There was a deep cavern on the green hillside of Parnassus in Greece where a goat herd, passing by its mouth in ancient times, had inhaled a strange fragrance that had made him able to speak with the knowledge of a seer. Apollo decided to preserve this cave. The city of Delphi grew around it and Apollo sent a priestess crowned with laurel to be its oracle and welcome those mortals who wanted to breathe its magic air. But a monster of darkness, the Python, placed itself in front of the oracle and allowed no man to approach Delphi. Apollo, with his shaft of light, drove away the Python and made it possible for any one who wanted better eyesight or keener hearing or more truthful speech to come to the oracle. That was not all, either, that Apollo had accomplished for the good of men. He protected the Muses, who were the daughters of Jupiter and Memory and could do all sorts of things to make happiness. They could sing, and draw music from the strings of the lire, write stories and poems, and paint pictures. It was said, also, that the laurel tree belonged to Apollo for making wreaths with which to crown those who had done great deeds or made dark paths bright. But the giants could see little value in Apollo's light. They thought mainly of how to wrest riches and nectar and ambrosia from the gods, and they decided to try and kill Apollo and the Muses first of all. Thessaly had the wildest forests and the most rocky coasts of any part of Greece. It was a fitting place for the giants to meet, and it must have been a terrible sight when they landed and formed their ranks for battle. They say that Tityus, one of their leaders, covered nine acres when he lay down for a nap on a plain. Certain others had a hundred arms, limbs made of huge serpents and could breathe fire. The worst part about this race of giants was the fact that their hearts were different from those of the celestials and the mortals. They had hearts made of solid stone which could never beat and feel warm. That was why the giants made preparations to climb up the steep sides of Mount Olympus. No one in all Greece dared to try and stop this war of the giants. They pulled up the mountain Ossa and balanced it on top of Pelion to bridge the way from the earth to the sky. They armed themselves by tearing up great oak and cypress trees for clubs and carrying rocks as large as small hills with them. Then the giants climbed up and attacked the habitation of the gods. It seemed as if the giants were going to win, for even the gods were frightened and made haste to change their forms. The mighty Jupiter took upon himself the figure of a ram. Apollo became a crow, Diana a cat, Juno a cow, Venus a fish and Mercury a bird. But Mars, the god of war, got out his chariot and went to meet the giants, and the others returned at last, for there was really no courage like theirs.