The anatomy of the pancreatic duct system has been the subject of numerous studies since the first published account by Wirsung (Fig. 1). This original and inaccurate report was later modified by Santorini to approximate more closely the arrangement found in human beings. Although studies of the pancreatic ducts continued, descriptions varied, largely because of the difficulty of demonstrating the exact relations of the ducts. When Opie popularized the common channel theory of pancreatitis, he lent an impetus to the efforts of anatomists and surgeons to demonstrate more clearly the finer anatomy of the duct arrangement at the ampulla of Vater and in the pancreatic head. It was not the object of this study to repeat the excellent observations made by Opie and his successors concerning the detailed anatomy of the ampulla of Vater; it was rather our effort to demonstrate the exact course of the pancreatic ducts through the