BACTERIA 



103 



they cannot be seen without staining and they can only be stained by 

 precipitating some chemical which may add considerably to their 

 width. They are frequently longer than the organism which possesses 



^v? 





'<' 



r 





V 



Fig. 81. 



Fig. 79. — Chromatium okenii; 2, Bacterium lineola; 3, 4 and s, sulpho-bacteria; 

 7, OpMdomonasjenensis; 8, and g,SpirUltMn undula; 10, Cladolhrix dichotoma. {After 

 Bittschli from Guilliermond review, Bull. Inst. Past.) 



Fig. 80. — Microspira comma. Monotrichous bacteria. {After Migula from 

 Schmidt and Weiss.) 



Fig. Si. — Pseudomonas pyocyanea. Monotrichous bacteria. {After Migula from 

 Schmidt and Weiss.) 



them and sometimes many times that length. B. symptomdUci 

 antkracis found in the soil has a flagellum sixty times its own length. 

 The arrangement of the flagella on the bacteria is quite constant and 



Fig. 82. Fig. 83. Fig. 84. 



Fig. 82. — Pseudomonas syncyanea. LophotrichoUs bacteria. {After Migula from 

 Schmidt and Weiss.) ' ■ 



Fig. 83. — Spirillum rubrum. Lophotrichous bacteria. {After Migula from 

 Schmidt and Weiss.) . ,,,„.,, „, ., 



Fig. 84. — Bacillus typhosus. Pentricnous bactena. {After Mtgulafrom Schmidt 

 and Weiss, and Frost and McCampbell.^ 



is used by some authors to differentiate genera. Very few of the 

 micrococci are provided with flagella, as was indicated above, and in 

 the bacilli and spirilla they may be arranged at the poles singly or in 



