50 BACTERIOLOGY 



nel), since it cannot be called Pseudomonas fluorescent, owing to 

 the fact that the specific name fluorescens is claimed by a pre- 

 viously described species of this same genus. Furthermore, 

 Bacillus (Pseudomonas} fluorescens-liquefaciens Flugge becomes 

 Pseudomonas fluorescens (Flugge) Migula, on the ground that it 

 was probably the first member of the genus to receive the 

 specific appellation fluorescens. In the same way, Pseudomonas 

 fluorescens-capsulata (Pettier) becomes Pseudomonas capsulata 

 (Pottier), and Pseudomonas fluorescens-Schuylkilliensis (Wright) 

 becomes Pseudomonas Schuylkilliensis (Wright). Should it, 

 however, be demonstrated that Pseudomonas Schuylkilliensis 

 (Wright) is only a variety of Pseudomonas fluorescens, then, of 

 course, the original name becomes again applicable. Again, the 

 second term in the trinomial should be retained, provided no 

 earlier species with the same name is known. Thus, Micrococcus 

 cumulatus-tenuis v. Besser becomes Micrococcus cumulatus. In- 

 stances such as these might be multiplied indefinitely, but the 

 few examples cited will serve to illustrate the principles involved. 



4. THE ARRANGEMENT OF BACTERIAL SPECIES IN GROUPS 



In the following pages the writer has undertaken to arrange, 

 for purposes of identification, all those forms of bacteria which 

 have been already described with any degree of detail. The 

 task has proved a laborious one, and has occupied several years 

 of close work. The final outcome has been more or less unsatis- 

 factory, and yet an entirely satisfactory system of bacterial classi- 

 fication cannot be expected until our knowledge is greatly 

 extended beyond its present limits. 



This much, however, has been accomplished in a provisional 

 way, i.e. the ability to cluster a considerable number of imper- 

 fectly described forms around a few reasonably defined species, 

 and thus to establish groups which may become the basis of 

 future comparative studies. 



