340 TSETSE FLIES 



disease," a sickness fatal to horses and generally 

 to domestic stock, was known as Glossina morsi- 

 tans, the two being by the layman practically 

 indistinguishable . 



Sleeping sickness has probably been in ex- 

 istence in West Africa for several centuries ; some 

 of the earliest writings descriptive of the voyages 

 of the slavers who visited the coast in the seven- 

 teenth century stating that care was exercised in 

 the selection of the negroes purchased lest any 

 should be included exhibiting swollen neck 

 glands, as it was found that these did not long 

 survive. How long this terrible malady took to 

 cross the continent from west to east there are, of 

 course, no means of knowing, but, about fifteen 

 years ago, attention in England began to be 

 attracted by the appalling reports of native mor- 

 tality occurring from this cause in Uganda, es- 

 pecially in Busoga, and on the shores and islands 

 of Lake Victoria as well as in the division called 

 Kavirondo. The services of such medical ex- 

 perts as we then possessed were promptly 

 requisitioned, and after careful study it was 

 found that the mysterious disease was caused by 

 the injection into the human system of a minute 

 parasite or trypanosome called Trypanosoma 

 gambiense, named after the region in West Africa 

 wherein it had first been recorded. It was also 

 conclusively proved that such injection was 

 effected during the bite of the tsetse fly stated 

 above. The progress of the disease to which 

 the bite of this fly was found to give rise 

 signalised itself in a swelling of the neck glands. 



