Diverticula occur in various portions of the alimentary canal and are usually classified as congenital or true and acquired or false, the distinction being based on the coverings. It was formerly supposed that acquired diverticula never contained all the intestinal coats, but this theory is not in accordance with existing conditions, as many of the smaller or more recent ones possess a mucous, muscular and serous coat. The congenital are usually single, while the acquired are more often multiple. Housman1found over four hundred of the latter in an 85-year-old man. When single the common situation is in the upper part of the small intestine; when multiple they occur throughout the canal; however, the ileocecal region is a favorite site. They appear at the mesenteric border or between its folds, in the appendices epiploicae or on the free border opposite the mesentery. Congenital diverticula usually occur through the persistence