234 Treatment of Ammals mfected with Trypanosomes. 
prolonged when compared with the average life of 22 controls, the average 
life of which was only 11:3 days. 
In spite of five exposures, each of 20 minutes’ duration, during which 
period the whole body of the rat was exposed to the direct action of the rays, 
the trypanosomes remained lively and increased steadily in numbers in the 
peripheral circulation. The rays were not therefore trypanocidal in the 
exposures given by us, but, curiously enough, the hfe of the animal was 
prolonged. The animal always seemed livelier during the exposure to the 
rays, and suffered no discomfort. There was no destruction of the trypano- 
somes, and this is comparable to the experiments made by one of us (R. RB.) 
several years ago, who found that exposure of trypanosomes i vitro to the 
action of X-rays had no trypanocidal effect. 
V. Leucocytic Extract. 
This experiment was carried out by the suggestion of Dr. Moore Alexander, 
Pathologist to the Royal Southern Hospital, and he kindly advised us and 
supplied the leucocytic extract. A white rat, weighing 120 grains, was 
inoculated with the Rhodesian strain, and the disease was allowed to 
incubate. On the 12th day the trypanosomes numbered 89,000 per cubic 
millimetre, and we injected 0°5 c.c. of leucocytic extract. The leucocytes rose 
from 8,160 per cubic millimetre to 10,760 per cubic millimetre, and the 
trypanosomes rose from 89,000 to 220,800. The animal lived 14 days. 
We cannot, therefore, draw conclusions here, and much further work will 
require to be undertaken, before we conclude as to the value of leucocytic 
extract in trypanosomiasis. 
