more than twenty feet wide and eroded from solid granite cliffs. Here there was no concealment whatsoever, and the ape-man realized that to enter it would mean almost immediate discovery. Glancing about, he saw that by making a slight detour he could reach the summit of the gorge, where, amid tumbled, granite boulders and stunted trees and shrubs, he knew that he could find sufficient concealment, and perhaps a plainer view of the trail beyond. Nor was he mistaken, for, when he had reached a vantage point far above the trail, he saw ahead an open pocket in the mountain, the cliffs surrounding which were honeycombed with numerous openings, which, it seemed to Tarzan, could be naught else than the mouths of tunnels. Rough wooden ladders reached to some of them, closer to the base of the cliffs, while from others knotted ropes dangled to the ground below. Out of these tunnels emerged men carrying little sacks of earth, which they dumped in a common pile beside a rivulet which ran through the gorge. Here other blacks, supervised by Bolgani, were engaged in washing the dirt, but what they hoped to find or what they did find, Tarzan could not guess. Along one side of the rocky basin many other blacks were engaged in quarrying the granite from the cliffs, which had been cut away through similar operations into a series of terraces running from the floor of the basin to the summit of the cliff. Here naked blacks toiled with primitive tools under the supervision of savage Bolgani. The activities of the quarrymen were obvious enough, but what the others were bringing from the mouths of the tunnels Tarzan could not be positive, though the natural assumption was that it was gold. Where, then, did they obtain their diamonds? Certainly not from these solid granite cliffs. A few minutes’ observation convinced Tarzan that the trail he had followed from the forest ended in this little cul-de-sac, and so he sought a way upward and around it, in search of a pass across the range. The balance of that day and nearly all the next he devoted to his efforts in this direction, only in the end to be forced to admit that there was no egress from the valley upon this side. To points far above the timber line he made his way, but there, always, he came face to face with sheer, perpendicular cliffs of granite towering high above him, upon the face of which not even the ape-man could find foothold. Along the southern and eastern sides of the basin he carried his investigation, but with similar disappointing results, and then at last he turned his steps back toward the forest with the intention of seeking a way out through the valley of Opar with La, after darkness had fallen.