The gambling instinct is not strong among creatures of the wild; the chances of their daily life are sufficient stimuli for the beneficial excitement of their nerve centers. It has remained for civilized man, protected in a measure from the natural dangers of existence, to invent artificial stimulants in the form of cards and dice and roulette wheels. Yet when necessity bids there are no greater gamblers than the savage denizens of the jungle, the forest, and the hills, for as lightly as you roll the ivory cubes upon the green cloth they will gamble with death--their own lives the stake. And so Tarzan would gamble now, pitting the seemingly wild deductions of his shrewd brain against all the proofs of the bestial ferocity of his antagonists that his experience of them had adduced--against all the age-old folklore and legend that had been handed down for countless generations and passed on to him through the lips of Pan-at-lee. Yet as he worked in preparation for the greatest play that man can make in the game of life, he smiled; nor was there any indication of haste or excitement or nervousness in his demeanor. First he selected a long, straight branch about two inches in diameter at its base. This he cut from the tree with his knife, removed the smaller branches and twigs until he had fashioned a pole about ten feet in length. This he sharpened at the smaller end. The staff finished to his satisfaction he looked down upon the triceratops. "Whee-oo!" he cried. Instantly the beasts raised their heads and looked at him. From the throat of one of them came faintly a low rumbling sound. "Whee-oo!" repeated Tarzan and hurled the balance of the carcass of the deer to them. Instantly the gryfs fell upon it with much bellowing, one of them attempting to seize it and keep it from the other: but finally the second obtained a hold and an instant later it had been torn asunder and greedily devoured. Once again they looked up at the ape-man and this time they saw him descending to the ground. One of them started toward him. Again Tarzan repeated the weird cry of the Tor-o-don. The GRYF halted in his track, apparently puzzled, while Tarzan slipped lightly to the earth and advanced toward the nearer beast, his staff raised menacingly and the call of the first-man upon his lips. Would the cry be answered by the low rumbling of the beast of burden or the horrid bellow of the man-eater? Upon the answer to this question hung the fate of the ape-man.