596 BACTERIOLOGY. 
Within recent years numerous other vibrios, the so- 
called ‘‘ water vibrios,’’ have been found while looking 
for the cholera bacillus, the identity or variation of 
which from the spirillum of cholera it has been ex- 
tremely difficult to determine, as morphological, biolog- 
ical, and pathogenical examinations have Jed to no posi- 
tive results. 
SPIRILLUM OBERMEIERI (Spirillum of Relapsing Fever). 
First observed by Obermeier (1873) in the blood of 
persons suffering from relapsing fever. 
Morphology. Long, slender, flexible, spiral, or wavy 
filaments, with pointed ends, from 16 to 40y in length 
and from one-quarter to one-third the thickness of the 
cholera spirillum. 
Stains readily with the ordinary aniline colors, es- 
pecially with fuchsin, Loffler’s solution of methylene- 
blue and Bismarck-brown. Does not stain by Gram’s 
method. 
Biological Characters. A motile spirilluam which 
has not been cultivated in artificial media. Spore 
formation has not been demonstrated. In fresh prep- 
arations from the blood the spirillum exhibits active 
progressive movements accompanied by very rapid 
rotation in the long axis of the spiral filaments or by 
undulating movements. The spirilla are found exclu- 
sively in the blood and spleen of persons suffering from 
relapsing fever, never in the secretions, and only during 
the fever, not in the intermissions, or at most singly at 
the beginning of an attack. When preserved in blood- 
serum or a 0.5 per cent. solution of salt they continue 
to exhibit active movements for a considerable time. 
