DISEASES CAUSED BY SPIROCILETES 595 



his first investigations, Schaudinn was unable to discover flagella and 

 believed that he saw a marginal undulating membrane similar to that 

 noticed in the trypanosomes. Later observations by this observer, as 

 well as by others, revealed a delicate flagellum at each end, but left the 

 existence of an undulating membrane in doubt. Uncertain, in his later 

 investigations, whether the microorganisms described by him could 

 scientifically be classified with the spirochsete proper, Schaudinn sug- 

 gested the name of " Treponema pallidum." 



In the same preparations in which Spirochseta pallida was first 

 seen, other spirochsetes were present, which were easily distinguished 

 from the former by their coarser contours, their flatter and fewer undula- 

 tions, their more highly refractile cell bodies, and, in stained prepara- 

 tions, their deeper color. These microorganisms were not found 

 regularly, and were interpreted merely as fortuitous and unimportant 

 companions. To them Schaudinn gave the name of "Spirochseta re- 

 fringens." 



The epoch-making discovery of Schaudinn and Hoffmann was soon 

 confirmed by many observers, and the etiological relationship of Spiro- 

 chseta pallida to syphilis may now be regarded as an accepted fact. 

 Although our inability to cultivate the microorganism has made it 

 impossible to carry out Koch's postulates, nevertheless indirect evi- 

 dence of such a convincing nature has accumulated that no reasonable 

 doubt as to its caustive importance can be retained. The spirochaetes 

 have been found constantly present in the primary and secondary 

 lesions of all carefully investigated cases, and, so far, have invariably 

 been absent in subjects not afflicted with syphilis. 



Schaudinn himself, not long after his original communication, was 

 able to report seventy cases of primary and secondary syphilis in which 

 these microorganisms were found. Spitzer l found them constantly 

 present in a large number of similar cases. Sobernheim and Tomas- 

 czewski 2 found the spirochaetes in fifty cases of primary and secondary 

 syphilis, but failed to find them in eight tertiary cases. Mulzer, 3 who 

 found the microorganisms invariably in twenty cases of clinical syphilis, 

 failed to find them in fifty-six carefully investigated non-syphilitic sub- 

 jects. The voluminous confirmatory literature which has accumulated 

 upon the subject can not here be reviewed. The presence of these 

 spirochsetes in the blood at certain stages of the disease has been demon- 



1 Spitzer, Wien. klin. Woch., 1905. 



2 Sobernheim und Tomasczewski, Munch, med. Woch., 1905. 



3 Mulzer, Berl. klin. Woch., 1905, and Archiv f. Dermat. u. Syph., 79, 1906. 



