The struggle between the races lasted for ages on ages, but finally Odin, Vili and Ve, the grandsons of Bori, succeeded in putting to death Ymir, the greatest and worst of the giants. And in killing him they accomplished much more than they expected; for from his wounds the blood gushed in such streams that it drowned all the wicked giants except Bergelmir and his wife, who saved themselves in a boat. Had they, too, but died, there would have been, to the end of time, no giants to trouble the gods; but their descendants kept up from Jotunheim, their home at the end of the world, their plots and warrings against the gods. Odin, who was from the first the wisest and strongest of the gods, gazed upon the huge corpse of the slain giant, and then called the other gods about him. "We cannot waste," he said, "the body of this giant. Where is the use of our power and wisdom if we cannot, out of this evil thing, make something good and beautiful?" Eagerly the gods set to work. It was by far the most interesting task they had ever been called upon to perform, and right well they performed it. In the exact center of the ice abyss they formed, of Ymir's flesh, the earth, and about it and through it they caused his blood to flow, as the sea, the rivers and the lakes. Of his teeth they made steep cliffs to front the sea, and of his bones they formed mountains and hills. His curly hair became grass and trees and flowers, and his eyebrows were set about the new earth as a high fence, to keep out the revengeful giants. Then, taking up the great skull, the gods set it over the earth to form the arch of the heavens, while the brains that it had contained they scattered about as clouds. No wonder the gods were pleased with their work! But Odin saw that there was one thing lacking. "Were we ourselves to dwell on this new created earth," he said, "it would be well; for to a god's eyes all things are clear. But those whom we shall fashion to inhabit it shall see with other eyes than ours, and lights will be needed--lights for day, and lights for night."