157 
THE PRESENCE OF SPIROCHAETA 
D UTTONI IN THE OVA OF ORNI- 
THOD OR OS MO UBA TA 
BY 
Capt. R. MARKHAM CARTER, I.M.S. 
From the Runcorn Research Laboratories of the Liverpool School »f 
Tropical Medicine 
Koch, while discussing the question of the transmission of 
Spirochaeta duttoni , the organism of African relapsing fever 1 states 
that he finds on the surface of the ovaries of infected ticks large 
numbers of spirochaetes. He considers that these organisms multiply 
in this position in the tick. He further states that the eggs, when first 
laid, show scanty infection, whereas in those examined later lie 
describes the occurrence of spirochaetes in vast numbers arranged in 
densely-tangled masses. This he considers an undoubted proof of 
the rapid multiplication of the spirochaetes in the eggs. Lastly, he 
again draws attention to the fact that ticks bred from batches of 
infected eggs transmit the disease. 2 The following observations were 
made with the object of confirming the second of these important 
statements. 
Forty-two, naturally-infected, adult specimens of Ornithodoro > 
moubala, collected in the Congo Free State, were fed on January 2;th, 
I9°6, upon an animal infected with Spirochaeta duttoni. These tick 
were again fed on an uninfected rat on July 26th, 1906. This rat 
showed infection on August 1st, innumerable spirochaetes to the field 
were seen on August nth. As no eggs were laid, the ticks were 
a gain fed ; ovulation then commenced, but it was very scanty'. Some 
twenty-six adults were therefore fed once more on an uninfected rat 
ten day's later. Large numbers of eggs were now found in batches 
about the dish ; 32 ova were taken from different collections of the-- 
eggs and microscopically examined to determine the presence or 
otherwise of the spirochaetes. Six of them were found to be infected 
The method used was as follows-.—The egg, having been placed 
