Cult, as used in this book, means a system of religious belief and worship, especially the rites and ceremonies employed in such worship. The present book treats of the cults of a few of the Siouan tribes—that is, with two exceptions, of such tribes as have been visited by the author. "Siouan" is a term originated by the Bureau of Ethnology. It is derived from "Sioux," the popular name for those Indians who call themselves "Dakota" or "Lakota," the latter being the Teton appellation. "Siouan" is used as an adjective, but, unlike its primitive, it refers not only to the Dakota tribes, but also to the entire linguistic stock or family. The Siouan family includes the Dakota, Assiniboin, Omaha, Ponka, Osage, Kansa, Kwapa, Iowa, Oto, Missouri, Winnebago, Mandan, Hidatsa, Crow, Tutelo, Biloxi, Catawba, and other Indians.