FLAGELLUM 



43 



bundle of flagella at one end and are called lophotrichic (Fig. 



21) (Xo</)os = tuft). Sometimes at approaching division the 

 flagella may be at both ends and are then amphitrichic (Fig. 



22) (an(l)i = both). It is probable that this condition does not 



Fig. 20. — A bacterium showing a 

 single flagellum at the end — mono- 

 trichio. 



Fig. 21. — A bacterium showing 

 a bundle' of four flagella at the 

 end — lophotrichic. 



persist long, but represents the development of flagella at 

 one end of each of a pair resulting from division of an organ- 

 I'cTvi mV,;/.Vi Vips flagella at one end only. In many bacteria 



Pig. 22. — A bacterium showing 

 flagella at each end — amphitrichic. 



Fig. 23. — ^A bacterium showing 

 flagella all around — peritrichic. 



the flagella arise from all parts of the surface of the cell. 

 Such bacteria are peritrichic (Fig. 23) (Trept = around). The 

 position and even the number of the flagella are very con- 

 stant for each kind and are of decided value in identification. 



