There was no apparent effect; he had not dared to strike too hard, for fear of crushing the shell. He struck several more times, with identical results and increasing impatience; and at last there occurred the result he had feared. The black armor gave way, and the point penetrated deeply enough to insure the damage of most of the interior organs. The legs gave a final twitch or two, and ceased moving, and Cunningham gave an exclamation of annoyance.

On hope, he removed the broken bits of shell, and for a moment looked in surprise at the liquid which seemed to have filled the body cavities. It was silvery, even metallic in color; it might have been mercury, except that it wet the organs bathed in it and was probably at a temperature above the boiling point of that metal. Cunningham had just grasped this fact when he was violently bowled over, and the dead creature snatched from his grasp. He made a complete somersault, bringing up against the rear wall of the cave; and as he came upright he saw to his horror that the assailant was none other than the giant centipede.

It was disposing with great thoroughness of his specimen, leaving at last only a few fragments of shell that had formed the extreme tips of the legs; and as the last of these fell to the ground, it raised the fore part of its body from the ground, as the man had seen it do before, and turned the invisible pin-points of its pupils on the spacesuited human figure.

Cunningham drew a deep breath, and took a firm hold of his pointed rock, though he had little hope of overcoming the creature. The jaws he had just seen at work had seemed even more efficient that those of the plant-eater, and they were large enough to take in a human leg.

For perhaps five seconds both beings faced each other without motion; then to the man’s inexpressible relief, the centipede reached the same conclusion to which its previous examination of humanity had led it, and departed in evident haste. This time it did not remain in sight, but was still moving rapidly when it reached the limit of Cunningham’s vision.