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THE TRANSMISSION OF SPIROCHAETA DU ETONL 
By EDWARD KINDLE, Ph.D., A,R.C.S., F.L.S., 
Beit Memorial Research Fellow. 
{From the Quick Laboratory, University of Cambridge.) 
Although Livingstone, in 1857, suggested that ticks were responsible 
for the transmission of the Relapsing Fever of Tropical Africa, it was 
not until 1905 that Dutton and Todd experimentally proved that 
Ornithodorus moubata transmitted this disease. They found that spiro- 
chaetes appeared in the blood of monkeys, on which had been fed ticks 
collected from native huts in the Congo, and as they had previously 
recognized that spirochaetes were the parasites which caused this fever, 
the transmission of the disease was thus proved experimentally to be 
due to 0. moubata. They also found that the offspring of infected ticks 
were capable of infecting animals on which they fed, and thereby proved 
that 0. moubata is the true intermediate host of Sjoirochaeta duttoni, 
and that some development must take place in the tick after the spiro¬ 
chaetes have entered the gut. Owing to lack of appliances etc., these 
two investigators were unable to follow the life-cycle of the parasite 
within the intermediate host, but they described certain changes taking 
place in the Malpighian tubules, and the passage of the spirochaetes 
through the wall of the alimentary canal. 
The same year Koch (1905) made some observations on this disease 
in East Africa, and independently confirmed the work of Dutton and 
Todd. He found that 5—15 per cent, of the ticks were infected; and 
also made some observations on the life-history of the spirochaete in the 
body of the tick. The parasites penetrated the gut-wall into the tissues 
of the tick, and were found to enter the undeveloped eggs within the 
ovaries, and Koch figures tangled masses of spirochaetes as occurring in 
9—2 
