CHAPTER XXVIII 

 GROUP V. 



DISEASES DUE TO SPIRILLA. 

 I. RELAPSING FEVER. 



The Or saii- j n 1868, Obermeier discovered in the blood of 

 patients suffering from relapsing fever, "Very fine 

 threads exhibiting motility." These "threads" 

 have since been known as the Spirillum obermeieri 1 

 and are recognized as the cause of the disease. 

 Novy describes two forms of the organism. The 

 short forms vary from 7 to 9 microns, and are 

 about 0.25 microns in width. The long forms vary 

 from 16 to 19 microns. They result from processes 

 of agglutination or multiplication. The organism 

 is provided at one end with a long flagellum. The 

 turns of the spirals of the short forms are two or 

 three in number. The spirilla are very motile, 

 and not only move from place to place but rotate 

 on the long axis. 



1. The spirillacae, Migula's third family under the 

 Order of Eubacteria, comprises organisms with these char- 

 acteristics : "Cells which are twisted screw-fashion or repre- 

 sent a segment of a spiral. Division takes place only in one 

 direction of space after the cell has elongated." The dif- 

 ference between spirillum and spirochaeta is shown by the 

 following : "3. Genus : Spirillum. Cells rigid, with polar 

 tufts, for the most part bent in the form of a half-circle, 

 as organs of locomotion. 4. Genus : Spirochaeta. Cells with 

 snake-like bending, organs of locomotion unknown." 

 Although Migula classes this organism with the bacteria, 

 there is some ground for considering it protozoon in nature. 

 According to Novy, the organism of relapsing fever has a 

 rigid cell body with an end flagellum and would therefore be 

 be classed as a spirillum. 



