Open country in such cases demands increased depth in order to minimise loss, while close country requires that depth should be diminished, and it will be found advisable to act accordingly. Close formation can and must be maintained as long as the terrain and the hostile fire admit. It will of course be impossible to expose such formations within range of the enemy's fire. The advance will then consist of rushes, with pauses for breath, of distribution into small units, and the adoption of extended order. The nearer the decision of the fight, the closer must the supports follow, ready to co-operate. In difficult country the order and cohesion of units must not be lost. It is especially important for the supports as well as the firing-line to make use of any available cover, so that units may be re-formed, ammunition supply regulated, and that the officers may regain their influence over the troops. This latter moral element deserves especial consideration. When feeling its way forward the firing-line should avoid regular formation, and its rushes should not be made in too small bodies, as such a proceeding is apt to mask the fire of neighbouring detachments. It will likewise generally happen that some portions of the line are able to advance under cover of the ground more rapidly than others. These must then ask themselves the question whether their isolated advance might not lead to a reverse which would imperil the success of the attack. On the other hand, the unceasing pressing forward of all the various detachments is conditional to success. If localities exist in the foreground which might serve as supporting points for the further development of the attack, it should be considered whether they should not be occupied as rapidly as possible, and, where necessary, secured against counter-attack by being placed in a state of hasty defence. The advance of neighbouring detachments may then be facilitated from such points by energetic fire action. Such points at the same time secure the possession of the ground won and, under certain circumstances, protect those portions of the artillery and the machine-gun detachments which may accompany the attack, according as circumstances dictate. In any case such a measure (the co-operation of artillery and machine-guns) brings moral support to the attacking-line, and may at times prevent a defeat.