(_b_) No element moves in =double time= unless the movement be executed when marching in =double time= or =double time= be commanded (par. 47) or otherwise indicated by the leader. No trooper increases the length of the step or the cadence unless specially so prescribed. (_c_) The leader so controls the movements of the base as to facilitate the execution of the movement in accordance with (_b_), above. This will involve halting the base whenever certain movements (e.g., those from column into line) are executed in =quick time=. (_d_) If =double time= be included in the preparatory command for a movement, the indication is obeyed in accordance with the principles of par. 337. (_e_) In movements from line into column, and in other similar movements, if executed at =attention=, the troopers while waiting to take their places in the column do not =halt= unless halt be commanded by a platoon (or troop) commander. They =mark time= instead if necessary for the execution of the movement. (_f_) In applying the rules for mounted movements to movements on foot =quick time= will be understood where =walk= is referred to and =double time= where any faster gait is referred to. (_g_) Any exceptions to the above rules are stated where they occur. =Section 7. The School of the Squad.= =340.= As soon as the troopers are sufficiently advanced in their instruction in the =School of the Trooper= they will be grouped into temporary squads for elementary collective instruction. This instruction will be conducted in accordance with the general principles indicated in par. 42; progress therein should be so regulated that no collective movement will be taken up until the trooper, by previous individual instruction, has been properly prepared for its execution. =341.= Instruction in the =School of the Squad= is intended primarily to teach recruits the elementary movements upon which the entire drill is based. It may be recurred to whenever necessary in cases where troopers evidence the need of further elementary work. =342.= For elementary collective instruction groups of not to exceed six or eight men can be used to best advantage. The actual instruction of each group should be conducted by a noncommissioned officer, but the instruction must be closely supervised by a commissioned officer (par. 37). =343.= The system of drill contained in these regulations is based largely upon the actual leading of units by their respective chiefs or commanders. During the elementary instruction of recruits, both mounted and dismounted, leading will be emphasized as indicated in par. 344. Thereafter the application of leading will conform to pars. 448 to 456.