after these injections. The last injection of vaccine, given on the 
twentieth day, was prepared from a rat when the trypanosomes 
were very numerous, and we note that there was in the next 
twenty-four hours an enormous increase in the numbers of 
trypanosomes, from which the animals were evidently unable to 
recover. 
CONTROLS NO TREATMENT 
Rat 14.—Piebald. weight 12 7 grains. l>ose of inoculation : 200.000 Trypanosomes 
T. rhndesiensr 
Day . 
^ t 
2 
3 
4 
5 
6 
7 
Number of Trypanosomes per 
c.nun. ... ... . 
— 
— 
1,440 
45,600 
66,240 
7)’44 
Leucocytes ... . 
— 
— 
— 
26,080 
3 < 5 , 7 8 4 
59,64s 
Dav . 
8 
, 
10 
11 
12 
- 
- 
Number of Trypanosomes per 
c.mm. 
5 °,232 
77 ; 44 ° 
250,000 
464,640 
— 
500,000 
_ 
— 
Leucocytes 
— _ 
— 
— 
- 
- 
R'i 15. I iebnld, weight 104 grains. Dose of inoculation : 200.000 Trypanosomes 
T. rbodesiensc 
Day . 
2 3 4 5 
6 
7 
Number of Trypanosomes per 
c.mm. ... 
— 
1 ! - 
~ ~ 
4,620 
45)44° 
Day . 
8 
9 
10 
u 
— 
- 
Number of Trypanosomes "per 
c.mm. 
24,472 
44,352 
194,128 
410,000 
— 
— 
