207 
Experiment 231.— Monkey ( Cereofithecus schmidti). On April 24, 25, 26, 1905, 
22 flies were fed. The blood was regularly examined up to November, 1905. 
Trypanosomes were never seen. The animal died of dysentery on l ebruary 21, 
1906; no trypanosomes or signs of trypanosomiasis were seen at the autopsy. 
IV. EIGHT TO TWELVE HOURS INTERVAL 
To infect a susceptible animal with trypanosomes by the bites of tsetse 
flies fed at least 8 to 12 hours previously on an infected man or animal. 
Leopoldville. 
Trypanosoma gambiense 
Experiment 88.—Monkey ( Cereofithecus schmidti). Prom January 27 to May 
28,1904, 634 flies, previously fed on a sleeping sickness patient, fed on this animal. 
Its blood was examined frequently until March 15, 1904, and then at inter\als 
until it was killed by rats on March 30, 1905. Its temperature was always normal 
and trypanosomes were never seen in its blood. 
River Series. 
Experiment 128. Monkey (Cereofithecus schmidti). Prom June 24 to July 22, 
1904, 87 flies, previously fed on a monkey infected with 7 rypanosoma gam lense, 
were allowed to feed on this animal. Its blood was examined at intervals until 
September 28, 1904; trypanosomes were never seen. I he temperature-c art was 
not characteristic of trypanosomiasis (malaria present). 
Kasongo. 
(a) Trypanosoma gambiense 
Experiment 187.— Monkey ( Cereofithecus sp. ?)■ P rom January 28 to April 10, 
'^S. 939 flies, previously fed on a sleeping sickness patient, fed on this amma . 
Its blood was examined almost daily until May 5, 1905, when it was sto en , 
trypanosomes were never seen. 
Experiment 197. Monkey (.1 Cereofithecus man a). From February 9 to Apri 
2 °. >9°5, 943 flies, previously fed on infected guinea-pigs, were fed on this anuna . 
Its blood was examined regularly until it died on July 6 (on river steamer) iroi 
exposure. Trypanosomes were never seen (malaria present) during life, or at e 
autopsy done immediately after death. 
(b) Trypanosoma dimorphon 
Experiment 216.— Monkey (Cercopitlucus mana). From March 25 to April 25> 
' 9 ° 5 , 388 flies were fed. Blood was regularly examined until June 13, " 
^mal was moribund. It was therefore killed. Trypanosomes were never see 
curing life, and no signs of trypanosomiasis were seen at the autopsy. a 
df *th ? exposure).* 
lb* ^ r ' n S the journey of the expedition, on foot, from Kasongo 
monkeys unavoidably received considerable hard usage. 
to Lusambo (5), 
