Helpless, Kirby realized that Naida and all the others had clapped over their faces curious masks which seemed to be made of some crystalline substance, and that now others had armed themselves with the tennis balls. And that was the last observation he made before the battle opened furiously. With a cry muffled behind her mask, Naida leaped out in front of her squadron and cut loose her queer vegetable ball with whizzing aim and force. Full into the snarling face of one of the ape-men the thing smashed, filling the air all about the creature with a yellow, mistlike powder. Kirby was half deafened by the yells of rage and terror which went up from the entire attacking band. The creature who had been hit fell to his knees the while he made agonized tearing movements at his face and uttered shrill, jabbering yelps. Other balls flashed instantly from Naida's ranks, and each brought about the same ghastly result as the first. But then Kirby saw that the whole jungle seethed with the hairy, awful men. "Keep back!" Naida shrieked at him through her mask. "We have no mask for you. If the powder from our fungi touches you, it will be the end!" * * * * * With gaps in the advancing line filled as soon as each screeching ape went down, the attackers leaped on until Kirby knew they would be upon the girls in a matter of seconds. A sweat broke out on his neck. But then an idea gripped him, and suddenly, without even a last glance at Naida, he leaped away even as she had commanded. A great boulder lay on the shore fifty yards away. Toward it Kirby streaked as though he had become coward. But he had not turned coward. By the time he reached the shelter which would protect him from the fungus mist, a turning point had come in the battle. The ape-men had closed in on the girls, were swarming about them, and the mist balls had almost ceased to fly. But the thing which gave Kirby hope was that the apes were not attempting to harm the girls. They seemed victors, but they were not committing atrocities. It was the sharp intuition that something like this might happen which had sent Kirby fleeing from the fight. He believed he might yet prove useful. The thickest group of attackers were jostling about Naida. As the screams and sobs of the girls quivered out, mingled with the guttural roaring of the men, Naida was shut off by a solid wall of aggressors. Then Kirby saw her again. But now two of the most powerful of the ape-men had caught her up and was carrying her. Her kicking and writhing and biting accomplished nothing. The apes were headed directly back to the jungle. * * * * *