616. If written, messages should state the place, date, hour, and minute of their dispatch. The information contained in them should be clearly and concisely expressed. They should be signed by the patrol leader. The authorized message book should be used and the form therein adhered to. 617. If the message be an oral one, the patrol leader should require the messenger to repeat it before starting back. In general, an oral message should cover but one point. Except when there is little chance of error in transmission, messages should be written. 618. When in friendly territory and not very far from friendly troops, one messenger is sufficient unless the message is very important. In hostile territory, either two men should go together or the message should be sent in duplicate by different routes. 619. Whether the information gained is of sufficient importance to be reported at once or may await the return of the patrol is a question which must be decided in each case. In case of reasonable doubt, it is generally better to send the report promptly. If the patrol leader has received proper instructions before starting out and has the requisite ability to lead a patrol, he can generally decide such questions satisfactorily as they arise. 620. Infantry patrols are generally used for work within 2 miles of supporting troops, but cases arise where they must go to greater distances. 621. Patrols composed of mounted scouts are conducted like cavalry patrols and should be trained in accordance with the Cavalry Drill Regulations. For distant patrolling, a mounted patrol under an officer should be used. 622. For controlling the movements of the patrol, the leader should, when necessary, make use of the arm signals prescribed in these regulations. On account of the short distances separating them, ordinary communication between members of the patrol is best effected quietly by word of mouth. When a member of a patrol is sent to a distant point, communication may be effected by means of simple, prearranged signals. When practicable, the patrol leader may communicate with the main body by means of visual signaling. PART III.--MARCHES AND CAMPS. MARCHES. _TRAINING AND DISCIPLINE._ 623. Marching constitutes the principal occupation of troops in campaign and is one of the heaviest causes of loss. This loss may be materially reduced by proper training and by the proper conduct of the march. 624. The training of infantry should consist of systematic physical exercises to develop the general physique and of actual marching to accustom men to the fatigue of bearing arms and equipment. Before mobilization troops should be kept in good physical condition and so practiced as to teach them thoroughly the principles of marching. At the first opportunity after mobilization the men should be hardened to cover long distances without loss.