SPIRILLUM OBERMEIERI. 597 



Efforts to cultivate this spirillum in artificial culture 

 media have thus far been unsuccessful, although Koch 

 has observed an increase in the length of the spirilla 

 and the formation of a tangled mass of filaments. 



Pathogenesis. Inoculation experiments have been suc- 

 cessfully made on man and monkeys. Monkeys when 

 inoculated with human blood containing the spirilla 

 take sick after about three and a half days, but show 

 only the initial febrile attack; no relapses, such as are 

 characteristic of the disease in man. The organisms 

 are found in the blood, and at the height of the fever 

 in the other organs on autopsy. Extirpation of the 

 spleen renders the disease more dangerous for monkeys. 



Blood from one animal, taken during the attack, in- 

 duces a similar febrile paroxysm when inoculated in 

 another monkey. One attack does not preserve the 

 animal experimented on from a second attack (Koch 

 and Carter). 



Very little is known bacteriologically of this disease, 

 but from the fact that these peculiarly shaped organ- 

 isms are constantly and exclusively found in relapsing 

 fever, and that the disease can be transmitted to mon- 

 keys by inoculating them with the blood containing the 

 spirilla, it may be assumed that they are the true cause 

 of the disease. 



