35i 
ON THE PATHOGENICITY OF A 
TRYPANOSOME (T. RHODESIENSE, 
STEPHENS AND FANTHAM) FROM 
A CASE OF SLEEPING SICKNESS 
CONTRACTED IN RHODESIA 
BY 
WARRINGTON YORKE, M.D. 
(From the Runcorn Research Laboratories of the Liverpool School 
of Tropical Medicine ) 
( Received for publication 5 December , 1910) 
The question as to whether more than one trypanosome acts as 
a pathogenic agent in man is one which in the past has been much 
discussed.* 
The findings of practically all workers are agreed in deciding 
that the trypanosomes infecting human beings in different parts of 
tropical Africa are identical. 
Recently, however, doubt has been expressed regarding the 
identity of a human trypanosome of Rhodesia with that of 
T. gambiense ^. 
In December, 1909, a patient, W.A. (European), suffering from 
trypanosomiasis, was admitted into Major Ross’s clinic in Liverpool. 
So far as could be ascertained the patient had never been into 
any of the districts in which G. palpalis is known to occur. E xactly 
* CasteUani. ■ Researches on the Etiology of Sleeping Sickness,’ Jour, of Trop. Med. and Hyg., 
P- 167, 1903. 
Thomas and Linton. ‘ A comparison of the animal reactions of the Trypanosomes of Ugan 
and Congo Free State Sleeping Sickness with those of T. gambiense,' Lancet, May 4 > 9 4 - 
Plimmer. * Note on the effect produced on Rats by the trypanosomata of Gambian fever an 
Sleeping Sickness,’ Proc. Roy. Soc., No. 504, p. 388, i 9 °S- 
Laveran. • Sur trois virus de trypanosomiase humaine de provenances differentes, Comptes 
Rcndus de l’Acad. Sciences, p. 1065, 1906. 
Gray and Tulloch. Reports of the S.S. Commission of the Royal Society, No. 8, P- 53 - 
Bentmann und Gunther. ‘ Beitragc zur Kenntnis dcs T. gambiense , Archiv fur Sc 
Hope nhygiene, B. XI, Bciheft 2, 1907. . , . ■ 
. t Bevan and MacGregor. * Note on the passage of a Human Trypanosome through domest 
animals,’ Journal of Comparative Pathology and Therapeutics, p. ibo, 1910- 
