Introduction GALEN REFERRED to catgut as early as 175AD. The widespread use of this suture material followed the demonstration of its strength and surgical adequacy in 1840 by Luigi Porta, Professor of Surgery in Pavia.1 The early clinical use of catgut presented two disadvantages: increased infections and allergic reaction. Asepsis and improved manufacture of catgut eliminated the first problem, but the entire question of catgut allergy remains unsettled. Collagen has long been recognized as a basic component in the healing process, worthy of consideration as a suture material. The recent development of reconstituted collagen sutures appears promising. The use of these sutures in the repair of experimental wounds form the basis of this report. Methods and Materials Unselected mongrel dogs were anesthetized with intravenous pentobarbital sodium (Nembutal). Sterile, transverse midabdominal incisions extending from one nipple line to the other were made in one group of animals. One half