MICROBES, OB BACTERIA. 91 



II. CLASSIFICATION OF MICROBES, OR BACTERIA. 



It is very difficult to make any natural classifica- 

 tion of the organisms which belong to the group of 

 microbes ; we have, in fact, seen that they only differ 

 from each other in external form, and that these forms 

 are very variable, since the same organism may present 

 itself successively as an isolated globule, a chaplet, a 

 chain, and a more or less articulated rod Microbes are 

 essentially polymorphous, and adapt themselves to 

 varied conditions of existence, which influence the 

 form taken by these microscopic organisms. For this 

 reason their classification has often varied, their dis- 

 tinction into genera and species does not yet rely on 

 precise data, and the opinions formed by various 

 authors in accordance with their personal researches 

 still differ widely. 



We will, however, subjoin Wunsche's classification. 



Schizophyta, or Schizomycetes. 



A. Division of cells always occurring in the same direc- 

 tion, so as to form a chaplet before the joiuts 

 or members separate. 



1. Cells united in mucilaginous or gelatinous families. 

 o. Cells united (in a state of repose) in amorphous 



families. 



a. Spherical or elliptic cells, colourless and gene- 

 rally motionless ... ... ... Micrococcux. 



j8. Cells elongated in short, movable rods ... Bacterium. 



6. Cells united in families with sharp outlines, lobu- 



lated and agglutinated like frog-spawn ... Ascococcus. 



2. Cells arranged in filaments. 



