398 MICROBIOLOGY 



cattle may in this way often become sources of infection. The 

 evidence that has been accumulated during recent years tends 

 to disprove Lingard's hypothesis that surra was transmitted 

 by infected water or food. 



TRYPANOSOMA EQUIPERDUM DOFLEIN. 



Place in nature. Tr. equiperdum is the cause of the 

 venereal disease of horses and asses known as dourine, 1 which 

 occurs naturally in breeding horses and asses but which is 

 readily transmitted to others by inoculation. Dourine is 

 characterized by (1) an irregular period of incubation varying 

 from thirty or forty days to a year or more after primary in- 

 fection (Lingard), (2) by the localization of the primary 

 lesions in the organs of reproduction and later by the appear- 

 ance of placques, (3) by a chronic course, (4) by the produc- 

 tion in the later stages of the disease of a paralysis. of the pos- 

 terior extremities and (5) by its terminating fatally in from 

 a few months to two years or longer. The disease has occurred 

 in many places in Europe. It was discovered in the United 

 States by Williams 2 in 1882. Since that time it has been re- 

 ported from several western states and in 1911 Mohler * found 

 Tr. equiperdum. The disease was discovered in the Canadian 

 Northwest and studied experimentally at Ottawa by Higgins 3 

 who found the specific organism. This trypanosome seems to 

 have been first observed by Rouget 4 in 1894. In 1901 Doflein 5 

 gave it the name Tr. equiperdum. It is found in the blood 

 taken from the regions of the oedematous swellings and 

 placques. Laveran and Mesnil state that they have rarely 



'French, Mai du coit; German, Beschalkrankheit. 



2 Williams. Annual Report of the Board of Livestock Commis- 

 sioners for the State of Illinois, 1887. 



* For a summary of the appearance and study of dourine in the 

 United States see report by Mohler. Bulletin No. 142, B. A. I., U. S. 

 Dept. of Agric., 1911. 



3 Higgins. Special Report on Maladie du coit or Dourine, Dept. 

 of Agric., Ottawa, 1907. 



4 Rouget. Ann. de 1'Inst. Pasteur, Vol. X (1896) p. 716. 



5 Doflein. Die Protozoen, etc., Jena, 1901, p. 66. 



