The development of the Pars intestinalis of the common bile duct in the human fetus, with special reference to the origin of the ampulla of Vater and the Sphincter of Oddi. I. The involution of ampulla. Anat Rec 1937; 67: 441 - 467; II. The early development of the musculus proprius. Anat Rec 1937; 68: 17 - 42; III. The composition of the musculus proprius. - Schwegler,R.A.; Boyden,E.A. (Anat Rec, 1937)