-1910.] Reservoir of the Virus of Sleeping Sickness. 815 
again on the 11th, and were seen for the last time, in fair numbers, on May 12. Almost 
daily blood examinations were made, with negative results, up to August 5, 1910. 
Experiment 2428. Bush-buck. 
On May 4, 1910, 1 c.c. of this buck’s blood was injected, subcutaneously, into a normal 
white rat. This rat remained healthy, its blood being examined for one month after the 
injection. 
Buck was fed on for 13 days (May 2—16, inclusive, May 9 and 15 being excepted) by 
laboratory-bred Glossina palpalis known to be infected with a human strain of Trypano- 
soma gambiense. Trypanosoma gambiense was never seen in this animal’s blood, though 
examined for almost daily from May 4 to August 5, 1910. 
On May 16, 14 days after infected flies’ first feed on the buck, a few drops of the 
buck’s blood were injected, subcutaneously, into a normal white rat. This rat showed 
Trypanosoma gambiense in its blood on May 23. No trypanosomes were ever seen in 
buck’s blood. 
esult.— Positive. 
Remarks.—On its arrival at the laboratory the buck was free from trypanosomes 
inoculable into a rat. No trypanosomes were ever seen in the buck’s blood, nevertheless 
its blood was infective on inoculation, and, as will be seen later (Table II), capable of 
infecting clean laboratory-bred Glossina palpalis. 
: Experiment 2429. Reed-buck. 
On April 13, 1910, 5 cc. of this buck’s blood were injected, subcutaneously, into a 
normal monkey. This monkey remained healthy, its blood being examined bi-weekly 
for a month after the injection. On May 3, 1910, 1 cc. of the buck’s blood was injected, 
subcutaneously, into a normal rat. This rat remained healthy, its blood also being 
examined bi-weekly for a month after the injection. 
The buck was fed on for eight days (May 2—7, and 9 and 10, inclusive) by Glossina 
palpalis known to be infected with a human strain of Trypanosoma gambiense. 
On May 11, the ninth day after the infected flies’ first feed on the buck, 7rypanosoma 
gambiense appeared in scanty numbers in its blood for the first time. On May 13, the 
trypanosomes being numerous in the blood of the buck, a few drops of the blood were. 
injected, subcutaneously, into a normal white rat. This rat showed Trypanosoma 
gambiense in its blood on May 17. 
On July 2, 1910, this buck accidentally broke its leg and had to be killed, 4 c.c. of its, 
heart’s blood being injected into a normal monkey. This monkey showed Trypanosomea. 
gambiense in its blood on July 12. 
Result.—Positive. 
Remarks.—On its arrival at the laboratory the buck was free from trypanosomes inocu- 
lable into monkeys or rats. Trypanosoma gambiense appeared in its blood for three days 
—on May 11 for the first time in scanty numbers, on May 12, many, and on May 13, 
very many—thereafter no trypanosomes were seen, though almost daily examinations 
were made up to July 2, 1910. It will be noted that the buck’s blood was still infected 
with Trypanosoma gambiense on July 2—that is, 50 days after the last date ai 13) 
that trypanosomes were seen in it. 
Experiment 2451. Reed-buck. 
On May 3, 1910, 1 c.c. of this buck’s blood was injected, subcutaneously, into a normal 
white rat. Rat remained healthy, its blood being examined bi-weekly for a month after 
the injection. 
