W. S. Patton 
107 
after they had sucked the blood of an infected animal; and further that 
such infection can be produced up to an interval of forty-eight hours 
after sucking infected blood. Bruce also carried out one experiment 
(No. 225) in order to answer the question : “ Is the tsetse fly capable of 
giving rise to the disease if taken out of the fly country into a healthy 
locality ? ” Bruce collected Glossincie in the low-lying fly country in the 
early morning, took them up to his camp on the top of Ubombo and 
immediately fed them on a healthy animal which subsequently became 
infected. It is presumed that these flies had already fed on an animal 
infected with T. brucei and that while they were feeding for the second 
time on a clean animal they were captured; yet when fed a third time 
on Bruce’s clean animals on Ubombo they produced the infection. Re¬ 
marking on these experiments Minchin (1908) says: “in our experi¬ 
ments on direct transmission, already recorded ( loc. cit. p. 244), we found 
that if the fly, after feeding on an infected animal, were fed on two 
healthy animals in succession, only the first healthy animal became 
infected, not the second—that is to say, that by puncturing the skin of 
a healthy animal the proboscis is ‘ cleaned ’ for a second one. Hence, 
if the infection of T. brucei were only by the direct method, the flies 
caught off a healthy animal, in Bruce’s experiment, should have been 
non-infective. The experiment seems to me, therefore, to indicate that 
in the case of T. brucei there is infection of a type other than the direct 
—that is to say, that cyclical infection occurs doubtless in addition to 
direct infection.” 
In a recent paper Kleine (1909) records some observations which seem 
to show that distant transmission, presumably after a developmental 
cycle, takes place in the case of T. brucei in G. palpalis. Kleine states, 
that as Nagana was not present in the Kirugo region, some sheep and a 
mule, which had been naturally infected by the bites of G. morsitans, were 
brought from a place seven days’ march away ; the infected animals were 
kept apart from the rest. Specimens of G. palpalis caught on the Mori 
river were fed for three days on a mule and two sheep infected with 
Nagana, and from the fourth day onwards they were fed daily on a fresh 
healthy animal. 
From the 18th to the 24th day the flies fed on the same sheep (No. 80), 
and from the 25th to the 39th on the same ox (No. 2). The blood of the 
experimental animals was examined with negative results. On the 
12th day after the flies were fed on ox No. 2 a preparation of its blood 
was examined and numerous trypanosomes were found ; as a result of 
this discovery sheep No. 30 was examined and in its blood many parasites 
