Abstract
It has been possible by the intratracheal or intrabronchial inoculation of Type III Pneumococcus to produce in monkeys of the M. cynomolgos species an experimental pneumonia which in its clinical aspects closely resembles pneumococcus lobar pneumonia in man. The experimental disease is characterized by the development of a well localized pulmonary lesion of lobar distribution which tends to spread, the frequent occurrence of septicemia, a sustained fever, and the termination of the infection after a variable interval, in recovery or death of the animal. Wide variations in the severity of the disease in different monkeys have been noted. These variations appear to be due primarily to differences in the resistance of individual animals. The height of the septicemia accompanying the experimental pneumonia has been found to be the most valuable objective index of the probable outcome of the disease. Other factors which may influence the course and outcome of the disease are discussed.