516 SYPHILIS 



thin, its thickness being only -25 /t. 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 ; there is little actual 

 locomotion, and a specimen will often remain in the same field for 

 a long time. The ends are pointed and tapering, and, as was first 

 shown by Schaudinn, a flagellum is present at each end. Both in 

 fresh specimens and in dried films (Figs. 156-158) the regu- 

 larity of the spirals is well maintained, though in the latter there 

 is sometimes distortion or drawing out of a spiral. The use of 

 dark-ground illumination (p. 90) is of great service in searching 

 for the organism. 



/ 



^^HSB 



Figs. 156 and 157. — Film preparations from juice of hard chancre 

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

 parations by Dr. A. MacLennan.) 



In ulcerated syphilitic lesions, and also in non-syphilitic 

 lesions of the genitals, other organisms are, of course, present, 

 and not infrequently various other spirochetes. Of these several 

 species have been described, e.g., sp. refringens, sp. balanitidis, 

 sp. gracilis, but there are others which have not yet been 

 differentiated. The first mentioned is a comparatively coarse 

 organism, more highly refraqtile, while its curves vary during 

 the movements ; in film preparations the curves appear irregulat 

 or are lost to a large extent. Some of the other species are of 

 smaller size, but they differ from the sp. pallida in their appear- 

 ance and in the character of their movements. We believe that 

 in the case of genital lesions there is little difficulty to the 

 experienced observer in recognising the sp. pallida, but any 

 difficulty will be removed if the superficial organisms are re- 

 moved and the lymph is taken from the lesion for examination. 



