeon's diagnostic and technical skill. In reviewing causes for some of the unsatisfactory surgical results, we find stones in the common duct to be one of the most frequent offenders. The simple case of a large stone high in the common duct, with a typical history of obstruction of the biliary tract, of course, offers no difficulty. However, the small stones low in the common duct frequently remain undiagnosed before and even during operation. Many observers have called attention to the symptomatic silence of this condition. Clute,1 in reviewing seventy-nine cases of stones in the common duct, found that there was no history of jaundice in twenty-nine.