As he flew along the seacoast he saw in the distance a dark cavern among the rocks, and in front of it, on the glaring white sand, lay a monster which, even from his great height above the water, Perseus could not glance at without shuddering. Remembering Minerva's caution when she gave him her shield, he used its bright surface as a mirror in which were reflected all the objects below; and never once was he tempted to turn his eyes toward the dreadful figure on the beach. Its scaly hide glistened in the sunlight, its brazen claws shone like live coals, and the snakes that lay coiled around its head shot out their tongues and hissed whenever the Gorgon stirred in its sleep. As Perseus drew nearer he saw, reflected in his polished shield, the forms of men and animals that had been turned to stone by one glance at Medusa's face. These were very numerous around the mouth of the cave, and Perseus silently prayed to the gods that his figure might not be added to the number. Some distance away lay the other two Gorgons, Medusa's sisters, but the young hero had no thought for them. His whole attention was centered on the blow that he must deal the sleeping Medusa before the snakes hissed so loudly that she would awaken. Even in his shield the sight of that twisting, wriggling mass of reptiles was so repulsive that Perseus shuddered and was tempted to turn away; but just then he heard a whisper. "Be quick. Strike swift and sure;" and as he recognized the voice of Mercury, all his courage returned. Grasping his sword more firmly and holding his bright shield above the sleeping monster, he swooped suddenly down upon it, and with one swift stroke cut off the great head with all its coils of serpents. It was only a moment's work to sheathe his sword and grasp the hideous trophy in his hands; but even then the danger was not over, for the snakes on Medusa's head began to hiss so loudly that their noise awoke the other two sleeping Gorgons, and they looked around to find why their sister had disturbed their rest. Seeing Medusa's headless body on the sand, they set up such terrible cries that the noise re-echoed like thunder through the cavern, and as far away as Perseus had already flown, he could hear the awful sounds that made the seashore seem like some vision in a dreadful nightmare. [Illustration: Perseus] As he hurried over the sea with Medusa's head held firmly in his hand, some of the blood dripped down into the white-capped waves and was cherished by Neptune, who had once loved Medusa when she was a beautiful maiden. From these drops of blood the sea-king created the wonderful winged horse, Pegasus, who was to share in the adventures of another famous hero, Bellerophon. Some of the Gorgon's blood had also dropped on the hot African sand, as Perseus was flying upward from the Gorgon's cave, and from this sprang a brood of poisonous reptiles that ever afterward infested that region and brought death to many an unwary explorer.