1 88 RELATIONSHIPS OF THE COCCACE/E 



ceding ones. Eighteen of the thirty-five cultures showed 

 better chromogenic power at 20 degrees, but fifteen were 

 as good at 37 degrees as at 20 degrees, and two were bet- 

 ter at 37 degrees. Five cultures, which we have classed 

 with this type, failed to liquefy gelatin, and it is possible 

 that a fourth type center of nitrate-reducing non-liquefy- 

 ing aurococci should be recognized. We have felt it 

 unwise, however, to create specific names for rare aberrant 

 strains; and until there is evidence that such forms are 

 sufficiently common to constitute a true center of varia- 

 tion it seems best to let them pass as "variants by sub- 

 traction" from the main nitrate-reducing type. 



The only published description of a nitrate-reducing 

 orange coccus with which we are familiar is that given by 

 Dyar under the name Merismopedia mollis (Dyar, 1895). 

 According to Dyar's description, the organism with which 

 he worked did not change the color of litmus-lactose 

 media, but did coagulate milk and liquefy the clot. It 

 seems possible that there may have been some error in the 

 observation, or in the description, as no other case has 

 been recorded in which a coccus has coagulated milk 

 except by acid production. Dyar's name, with emended 

 characters, may, however, be applied to our third type 

 center and characterized as follows: 



3. Aur. mollis (Dyar) Winslow. A parasitic coccus, 

 living normally on the surf axes of the human or animal 

 body, or in diseased tissues; often found in the air. Occurs 

 singly j or in pairs, or irregular groups, rarely in short 



