As he watched these, sitting at a respectful distance from the tigers or slinking hungrily in the background, he realized that they might easily prove as much of a bar to his escape as the saber-tooth tigers themselves.

The hyaenodons especially were most discouraging to contemplate. Their bodies were as large as that of a full grown mastiff. They walked upon short, powerful legs and their broad jaws were massive and strong. Dark, shaggy hair covered their backs and sides, turning to white upon their breasts and bellies.

Gnawing hunger assailed Jason Gridley and also an overpowering desire to sleep, convincing him that he must have been many hours away from the O-220, and yet the beasts beneath him continued to feed.

A dead thag lay at the foot of the tree in which the American kept his lonely vigil. So far it had not been fed upon and the nearest tiger was fifty yards away. Gridley was hungry, so hungry that he eyed the thag covetously. He glanced about him, measuring the distance from the tree to the nearest tiger and trying to compute the length of time that it would take him to clamber back to safety should he descend to the ground. He had seen the tigers in action and he knew how swiftly they could cover ground and that one of them could leap almost as high as the branch upon which he sat.

Altogether the chance of success seemed slight for the plan he had in mind in the event that the nearest tiger took exception to it. But great though the danger was, hunger won. Gridley drew his hunting knife and lowered himself gently to the ground, keeping an alert eye upon the nearest tiger. Quickly he sliced several long strips of flesh from the thag's hind quarter.

The tarag feeding fifty yards away looked up. Jason sliced another strip, returned his knife to its sheath and climbed quickly back to safety. The tarag lowered its head upon its kill and closed its eyes.

The American gathered dead twigs and small branches that still clung to the living tree and with them he built a small fire in a great crotch.

Here he cooked some of the meat of the thag; the edges were charred, the inside was raw, but Jason Gridley could have sworn that never before in his life had he tasted such delicious food.

How long his culinary activities employed him, he did not know, but when he glanced down again at the clearing he saw that most of the tigers had quitted their kills and were moving leisurely toward the forest, their distended bellies proclaiming how well they had surfeited themselves. And as the tigers retired, the hyaenodons, the wild dogs and the jackals closed in to the feast.

The hyaenodons kept the others away and Gridley saw another long wait ahead of him; nor was he mistaken. And when the hyaenodons had had their fill and gone, the wild dogs came and kept the jackals away.

In the meantime Gridley had fashioned a rude platform among the branches of the tree, and here he had slept, awakening refreshed but assailed by a thirst that was almost overpowering.

The wild dogs were leaving now and Gridley determined to wait no longer. Already the odor of decaying flesh was warning him of worse to come and there was the fear too that the tigers might return to their kills.

Descending from the tree he skirted the clearing, keeping close to the forest and searching for the trail by which his party had entered the clearing. The wild dogs, slinking away, turned to growl at him, baring menacing fangs. But knowing how well their bellies were filled, he entertained little fear of them; while for the jackals he harbored that contempt which is common among all creatures.

Gridley was dismayed to note that many trails entered the clearing; nor could he recognize any distinguishing mark that might suggest the one by which he had come. Whatever footprints his party had left had been entirely obliterated by the pads of the carnivores.

He tried to reconstruct his passage across the clearing to the tree in which he had found safety and by this means he hit upon a trail to follow, although he had no assurance that it was the right trail. The baffling noonday sun shining down upon him seemed to taunt him with his helplessness.

As he proceeded alone down the lonely trail, realizing that at any instant he might come face to face with some terrible beast of a long dead past, Jason Gridley wondered how the ape-like progenitors of man had survived to transmit any of their characteristics however unpleasant to a posterity. That he could live to reach the O-220 he much doubted. The idea that he might live to take a mate and raise a family was preposterous.

While the general aspect of the forest through which he was passing seemed familiar, he realized that this might be true no matter what trail he was upon and now he reproached himself for not having had the trees along the trail blazed. What a stupid ass he had been, he thought; but his regrets were not so much for himself as for the others, whose safety had been in his hands.

Never in his life had Jason Gridley felt more futile or helpless. To trudge ceaselessly along that endless trail, having not the slightest idea whether it led toward the O-220 or in the opposite direction was depressing, even maddening; yet there was naught else to do. And always that damned noon-day sun staring unblinkingly down upon him—the cruel sun that could see his ship, but would not lead him to it.

His thirst was annoying, but not yet overpowering, when he came to a small stream that was crossed by the trail. Here he drank and rested for a while, built a small fire, cooked some more of his thag meat, drank again and took up his weary march—but much refreshed.

Aboard the O-220, as the hours passed and hope waned, the spirit of the remaining officers and members of the crew became increasingly depressed as apprehension for the safety of their absent comrades increased gradually until it became eventually an almost absolute conviction of disaster.

"They have been gone nearly seventy-two hours now," said Zuppner, who, with Dorf and Hines, spent most of his time in the upper observation cabin or pacing the narrow walkingway along the ship's back. "I never felt helpless before in my life," he continued ruefully, "but I am free to admit that I don't know what in the devil to do."

"It just goes to show," said Hines, "how much we depend upon habit and custom and precedence in determining all our action even in the face of what we are pleased to call emergency. Here there is no custom, habit or precedence to guide us."

"We have only our own resources to fall back upon," said Dorf, "and it is humiliating to realize that we have no resources."

"Not under the conditions that surround us," said Zuppner. "On the outer crust there would be no question but that we should cruise around in search of the missing members of our party. We could make rapid excursions, returning to our base often; but here in Pellucidar if we should lose sight of our base there is not one of us who believes he could return the ship to this same anchorage.