716 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1909. 
allied to, if not identical with, S. obermeieri, is inoculated by punc- 
tures of Ornithodorus moubata (Ross and Milne, 1904, confirmed 
experimentally by Dutton and Todd). 
Karapatti, a third human spirochetosis, 
which afflicts the basin of the Zambesi, 
is carried by the “kufu,” a tick which is 
not well identified. 
The spirochetosis of fowl, due to S. 
: gallinarum, is disseminated among Bra- 
ailian fowl by Argas miniatus (Mar- 
choux and Salimbeni, 1903). Bovine 
spirochetosis, due to S. theileri, which 
Fic. 11.—Two spirochwts of a Was observed in the Transvaal by Theiler 
bat. Phe rounded Geurcs'rep’ and in the Cameroons) by \Ziemanusae 
resent blood corpuscles. En- 
largement : 2,000. After Nic- carried by Rhipicephalus decoloratus 
Cen ote (Theiler, confirmed by Laveran and 
Vallée, 1905). It is probably the same for S. ovina, which has been 
~found in the blood of sheep in Erythrea and in the Transvaal 
(Theiler). 
O. Heartwater.—Finally, 
to close this list, which is 
already too long, it is 
necessary to add a disease, 
the origin of which is quite 
different from that of the 
preceding ones. This af- 
fection, which afflicts South 
African ruminants, is due, 
like yellow fever, to an in- 
visible microbe, and Louns- 
bury, the expert entomolo- 
gist of the Cape govern- 
ment, showed in 1905 that 
it is propagated -by a tick 
allied to the ixodids, Aim- 
Biyorma ‘hebroum. Sach," 7?~ Darna seuouetey Ate Ai 
in its entirety is the patho- 
genic work of the Ixodide., Let us now see the minute mechanism 
of this action. 
THE MECHANISM OF THE PATHOGENIC ACTION. 
The role of the ticks in the transmission of piroplasmosis and 
spirochetosis is to-day irrefutably demonstrated as much by fact as 
by observation and experience. Notwithstanding, it is contested by 
