The medical profession is indebted to Dr. Heffron for this scholarly volume on pneumonia, published by the Commonwealth Fund at a price permitting wide distribution. It is a well conceived and splendidly executed monograph of permanent value. Our current knowledge of pneumonia in the clinic, in the laboratory and in the community is presented with evident diligence, careful documentation and balanced judgment in twenty chapters dealing with causative organisms in pneumonia and pneumonia not due to pneumococci, the pneumococcus and type incidence in pneumonia, pathology of lobarpneumonia, aspects of immunity, experimental pneumococcic infections and pathogenesis of lobar pneumonia, epidemiology, measures for the prevention of pneumonia, symptoms of lobar pneumonia, physical signs in lobar pneumonia, clinical varieties of pneumonia and association with other conditions, special features in the course of the disease, complications, incidence and treatment, diagnosis, differential diagnosis, prognosis, recovery factors and duration of immunity, general therapeutic measures, serum treatment,