"When Lone Bull came home that night she told him what she had learned, but he could hear nothing, although he put his ear close to the ground. Nor could he hear the singing the next evening, nor the next, although his woman could hear it plainly. So now the woman got her knife and cut a round hole in the ground, and Lone Bull laid his head in it and could then hear the singing. He told her to make the hole deeper; larger. She did so, and cut clear through the ground, and looking down he could see the beavers sitting in their home, singing beautiful songs, and dancing strange and beautiful dances in time to them. "'Younger brothers, have pity on me!' he cried. 'Oh, my young brothers, teach me your medicine!' "They looked up and saw him, and one answered: 'Close the hole that you have made, because the light disturbs us, and we will soon be with you.' "They soon came in through the doorway, four fine-looking men, beautifully dressed. They had changed themselves from beavers to men. They took seats, and then one of them said to Lone Bull: 'Elder brother, what is it that you want of us? How can we help you?' "Lone Bull told them what it was: his great desire to obtain _na-wak´-o-sis_ and grow it for the people. "'We have that plant; like us it is from the water, a water medicine,' the beaver man told him; 'but before you can use it you have much to do, much to learn. You have to learn all our songs and prayers and dances and different ceremonies, and gather for the ceremonies a skin of every animal and bird that is of the water, one of each except the beavers, and of them there must be two. You know these animals and birds: otter, mink, muskrat; different kinds of ducks; the fish hawk, and all the other birds that get their food from the life of the water. Why? Because there are two great life-givers of this world: the sun, which gives heat, and water, that makes growth, and in our ceremonies the skins of these different animals are symbols of the water.' "'I shall collect them all, so teach me everything,' Lone Bull told them. And they began that very night. "Day after day Lone Bull hunted the animals and birds, brought in their skins for his woman to cure, and night after night the beavers taught him their medicine, all the sacred prayers and dances and ceremonies of it. And at last he knew them all thoroughly. "Then, one night, the beaver chief handed him some stalks of _na-wak´-o-sis_, the top stems all covered with little round seeds.