AFRICAN TICK FEVER 513 



only negative results by means of bugs. Fehrmann considers 

 that the clothes louse may carry the infection. Further observa- 

 tions are still necessary. 



African Tick Fever. 



The disease long known by this name as prevalent in Africa 

 has also been shown to be caused by a spirillum or spirochaete, sp. 



^ 



FIG. 154. Film of human blood containing spirochsete of tick fever, 

 x lOOO.i 



Duttoni. Organisms of this nature had been seen in the blood 

 of patients in Uganda by Greig and Nabarro in 1903, and Milne 

 and Ross in the end of 1904 recorded a series of observations 

 which led them to the conclusion that tick fever was due to a 

 spirochsete. It is, however, chiefly owing to the work of Button 

 and Todd in the Congo Free State, on the one hand, and of Koch 

 in German East Africa, on the other, that our knowledge of the 

 etiology of the disease has been obtained. 



*We are indebted to Lieut.-Col. Sir William Leishman, R.A.M.C., for 

 the preparations from which Figs. 153-155 were taken. 



33 



