It is only in recent years that the presence and extent of sleeping sickness amongst the pagan tribes on the Bauchi Plateau have been recognised. This is partly owing to the fact that endemic sleeping sickness of a very mild type with a low mortality has prevailed hitherto. The epidemic disease with a high mortality seems to be of recent origin and is probably due to the improved communications and unrestrained movement between different tribes and races throughout the Province, resulting in the introduction of new and virulent strains of Trypanosoma gambiense. The large labour camps at the tin mines are doubtless responsible for a good deal of this movement of population. Tsetse on the Plateau is usually scanty, as suitably heavy shade and an adequate food supply are comparatively rare. Wherever conditions permit, however, Glossina palpalis is present. The following report is based on a visit made by the author during November and December, 1929, to Ganawuri, where the most severe epidemic of sleeping sickness yet recorded on the Plateau was in progress. The objects of the visit were primarily an investigation into the bionomics of G. palpalis in this locality, and the determination of the part played by it in the transmission of the disease.