42. MEDICAL SERVICE DURING DEFENSE. In a defensive situation, the medical service is usually organized more completely than in an attack. Bat- talion aid stations are located farther to the rear to prevent overrunning of the site in a local reverse. Battalion aid stations are set up and are improved progressively during the period of occupancy. The regimental aid station usually is established within 300 yards of the regimental command post. Routes of evacuation providing cover for litter bearers are selected and marked. In stabilized situations, com- pany aid posts are established at places near com- pany command posts where the sick and injured may receive emergency treatment and from which litter bearers can evacuate serious cases to the battalion aid station.
43. MEDICAL SERVICE DURING RETROGRADE MOVEMENTS. During a withdrawal, a delaying action, or a retreat, aid stations displace rearward by bounds. Temporary aid stations are set up near the avenues of rearward movement. All available transportation is utilized to evacuate wounded and prevent their capture. The collecting company sup- porting the regiment may be called upon to furnish reinforcements consisting of litter bearers and/or ambulances. When wounded must be abandoned, a portion of the medical detachment with the neces- sary supplies is left with them under the protection of the Red Cross flag. The decision to abandon cas- ualties is a command decision.