Just as in nature no mere assemblage of cells, or even of functional parts, can form a living organism, so no collection of individuals, however efficient--or of small units, however perfect--can in any true sense be called an Army. It might have the appearance of a real military force, but it would only be suited to peace. The means by which it can be made fit for war is _Organization_, without which it would be little better than an armed mob--inert, or at best irregular and spasmodic in its movements. An ill-organized army is not capable of co-ordinated or of sustained action, owing to the difficulty of either directing its movements or supplying its wants. THE CHAIN OF COMMAND It is obvious that a Commander of a Military Force cannot deal personally and directly with all those under his command, but only with a limited number of subordinate commanders. Each of the latter in his turn conveys his will to his own subordinates, and this gradually broadening system, called the _Chain of Command_, is carried on, till every individual of the Force receives his Orders. These Orders are founded on the original directions of the Commander-in-Chief, with modifications and details added by each lower authority in the chain, so as to suit the special circumstances of his own Command. This principle combines unity of control with decentralization of command and devolution of responsibility. In no other way can ready and effective co-operation of all fractions of the force to a common end be ensured. UNITS OR FORMATIONS OF TROOPS The method, generally speaking, of War Organization is to provide the links in the chain of Command by a systematic arrangement, in suitable groups, of the various troops composing the Army. The smallest groups, or _Units_, are combined in larger ones, and these again are built up into more complex bodies, and so on, until the whole Army is formed in a small number of large bodies, whose Commanders receive direct orders from the Supreme Commander. For want of a general name for these bodies it is usual to speak of them all as _Formations_. The term _Units_, which is often used, properly applies only to the elementary groups. The largest Formations are conveniently styled the _Subordinate Commands_ of the Army. Each category of Formations forms a step in the pyramid of organization, in which the lowest layer is formed by the Units, the top layer by the Subordinate Commands, and the apex by the Supreme Commander. The Commanders of each Formation, from the largest to the smallest, form the successive links in the chain of Command.