CHAPTER II. 



THE GENERAL SYSTEMATIC RELATIONS OF THE 

 COCCACE^}. 



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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