ferent sizes, similar to others scattered along the entire base of the cliff, and it was in Tarzan's mind that if he found the cave unoccupied, he would barricade the door and insure himself a quiet and peaceful night's repose within the sheltered interior. Let the storm rage without, Tarzan would remain within until it ceased, comfortable and dry. A tiny rivulet of cold water trickled outward from the opening.
Close to the cave Tarzan kneeled and sniffed the ground. A low growl escaped him and his upper lip curved to expose his fighting fangs. "Numa!" he muttered; but he did not stop. Numa might not be at home—he would investigate. The entrance was so low that the ape-man was compelled to drop to all fours before he could poke his head within the aperture; but first he looked, listened, and sniffed in each direction at his rear—he would not be taken by surprise from that quarter.
His first glance within the cave revealed a narrow tunnel with daylight at its farther end. The interior of the tunnel was not so dark but that the ape-man could readily see that it was untenanted at present. Advancing cautiously he crawled toward the opposite end imbued with a full realization of what it would mean if Numa should suddenly enter the tunnel in front of him; but Numa did not appear and the ape-man emerged at length into the open and stood erect, finding himself in a rocky cleft whose precipitous walls rose almost sheer on every hand, the tunnel from the gorge passing through the cliff and forming a passageway from the outer world
