2io RELATIONSHIPS OF THE COCCACE^ 



Migula himself divided his genus Micrococcus (includ- 

 ing our Aurococcus, Albococcus, and Rhodococcus) into the 

 following eight groups: 



A. Cultivated on gelatin. 



1. White growth. 



a. Non-liquefying. 



b. Liquefying. 



2. Yellow growth. 



a. Non-liquefying. 



b. Liquefying. 



3. Red growth. 



a. Non-liquefying. 



b. Liquefying. 



4. Blue and violet growth. 



B. Not cultivated on gelatin. 



Chester arranges the same species in a somewhat more 

 complicated scheme as follows: 



A. Without pigment on gelatin or agar. 



1. Fail to grow, or grow poorly, on media. 



2. Grow on ordinary media. 



a. Grow best at 37 degrees and not at 20 



degrees C. 



b. Grow at 20 degrees C. 



* Gelatin liquefied. 

 ** Gelatin not liquefied. 



