SPIRILLUM OBERMEIERL 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. 
