270 DEFINITION OF TSETSE-FLY DISEASE. 



PAGE 



7. — Inoculation of Blood from Affected to Healthy Animals 41 

 A. — Inoculation of Blood in which the Hsematozoa 



can be demonstrated by the Microscope .. .. 41 



B. — Inoculation of Blood in -which the Hsematozoa 



cannot be demonstrated by the Microscope . . 45 



8. — Feeding Experiments .. ,. .. ,, ..46 



" .. 46 



.. 47 



.. 64 



.. 66 



9. — Treatment, Medicinal 



A. — Arsenic as a Curative Agent 

 B. — Arsenic as a Prophylactic Agent 

 10. — Concluding Remarks 



The following is the author's " Definition " of Tsetse-Fly 

 disease : — 



" The Fly Disease or Nagana is a specific disease which 

 occurs in the horse, mule, donkey, ox, dog, cat, and many other 

 animals, and varies in duration from a few days or weeks to 

 many months. It is invariably fatal in the horse, donkey, and 

 dog, but a small percentage of cattle recover. It is characterised 

 by fever, infiltration of coagulable lymph into the subcutaneous 

 tissue of the neck, abdomen or extremities, giving rise to swelling 

 in these regions, by a more or less rapid destruction of the red 

 blood corpuscles, extreme emaciation, often blindness, and the 

 constant occurrence in the blood of an infusorial parasite, either 

 identical with or closely resembling the Tryjpanosoma Ecansi 

 found in Surra, a disease of India and Burma. On post-mortem 

 examination the following changes are noticed ; deposition of a 

 yellow jelly-like material in the subcutaneous tissue, inter- 

 muscular layers, and under the serous covering of the heart ; 

 with pui'plish stains or ecchyraoses in various regions, as on the 

 inner aspect of the skin, the serous membrane covering the 

 lungs, and outer and inner surfaces of the heart ; enlargement 

 and softening of the spleen and congestion and fatty degenera- 

 tion of the various organs " (p. 1). 



Meaning of the term " Nagana." — " Nagana " is a Zulu word 

 meaning " to be low or depressed in spirits," and has reference 

 to " the symptoms presented by the animals sufi'ering from the 

 disease" (p. 1). 



In the Congo Free State the disease is known as "la mouche " 



Distribution of the disease m Zululand. — " Broadly it may be 

 stated that the disease is limited to certain tracts, the physical 

 conditions of which imply heat and moLsture. These tracts in 

 Zululand are situated in the level coast plain which extends some 

 fifty miles inland, and in the river valleys which enter or debouch 

 on this plain" (p. !)• 



"Etiology. — The opinions of the Europeans settled in Zulu- 

 land and of the natives themselves are so eotiflicting that little or 

 no good will be gained hy entering fully into their evidence. 



