494 MANUAL OF DETERMINATIVE BACTERIOLOGY 



The nomenclature used in the present edition of the Manual is slightly modified 

 from that used in the fifth edition. The form adopted is in accordance with the view 

 that the recognition of similar antigenic structures really identifies serotypes rather 

 than species. In a way, serotypes are varieties in a taxonomic sense, though like 

 horticultural varieties in higher plants, they do not exactly correspond with varieties 

 as usually defined by taxonomists. Where cultural differences rather than antigenic 

 structure have been used to subdivide species, these subdivisions are designated as 

 varieties. 



As it is not clear as yet how many and what species will eventually be recognized, 

 the form Salmonella sp. has been used as before to indicate that the serotypes belong 

 to species in the genus Salmonella which are not yet definitely defined. Geographic 

 and other proper names are used to designate types as these have been used exten- 

 sively in the literature. They have an historic significance and are not as easily 

 confused as are letters and numbers. No Latin endings have been used for these 

 place names as this might indicate that the serotype names are accepted as species 

 names. 



The genus Eberthella has been combined with the genus Salmonella as recommended 

 by Schiitze et al. Hoc. cit.). With the exception of the typhoid organism, other 

 species previously listed in Eberthella appear not to exist in type culture collections. 

 As cultures are not available for study, these species are merely listed in an appendix 

 to the genus Salmonella. 



The type species is Salmonella choleraesuis (Smith) Weldin. 



The table on pages 495 to 500 is used in place of the usual key. 



