136 SCHIZOMYCETES 



sively proved to exist, but in some bacteria chromatin 

 particles have been observed near the centre of the 

 bacterial cell and denser masses of protoplasm situated 

 at the poles which exhibit a more marked affinity than 

 the rest of the cell protoplasm for aniline dyes. These 

 latter are termed polar granules or Polkoerner (Fig. 85, 

 e). Occasionally these aggregations of protoplasm 

 alter the colour of the dye they take up. They are 

 then known as metachromatic bodies or Ernstschen 

 Koerner (e. g., B. diphtherias). 



5. Flagella (Organs of Locomotion, Fig. 85, a). 

 These are gelatinous elongations of the cell protoplasm 



(or more probably of the cap- 

 sule), occurring either at one 

 pole, at both poles, or scat- 

 tered around the entire periph- 

 ery. Flagella are not pseu- 

 dopodia. The possession of 

 flagella was at one time sug- 

 ,-, , , ... . gested as a basis for a system of 



FIG. 87. Types of ciliation. * 



classification, when the follow- 

 ing types of ciliation were differentiated (Fig. 87) : 



1. Polar: (a) Monotrichous (a single flagellum situ- 

 ated at one pole; e. g., B. pyocyaneus). 



(b) Amphitrichous (a single flagellum at each pole; 

 e. g., Spirillum volutans). 



(c) Lophotrichous (a tuft or bunch of flagella situated 

 at each pole; e. g., B. cyanogenus). 



2. Diffuse : Peritrichous (flagella scattered around the 

 entire periphery: e. g., B. typhosus). 



PHYSIOLOGY. 



Reproduction. Active Stage. Vegetative, i. e., by 

 the division of cells, or " fission." 



1. The cell becomes elongated and the protoplasm 

 aggregated at opposite poles. 



2. A circular constriction of the organism takes 



