G. H. F. Nutt ALL 
87 
Expt. 
No. 
The ticks 
which produced 
infection 
were 
Day on 
which 
animal 
showed fever 
( = incuba¬ 
tion period) 
Day on which 
parasites 
were first 
found in 
animal’s 
hlood 
Day when 
animal died 
Maximum number 
of parasitized 
corpuscles recorded 
during illness 
I 
12 c?? 
14 
20 
30 
46 % 
II 
30 @s 
13 
23 
33 
8-0 % 
III 
40 @s 
14 
18 
29 
57-2 % 
IV 
12 c?? 
13 
18 
30 
55-2 % 
V 
18^? 
12 
15 
29 
41-6 % 
VI 
7c?? 
12 
19 
31 
75-8 % 
VII 
30 @s 
15 
19 
29 
43-6 % 
VIII 
12 c?? 
13 
20 
24 
21-0 % 
IX 
26,?? 
14 
18 
29 
84-2 o/o 
X 
14 @s, 8 (? 
? 12 
16 
27 
39-2 % 
XI 
12 ©s 
11 
15 
28 
24-0 % 
XIII 
9 @s 
12 
17 
30 
59-2 % 
XIV 
50 @s 
11 
19 
26 
36-0 % 
XV 
50 @s 
12 
16 
28 
47-2 % 
XVI 
24 ©s 
10 
17 
22 
16-8 % 
XVII 
50 ©s 
12 
18 
25 
66-0 % 
XVIII 
140 ©s 
11 
15 
28 
58-8 % 
Control I 
13 c?? 
14 
19 
29 
56-0 % (untreated) 
II 
19 c?? 
17 
19 
29 
17-6 % 
III 
? ©s 
13 
19 
26 
31-6 % 
Cow 1 
30<?? 
15 
17 
32 
75-0 % 
2 
12<?? 
14 
20 
30 
60-0 % 
Note : The last two experiments are recorded in Parasitology, ii. pp. 328, 329. These 
animals were infected by means of Ehipicephalus evertsi whereas all of the other animals 
were infected through our strain of R. appendicnlatus originally received from Cape Colony 
through the courtesy of Mr C. P. Lounsbury. 
