MY hesitation in accepting unreservedly Dr. Bruce's account of the reproduction of Glossina was due to a suspicion, not that he had mistaken some other fly for it, but that the extruded larvae might turn out to be those of a parasitic form, probably Tachinid. Mr. Peringuey's letter is most welcome as supplying the final proof of an extremely important fact, both economically and zoologically, in the insect's life-history.