104
y
11. The Tsetse Flies (Glossma pal-palis) which had previously fed on a case of Sleeping Sickness or ivere freshly caught , can produce in the Monkey an exactly similar disease to that produced by inocidation of fluid containing Trypanosoma gambiense.
Since the publication of the last Report the after-history of several of the monkeys in whom the infection was produced, either by freshly caught flies at Entebbe, or flies which had previously fed on sleeping’ sickness cases, has been studied.
The result of these investigations shows that the disease, whether induced by the injection of fluid containing the Trypanosoma gambiense, by the bite of the fresh fly or previously infected ones, is, in the monkey, identical in all respects. These facts strongly support the contention that the fresh fly trypanosoma is the Trypanosoma gambiense.
A point of interest and importance in this connection is that since the hut tax labourers (one in every two or three of whom had the Trypanosoma gambiense in bis blood) have left the fly belt at Entebbe, it has taken a very much larger number of flies to infect the monkey than it did when they were present. It is, therefore, fair to assume that the chief source at Entebbe, from which the wild 'fly obtained its supply of trypanosomes, was the body of men brought in from the various districts for the purpose of hut-tax labour.
Experiment 97. Monkey ( Cercopithecus sp.).
To observe the course of the disease after infection by feeding flies on this monkey eight hours after feeding on a sleeping sickness case.
July 1, 1903. Trypanosomes are noted as being in the blood for the first time.
December 18. Animal is beginning to get out of condition.
January 3rd, 1904. Animal has now assumed the characteristic attitude. He is very weak and ill.
January 13. This afternoon he collapsed on the ground, and had convulsive movements of limbs.
The following chart shows the temperature curve :—
DATE DECEMBER. JANUARY 1904 .
1903 9 10 11 12 13 14 1516 17 181920212223242526 2728 29 3031 I 23456789 10 H 12 13