230 GONORRHOEA, SOFT SORE, SYPHILIS 



their conclusions, and the general result may be said to be of a 

 confirmatory nature. These observers found in certain cases an 

 organism to which they gave the name spirochcete pallida ; it 

 now also goes by the name spironema pallidum. As described 

 by them, it is a minute spiral-shaped organism, showing usually 

 from six to eight curves, though longer forms are met with ; the 

 curves are small, comparatively sharp, and regular (Figs. 78, 79). 

 It may be said to measure 4-14 fj. in length, while it is extremely 

 thin, its thickness being only '25 p. 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, 



FIGS. 78 and 79. Film preparations from juice of hard chancre showing 

 spirochaete pallida, Giemsa's stain, x 1000. (From preparations by 

 Dr. A. MacLennan.) 



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 assistance in finding it. 



In ulcerated syphilitic lesions other organisms are, of course, 

 present, and not infrequently another spiral organism, to which 

 the name spirochcete refringens has been given. This organism 

 is usually somewhat longer, and is distinctly thicker than the 

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

 refractile, and is much more easily detected than the latter 

 organism ; its curves also are opener and much less regular, 

 and they vary in their appearance during the movements. In 

 stained films (see p. 107) the differences between the organisms 

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

 panying photograph (Fig. 81). The spirochaete pallida by the 



