have corresponded to those of the heavy infantry. The light cavalry, chiefly used for skirmishing and pursuit, and in part armed with the sarissa, was drawn from the Thracians and Paeonians, and was about the third of the number of the heavy horse. A smaller body of Greek cavalry probably stood in nearly the same relation to the other two divisions, as the Hypaspists to the heavy and light infantry. To the Hypaspists belonged the royal foot bodyguard, the Agêma, or royal escort, and the Argyraspides, so called from the silver ornaments with which their long shields were enriched. But the precise relation in which these bodies stood to each other does not appear very distinctly from the descriptions of the ancients. The royal horse-guard was composed of eight Macedonian squadrons, filled with the sons of the best families. The numbers of each are not ascertained, but they seem in all not much to have exceeded or fallen short of a thousand.” From this description of the Macedonian army, it may easily be imagined what a formidable aspect its main arm—the phalanx of panoplied infantry—would present to the enemy. Polybios informs us that the Roman officers who were present in the battle of Kynoskephalai, and then saw the phalanx for the first time, told him that in all their experience of war they had never seen anything so terrible. The phalanx, however, as that historian points out, could only operate effectively on level and open ground—was quite unfit for rapid advance and rough terrain, and useless if its ranks were broken. It was thus helpless in face of an active enemy unless well supported by cavalry and light troops. This explains why Alexander attached so much importance to his cavalry. In point of fact he owed none of his victories to the phalanx; his cavalry, rapid in its evolutions and charging with resistless impetuosity, gained them all. In addition to the troops which have been particularised in the extract, there was one kind organised by Alexander called _dimachai_, intermediate between cavalry and infantry, being designed to fight on horseback or on foot as circumstances required. His artillery formed a very useful part of his equipment. The _balistai_ and _katapeltai_ of which it consisted threw stones and darts to the distance of 300 yards, and was frequently employed with great effect. As he foresaw that in the course of his expedition he was likely to penetrate to regions either imperfectly or altogether unknown, he entertained on his staff men of literary and scientific requirements to write his deeds, and describe those countries and nations to which he might carry his arms.