204 
At Kasongo about a score of Glossina fit sea in all were caught. Most 
of them were allowed to remain in the rages. Where it is necessary 
experiments on which they fed are specified. Rare examples of 
Glossina pal l id ipcs or Glass nut want lata may have been present, 
undetected in the cages, at both localities.* 
At Leopoldville Trypanosoma gantbienst was alone used; at 
Kasongo Trypanosoma dimorphvn was also experimented with. 
I. FRESHLY-CAUGHT FLIES 
To infect susceptible animals by the bites of Glossina caught hi 
localities where trypanosomiasis is endemic. 
There was a great deal of sleeping sickness in the areas where 
the flies were caught at both Leopoldville and Kasongo. Because of 
the larger local population, the chances that a newly-caught fly had 
previously fed on a person infected with trypanosomes were rather 
greater at Leopoldville. The flies fed at Mswata and Coquilhatville 
on Experiments 128, 128a, 129, 141 and 211 were caught in very 
restricted areas where there were many people, the great majority of 
whom were infected with Trypanosoma gambiense. At both 
Leopoldville and Kasongo trypanosomiasis of animals was far from 
rare. Because of the presence of a herd of 280 cattle (about 5 per 
cent, infected) and of considerable game at Kasongo, the chances 
that a fly caught there had previously fed on an infected animal were 
much greater than at Leopoldville. 
Leopoldville. 
Experiment 45.—Guinea-pig. From December 8, 1903, to April 13, « 9 ° 4 - 45 | 
ies were fed. I he animal's blood was examined regularly until October, 1904 ’ 
trypanosomes were never seen. It died on October j 8, 1905, from other causes. 
° tr -Vpanosomes or signs of trypanosomiasis were seen at the autopsy. 1 
*^ ee ( 5 ) page 03. 
nr thrift r °utine, the blood in all these experiments was examined, as a rule, tvvo 
the hlmiH nf CS a , week ' f re sh in &-inch square coverslip preparations. In addin' 1 ' 
^ 0 eacp animal was occasionally centrifugalised (6). 
waslwl h ° Ugh U ' S n0t alwa y- s mentioned, in the following experiments an autopsy 
an d fresh eVery . CaSe s « e » withi » a few hours or minutes of the animal's death, 
By Pr ? a . rat,0ns ° f body fluids and of organ juices were always examined 
enlarge f At ° f tr yP anos °miasis" are meant in particular, enlarged spleen and 
enlarged, often much congested or haemorrhagic, lymphatic glands 
