CULTIVATION OF TRYPANOSOMA EVANSI. 179 



ON THE CULTIVATION OF TRYPANOSOMA EVANSI. 



BY F. G. NOVY AND WARD J. MACNBAL. 



Inasmuch as this paper will appear in full in the ''Journal of the Amer- 

 ican Medical Association," it will be suflQcient to give here a brief sum- 

 mary only. 



By the term ''Surra" is meant a disease of cattle, horses, camels and 

 other animals which prevails in India, and is said to exist in the Islands 

 of the Indian and Pacific Oceans. The cause of this disease is a trypa- 

 nosome discovered by Evans in 1880. Whereas in Africa there are known 

 at the present time not less than six distinct trypanosomatic diseases 

 it has been held that surra is but one disease and some have even main- 

 tained that it is identical with the various African diseases in which 

 these protozoa have been found. 



The paper approaches the question of the identity of the surra of the 

 Philippines, with the nagana or tsetse-fly disease of South Africa. It 

 is shown that the trypanosome present in the Philippine surra can be 

 cultivated artificially, and that it can be obtained in an attenuated form. 

 The cultural characteristics of this trypanosome differentiate it clearly 

 from Tr, lewisi and Tr. hrucei, and the conclusion is therefore reached 

 that the Philippine surra is a distinct disease from nagana, and con- 

 firms that of Laveran and Mesnil, based on immunity experiments, as 

 to the non-identity of the surra of Mauritius and nagana of S. Africa. 



It is further shown that the trypanosome present in the Mauritian 

 surra presents marked differences from that found in the Philippine 

 surra. The difference is such as to justify the belief that these are two 

 distinct diseases and that the term surra as used at present includes 

 a number of distinct affections which it may be possible to differentiate 

 to some extent by the morphological characteristics of the trypanosomes 

 present, but above all by the cultural properties of these organisms. 

 F. G. NovY, Sc. D., M. D., 



Professor of Bacteriology, 

 Hygienic Laboratory, University of Michigan, 

 Ann Arbor. 



Ward J. MacNeal^ Ph.D., 



Fellow of the Rockefeller Institute for Medical Research, 

 Hygienic Laboratory, University of Michigan, 

 Ann Arbor. 



