DISEASES CAUSED BY SPIROCH^TES 847 



membrane extending along the long axis of the microorganisms 

 similar to that observed in trypanosomes. He also asserted that 

 most of the spiral forms reproduce by cleavage along the longi- 

 tudinal axis. On the other hand, Laveran, 1 Novy and Knapp 2 and 

 others maintained a close relationship of these microorganisms to 

 the true bacteria. 3 



A review of observed facts seems to show that most of these 

 spiral organisms have the power of multiplication by transverse 

 fission. Many of them possess flagella and in some of them definite 

 immune bodies can be demonstrated in the serum of infected sub- 

 jects, similar to those produced by bacteria during infection. In 

 others again, like the treponema pallidum, no true circulating anti- 

 bodies against the virulent parasitic forms can be found. Indeed, 

 in syphilis it seems that immunity exists only so long as the living 

 organisms still persist in the body, an observation which is entirely 

 analogous to that made with certain trypanosomes, and with malaria. 

 Also, with some of them, transmission by an intermediate insect 

 host in which the spirilla undergo multiplication has been definitely 

 shown, a state of affairs which corresponds with conditions in many 

 protozoan infections. Kolle and Hetsch favor a classification mid- 

 way between the protozoa and the bacteria, a view which is probably 

 as correct as any that we have any justification for holding at the 

 present time. 



Noguchi, 4 who has had extensive experimental experience with 

 the spirochaete has suggested the tentative classification which 

 follows : 



He calls attention to the fact that the term "spirochaeta" was 

 applied first by Ehrenberg in 1838 to a free living, fresh water 

 or marine form of spiral organism which creeps along the surface 

 of an object but does not swim, divides by transverse fission, and 

 probably has nothing to do with the organism to which we now 

 apply this word. 



Noguchi divides the spiral organisms of the group which we are 

 now considering into : 



I. Cristispira or Saprospira. This is a limited group of motile 

 spiral organisms which infest the great crystalline styles of certain 



1 Laveran, Comptes rend, de 1'acad. des sei., 1902 and 1903. 



Novy and Knapp, Jour. Infec. Dis., 3, 190(1. 

 ' Kolle and Hetsch, "Die experimentelle Bakt.," Berlin, 1906. 

 * Noguchi, Jour. Exper. Med., 27, 1918, 575. 



