No. 498] 



THE SPIROCHETE* 



375 



Yet both descriptions and figures are far too indefinite to 

 permit of more than a guess as to the genus under con- 

 sideration. Even Ehrenberg's work affords scanty 

 means for the recognition of the forms of which he listed 

 one spirochete and three spirilla. The group, though 

 familiar to all students of microscopic life, has remained 

 only superficially known up to very recent times, in fact 

 until the discovery of the important role which certain 

 of them play in the production of disease turned once 

 more the attention of investigators in this direction. De- 

 spite the characteristic of flexibility noted by Ehrenberg, 

 and the indifference they displayed towards ordinary 

 methods of bacteriological culture, most authors have 

 grouped these organisms together among the bacteria. 

 Renewed attention to the group served to emphasize at 

 once radical differences of opinion as to its interpreta- 

 tion. 



Undoubtedly the impetus to this study was given by 

 Scliaudinn's discovery of such an organism in syphilis 

 and the intuitive inference which has been abundantly 

 verified that others would be found in similar relation to 

 diseases as yet entirely unexplained. Working on this 

 and on other species, Scliaudinn confirmed the view of 

 Ehrenberg as to the characteristic flexibility of the 

 spirochetes, and determined the occurrence of longi- 

 tudinal division and the presence of polar flagella, single 

 save just before division. He also demonstrated certain 

 differences between the form found in syphilis and other 

 common spirochetes, which he thought served to justify 

 their generic separation. Throughout he maintained 

 firmly the animal nature of the group. 



Almost simultaneously there appeared in 1906 several 

 papers which dealt with the problem as to the nature of 



sions g Ii/the first, by the, parasitologist Blanchard 

 (1906), was analyzed briefly the morphological basis for 

 the genera of microorganisms in which the body has the 



