The legion consisted of three lines or battalions; the _Hasta'ti_, the _Prin'cipes_, and the _Tria'rii_; there were besides two classes, which we may likewise call battalions, the _Rora'rii_, or _Velites_, consisting of light armed troops, and the _Accen'si_, or supernumeraries, who were ready to supply the place of those that fell.
Each of the two first battalions contained fifteen manip'uli, consisting of sixty privates, commanded by two centurions, and having each a separate standard (_vexil'lum_) borne by one of the privates called Vexilla'rius; the manip'uli in the other battalions were fewer in number, but contained a greater portion of men; so that, in round numbers, nine hundred men may be allowed to each battalion, exclusive of officers.

If the officers and the troop of three hundred cavalry be taken into account, we shall find that the legion, as originally constituted, contained about five thousand men.

The Romans, however, did not always observe these exact proportions, and the number of soldiers in a legion varied at different times of their history.[1] 9.

A cohort was formed by taking a manipulus from each of the battalions; more frequently two manipuli were taken, and the cohort then contained six hundred men.

The cavalry were divided into tur'mae, consisting each of thirty men.
10.