L. But when he observed that the Numidians remained quiet, and did not offer to descend from the hill, he became apprehensive that his army, from the season of the year and the scarcity of water, might be overcome with thirst, and therefore sent Rutilius, one of his lieutenant-generals, with the light-armed cohorts and a detachment of cavalry, toward the river, to secure ground for an encampment, expecting that the enemy, by frequent charges and attacks on his flank, would endeavor to impede his march, and, as they despaired of success in arms, would try the effect of fatigue and thirst on his troops. He then continued to advance by degrees, as his circumstances and the ground permitted, in the same order in which he had descended from the range of mountains. He assigned Marius his post behind the front line[168], and took on himself the command of the cavalry on the left wing, which, on the march, had become the van[169]. When Jugurtha perceived that the rear of the Roman army had passed his first line, he took possession of that part of the mountain from which Metellus had descended, with a body of about two thousand infantry, that it might not serve the enemy, if they were driven back, as a place of retreat, and afterward as a post of defense; and then, ordering the signal to be given, suddenly commenced his attack. Some of his Numidians made havoc in the rear of the Romans, while others assailed them on the right and left wings; they all advanced and charged furiously, and every where threw the consul's troops into confusion. Even those of our men who made the stoutest resistance, were baffled by the enemy's versatile method of fighting, and wounded from a distance, without having the power of wounding in return, or of coming to close combat; for the Numidian cavalry, as they had been previously instructed by Jugurtha, retreated whenever a troop of Romans attempted to pursue them, but did not keep in a body, or collect themselves into one place, but dispersed as widely as possible. Thus, being superior in numbers, if they could not deter the Romans from pursuing, they surrounded them, when disordered, on the rear or flank, or, if the hill seemed more convenient for retreat than the plain, the Numidian horses, being accustomed to the brushwood, easily made their way among it, while the difficulty of the ascent, and want of acquaintance with the ground, impeded those of the Romans.