Source : Webster's Revised Unabridged Dictionary (1913)

Micrococcus \Mi`cro*coc"cus\, n.; pl. {Micrococci}. [NL. See
   {Micro-}, and {Coccus}.] (Biol.)
   A genus of {Spherobacteria}, in the form of very small
   globular or oval cells, forming, by transverse division,
   filaments, or chains of cells, or in some cases single
   organisms shaped like dumb-bells ({Diplococcus}), all without
   the power of motion. See Illust. of {Ascoccus}.

   Note: Physiologically, micrococci are divided into three
         groups; chromogenic, characterized by their power of
         forming pigment; zymogenic, including those associated
         with definite chemical processes; and pathogenic, those
         connected with disease.

Spherobacteria \Sphe`ro*bac*te"ri*a\, n. pl.; sing.
   {Spherobacterium}. [NL. See {Sphere}, {and Bacterium}.]
   (Biol.)
   See the Note under {Microbacteria}.