"The reason is obvious," he said a little contemptuously. "Where did they obtain water? From the spring which welled up at the foot of that cactus to the left. But now it is dry and cracking mud."
Daoud nodded grudgingly.
"Possibly," he allowed. "The nearest wells are at Ain Djemma."
"Held in force by two companies of the Legion," said Perinaud. "They are hardly likely to show themselves there. No, if they have gone south they are seeking the Wad el Mella. They will follow the stream through the gorge towards their own foothills from which it issues."
"This river? How far is it?" asked Aylmer.
"Eight kilometres, possibly ten," said Perinaud. "There are duars and encampments along its banks in a dozen places. We ought to get news of our men, even if we do not overtake them."
"Our horses have come a matter of thirty kilometres already," said Aylmer.
"Then as soon as possible they must do ten more," answered the sergeant, energetically. "Without water we cannot camp, any more than our friends of the Beni M'Geel. En avance!"
Aylmer drew his horse up beside Perinaud's as for the second time they left the shelter of the trees and ambled out on to the plain. The westering sun was turning it to broad belts of dun, and yellow, and green, as the slanting beams fell upon earth, or marigold weed, or crops. Four or five miles distant to their front the rolling uplands culminated in a belt of squat but far-branching trees.
"There, one may suppose, are the river and the gorge," he suggested. "The inhabitants of these duars, of which you speak? How will they greet us?"