Braune's Os Internum and the Retraction Ring

By A. H. Freeland Barbour, M.D., F.R.C.P. Ed. The Venezuela frontier question has not given rise to more discussion than the delimitation of the area of the body of the uterus in labour. The story of the dispute with Venezuela goes back to the map on which Schomburg drew his now famous line. The discussion which has gone on for five and twenty years round the disputed area in the lower portion of the uterus goes back to Braune's classical section, and a line on it which he labelled the Os Internum. Like the old map, this section has raised a dispute which it is powerless to settle. Braune himself has said1?"That