For perhaps five minutes the two retained their relative positions and then Billie began to regain consciousness. Several times he moved uneasily and then he suddenly sat up and looked around. "I wonder what happened," he finally thought, and then he became conscious of a pain in his head. He raised his hand to the aching spot and his fingers encountered a big lump. The truth came upon him like a flash. He dropped his hand to his holster, and sprang to his feet. As he did so he caught sight of the ape and found himself looking into the business end of his own weapon. With a yell he dropped to the ground as though the expected had happened. But when no shot followed, he began to regain his wits and lay still trying to figure out once more just how much the ape might know about the use of the weapon. He remembered the old saying that a gun was a dangerous weapon without lock, stock or barrel, because a man killed his wife with the ramrod; and so he figured that an animal which had intelligence enough to throw a stone and knock him senseless, might have sense enough to fire a revolver. "If I only knew something about his history," soliloquized Billie, "I might be able to guess how much he knew. But he is a perfect stranger to me. I don't even know his name." After several minutes and nothing had happened, Billie decided to make some effort to get away. "I might as well be shot as to be prisoner to an ape," he thought, and so he arose to a sitting posture and surveyed the scene. There sat the ape as before, with the automatic pointed at Billie, but with a puzzled look upon its face. When the lad finally arose, the ape appeared still more puzzled and at length, turning the weapon away from Billie, looked into the muzzle. "That settles it," exclaimed Billie. "He doesn't know how to fire it. I'll go and take it away from him." He started toward the animal, which at once pointed the revolver in Billie's direction. There came a sharp report and a bullet whizzed by the boy's head. "Worse and more of it," exclaimed Billie. "He doesn't know how to use the thing, but he's liable to shoot me as long as I stay in range. I'll just make myself scarce." Stooping down, he picked up a good-sized stone and hurled it at the ape and then, without waiting to see the result of his throw, jumped into the jungle which lined both sides of the track, determined to make a detour and if possible lose his unpleasant companion. He had not run far before he realized that the ape was following, but this he did not mind. There were plenty of trees between them, and he felt sure he would soon be able to reach some sort of a habitation, when he suddenly found himself on the edge of a deep basin into which he plunged before he was able to gain his equilibrium. CHAPTER IV. THE ROSARIO VIEJO.