THE GENUS ALBOCOCCUS 193 



mark them off as distinct from the saprophytic forms. 

 Furthermore, the white forms differ from the orange ones 

 so distinctly, in abundance of surface growth and in 

 action upon gelatin, as to warrant their separation as a 

 distinct type center, for which we have suggested the 

 name Albococcus. 



The orange staphylococci differ from the yellow sapro- 

 phytic forms in almost every point; and the chromogenic 

 power seems a trustworthy mark of these group differ- 

 ences, since orange pigment formers are very rarely found 

 except on or in the animal body. When they are isolated 

 from water or earth their presence may generally be 

 accounted for by excretal pollution. The white staphylo- 

 cocci, on the other hand, are less easily distinguished from 

 the micrococci, for two reasons. In the first place, the 

 typical Albococcus is somewhat intermediate in charac- 

 ters between Aurococcus and Micrococcus. It resembles 

 Aurococcus in reaction to the Gram stain and in fermen- 

 tative power; it resembles Micrococcus in abundance of 

 surface growth and slow action on gelatin. In the second 

 place, observation of chromogenesis alone is not sufficient 

 to distinguish true albococci from certain saprophytic 

 forms. The earth and water bacteria belonging to the 

 genus Micrococcus usually produce a yellow pigment; 

 but not infrequently forms will be found in a saprophytic 

 environment which possess the fermentative powers and 

 show the Gram reaction of Micrococcus, but give a whitish 

 or light yellow growth on media. As a rule some tinge of 



