206 
II. INTERRUPTED FEEDING 
1 o infect susceptible animals with Trypanosoma gambiense 
by the bites of tsetse flies fed immediately previously on an infected animi 
or man. 
Leopoldville. 
Successful Experiment 63. —Guinea-pig. This animal was immobilized and placed 
xpenment together with an infected guinea-pig in a rage containing tsetse-flies. From 
December 24, 1903, to January 15, 1904, 219 Hies fed on one or both animals 
I rypanosomes appeared in the blood of this animal on January 15, 1904, and it 
died of the disease (and other complications) on March 16, 1904. The morphology 
and animal reactions of the parasites agreed with Trypanosome gambiense. 
I he flies used in this experiment were infected by feeding on guinea-pigs 
inoculated directly from an early case of trypanosomiasis. Trypanosomes were 
very numerous in their peripheral blood, and they had been infected for about 
two months. 
Experiment 76. Monkey ( Colobus sat,mas). Flies in a small cage were 
a owed to partially fill themselves with blood from a “ sleeping sickness” patient, 
.me were then permitted to finish their feed on this monkey. From January 2 to 
prtl r 2 , 1904, when the monkey died of sunstroke, r^7 flies were fed in fe 
manner. Trypanosomes were never seen in the monkey’s blood and its temperature 
remained normal. 
. *' X1 1 ^ 7 -—Guinea-pig. As in Experiment 63, this animal was placed 
1 i an in ected one in a cage containing tsetse-flies. From January 23 to March 
1 372 " Ies were fed - Its blood was examined regularly until June 7, and 
rom tun at intervals until it died of exposure in October, 1905. Trypanosomes 
ne\er seen ; there were no signs of trypanosomiasis at the autopsy. 
Kasongo. 
•xperiment 209.— Monkey [Cercofithecus Schmidt,). 
•s rnmnlotolir . j .1 . ... 
iX inor o j m nrruuti ). 1'lUlll iUclM-11 j w —j~ 
having 3 S , COm I jle,el y filled themselves with blood from this animal aft. 
blood wa! mmencei immediately previously to feed on an infected animal, f 
on \nril e * annne daily, but trypanosomes were never seen. The animal die 
were feause, ? starvation). No trypanosomes or signs of trypanosomias 
were seen at the autopsy done immediately after death. 
III. THREE TO FIVE HOURS INTERVAL 
7 o infect a susceptible animal with Trypanosoma gambiense by 
hits of tselsi J lies fed from 3 to 5 hours previously on an infected 
Very few flies were used in these experiments, since it was 
xcee mgly difficult to get them to feed at such a short interval- 
Mar^^o^qoe 1 J°flir M ° nke ? \ Cerco P ith “** schmidti). From February 24 <° 
result (malaria i re - * were e d- Hlood was examined for trypanosomes without 
trypaniomw orKl o t" nt a " imaI dled ° f dysentery on Apr,. , 7 - * 
or signs of trypanosomiasis were seen at the autopsy. 
