IN THIS discussion the term "duplication of the alimentary tract" will have the connotation applied by Ladd and Gross.1 They use it to refer to any cyst or diverticulum associated with the alimentary tract (except diverticula of the Meckel variety), the wall of which contains smooth muscle and is lined with a mucosa capable of having been derived from entoderm. Where the duplication is in the form of a diverticulum, it differs from the acquired variety in that the muscle in the wall is common to both the diverticulum and the adjacent bowel.
Duplications are by no means rare. Dohn and Povlsen,2 in a recent review of the literature, found reports on 315 cases. The duplicated portions were distributed along the entire length of the alimentary tract, as is shown in the Table. Multiple duplications were present in 13 cases. When the duplication occurred in the abdominal cavity,