By means of constant effort and the correlation of experimental and clinical observations, neurologists have given us an amazingly precise topography of the brain. In recent years, with the aid of x-rays, the gastro-intestinal tract is the subject of a similar survey. Today only the small intestine can truly be called the "silent area" of the alimentary tract. In presenting the following cases, I am making an attempt to encroach on this uncharted sea. The duodenal-jejunal junction has been relatively little studied. In a vast majority of cases it is hidden by the barium-laden stomach, and its anatomic position renders it relatively inaccessible to examination. Chomel,1in 1710, first described diverticulum of the duodenal-jejunal junction anatomically. In 1778 Morgagni1and in 1815 Fleischmann1added additional references to the anatomic data. In 1896 Hauseman2reported the observation at autopsy of a single diverticulum of the upper jejunum