Complete occlusion of the common bile duct causes changes in the standard liver function tests, which in general reflect accurately the severity of the lesion and the degree of hepatic damage which results; conversely, the return of these tests to normal indicates recovery from the lesion. In partial obstruction of the common duct this relationship between laboratory evaluation and actual degree of hepatic damage is by no means so clear-cut. With this in mind, the present study of partial common duct obstruction was undertaken. The goat was selected as the experimental animal, since its anatomic configuration permits obstruction of the common bile duct to be effected either above or below the entry of the pancreatic duct into the common duct. Method Operations were carried out under intravenous pentobarbital (Nembutal) anesthesia on female goats of mixed breed aged 6 to 12 months. After a preliminary laparotomy through a right subcostal incision