E. Hindle 
135 
Manteufel (1908) showed that 0. mouhata could transmit 8. recurren- 
tis as well as 8. duttoni, and Brumpt (1908 b) showed that the same 
species of tick could carry 8. marchouxi (gcdlinarum). The latter 
author, however, was unable to transmit the respective spirochaetes of 
the Algerian and American Relapsing Fevers, by 0. mouhata. 
Brumpt (1908a) described the existence of a “tick-fever” in Abyssinia 
which at first was supposed to be transmitted by 0. mouhata, but 
afterwards Doreau (1908) proved that this was not the case. In a 
subsequent paper, Brumpt (1908 6) proved by experiments on animals, 
that this spirochaete of Abyssinia was transmitted by 0. savignyi. 
The transmission of 8. duttoni, recurrentis and novyi, respectively, 
by means of 0. mouhata, was successfully accomplished by Neumann 
(1909), and thus one of the points of distinction between these three 
kinds of spirochaetes was removed. He also found that 8. duttoni could 
occasionally be transmitted from rat to rat by means of the rat-louse 
Haematopinus spinulosus. 
The results of all the recorded experiments and observations, both 
in the laboratories and in nature, have shown, however, that 0. mouhata 
is probably the only ectoparasite which naturally transmits 8. duttoni, 
and also that it is the true intermediate host. 
Although the main facts regarding the transmission of this disease 
are thus well established, the exact manner in which the tick conveys 
the infection to the animal it feeds upon is in some doubt. The 
majority of investigators have assumed that the spirochaetes make 
their way to the salivary glands and from there are directly injected 
into the wound caused by the tick’s bite. 
The most important work on this subject, and on the life-cycle of 
8. duttoni within the intermediate host, is that of Leishman (1909,1910) 
who brought forward considerable evidence to show that at ordinary 
temperatures the salivary glands of the tick do not become infected, 
and that infection probably takes place, either by the regurgitation, or 
by the excretion, of infective matter from the alimentary canal. In 
either case the spirochaetes could make their way into the animal 
through the wound caused by the tick’s bite. To test the truth of this 
hypothesis Leishman performed the following experiment, which may 
be described in his own words:— 
“ Nine ticks which I had infected some months before were allowed 
to bite a monkey. After they had fixed and commenced to feed they 
were gently removed and placed on another monkey on whom they 
