British Contributions To Tropical Health -- Here in the Insectory at Liverpool, tsetse flies are bred in large cages. One of which can be seen on the bench (left) where technicians are transferring the flies to small containers where they can be fed and infected with sleeping sickness, for research work. Model of the tsetse fly and its larvae can be seen at the far end of the bench. (left). May 1, 1951. (Photo by British Official Photograph).