162 



WINSLOW, ROTHBERG AND PARSONS 



His commonest type found on the skin coagulated milk but did 

 not peptonize it, liquefied gelatin, reduced nitrates and neutral 

 red, and fermented lactose, maltose and glycerol but not man- 

 nitol. A second type common on the scalp was the opposite of 

 the first in every respect except that it also reduced nitrates. 

 A third type fermented maltose and lactose but gave negative 

 reactions to the other seven tests. 



The characteristics of these three types of Gordon's (which 

 are of importance from the fact that they were based on the 

 study of 300 strains) are indicated in table 9. 



TABLE 9 



Characteristics of Gordon's three types of white staphylococci 



Gelatin 



Milk, coagulation 



Milk, peptonization. . . 



Nitrate reduction 



Neutral red, reduction 



Lactose 



Maltose 



Glycerol 



Mannitol 



COMMONEST 



FORM ON SKIN 



ST. EPIDER- 



MIDI8-ALBTJS 



+ 

 + 



+ 



+ 

 + 

 + 

 + 



COMMONEST 

 FORM ON SCALP 



+ 



+ 



+ 



SECOND FORM 



ABUNDANCE 

 ON SKIN 



+ 

 + 



The Winslows used the liquefaction of gelatin and the reduc- 

 tion of nitrates for establishing their specific types in both the 

 orange and white series, Aur. aureus being defined as liquefying 

 and non-reducing, Aur. aurantiacus as non-liquefying and non- 

 reducing, and Aur. mollis as reducing; Alb. pyogenes as liquefying 

 and non-reducing, Alb. epidermidis as liquefying and reducing 

 and Alb. candidus as non-liquefying. 



If our practically universal positive results in regard to nitrate 

 reduction are correct, the differentiation based on this character- 

 istic in the earlier investigations must be considered as of doubt- 

 ful value. There remain chromogenesis, liquefaction of gelatin 

 and fermentation of lactose as the chief differential characters 

 available for classification, with coagulation of milk closely cor- 



