When one considers the embryology of the alimentary canal, it is surprising that anomalies of the intestinal rotation are not more common; probably they do occur oftener than they are recorded, owing to the fact that symptoms are absent. Out of a total of forty-eight cases reviewed by Dott, thirty-five were accidentally discovered, as misplacement did not give rise to symptoms or diagnosis was made late.
The case about to be reported is the first, we believe, in which operation was successfully performed when the patient was 4 days old. To understand clearly the condition to be described, the embryologic course will be discussed briefly in the embryo from the fifth week. At this time the canal consists mainly of three parts, foregut, midgut and hindgut, and all are attached by the common dorsal mysentery. The distal portion of the foregut forms the stomach and duodenum. From