The material for the following account of this interesting Osage ceremony was collected in April of this year, while the writer was engaged in work, among certain tribes in Oklahoma, for the Field Columbian Museum. On only three of the four ceremonial days were observations made; whatever is here recorded of the other ceremonial day or of events after the ceremony, was obtained largely from Charles Michell, an English-speaking Osage who took an active part in the performance. . The spirit of a dead Osage must be avenged, whether the dead be a child, woman, warrior, or old man. The fulfilment of this obligation is in the immediate charge of a very near relative of the decedent, it is necessary that certain rites be performed.