THE VOYAGE OF THE ARGONAUTS. 27 was told that if he wished to prove his descent from the gods and their sanction of his voyage, he must harness these terrible animals, plough with them a large field, and sow it with dragons’ teeth. Perilous as this task seemed, each of the heroes was eager to undertake it, but Jason, as the leader of the expedition, took it upon himself. Fortune favored him in the desperate undertaking. Medea, the daughter of Metes, who knew all the arts of magic, had seen the handsome youth and fallen in love with him at sight. She now came to his aid with all her magic. Gathering an herb which had grown where the blood of Prometheus had fallen, she prepared from it a magical ointment which, when rubbed on Jason’s body, made him invulner- able either to fire or weapons of war. Thus pre- pared, he fearlessly approached the fire-breathing bulls, yoked them unharmed, and ploughed the field, in whose furrows he then sowed the dragons’ teeth. Instantly from the latter sprang up a crop of armed men, who turned their weapons against the hero. But Jason, who had been further instructed by Me- dea, flung a great stone in their midst, upon which they began to fight each other, and he easily subdued them all. Jason had accomplished his task, but Aetes proved unfaithful to his words. He not only withheld the prize, but took steps to kill the Argonauts and burn their vessel. They were invited to a banquet, and armed men were prepared to murder them during the night after the feast. Fortunately, sleep over- came the treacherous king, and the adventurers,