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 led 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//to40// 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 spirillum 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. 



