342 Veranus Alva Moore 



using a stronger solution of tannic acid in the preparation of 

 the mordant and by the use of acetic instead of sulphuric acid 

 in acidifying it. A very few other minor modifications of 

 lyOefHer's and other processes have been suggested, but they 

 have in no way brought out results which entitle them to a 

 consideration. Brown's" method is practically a modification 

 of Trenkmann's process. 



During the brief period of time that the existence of flagella 

 on the smaller and especially the pathogenic bacteria has 

 been known, two valuable applicationsof this knowledge have 

 been made : 



(i) Their use as a basis for a general dassificatiori of the 

 Schizomycetes. Soon after the appearance of Loeffler's first 

 method (1889) Messea**, an Italian investigator, proposed a 

 new systematic classification"'* of bacteria based upon the num- 

 ber and arrangement of the flagella. His classification is as 

 follows : 



I. Gymnobacteria {non-motile). 

 II. Trichobactbria {motile'). 



1. Monotricha. 3. Amphitricha. 



2. Lophotricha. 4. Peritricha. 



The Monotricha have one flagellum at one pole of the bacil- 

 lus {Bacillus pyocyaneus). The Lophotricha have a tuft or 

 bunch of flagella at one pole of the bacillus {^Bacillus of blue 

 milk). The Amphitricha have a flagellum at each pole 

 {^Spirilhun volutans). The Peritricha are provided with rows 

 of flagella {Bacillus typhosus). 



*Kruse {Centratblattf. Bakteriologie u. Parasitenkunde, IX, (1891), 

 p. 107) in reviewing Messea's classification, considers it of onlj- second- 

 ary importance. His reason for this is, that it is unnatural in that it 

 places bacilli, spirilla, and a micrococcus together in one group (the 

 Monotrichia). It does not seem necessary- to consider a pioneer classi- 

 fication secondary merely because of an apparent inconsistency, espe- 

 cially in a subject about which so little is known. Undoubtedly 

 Messea's classification was based on too limited a number of examina- 

 tions, and more extended investigations will probabl}' cause man)' 

 changes to be made. At present, however, it is the oulj- classilication 

 which incorporates the complete morphology, as known at the present 

 time, of motile bacteria. 



