14 THE QUESTION OF THE RELATION OF 
4 In India Lingard found the trypanosome of surra in the 
blood of two species of rats ( Mus decumanus and Mus 
rufescens) : 1107 rats were examined, and trypanosomes were 
found to be present in 421. The infected rats were apparently 
in perfect health. Horses inoculated with blood from these rats 
developed virulent surra after a rather prolonged incubation 
period, but horses inoculated from a horse thus infected 
develop surra after the usual incubation period of seven to 
eight days. 5 (See 4 A Further Report on Tsetse-fly Disease 
or Nagana in Zululand, 5 by Surgeon-Major (now Sir) David 
Bruce, May 1896, p. 19.) 
In England Mr. S. Stockman discovered trypanosomes 
indistinguishable from T. theileri in the blood of pedigree 
cattle. This trypanosome appeared to produce no disease 
in the infected cattle, and Mr. Stockman considered that it 
would not appear to give rise by itself to any serious illness 
in domestic animals. Three puppies, 2 guinea-pigs, 2 
rabbits, 2 white mice, 1 pigeon, 1 pig, 2 heifers, 1 
calf, 4 ewes, and 6 lambs were inoculated from these 
cattle. No trypanosomes could be found by microscopical 
examination or sub-inoculations. One lamb was killed eight 
days after inoculation, and two died emaciated on about the 
hundredth day after receiving the injection of blood from the 
infected cattle. (See 4 Sleeping Sickness Bulletin, 5 No. 80, 
p. 876.) 
Besides this, trypanosomes have been grown in cultures 
from the blood of cattle in Germany, France, Denmark, Russia, 
Japan, the Philippines, Siberia, Algeria, Tunis, Greece, Holland, 
the United States, and Brazil. (See 4 Sleeping Sickness Bulletin,’ 
Vol. 4, No. 34, p. 78.) 
It is also interesting to notice that in France numbers of 
cattle, sheep, and goats have been infected with various virulent 
trypanosomes brought from Africa (F. Mesnil and M. Leger) 
from which they have recovered, and as a rule they acquire 
complete immunity afterwards. (See 4 Sleeping Sickness Bulle- 
tin, 5 No. 35, p. 105.) 
The next point of importance in regard to trypanosomiasis 
is the question of what blood-sucking insects act as the trans- 
mitting agents of the various trypanosome diseases, and whether 
