504 SYPHILIS 



are small, comparatively sharp, and regular (Figs. 152, 153). It 

 may be said to measure 4 to 1 4 /A in length, while it is extremely 

 thin, its thickness being only '25 /x. In a fresh specimen, say a 

 scraping from a chancre suspended in a little salt solution, the 

 organism shows active movements, which are of three kinds 

 rotation about the long axis, gliding movements to and fro, 

 and movements of flexion of the whole body. The ends are 

 pointed and tapering. Its detection is comparatively difficult, 

 as the organism is feebly refractile, and more difficult to see than 

 most other organisms ; the movement of small particles in the 

 vicinity, however, is of asistance in finding it. The use of the 



FIGS. 152 and 153. Film preparations from juice of hard chancre 

 showing spirochaete pallida, Giemsa's stain. xlOOO. (From pre- 

 parations by Dr. A. MacLennan.) 



parabolic sub-stage condenser (p. 93) is of great service in 

 searching for the organism. 



In ulcerated syphilitic lesions other organisms are, of course, 

 present, and not infrequently another spiral organism, to which 

 the name spirochaete refringens has been given. This organism 

 is usually somewhat longer, and is distinctly thicker than the 

 spirochsete pallida. As the name implies, it is more highly 

 refractile, and it is much more easily detected than the latter 

 organism; its curves also are more open and much, less regular, 

 and they vary in their appearance during the movements. In 

 stained films (see p. 115), the differences between the organisms 

 come out more distinctly, as can be gathered from the accom- 

 panying photograph (Fig. 156). The spirochaete pallida by the 

 Giemsa stain is coloured somewhat faintly, and of reddish tint, 

 whilst the regular spiral twistings are preserved ; the spirochsete 

 refringens shows flatter, wave-like bends, and, like other organ- 

 isms, is stained of a bluish tint. By using Loffler's stain for the 



