620 Relapsing Fever 



placed in distilled water. When trypanosomes are so 

 treated, plasmolysis takes place almost immediately, but 

 spirochaetes are not affected. 



It thus seems that in the present state of knowledge we 

 must accept the spirochaetes as bacteria. 



Fevers characterized by relapses and by the presence of 

 spirochaetes in the blood have been found in northern and 

 northeastern Europe (true relapsing fever with Spirochaete 

 obermeieri), in various parts of Africa (African relapsing 

 fever with Spirochaete duttoni), in Bombay, and in America. 



Fig. 183. Spirochaete obermeieri (Novy). Rat blood No. 321 a. 



X 1500. 



The question, therefore, arises whether these similar diseases 

 are slight modifications of the same thing caused by the same 

 parasite, or whether they are four different diseases caused 

 by four slightly different parasites. Fulleborn, Mayer, and 

 Martin * consider them to be four different organisms : 



Spirochaete obermeieri. 



Spirochaete duttoni. 



Spirochaete of American relapsing fever. 



Spirochaete of Bombay relapsing fever. 



As the differences between these organisms are minute, it 

 scarcely seems well to devote space to the consideration of 

 each, but better to select the oldest and best known 



* "Med. Klinik," No. 17, April, 1907. 



