548 Relapsing Fever 



parasite, or whether they are different diseases caused 

 by slightly different parasites. Fulleborn, Mayer, and 

 Martin* consider them to be four different organisms: 



Spirochaeta obermeieri, of the European relapsing fever. 



Spirochaeta duttoni, of the African relapsing fever. 



Spirochaeta novyi, of American relapsing fever. 



Spirochaeta carteri, of Bombay relapsing fever. 



As the differences between these organisms are minute, it 

 scarcely seems well to devote space to the consideration of 



Fig. 187. Spirochaeta obermeieri (Novy). Rat blood No. 32 la. 



X 1500. 



each, but better to select the oldest and the best known 

 Spirochaeta obermeieri as the type, describe it, and point out 

 such variations as are shown by its close relations. 



General Characteristics. An elongate, flexible, flagellated, non- 

 sporogenous, actively motile spiral organism, pathogenic for man and 

 monkeys, not susceptible of cultivation in artificial media, stained by 

 ordinary methods, but not by Gram's method. 



Morphology. The Spirochaeta obermeieri is extremely 



slender, flexible, spirally coiled, like a corkscrew, and pointed 



at the ends. It measures approximately i ^ in breadth and 



10, 20, or even 40 ^ in length. The number of spiral coils 



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



