604 PATHOGENIC MICROORGANISMS 



organisms. The latter, indeed, seem to be entirely insulated against 

 such antibodies and do not induce antibody formation to any great 

 extent, in either the infected animal or man. Both active and passive 

 immunization with culture pallida and the sera produced with them 

 have no effect. We have obtained some evidence, however, that in rab- 

 bits a purely local resistance developes in the tissue previously the site 

 of a lesion. 



The occurrence of a Wassermann reaction was formerly supposed to 

 indicate the existence of specific syphilitic antibodies in the serum of 

 patients. More recent information regarding this reaction seems to 

 show that it depends upon the presence in the serum of syphilitic 

 patients of substances produced indirectly because of the presence of* 

 syphilitic infection. It may be a relative increase of globulins or, as 

 Schmidt has suggested, a change in the physical state of the globulins 

 or other substances present in the serum. At any rate it has been found 

 that the fixation of complement in the Wassermann reaction does not 

 depend upon the occurrence of a specific antigen-antibody reaction. 

 In the first place the antigens most commonly used, and successfully 

 so, in the Wassermann reactions, are non-specific lipoidal extracts of 

 normal organs. 



Again it has been demonstrated that extracts of cultures of the 

 Spirochseta pallida as well as extractions from the testes of syphilitic 

 rabbits do not furnish an antigen suitable for the Wassermann reaction. 

 This has followed especially from the work of Noguchi, 2 of Craig and 

 Nichols, 3 and ourselves. This forms a corollary to the other experi- 

 ments previously mentioned and shows that, whatever the Wassermann 

 reaction may be, it is not a- specific complement fixation in the sense of 

 Bordet and Gengou. It must be admitted, therefore, that our knowl- 

 edge of syphilis immunity is in its infancy and that we know very little 

 about the systemic reactions which follow infection with the Spirochseta 

 pallida. 



The fact that the syphilitic virus does not pass through a filter has 

 been demonstrated by Klingmuller and Baermann, 4 who inoculated 

 themselves with filtrates from syphilitic material. 



1 Zinsser and Hopkins, Jour, of Exp. Med., xxi, 1915, p. 576; xxiii, 1916, p. 323; 

 xxiii, 1916, p. 329; xxiii, 1916, p. 341. 



2 Noguchi, Jour. Am. Med. Assoc., 1912. 



3 Craig and Nichols, Jour. Exp. Med., xvi, 1912. 



* Klingmuller und Baermann, Deut. med. Woch., 1904. 



