CLASSIFICATION OF BACTERIA IN FAMILIES. 53 



1. Family: Coccacecc (Zopf, Migula). 



Cells in a free state, spherical, becoming slightly 

 elliptical before division. Division occurs in 

 one, two, or three directions of space. Motile 

 organs are present only in a few species. 

 Endospore formation not known to occur. 



1. Genus: Streptococcus (Billroth). Cells spher- 



ical and without motile organs. Division 

 only in one direction of space. After divi- 

 sion the cells separate or they remain for 

 a shorter or longer time in apposition and 

 frequently form long chains. Usually two 

 cells are seen lying close together with a 

 slightly greater interval between the next 

 two members in the chain. 



2. Genus: Micrococcus (Hallier, Cohn). Cells 



which in their free state are spherical. 

 Division in two directions of space. If the 

 cells after division remain for a shorter or 

 longer time in apposition they form simple 

 or flat aggregations of the cells in which the 

 opposing sides of the organisms are flat- 

 tened. Motile organs are absent. Endo- 

 spore formation has not been demonstrated. 



3. Genus: Sarcina (Goodsir). Cells which in 



their free state are spherical. Division in 

 three directions of space, forming the well- 

 known packet-form aggregations. Besides 

 this, cells frequently occur singly and as 

 diplococci or tetracocci or in irregular 

 aggregations. Motile organs are absent. 

 Endospore formation has not been definitely 

 demonstrated. 



