DISEASES CAUSED BY SPIROCH^TES 



605 



THE SPIROCBLETES OF RELAPSING FEVER 



The microorganisms causing relapsing 'fever were first observed in 

 1873, by Obermeier, 1 who demonstrated them in the blood of patients 

 suffering from this distinct type of fever. Since his time extensive 



FIG. 132. SPIROCH^TE OF RELAPSING FEVER. 



and Flournoy.) 



(After Norris, Pappenheimer, 



studies by many other observers have proven beyond question the 

 etiological connection between the disease and the organisms. 



Morphology and Staining. The spirochaete of Obermeier is a delicate 

 spiral thread measuring from 7 to 9 micra in length (Novy), and about 

 1 micron in thickness. While this is its average size, it may, according 

 to some observers, be considerably longer than this, its undulations 

 varying from 4 to 10 or more in number. Compared with the red blood 



1 Obermeier, Cent. f. d. med. Wiss., 11, 1873. 



