CHAPTER II. 



THE GENERAL SYSTEMATIC RELATIONS OF THE 

 COCCACEjE. 



The bacteria which generally appear in a spherical 

 form were called Coccaceen by Zopf (1885); he was an 

 ardent believer in the transformation of bacterial species, 

 and considered the coccus-shape as a transitory form 

 which any bacteria might assume under favorable con- 

 ditions. As the general stability of bacterial charac- 

 ters was gradually established by more careful observa- 

 tions, the name Coccaceae was applied to the spherical 

 bacteria, which were found to constitute a well-marked 

 natural group. The family is defined by Migula (1900) 

 as follows: 



Family Coccaceae (Zopf) Migula. Cells, in their 

 free condition, spherical; during division somewhat 

 elliptical. In the latter condition, division has already 

 set in, altho it may not be apparent Division in one, two, 

 or three planes, without previous elongation of the cells. 

 If the cells remain in contact after division they are fre- 

 quently flattened in the plane of division. Motility is 

 present only in a few forms. Formation of endospores 

 appears to be absent or very rare. 



Recent investigations of these bacteria make it in- 



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