376 



The genus Treponema has a spiral body, not 

 flattened, cylindrical in section, flagellum at each end. 

 No undulating membrane, e.g., T. pallidum of syphilis 

 and T. pertenue of yaws. 



I. Sp. recurrentis. The cause of relapsing fever in 

 Europe. It remains to be seen whether the spiro- 

 chaetes of relapsing fever elsewhere are identical with 

 this or not. 



Symptoms. The attack lasts, as a rule, about six 

 to seven days. The apyretic interval five to ten days. 

 The following attack is shorter and the apyrexia longer. 

 In two-thirds of the cases there may be a third attack, 

 and even five or six relapses occur (cp. S. duttoni). 



Fig. 115. (Upper figure] Plan of a spirochaete ; 

 (Lower figure] Plan of a treponeme (after Schaudinn) 



Blood Examination. Examine during the pyrexia 

 a fresh film with a 1/6 lens. Note the slight dis- 

 turbance among the corpuscles and, when attentively 

 focussed, the gliding undulating movement of the 

 parasite. If not .found fresh, make a thick smear of 

 blood on a slide as big as the area of a sixpenny bit. 

 Dry thoroughly. Do not fix. Stain with gentian 

 violet (a few drops of a saturated alcoholic solution to 

 a teaspoonful of water) for about five minutes or less, or 

 with Romanowsky. Parasites are generally numerous 

 during the pyrexia, but disappear completely during 

 the apyretic interval. 



