CLASSIFICATION 



II 



them, trichobacteria but these terms are falling into disuse 

 because the latter is now-a-days applied to higher groups that grow 

 in hair like forms. However the following may be described: 

 When they have one flagellum we call them monotrichous bacteria, 

 and amphitrichous when there are two flagella, one at each pole 

 (Fig. 7). When the cell is surrounded by flagella, it is known as 

 a peritrichous bacterium, and lopho- 

 trichous when the flagella are ar- 

 ranged in tufts of two or more. 

 These are simple adjectives and not 



FIG. 7. Spirillum undula with polar 

 flagella. (Kolle and Wassermann.) 



FIG. 8. Bacillus proteus vul- 

 garis, showing peritrichous fla- 

 gella. (Kolle and Wassermann.) 



now used as terms of classification. The tetanus bacillus is an 

 example of a peritrichous organism, while the bacillus of green 

 pus is called monotrichous, because of its single flagellum. 



Flagella are not pseudopods, but distinct organs of locomo- 

 tion. 



In certain bacteria of the Beggiatoa, locomotion is accom- 

 plished by a peculiar amoeboid motion, or by an undulating 

 membrane. On looking at bacteria known to have no powers 



