=Assaulting Companies.= The advance of the assaulting platoons regulates the advance of all the successive elements. These platoons, after crossing the first hostile line, continue their movement without hesitation. The rate of advance is, of course, variable with the difficulties of the ground and the strength of the hostile organization. For this reason it cannot be very rapid. The pace of the leading elements of the assaulting column is foreseen in the plan of battle (depends upon the strength of the enemy’s position), and this becomes the rate of advance of the moving barrage. If no unforeseen and serious resistance is encountered, the assaulting platoons will be able to keep up with their protective barrage. Sometimes, however, they may halt for a moment in their progress under cover of some shelter to regain their alignment. As a part of the assaulting platoon comes the trench-cleaner detachment. The trench cleaners are armed with hand grenades and trench knives. Their function is to enter the hostile trenches taken and, profiting by the surprise effect of the attack, to vanquish the last resistance and to make prisoners of the defenders still in the dugouts. They pay special attention to picketing all entrances, exits, and shafts of dugouts so that detachments of the enemy cannot come out and fire into the rear of the waves that have already crossed. If the different lines of the hostile platoon are very far apart, the number of trench cleaners is increased, a detachment dropping off in each line. As long as the assaulting platoons do not meet resistance, the reinforcing platoons follow the former at the regulation distance to avoid mixing of the different waves of the attack. If, however, the assaulting platoons suffer severe losses, and are unable to continue the progress, the reinforcing platoon, either by order of the captain or upon the initiative of its leader, moves up and reinforces the combat line. Its function then becomes the same as that of the assaulting platoon. Again, if a gap should occur in the combat line, due to losses or extension of the front, the reinforcing platoon moves in that direction and fills the gap. In general, the tactics of the reinforcing platoon are always to assure continuity of progress by outflanking resistances that have stopped the advance of the platoon in front. The machine guns attached to an assaulting unit follow and protect the flanks. When halted they fire on retreating hostile troops and on special points of resistance. Their special use, however, is against counterattacks.