1 88 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
symptoms were violent headache, fever, constant vomiting, pain in the abdomen, and 
some purging. For a time I almost gave up hopes of his recovery, but. seven days 
after the onset he had nearly recovered his usual health. There was no enlargement 
of liver or spleen, or other physical signs that 1 could discover. 
On several occasions during the months previous to his illness, I examined 
this man's blood without finding Filariae. During his attack, and for a week after it, 
the blood examinations were negative. Two months afterwards, however, I again 
examined his blood, and found a Filaria perstans embryo. Subsequently 1 found two 
more. 
The distribution of the tick as I found it in Equatorial Africa, agrees to some 
extent with that of Filaria perstans, or at least with one of its sub-species ; and in a 
district near the north end of the Albert Edward Nyanza, where the bibo was abundant, 
I discovered that, not only was a larger percentage than usual of the natives infected 
with Filaria, but their blood in very many cases was so full of perstans embryos that I 
could count a hundred and fifty or two hundred on one slide. 
From these facts, together with the apparently permanent immunity and other 
considerations, I have been lead to assume that the above-ciescribed symptoms, known 
amongst human diseases as ' tick fever,' a very different thing to the tick fever of 
cattle, are the result of a primary inoculation with Filaria perstans, by the tick known 
in Uganda as the bibo. In other words, 1 believe the tick here described acts as 
intermediary host for the Filaria perstans. 
As inoculation and sectional experiments cannot for some time be completed, 
and as the occurrence of ticks harmful to man has not, I believe, hitherto been re- 
ported from Uganda, I have thought it best to publish this note without further delay. 
I shall go into the subject in detail in a forthcoming publication. 
Mr. R. I. Pocock, of the British Museum, has kindly furnished me with the following 
note upon the specimens which I submitted to him for determination : — 
The ticks above referred to by Dr. Christy are identical with those collected 
in Angola by Dr. Welwitsch, which Andrea Murray described in 1877 as 
Argas moubata, stating that the essential difference between this species and the earlier 
described Egyptian Argas savignyi is the presence of the pale integumental spots, 
independently observed by Dr. Christy, in the former — and well seen in a live 
specimen amongst those he has submitted to me. The specimens are also specifi- 
cally identical with examples in the British Museum, collected by Dr. Dowson at 
Tete, on the Zambesi. 
