Bruce continued his work in Uganda until the end of August, 1903, having been joined there by Colonel Greig of the Indian Army, who has continued the work of the Royal Society’s commission since Bruce left. Other valuable observations have been carried out by various medical men officially connected with the Uganda Protectorate. Bruce soon showed that in every case of sleeping sickness, when examined with sufficient care, the trypanosome parasite is found to be present in the cerebro-spinal fluid. He also showed that it is absent from that fluid in all negroes examined who were not afflicted with the disease, but made the very important discovery that the trypanosome is present in the blood (not the cerebro-spinal fluid) of twenty-eight per cent. of the population in those areas where sleeping sickness occurs, the persons thus affected having none of the symptoms of sleeping sickness, but being either perfectly healthy or merely troubled with a little occasional fever. The subsequent history of all the cases thus observed has not as yet been recorded. But in many such, even in some Europeans, the earlier presence of the trypanosome in the blood has been followed by its entry into the cerebro-spinal lymphatics, and by the fatal development of sleeping sickness. As already indicated, it was found by Bruce, on recording the cases of sleeping sickness brought into or reported in Entebbe, that there were certain “sleeping-sickness areas” and other areas free from sleeping sickness. The theory now took shape in Bruce’s mind that the trypanosome first gets into the blood, and then after a time, makes its way into the cerebro-spinal system, only then producing its deadly symptoms. Very generally, when once in the blood, the trypanosome multiplies itself, and sooner or later--apparently, in some cases, even after two or three years--gets into the cerebro-spinal fluid. It is probable that it may be destroyed by natural processes in the human body before this final stage is reached; and thus the infected person may recover and escape the deadly phase of the disease. But nothing certain is known, as yet, on this head. Later observations show that the trypanosome is found alive and in large quantity in the lymphatic glands, especially those in the region of the neck in infected persons. These glands were known to be enlarged in persons suffering from the disease.