Beneath the crest of the British Royal Artillery appears the word “_Ubique_”—“Everywhere.” It is a motto which might more fittingly be applied to the Medical Department of our own army, however, for that corps has its representatives in every branch of the service—on land, afloat, and in the air. It directed the designing and production of our first gas-masks and from it was drawn the nucleus of our original Gas Defense Service. It provided the medical staffs for the hospital ships and for the army transports. By means of the ingenious system of tests which it devised, it selected our flying-men, determined on the form of aviation work for which they were mentally and physically fitted, and, by a system of unceasing observation, kept them constantly in condition to fight the Boche in the skies. It organized an ambulance service which won the admiration of the world. No battery or battalion went into action without its quota of medical officers, who shared all the perils and privations of their comrades of the line and worked longer. Only two units in the American Army were granted by the French the coveted distinction of wearing the _fourragère_: one of them was an Air Service squadron, the other a unit of the Sanitary Corps of the Army Medical Department. Our medical officers were actually the first in the field and the first to sustain wounds; the first American killed after the declaration of war was a medical officer. A list of the Medical Department’s activities would include the Dental Corps, the Sanitary Corps, the Veterinary Corps, the Nurse Corps; laboratories for the study and prevention of infectious diseases; organizations for the isolation and the special care of the tuberculous, the insane, the victims of war neuroses; convalescent centres and sanatoria; a division of psychology for gauging the mental capabilities of the army’s enlisted personnel; a division of physical reconstruction for the rehabilitation of the sick and wounded; a hospital division which planned and equipped hospitals to meet the constantly increasing needs of the army; a motion-picture industry which enabled the staffs of the various hospitals to see depicted on a screen the latest methods of surgery and medicine and which also illustrated to the soldier the danger of breaking sanitary regulations; the publication of a chain of hospital papers to strengthen the morale of the soldier patients; a system, working in co-operation with the War Risk Insurance Bureau and the Adjutant-General’s Office, designed to expedite the settlement of war claims, and a remarkable statistical classification of the sick and wounded, including a complete medical history of each individual case. To this array of extraordinary activities must be added, of course, the features usual to any well-organized medical department: services of internal medicine and surgery working in the closest harmony in every hospital unit; divisions of head surgery (including eye, ear, nose, and