89 



The Trypano somes causing Dourine (Mai de Coit or 

 Beschalseuche). 

 By B. Blacklock, M.D., and Warrington Yorke, M.D. 



(Communicated by Sir Eonald Eoss, K.C.B., F.E.S. Eeceived May 19, 1913.) 



(From the Runcorn Research Laboratory, Liverpool School of Tropical Medicine.) 



[Plate 11.] 



About the middle of the year 1910, whilst examining our laboratory strain 

 of Trypanosoma equiperdum, short parasites, certain of which exhibited a 

 posterior displacement of the nucleus, were observed. This strain had been 

 preserved at the Runcorn Laboratory by passage through experimental 

 animals since 1907, when it was obtained from the Kaiserliches G-esund- 

 heitsamt, Berlin. As these posterior nuclear forms had not been described in 

 T. equiperdum we asked Prof. Schilling for further animals infected with this 

 strain which had been preserved by him. Examination of the parasites in 

 these animals likewise revealed the presence of the posterior nuclear forms. 



Having satisfied ourselves that these forms are a constant feature of the 

 strain, we published a short preliminary note* drawing attention to this fact. 



As previously T. equiperdtim had always been described as a monomorphie 

 parasite invariably furnished with a free flagellum, we decided to examine for 

 ourselves various strains of this parasite preserved at the present time in the 

 European laboratories. We were enabled to collect the following three strains 

 of the trypanosome. 



Strain A. — Berlin strain. This is our old laboratory strain. Prof. Schuberg 

 informs us that this was the trypanosome used by Uhlenhuth, Hiibener, and 

 Woithef in their experimental work on Dourine in 1908. These authors 

 state that the virus was obtained from a horse suffering from Dourine brought 

 over to Germany from Algiers for experimental purposes by the firm of 

 Hagenbeck. The work of Salvin Moore and Breinl,| and others, on 

 T. equiperdum, was done with this strain. 



Strain B. — Frankfurt strain. This strain was obtained in 1906 from 

 Prof. Ehrlich. Unfortunately, no record of its origin is available, but 



* Yorke, W., and Blacklock, B., " A Note on the Morphology of a Strain of T. equi- 

 perdum," ' Brit. Med. Journ.,' August 31, 1912. 



t " Experimentelle Untersuchungen liber Dourine," ' Arb. a. d. Kaiserl. Gesund.,' 

 1907, vol. 27, p. 256. 



% " Life History of T. equiperdum? ' Roy. Soc. Proc., : 1908, B, vol. 80, p. 288. 



VOL. LXXXVII. — B. H 



