The catching of flies in traps or with a sticky lime does not offer much encouragement. As regards personal prophylaxis, white clothes are to be worn as the tsetse fly, along with mosquitoes, prefers dark-colored garments. The legs should be protected by leggings and possibly one could consider the wearing of gloves or veils. As a matter of fact, however, the heat of the tropics precludes these latter measures. As the fly only bites in the daytime one should choose the night for going about, if practicable. =Treatment.=—The general opinion is that trypanosomiasis is only curable at a time prior to the appearance of trypanosomes in the cerebro-spinal fluid. Consequently, the stage of sleeping sickness offers little chance of cure by treatment. Such cases have been treated with injections of 10 cc. of 1 to 1000 solution of neosalvarsan into the spinal canal, after withdrawing about 15 cc. of spinal fluid, but without appreciable curative effect. On the assumption that trypanosomes invading the central nervous system are protected from drug action, Marshall proposed the injection of salvarsanized serum intrathecally. Three hours after the administration of 0.6 gm. of salvarsan enough blood is withdrawn from a vein to give about 20 cc. of serum. Following the withdrawal of a slightly greater amount of cerebro-spinal fluid from 5 to 20 cc. of the serum is injected in its place. Yorke in a critical article on the claims for this treatment is of the opinion that there is no satisfactory evidence that such a method sterilizes the infected cerebro-spinal fluid. He cites cases where the trypanosomes disappeared from the spinal fluid after ordinary treatment and where cases lived for extended periods after trypanosomes were found in their spinal fluid. Corbus and associates have described a new method of obtaining a high medicinal content in the cerebro-spinal fluids. Their work was done with neo-arsphenamine, but there seems to be no reason why other drugs may not be similarly administered. The basis of the method is the observation that hypertonic salt solution, injected intravenously, will dehydrate the central nervous system, and that restoration of fluid begins at about the sixth hour. If a drug is injected into the circulation just at the time when the restorative formation of spinal fluid is taking place, it appears that a large quantity is carried into the subarachnoid spaces with the fluid, as on a flood tide. Method: 1. 8 A.M. Patient is put to bed. 2. 10 A.M. Intravenous injection of 100 cc. of 15% saline, warmed and administered slowly by gravity. The symptoms produced by this injection are mild and transitory. 3. No food is permitted at midday. 4. 4 P.M. Neo-arsphenamine is injected with the usual technic. 5. 8 P.M. Light nourishment is allowed. Patient is kept under observation, preferably in bed, for the ensuing thirty-six hours.