35 ^ 
T. gambiense. Four experiments. Macacus rhesus and 
Cercopithecus callitrichus were used. With this strain the disease 
ran a much more chronic course. Parasites were usually scanty, or 
absent from the peripheral circulation. Incubation period, three to 
twenty-one days; average twelve days. Duration, twenty-seven 
days to over four months. 
Table 2. — Monkeys infected with T. gambiense 
Description of 
animal 
Amount of virus 
injected subcutaneously 
or intraperitoneally 
Day on 
which 
parasites 
were first 
seen in 
blood 
Day on 
which 
death 
occurred 
Remark 
i. Macacus rhesus. 
Weight, 2490 g. 
Intraperitoneally with 
1 c.c. of diluted blood 
solution containing 
5000 trypanosomes per 
c.mm. 
3rd day 
27th day 
Parasites always scanty or 
absent. 
Weight at time of death. 
2130 g. 
2. M. rhesus. 
Weight, 3380 g. 
’? » 
5 th „ 
91st „ 
Parasites scanty or abs«t 
generally, but fofy 
numerous during the 
last few days. 
Weight at time of death. 
2600 g. 
3. Cercopithecus 
callitrichus 
Weight, 2450 g. 
» » 
21st „ 
149th „ 
Parasites as a rule scanty 
or absent. Animal very 
drowsy during last «e» 
Weight at time of death, 
1820 g. 
4. C. callitrichus. 
Weight, 2730 g. 
Intraperitoneally with 
1 c.c. of diluted blood 
solution containing 
10,000 trypanosomes 
per c.mm. 
6th „ 1 
108th „ 
Parasites occasionally 
present in large num¬ 
bers, but usually ttant)' 
or absent. 
Weight at time of dealt, 
> 75 ° * 
Rabbits. 
Rhodesian strain. Eight experiments. In these animals the 
disease was fairly acute. Incubation period, from three to fourteen 
days, average eight days. Duration, nineteen to forty-five dajs, 
average twenty-eight days. Parasites were almost constantly 
present in the blood, although usually only in small numbers, 
except during the last few days, when they were generally present 
in considerable numbers. Posterior nuclear forms were usually to be 
OUn d ' n s mall numbers on the occasions when the blood contained 
numerous parasites. 
