THE DUODENAL END of the biliary and pancreatic drainage systems constitutes the "Vaterian segment." At first, our understanding of the anatomy of the distal biliary and pancreatic ducts was poor and constituted a legitimate handicap to discussions of pathology and pursuit of therapeusis. We would like to call attention to the accurate anatomy which now has been established, point out that persistent use of an archaic concept and loose use of otherwise accurate terms perpetuate a discouraging degree of confusion, and make a plea for the modernization of our talk and writing concerning the Vaterian segment.
In the first half of the eighteenth century, a German anatomist named Abraham Vater investigated the anatomy of the confluence of the biliary and pancreatic ducts. His work is preserved for us in the third volume of Albert Haller's Disputalionum Anatomicarum Selectarum. Excerpts from Vater's dissertation pertinent to this discussion are reproduced in the