Report on the anatomy of the tsetse-fly (Glossina palpalis)

Abstract

The following description is based upon dissections and preparations made in the laboratory of the Sleeping Sickness Commission at Entebbe since my arrival here at the beginning of April. I hope on my return to England to work up my material into a detailed memoir on the anatomy and histology. Time does not suffice for me to complete my work out here, but it seemed worth while, nevertheless, to bring forward as soon as possible a brief description of the general anatomy of the fly, and especially of its digestive tract, on account of its importance for the study of the evolution of the trypanosomes of Sleeping Sickness, and other tsetse-fly diseases, within the body of their invertebrate host. In this paper I do not propose to attempt to deal with either the muscular system or the respiratory tracheal system. The former of these is so complex that much more time would be required for working it out than I could afford to spend, and it is, moreover, of little or no importance for the aim in view; while the tracheal system, or at least its finer branches, are so intimately connected with the fat-body, which here, as in other insects, fills up the body-cavity, that in the process of clearing up and laying bare the organs, the tracheæ are for the most part removed. Special muscles or tracheae will be mentioned in places, but otherwise no account will be taken of these two systems.