CORRELATED with the viviparous type of reproduction found in the tsetse fies, the essential features of which were worked out as early as 1895 by Bruce1, there is a great reduction in the number of ovarioles. Stuhlman2 and Roubaud3 studied the anatomy of the female reproductive organs and considered that each ovary consisted of a single ovariole, a view which has been perpetuated by every subsequent author. This communication, however, reports that in Glossina morsitans dissections have proved that each ovary contains, in fact, two ovarioles.