CHAPTER II 

 CLASSIFICATION 



Bacteria have some properties allied to the lower forms of animal life 

 flagellata but their closest relationship is to the lower algae. They are gen- 

 erally considered to be vegetable organisms and are classified as fission fungi or 

 schizomycetes. They are microscopic, unicellular organisms which propagate 

 by cleavage or fission. Of the various systems of classification of bacteria, none 

 of which is complete or satisfactory, the one most commonly adopted by writers 

 is the following by Migula. 



CLASSIFICATION OF BACTERIA 



Coccaceae. Spherical forms, with divisions in one to three planes, forming 

 two to eight daughter cells. 



Streptococcus. Cocci without flagella, dividing in one plane, often remain- 

 ing connected so as to form beaded chains. 

 Micrococcus. Without flagella dividing in two planes. When remaining 



connected, after fission, they form grape-like clusters (staphylococci). 

 Sarcina. Without flagella, dividing in three planes. Usually remaining 



connected to form cubical packets. 



Planococcus. Possessing flagella, dividing in two planes, sometimes re- 

 maining connected to form sheets. 



Piano sarcina. Possessing flagella, dividing in three planes, 

 Bacteriaceae. Elongated straight cells dividing in the transverse plane only. 

 Bacterium. Without flagella, sometimes with endospores. 

 Bacillus. With flagella and sometimes endospores. 

 Pseudomonas. With polar flagella, seldom with endospores. 

 Spirillaceae. Cells forming spirals or parts of spirals, dividing in the transverse 

 plane only. 



Spirosoma. Inflexible cells without organs of locomotion. 

 Microspira. Inflexible cells with from one to three polar flagella. 

 Spirillum. Inflexible cells with from five to twenty curved polar flagella, 



forming tufts. 

 Spirochceta. Flexible undulating cells without flagella, but possibly a 



lateral undulating membrane. 



Chlamydobacteriaceae. Cells of different forms, united in branches or 

 unbranched chains and provided with capsules or envelope. 

 Streptothrix. Elongated cells in non-branching chains, divisions in one 



plane only; reproducing by non-motile -conidia. 



Cladothrix. Branching chains, dividing in one plane only. Motile repro- 

 ductive cells (Zoogonidia) with polar flagella. 



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