Summoning the AncestorsA survey of little studied sacred African bells and ritual objects Summoning the Ancestors explores a collection of 72 ofo (small ritual objects) and 74 bells produced in southern Nigeria by Igala, Igbo, Edo, Yorb, and other neighboring peoples, which was gifted to the Fowler Museum by Mark Clayton. The use of bronze ofo, dynamic symbols of ones relationship with the ancestors, dates back to at least the fifteenth century. Ofo likely derive from wire