The occurrence of aberrant pancreatic tissue, discovered either at operation or at autopsy, has been reported from time to time since the first case was described by Klob1 in 1859. From that date until 1904, when Warthin2 made the first comprehensive study of the literature, reports of isolated cases were published. Warthin collected forty-seven cases, to which he added two. Since then surveys of the literature have been made by Horgan3 in 1921, by Simpson4 in 1927 and by Hunt and Bonesteel5 in 1934. The last review brought the total number of cases to one hundred and eighty-six. Since the completion of Hunt and Bonesteel's paper at least ten additional examples6 have been reported, to which we are adding reports of twenty-four cases in which aberrant pancreatic tissue was found at various locations in the gastro-intestinal tract. In the cases previously reported the most