Opening Paragraph It is proposed to describe two specialized aspects of the practice of magicians in the northern part of Sukumaland, Tanganyika Territory, in curing patients who are assumed to be ill because of the malevolence of the spirits of their ancestors. Both the curative powers of these specialists and the diseases they treat are closely connected with the cult of the ancestors, which remains the basic spiritual force in the lives of the majority of the Sukuma people. This cult rests on the belief that the spirits of ancestors may take control of their descendants either partially or completely, and also that to establish contact with the ancestors requires the offices of a magician. It is alleged that these magicians become at times temporary and passive mediums through which their ancestors assist them to diagnose the ills of the people who have paid to consult them; this usually takes the form of self-induced hysteria. Certain other specialized magicians are able to induce hysteria in others as a means of curing them of sickness.