28 
On the Peculiar Morphology of a Trypanosome from a Case of 
Sleeping Sickness and the Possibility of its beeng a New 
Species (T. rhodesiense). 
By J. W. W. STEPHENS, M.D. Cantab., D.P.H., and H. B. FANTHAM, 
D.Se. Lond., B.A. Cantab. 
(Communicated by Prof. Major R. Ross, F.R.S. Received July 19, 1910.) 
[PLATE 6.] 
Prefatory Note. 
As already stated in a report to the Advisory Committee for the Tropical 
Diseases Research Fund, dated May 9, 1910, I noticed early in February, 1910, 
while examining in class work a stained specimen of rat’s blood infected with 
what was supposed to be 7. gambiense, a marked pecularity in the morphology. 
This peculiarity was so striking that I doubted whether the trypanosome with 
which I was dealing was really 7. gambiense. On making enquiries I was 
told that the strain was derived from a case of Sleeping Sickness then in 
Prof. Ross’s clinic in the Royal Southern Hospital, Liverpool. To make 
certain that there was no error in this statement I myself infected a rat from 
the patient’s blood. The same forms were, however, again encountered. 
After convincing myself that these forms were constantly present in infected 
rats, and that they were not shown by the rats infected with the old 
laboratory strain of 7. gambiense maintained at the Runcorn Laboratory, I 
decided through pressure of work to ask Dr. Fantham (now working in the 
Liverpool School of Tropical Medicine, under funds allotted by the Advisory 
Committee for the Tropical Diseases Research Fund) to be so good as to 
assist me in the description of the morphology of this trypanosome. The 
following paper is the outcome of our joint work.—[J. W. W. Stephens. ] 
Fiistory of the Strain. 
The trypanosomes used during this investigation were obtained from W. A., 
male, aged 26, a native of Northumberland, who was infected in North-East 
Rhodesia in September, 1909. It is necessary to set forth the itinerary of 
W. A. while in Africa, as he was never actually in an area infested with 
Glossina palpalis, so far as records are available, and indeed was never nearer 
(Kasama) than some 86 miles from such an area. 
He first went to South Africa in July, 1904, living in Johannesburg till the 
end of 1906. He then went to Salisbury for two years. About the end of 
November, 1908, he left Salisbury for North-Eastern Rhodesia, with a view 
