i;o 'INFINITE TORMENT OF FLIES' 



the cases recently investigated. Apparently the 

 Trypanosoma can live in the blood without doing 

 much harm, and only when it reaches the cerebro- 

 spinal canal does it set up the sleeping-sickness. It is 

 also found in great numbers in the lymphatic glands, 

 especially those of the neck, which in patients infected 

 by the parasite are usually swollen and tender. From 

 the similarity of the parasite to that causing the cattle 

 disease of South Africa, the idea at once arose that the 

 Trypanosoma was conveyed from man to man by a 

 biting insect. Along the lake shores a species of 

 tsetse (Glossina palpalis) abounds; and it was noticed 

 that if the fly, having fed off a sleeping-sickness patient, 

 bit a monkey, the monkey became infected. Further, 

 flies which were captured in a sleeping-sickness 

 district were also capable of conveying the disease to 

 healthy monkeys. The proof that sleeping-sickness is 

 due to a Trypanosoma known as T. gambiense present 

 in the cerebro-spinal fluid of the patient, and that it is 

 conveyed from man to man by Glossina palpalis, 

 seems now complete. Fortunately, like its congener, 

 G. palpalis is confined to certain districts. The know- 

 ledge of these, and of the habits of this species of fly, 

 will suggest preventive measures; and the brilliant 

 research of Colonel Bruce and his colleagues, Captain 

 Grieg and Dr. Nabarro, may yet save the much- 

 tried African continent from the most fatal of recent 

 diseases. 



Finally, we come to a last class of disease which is 

 of the utmost interest to the agriculturist and settler, 

 and yet at present is but little understood. These 

 diseases are caused by various species of a Protozoon 

 named Piroplasma, and the diseases may collectively be 

 spoken of as piroplasmosis. When they are present 

 in cattle they are spoken of in various parts of the 

 world as Texas fever, tick fever, blackwater, redwater, 

 and many other French, German, Italian, and Spanish 



