76 VETERINARY BACTERIOLOGY 



organisms, for example, names such as the following have been 

 applied to bacteria: Bacillus membranaceous amethystinus mobilis, 

 Bacillus argenteus phosphorescens liquefaciens, and even the fol- 

 lowing, Bacillus saccharobutyricus fluorescens liquefaciens im- 

 mobilis. Such names are given under the mistaken idea that 

 the specific name should be a description of the species. This is 

 not customary in naming any of the higher plants and animals, 

 and it is certainly not more desirable in bacteria. The yeasts, 

 molds, and protozoa have more commonly been studied by those 

 who have had technical training in nomenclature than have the 

 bacteria, consequently the classification of these forms is on a 

 much more satisfactory basis. The only justification for a specific 

 name made up of more than two words is that the two words 

 taken together express but a single idea. 



CLASSIFICATION OF BACTERIA 



Many different classifications have been proposed for bacteria, 

 but not one of these has come into general use. A careful exam- 

 ination of different texts in bacteriology, particularly those 

 devoted to the pathogenic bacteria, will show that different sys- 

 tems and schemes of classifications are used in dealing with 

 closely related organisms. Not only have the groups been fre- 

 quently changed, but many different names have been applied 

 to almost every one of the pathogenic bacteria. The consequence 

 is that in studying any pathogenic organism it is necessary to 

 give not only the name preferred by the author but also a list 

 of the synonyms which have been used by others. It seems 

 probable that a satisfactory system of nomenclature is yet to be 

 devised. The system of bacterial classification which has been 

 most generally adopted and has given the best general satisfaction 

 is that of Migula, published in Engler and Prantl's Synopsis of 

 Plant Genera. This classification has been somewhat modified 

 by Frost and McCampbell and their regrouping is perhaps more in 

 accord with the facts. It is perhaps more important that a dis- 

 tinct and satisfactory classification should be adhered to than 

 that a single classification should be used for all purposes. 

 The following classification is the one which will be adopted in 

 this text. It is based upon Frost and McCampbell's modifica- 



