359 
Guinea-pigs. 
Rhodesian strain. Six experiments. Parasites generally present 
in the blood, often in considerable numbers. Posterior nuclear 
forms were usually found when the parasites were numerous. The 
animals presented no symptoms, and the disease ran a fairly chronic 
course. Incubation period, three to fifteen days; average eight 
days. Duration, thirty-nine to eighty-two days; average fifty-five. 
Table 5. — Guinea-pigs infected with the Rhodesian strain 
Amount of virus 
injected subcutaneously 
or intraperitoncally 
Day on 
which 
parasites 
were first 
seen in 
blood 
Day on 
which 
death 
occurred 
Remarks 
i- Intraperitoncally. 1 c.c. of 
diluted blood solution con¬ 
taining 1000 trypanosomes 
per c.mm. 
15th day 
41st day 
Parasites scanty except during the 
last week, when they were fairly 
numerous (15 to 20 to a field). 
Posterior nuclear forms found. 
2- Intraperitoncally. 1 c.c. of 
diluted blood solution con¬ 
taining 10,000 trypanosomes 
per c.mm. 
3 rd „ 
52nd „ 
>1 » 
3 ' » i> 
1 2th „ 
39 th » 
Parasites present in blood regu¬ 
larly, but in small numbers. 
No posterior nuclear forms 
seen. 
» » 
7 th » 
39 ‘ h » 
Parasites constantly present, 
generally in large numbers. 
Many posterior nuclear forms 
found. 
5 - Intraperitoncally. 1 c.c. of 
diluted blood solution con¬ 
taining 500 trypanosomes 
per c.mm. 
6th „ 
82nd „ 
,1 
Intraperitoncally. r c.c. of 
diluted blood solution con¬ 
taining 10,000 trypanosomes 
per c.mm. 
3 rd *> 
76th ,, 
Parasites always scanty until the 
last few days, when they were 
fairly numerous (10 to a held). 
Posterior nuclear forms seen. 
