"It is not in Pellucidar;" but that the Sagoth could not understand any more than he could understand that a creature might be lost at all, for inherent in him was that same homing instinct that marked all the creatures of Pellucidar and which constitutes a wise provision of nature in a world without guiding celestial bodies.

Had it been possible to transport Tar-gash instantly to any point within that mighty inner world, elsewhere than upon the surface of an ocean, he could have unerringly found his way to the very spot where he was born, and because that power was instinctive he could not understand why Tarzan did not possess it.

"I know where there is a tribe of men," he said, presently. "Perhaps they are your people. I shall lead you to them."

As Tarzan had no idea as to the direction in which the ship lay and as it was remotely possible that Tar-gash was referring to the members of the O-220 expedition, he felt that he was as well off following where Tar-gash led as elsewhere, and so he signified his readiness to accompany the Sagoth.

"How long since you saw this tribe of men," he asked after a while, "and how long have they lived where you saw them?"

Upon the Sagoth's reply to these questions, the ape-man felt that he might determine the possibility of the men to whom Tar-gash referred being the members of his own party, for if they were newcomers in the district then the chances were excellent that they were the people he sought; but his questions elicited no satisfactory reply for the excellent reason that time meant nothing to Tar-gash. And so the two set out upon a leisurely search for the tribe of men that Tar-gash knew of. It was leisurely because for Tar-gash time did not exist; nor had it ever been a very important factor in the existence of the ape-man, except in occasional moments of emergency.

They were a strangely assorted pair—one a creature just standing upon the threshold of humanity, the other an English Lord in his own right, who was, at the same time, in many respects as primitive as the savage, shaggy bull into whose companionship chance had thrown him.

At first Tar-gash had been inclined to look with contempt upon this creature of another race, which he considered far inferior to his own in strength, agility, courage and woodcraft, but he soon came to hold the ape-man in vast respect. And because he could respect his prowess he became attached to him in bonds of loyalty that were as closely akin to friendship as the savage nature of his primitive mind permitted.

They hunted together and fought together. They swung through the trees when the great cats hunted upon the ground, or they followed game trails ages old beneath the hoary trees of Pellucidar or out across her rolling, grassy, flower-spangled meadowland.

They lived well upon the fat of the land for both were mighty hunters.

Tarzan fashioned a new bow and arrows and a stout spear, and these, at first, the Sagoth refused even to notice, but presently when he saw how easily and quickly they brought game to their larder he evinced a keen interest and Tarzan taught him how to use the weapons and later how to fashion them.

The country through which they traveled was well watered and was alive with game. It was partly wooded with great stretches of open land, where tremendous herds of herbivores grazed beneath the eternal noonday sun, and because of these great herds the beasts of prey were numerous—and such beasts!

Tarzan had thought that there was no world like his own world and no jungle like his own jungle, but the more deeply he dipped into the wonders of Pellucidar the more enamored he became of this savage, primitive world, teeming with the wild life he loved best. That there were few men was Pellucidar's chiefest recommendation. Had there been none the ape-man might have considered this the land of ultimate perfection, for who is there more conversant with the cruelty and inconsideration of man than the savage beasts of the jungle?

The friendship that had developed between Tarzan and the Sagoth—and that was primarily based upon the respect which each felt for the prowess of the other—increased as each seemed to realize other admirable, personal qualities and characteristics in his companion, not the least of which being a common taciturnity. They spoke only when conversation seemed necessary, and that, in reality, was seldom.

If man spoke only when he had something worth while to say and said that as quickly as possible, ninety-eight per cent of the human race might as well be dumb, thereby establishing a heavenly harmony from pate to tonsil.

And so the companionship of Tar-gash, coupled with the romance of strange sights and sounds and odors in this new world, acted upon the ape-man as might a strong drug, filling him with exhilaration and dulling his sense of responsibility, so that the necessity of finding his people dwindled to a matter of minor importance. Had he known that some of them were in trouble his attitude would have changed immediately, but this he did not know. On the contrary he was only aware that they had every facility for insuring their safety and their ultimate return to the outer world and that his absence would not handicap them in any particular. However, when he did give the matter thought he knew that he must return to them, that he must find them, and that sooner or later he must go back with them to the world from which they had come.

But all such considerations were quite remote from his thoughts as he and Tar-gash were crossing a rolling, tree-dotted plain in their search for the tribe of men to which the Sagoth was guiding him. By comparison with other plains they had crossed, this one seemed strangely deserted, but the reason for this was evident in the close-cropped grass which suggested that great herds had grazed it off before moving on to new pastures. The absence of life and movement was slightly depressing and Tarzan found himself regretting the absence of even the dangers of the teeming land through which they had just come.

They were well out toward the center of the plain and could see the solid green of a great forest curving upward into the hazy distance when the attention of both was attracted by a strange, droning noise that brought them to a sudden halt. Simultaneously both turned and looked backward and up into the sky from which the sound seemed to come.

Far above and just emerging from the haze of the distance was a tiny speck. "Quick!" exclaimed Tar-gash. "It is a thipdar," and motioning Tarzan to follow him he ran swiftly to concealment beneath a large tree.

"What is a thipdar?" asked Tarzan, as the two halted beneath the friendly shade.

"A thipdar," said the Sagoth, "is a thipdar;" nor could he describe it more fully other than to add that the thipdars were sometimes used by the Mahars either to protect them or to hunt their food.

"Is the thipdar a living thing?" demanded Tarzan.

"Yes," replied Tar-gash. "It lives and is very strong and very fierce."

"Then that is not a thipdar," said Tarzan.

"What is it then?" demanded the Sagoth.

"It is an aeroplane," replied Tarzan.

"What is that?" inquired the Sagoth.

"It would be hard to explain it to you," replied the ape-man. "It is something that the men of my world build and in which they fly through the air," and as he spoke he stepped out into the opening, where he might signal the pilot of the plane, which he was positive was the one carried by the O-220 and which, he assumed, was prosecuting a search for him.

"Come back," exclaimed Tar-gash. "You cannot fight a thipdar. It will swoop down and carry you off if you are out in the open."

"It will not harm me," said Tarzan. "One of my friends is in it."

"And you will be in it, too, if you do not come back under the tree," replied Tar-gash.

As the plane approached, Tarzan ran around in a small circle to attract the pilot's attention, stopping occasionally to wave his arms, but the plane sped on above him and it was evident that its pilot had not seen him.

Until it faded from sight in the distance, Tarzan of the Apes stood upon the lonely plain, watching the ship that was bearing his comrade away from him.

The sight of the ship awakened Tarzan to a sense of his responsibility. He realized now that someone was risking his life to save him and with this thought came a determination to exert every possible effort to locate the O-220.

The passage of the plane opened many possibilities for conjecture. If it was circling, which was possible, the direction of its flight as it passed over him would have no bearing upon the direction of the O-220, and if it were not circling, then how was he to know whether it was traveling away from the ship in the beginning of its quest, or was returning to it having concluded its flight.

"That was not a thipdar," said Tar-gash, coming from beneath the tree and standing at Tarzan's side. "It is a creature that I have never seen before. It is larger and must be even more terrible than a thipdar. It must have been very angry, for it growled terribly all the time."

"It is not alive," said Tarzan. "It is something that the men of my country build that they may fly through the air.