The men are evacuated from the field hospital to a base hospital in motor ambulances or by a combination of motor ambulances and railway trains. Theoretically, this should be done within a day or two with all cases except the very gravest. In practice, the men frequently lie in field hospitals for weeks before the opportunity of evacuation is found. The base hospitals are in cities or large towns, and serve as clearing-houses. They are well out of the military zone, being from five to fifteen miles behind the zone of artillery fire. I will give a definite example. In October, I saw the front at Albert. There were dressing stations just behind the battle-line. There was a field hospital at Hénencourt. From Hénencourt the wounded were evacuated upon Amiens, which contained the base hospitals for a front extending from a point north of Sus St. Léger to the neighborhood of Guerbigny. Here the railway station had been converted into a receiving center to which all the wounded were brought for examination and classification. Those who could bear travel were immediately placed upon trains and shipped to the south of France. There were four other hospitals in Amiens, and all cases considered too grave for transportation to the south were sent to one of these. They were divided and classified so that cases of a kind were grouped together, each hospital and the various floors of each hospital having a different class of patient. Some of the classifications were: head cases, amputation cases, gangrene cases, cases in which the patient could not refrain from screaming, either because of delirium or for other reasons. It is on leaving the base hospital that wounded are first classified as to nationality. For the railway transportation of the wounded, luggage vans are used. I estimate the interior length of a French luggage-van or freight-car to be about twenty-five feet, the doors being placed, as in America, in the middle of each side. Wooden racks are built to the right and left of the door in the ends of the car. These racks are arranged to hold two layers of three stretchers each, so that each end of the freight car contains six lying cases. The men who are able to sit or stand and the orderlies in charge are placed in the aisle between the doors, a space about six feet wide between the stretcher handles. On their way to the south of France these trains stop about every twenty-four hours, the first stop being Aubervilliers, a station some two miles outside the gates of Paris. Here a large storage warehouse has been converted into a hospital. Food and water are distributed to the train on its arrival, the dead taken out, and the delirious or very grave cases are removed to the Paris hospitals. The others are allowed twelve hours' rest before continuing on the next stage of their journey.