The study surveys religious beliefs and ceremonial practices among several Siouan-speaking peoples, opening with definitions and the specialized vocabulary used for supernatural forces. It documents worship of wakanda and its many manifestations—sun, moon, stars, winds, a thunder-being, and subterranean powers—and outlines common ritual forms such as dances, invocations, offerings, and fasting. Close attention is paid to sacred objects and fetishes, personal and tribal mystery decorations on tents and robes, and the organization and duties of shamans. The work also treats taboos, sorcery and jugglery, death customs, and beliefs about a future life, supported by ethnographic notes and illustrative plates.