10 THE QUESTION OF THE RELATION OF 
(iii) It does not appear certain, in the cases in which wild 
animals have been found naturally infected with 
trypanosomes, whether these trypanosomes are, 
invariably, or only occasionally, pathogenic for 
domestic animals, or whether they are pathogenic 
at all. 
It is also interesting at this point to compare the experi- 
ments carried out by Sir David Bruce in Zululand in 1895-6. 
In his 4 Further Report on the Tsetse-fly Disease or Nagana 
in Zululand ’ a table is given on page 24 in which the results 
of the inoculation of the blood of wild animals into dogs are 
shown. Thirty-five animals were used, and of these 9 were 
shown to contain trypanosomes. But here again a most 
important point is conspicuous. Out of the 85 wild animals 
examined all, except 8, were game animals, chiefly wilde- 
beest and buffalo, while only 8 non-game animals, 2 pigs and 
a hyaena, were examined, one of which, the hyaena, contained 
trypanosomes. Of the 9 dogs which showed trypanosomes, 
4 died of the disease, 2 were shot — for what reason is not stated — 
and of the remaining 8 no information is given as to their fate. 
Now, it will be seen from the above summary that — 
(i) It has not yet been found that antelope act as reservoirs 
for the virus of sleeping sickness in nature. 
(ii) It has been found that antelope do act as reservoirs for 
other trypanosomes, some of which are pathogenic 
for domestic animals. But it has also been found 
at the same time, and a very important point, that 
other wild animals which are not game act as 
reservoirs for these trypanosomes. And this has 
come to light in spite of the fact that comparatively 
very few non-game animals have been examined. 
It is next of importance to ascertain whether domestic 
animals themselves, such as cattle, sheep, goats, and dogs, act 
as reservoirs of trypanosomes. 
In ‘ Sleeping Sickness Bulletin/ Vol. 2, No. 19, p. 285, the 
experiments of the Sleeping Sickness Commission of the Royal 
Society 1908-10 are given which were carried out for the purpose 
of investigating this question. 
It had been found that the fly on the shores of Lake Victoria 
