182 RELATIONSHIPS OF THE COCCACE^l 



differ from similar saprophytic forms, by their power to 

 produce hemolysis, and by their group reactions to the 

 agglutinins present in immune sera. 



With the exception of these investigations on immunity 

 reactions, comparative studies of the orange staphylococci 

 are almost wholly lacking. Gordon (1905) examined the 

 fermentative power of two cocci of this type, and found 

 that both liquefied gelatin, coagulated milk, reduced 

 nitrates, and fermented maltose, lactose, glycerin, and 

 mannite. In the next year he described (Gordon, 1906) 

 three more cultures which exhibited the same characters, 

 except that one failed to coagulate milk. It is said that 

 "staphylococci" form hydrogen sulphid and ammonia 

 under the proper conditions and reduce various organic 

 dyes (Neisser and Lipstein, 1903). All these points are 

 worth comparative study and may serve to distinguish 

 new species of Albococcus and Aurococcus. 



The finer relations of this group can only be cleared up 

 by an exhaustive study of a number of characters in a large 

 series of cultures, such as Andrewes and Horder made of 

 the streptococci. In the course of our investigation on the 

 generic types of the Coccaceae, we examined one hundred 

 and eighty strains belonging to the genus Aurococcus, and 

 the records of these observations make it evident that at 

 least three types occur within the genus. It is much to be 

 desired that this work should be extended. A study of a 

 larger number of cultures, and particularly a study includ- 

 ing determinations of serum reactions and fermentative 



