To those familiar with the effects of trauma on the brain and its envelopes, the importance of the mechanism by which the injury is produced in interpreting the pathologic picture is quite evident. Each type of injury is now known to produce its own characteristic train of lesions. The appalling increase in craniocerebral injuries consequent to traffic accidents has brought into prominence a number of effects which appear to be the direct consequence of striking of a stationary or relatively stationary object by the head in motion. These effects have been long described ascoup-contrecoupeffects. One of the lesions belonging to this group which to date has not been given any selective attention is gross hemorrhage into the cerebral substance—traumatic intracerebral hemorrhage. In 1891, Bollinger described 4 cases in which death occurred rather suddenly from twelve to fifty days after an injury to the head and proved at autopsy