395 
A CASE OF SLEEPING SICKNESS 
STUDIED BY PRECISE ENUMERATIVE 
METHODS: FURTHER OBSERVATIONS 
BY 
MAJOR RONALD ROSS, F.R.S., 
AND 
DAVID THOMSON, M.B., Ch.B., D.P.H. 
Received for publication 15 October , 191° 
I. INTRODUCTION 
In a previous papert by us, we recorded our observations on 
this case during two and a half months, and described particularly 
the regular periodical rises in the numbers of trypanosomes disclosed 
in the patient’s peripheral blood by methodical daily countings 
extending over that period. Our technique has been detailed in 
another paper by us on ‘ Enumerative Studies on Malarial Feven , 
We now record our further observations on the case during " 
months—until the patient's death. A chart and a table g-mg da ly 
details of the observations are attached; and accompanying papers 
by Drs. H. B. Fantham and J. G. Thomson record studies on 
animals and on the parasites themselves. We must refer also to a 
recen, communication by Drs. J. W. W. Stephens and 
suggesting that the species found in this case may not be identical 
"Th, scr. ... 
,54 lbs., was infected in N.E. Rhodesia near the Rner Lu ^ ^ 
September, 1909. The trypanosomes were found in 
Africa on November 17. __ 
• Reprinted from Proc. Roy. Sne.. B, Vnl. I.XXXIII. p- l8 7- 
I Proc. Roy. Soc., July 21 , 1910 , B » 557- 
; Ann. Trop. Med. nnd Parasit., Vol. TV., No- 3- 
S Ibid. 
