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.
The sun had just risen when Tarzan arrived at the native village in which he had left La, and no sooner did his eyes rest upon it than he became apprehensive that something was amiss, for, not only was the gate wide open but there was no sign of life within the palisade, nor was there any movement of the swinging huts that would indicate that they were occupied. Always wary of ambush, Tar-
