The certain prevention of a disease depends on knowledge of the specific cause. Thus a serious problem is encountered in combating osteomyelitis, the etiology of which is still a matter of dispute, although several plausible theories have been presented. In the long bones, where this disease has been fairly common for many years, trauma and hematogenous infection usually have been considered the causes. However, even here where demonstration is somewhat easier than in the frontal bone, I believe there is doubt in certain cases as to where the infective agent arose. Hastings1 of Los Angeles reports a case of acute diffuse osteomyelitis of the frontal bone in which it would appear likely that the focus was of dental origin, and hence, hematogenous. Lynch of New Orleans, who is the originator, I believe, of the theory that osteomyelitis is caused by stripping up the periosteum and the subsequent trauma