The Sun is, from many circumstances, a natural object of worship among the unenlightened nations of men. With the Dakotas, the sun is sometimes appealed to as a witness. Sometimes they pray to it, generally with the honorable title of _Hunkayapi_. Sometimes, as a god, it communicates with men in dreams and visions. But the nature of the communication is that the men should dance the _wiwanyagwacipi_, with the promise of success in hunting or war. Generally the object of dancing to the sun is to secure victory over enemies. In this aspect it is a _waihdusna_ or _self-immolation_ to the sun; it is an offering up of one’s strength and manhood to secure the aid of the sun in the day of battle. The Bible says, “the stars in their courses fought.” There are occasions, also, when a man dances the sun dance as a thank-offering. He is sick and apprehends he will die. He makes a vow that if his life is spared he will dance to the sun. Or, he is on the war path and he prays to the great _hunkayapi_ for success, promising in that event to dance to his honor. These are said to be the occasions and reasons for the _Wiwanyag-wacipi_. More than a quarter of a century has passed since I witnessed this ceremony, and I was there only a couple of hours about the middle of the day. On the north side a couple of tents, fastened together, were stretched around poles, forming a large semicircle. In the focus of the radii stood three dancers, with their eyes turned towards the sun, which was then in the south. Their faces and the upper part of their bodies were gaily painted, and their heads were adorned with feathers. A blue or red blanket was strapped around their waist, and hung down like a woman’s skirt. Each one had a fife made of the bone of a swan’s wing, on which they kept up a toot-toot-toot-ing, varied by the measures of the dance and the song. Behind them in the shadow of the tent sat the singers and players on instruments—the drums and rattles. A few women sat still farther back, who formed a part of the choir, and joined in the chorus. The chief dancer on this occasion, if I remember rightly, was _Mahipiya sua_, who afterwards shot himself. The dancers always make incisions in their flesh, in which they insert swan’s down or horse hair. These incisions are commonly made on the shoulders and arms. When the sacrifice is intended to be as complete as possible, an incision is made in the back, through which a cord of horse hair is passed, and a buffalo head is attached to the lower end, so that every time the body moves up and down, a slight motion is given to the buffalo head which lies on the ground behind him. At the close, if his strength remains sufficient, he drags the buffalo head around the place. Occasionally a man inflicts still more torture on himself than this. He makes an incision in his breast, and passing a cord through it he draws it tight and fastens the other end to a pole which stands immediately in front of him.