The repair of bone following injury may seem a trite and worn out subject, yet the mass of clinical material furnished by the war has afforded opportunity for some interesting and practical observations.
During the war, there was considerable controversy, at least in France, on the old subject of production of bone by periosteum; and although I have little to say as to the activity of periosteum as a bone former, I have a strong feeling as to its value as a protector and conservator of developing bone. Portions of bone in gunshot fractures are commonly detached and driven into the muscle. Surgeons have frequently placed bone in the muscles to bridge defects. Invariably, as fas as I know, fragments, not lying in immediate contact with bone, have been gradually absorbed and have disappeared. Quite the reverse happens when bone fragments or grafts lie in close contact with bone. They