CHAPTER XLIII 



DISEASES CAUSED BY SPIROCHETES (TREPONEMATA) 



The microorganisms known as spirochsetes are slender, undulating, 

 corkscrew-like threads which show definite variations both structurally 

 and culturally from the bacteria as a class. Most important among 

 them are the spirochaete of relapsing fever, Spirochsete pallida of 

 syphilis, the spirillum of Vincent, Spirochsete refringens, Spirillum 

 gallinarum, a microorganism which causes disease in chickens, 

 Spirochate anserina, which causes a similar condition in geese, and 

 several species which have been found as parasites, both in animals 

 and in man, without having definite etiological connection with disease. 



The classification of these various species in one group is rather more 

 a matter of convenience than one of scientific accuracy, since our knowl- 

 edge of them is not far advanced, and our inability to cultivate almost 

 all of them has not permitted their detailed biological study. Formerly 

 many of these organisms were regarded as bacteria belonging to the gen- 

 eral group of the spirilla. Recently Schaudinn,* the discoverer of the 

 syphilis spirochsete, has claimed, upon the basis of a careful morphological 

 study, that many of these forms are actually protozoa. He based this 

 claim upon the observation that stained preparations often showed undu- 

 lating membranes extending along the long axis of the microorganisms 

 and that definite nuclear structures were demonstrable. This observer 

 also claimed that many of the spiral forms reproduce by cleavage along 

 the longitudinal axis. Other observers have not agreed with this view, 

 Laveran,^ Novy and Knapp,^ and others asserting that their own obser- 

 vations indicate a close relationship of these microorganisms to the true 

 bacteria. Whatever the final conclusion may be, the question is more 

 or less an academic one, in that our ideas as to the exact line of division 

 between the unicellular animals and the unicellular plants is not by any 

 means founded upon a sound basis. In common with the bacteria, most 



• Schavdinn, Arb. a. d. kais. Gesundheltsamt, 1904. 

 'Laveran, Comptes rend, de I'acad. des sci., 1902 and 1903. 

 3 Novy and Knapp, Jour, of Infec. Dis., 3, 1906. 

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