neither the physiologic exhaustion nor the alterations in the
brain-cells which are characteristic of the effects of trauma.
On turning to the study of trauma, we at once found in the behavior
of individuals as a whole under deep and under light anesthesia
the clue to the cause of the discharge of energy, of the consequent
physiologic exhaustion, and of the morphologic changes in the brain-cells.

If, in the course of abdominal operations, rough manipulations
of the parietal peritoneum be made, there will be frequently
observed a marked increase in the respiratory rate and an increase
in the expiratory force which may be marked by the production
of an audible expiratory groan. Under light ether anesthesia,
severe manipulations of the peritoneum often cause such vigorous
contractions of the abdominal muscles that the operator is greatly
hindered in his work.

Among the unconscious responses to trauma under ether anesthesia
are purposeless moving, the withdrawal of the injured part, and,
if the anesthesia be sufficiently light and the trauma sufficiently
strong, there may be an effort toward escape from the injury.
In injury under ether anesthesia every grade of response may be seen,
from the slightest change in the respiration or in the blood-pressure
to a vigorous defensive struggle. As to the purpose of these
subconscious movements in response to injury, there can be no doubt--
THEY ARE EFFORTS TO ESCAPE FROM THE INJURY.

Picture what would be the result of a formidable abdominal operation
extending over a period of half an hour or more on an unanesthetized
human patient, during which extensive adhesions had been broken up,
or a large tumor dislodged from its bed! In such a case,