2og 
VI. FIFTEEN TO TWENTY HOURS INTERVAL 
To infect a susceptible animal with Trypanosoma gambiense by 
the bites of tsetse flies fed from 15 to 20 hours previously on an infected 
animal. 
Leopoldville. 
Experiment 97.— Guinea-pig- From February 20 to May 16, 1904, 395 flies 
were fed. Its blood was regularly examined for trypanosomes without success 
until May 16, when it died from a ruptured stomach. No trypanosomes or signs 
of trypanosomiasis were seen at the autopsy. 
VII. EIGHTEEN TO TWENTY-FOUR HOURS INTERVAL 
To infect a susceptible animal with Trypanosoma dimorphon 
by the bites of tsetse flics fed at least IS to 24 hours previously on an 
infected animal. 
Kasongo. 
Experiment 212.- Domestic cat. From March 13 to April 29, I9 ° 5 ’ 5 ' 0 ^ 
fed. Blood was examined regularly until July 26, 1905. trypanosomes 
seen. When examinations were recommenced in September, 1905, r > P 
were present. The animal died in November, 1906, of the disease. 11 ■ ' - 
Glossina fusca fed on this animal ; a single Glossina palhdtpes also Fad an 
opportunity of feeding. The flies used were infected by fee mg on re „ 
pigs inoculated about two mouths previously with blood from a sites 
infected with Trypanosoma dimorphon ; they frequently ec w icn 
were either absent or very scanty in the peripheral blood. 
Successful 
Experiment 
VIII. TWENTY-FOUR HOURS INTERVAL 
To infect a susceptible animal with Trypanosoma gambiense 
by the bites of tsetse flics fed at least 24 hours previously on an inf 
animal or man. 
Kasongo. 
Experiment 208— Monkey (Cercofilhecus schmidti). I' r0n L d ^'jhis monkey 
^S. 590 flies, previously ted OH an infected animal, October 2 , 1905, 
On June. 16, trypanosomes were first seen in its blood. tie osomes wer e 
from pneumonia. The spleen was considerably enlarge ■ . eding s i x 
seen at the autopsy, and none had been present in the > 00 animal, 
"■eeks. in March, 3 fusca had opportunities for feeing oh 
A " lhe flies used in this experiment were infected by being e o ^ mo ntbs 
"hose blood contained very numerous trypanosomes, >»< ,cl,la e ' flies had 
Previously with blood from a case of sleeping sickness. Many < con tained 
W three O, more davs previously on sloping sickness cases whose blood 
' erv * ew or no trypanosomes. 
Successful 
Experiment 
