A new résumé of the process of fracture healing is presented which differs from the several others in wide use in the teaching and in practical literature, in that it is based upon direct examination of a large series of normal clinical fractures with the use of improved microtechnical methods, and in that it includes:
1. The concept of the organization of the callus;
2. Precise localization of the calcification in the histological and roentgenographic pictures of the callus;
3. Description of the process of removal of displaced fragments of injured parts and the significance of interposition of the tissues at the fracture site;
4. An analysis of the dynamics of union.