Near the spot where the cow lay down there was a small stream which issued from a fountain not far distant, called the fountain of Dirce. Cadmus sent some of his men to the place to obtain some water which it was necessary to use in the ceremonies of the sacrifice. It happened, however, that this fountain was a sacred one, having been consecrated to Mars,--and there was a great dragon, a son of Mars, stationed there to guard it. The men whom Cadmus sent did not return, and accordingly Cadmus himself, after waiting a suitable time, proceeded to the spot to ascertain the cause of the delay. He found that the dragon had killed his men, and at the time when he arrived at the spot, the monster was greedily devouring the bodies. Cadmus immediately attacked the dragon and slew him, and then tore his teeth out of his head, as trophies of his victory. Minerva had assisted Cadmus in this combat, and when it was ended she directed him to plant the teeth of the dragon in the ground. Cadmus did so, and immediately a host of armed men sprung up from the place where he had planted them. Cadmus threw a stone among these armed men, when they immediately began to contend together in a desperate conflict, until at length all but five of them were slain. These five then joined themselves to Cadmus, and helped him to build his city. He went on very successfully after this. The city which he built was Thebes, which afterward became greatly celebrated. The citadel which he erected within, he called, from his own name, Cadmia.