io8 



SPIROCH^TES. 



he also finds that they make their way into the blood- 

 vessels and are not confined to the surface of the ulcera- 

 tive lesions, as is usually supposed. 



SPIROCH^TA PALLIDA. 



(Schaudinn, 1905.) 



(Spironema pallida, Vuillemin, 1905; Treponema pallidum, 



Schaudinn, 1905; Spiroschaudinnia pallida, 



Sambon, 1907.) 



This organism was discovered by Schaudinn in March, 

 1905, and announced in a communication by Schaudinn 

 and Hoffmann. It is usually from 4 to 14^ long, and 

 exhibits six to fourteen curls; but longer forms are 

 encountered, up to 40 /* or more. Its breadth is almost 

 immeasurable, and may be /* or less. 1 It has pointed 



\ 



FIG. 85. Spirochseta pallida: a, After Schaudinn; b, c, after 

 Krzystatowicz and Siedlecki. 



ends and terminal appendages of periplast, but no 

 undulating membrane (Fig. 85). Its body is round in 

 section, and the curls are very constant and regular. It 

 differs from most other spirochsetes in staining a red- 

 dish colour with Giemsa's stain, instead of blue. Its 

 movements are rotatory and undulating, occasionally 

 lashing, the curls remaining constant during these 

 motions. In certain conditions, however, the curves 



1 They appear considerably thicker when stained by Levaditi's 

 silver method than with ordinary stains. 



