1910. | Reservoir of the Virus of Sleeping Sickness. 313 
ascertain if the buck’s blood naturally harboured trypanosomes, was not made in this 
case. Though examined almost daily from March 29 to August 5, 1910, Trypanosoma 
gambiense was never seen in the blood of this antelope. Fresh and stained blood films 
were made and examined. On one occasion only—April 20—Trypanosoma ingens was seen. 
in a fresh preparation. Monkeys are not inoculable with (this parasite. | 
Experiment 2357. Reed-buck. 
April 8, 1910, 5 c.c. of this buck’s blood were injected, subcutaneously, into a normal 
monkey, to ascertain if buck’s blood naturally harboured trypanosomes. This monkey’s 
blood was examined bi-weekly for a month. Monkey remained healthy, no trypanosomes 
appearing in its blood. 
Buck was fed on for 12 days, between April 7 and 20, 1910, by laboratory-bred 
Glossina palpalis known to be infected with a human strain of Trypanosoma gambiense. 
On the 13th day after the first feed of these flies, 3 ¢.c. of the buck’s blood were inoculated 
into a normal monkey. Examined bi-weekly for a month this monkey remained 
healthy. 
Trypanosoma gambiense having appeared in the buck’s blood on May 2, a further 
inoculation of 5 cc. of its blood was made into a normal monkey on this date. This 
monkey showed Zrypanosoma gambiense in its blood on May 10. | 
Result.— Positive. 
Remarks.—This reed-buck was evidently free from any trypanosome infection 
inoculable into monkeys on its arrival at the laboratory. Trypanosoma gambiense 
appeared for the first time in the buck’s blood in scanty numbers on May 2, 1910, 
25 days after the first feed of the supposed infective Glossina palpalis. On May 3 and 4, 
the trypanosomes were fairly numerous in the blood, and on the 5th and 6th, scanty 
numbers only were seen. After May 6, Trypanosoma gambiense was never again seen in 
the blood, though examined for almost daily up to August 5, 1910. The long period of 
25 days which elapsed between the first feed of the supposed infected Glossina and the 
appearance of the trypanosomes in the buck’s blood may be accounted for by the 
supposition that the infected fly or flies in the cage which was fed on the buck from 
April 7 to April 19 had died before they had fed on the buck. On April 20, a fresh cage 
of Glossina palpalis, known to be infected with a human strain of Trypanosoma gambiense 
was fed. once only, on this buck, and on the 12th day after this feed, on May 2, 
trypanosomes appeared in the buck’s blood. This supposition is probably correct, and 
further accounts for the failure of the inoculation on April 20. 
Experiment 25359. Reed-buck. 
On April 8, 1910, 5 c.c. of this buck’s blood were injected, subcutaneously, into a normal 
monkey, to ascertain if buck’s blood naturally harboured trypanosomes. This monkey’s 
blood was examined bi-weekly for a month. Monkey remained healthy. 
Buck was fed on for six days (April 25—30, inclusive) by laboratory-bred Glossina 
palpalis known to be infected with a human strain of Trypanosoma gambiense. 
On May 6, the 11th day after flies’ first feed, Trypanosoma gambiense appeared in buck’s 
blood in fair numbers, and 5 minims were injected, subcutaneously, into normal white 
rat. On May 11 this rat showed Zrypanosoma gambiense in its blood. 
Result.— Positive. 
Remarks.—This reed-buck was evidently free from any trypanosome infection inoculable 
into monkeys on its arrival at the laboratory. Trypanosoma gambiense appeared for the 
first time in its blood in fair numbers on May 6, 1910, again on 7th, not examined for on 
8th, scanty on 9th, absent on 10th, scanty on 11th, very numerous on 12th, and never 
seen again, though examined for almost daily, till August 5. 
