400 MICROBIOLOGY 



Mohler succeeded, after many efforts, in cultivating* this 

 trypanosome on a medium composed of defibrinated rabbit's 

 blood 3 parts and agar 1 part. The medium was allowed to 

 congeal in the slanting position. The condensation water was 

 inoculated. 



Pathogenesis. Tr. equiperdum occurs naturally in the 

 horse kind but dogs and rabbits are very susceptible when 

 inoculated. In the horse kind it is transmitted by copulation. 

 No other means of dissemination are known. Rats and mice 

 are less susceptible. Birds are immune. 



The discovery of the Trypanosoma equiperdum by Hig- 

 gins and Mohler and the quite wide distribution of dourino in 

 the United States as indicated by Mohler 8 point to its im- 

 portance economically as well as etiologically in this country. 



TRYPANOSOMA BRUCEI PLIMMER AND BLANDFORD. 



Place in nature. Trypanosoma Brucei is .the cause of the 

 disease known as nagana or "tsetse" fly disease in South 

 Africa. It was first discovered by Bruce in Zululand. An 

 infected dog was sent to England by Bruce in 1896 where a 

 careful study of the organism was made by Kanthack, Durham 

 and Blandford l in London and Cambridge. Plimmer and 

 Blandford continued the study of the organism and assigned 

 the specific name in honor of Bruce, its discoverer. The disease 

 exists in the Transvaal and its immediate vicinity. This or- 

 ganism thrives better in the blood of some animals than it 

 does in that of others. It can not resist a long exposure at a 

 temperature of 40 to 41 C. When the temperature of the 

 infected animal is raised above 40 to 41 C. the parasites 

 dimmish in number and when the temperature falls the para- 

 sites begin to multiply again in the blood. The high tempera- 

 ture of birds seems to render them refractory. This parasite 

 is transmitted by the "tsetse" fly. According to Bruce, it 

 affects cattle, horses, and to a less extent sheep and goats and 



* Mohler, IGC. cit. 



1 Kanthack and others. Pro. of the Royal Soc., Vol. LXIV (1898) 

 p. 100. 



