The act authorizing the temporary increase of the military establishment empowered the department to create special organizations of technical troops. Under this provision railroad and stevedore regiments have been formed and special organizations of repair men and mechanics, some of which have proceeded to France and rendered service back of the British and French line in anticipation of and training for their later service with the American Army. No complete descriptions of these activities can be permitted at this time, but the purpose of the department has been to provide from the first for the maintenance of our own military operations without adding to the burdens already borne by the British and French, and to render, incidentally, such assistance to the British and French Armies as could be rendered by technical troops in training in the theater of operations. By this means the United States has already rendered service of great value to the common cause, these technical troops having actually carried on operations for which they are designed in effective cooperation with the British and French Armies behind hotly contested battle fronts. [Sidenote: The Red Cross organizes base hospital units.] [Sidenote: Doctors and nurses aid British and French armies.] [Sidenote: The medical profession rallies around the service.] [Sidenote: Convalescent and reconstruction hospitals.] [Sidenote: Physical fitness necessary for military service.] Working in close association with the medical committee of the Council of National Defense and the Red Cross and in constant and helpful contact with the medical activities of the British, French, and other belligerents, the Surgeon General has built up the personnel of his department and taken over from the Red Cross completely organized base-hospital units and ambulance units, supplemented them by fresh organizations, procured great quantities of medical supplies and prepared on a generous scale to meet any demands of our Army in action. Incidentally and in the course of this preparation, great numbers of base hospital organizations, ambulance units, and additional doctors and nurses have been placed at the disposal of the British and French armies, and are now in the field of actual war, ministering to the needs of our Allies. Indeed, the honor of first participation by Americans in this war belongs to the Medical Department. In addition to all this preparation and activity, the Surgeon General's department has been charged with the responsibility for the study of defense against gas attack and the preparation of such gas masks and other appliances as can be devised to minimize its effects. The medical profession of the country has rallied around this service. The special laboratories of the great medical institutions have devoted themselves to the study of problems of military medicine. New, effective, and expeditious surgical and medical procedures have been devised and the latest defensive and