WHITE AND ORANGE STAPHYLOCOCCI 165 



studied by us; and it is significant that these three types cor- 

 respond to the three types of white staphylococci described by 

 Gordon (compare table 9). 



The most abundant form in each investigation was the type 

 which fermented lactose and liquefied gelatin, called by Gordon 

 Staphylococcus epidermidis albus and by the Winslows Alb. epi- 

 dermidis and Alb. pyogenes (according as nitrates were or were 

 not reduced). This type (group I, table 10) may best perhaps be 

 known as Staph, epidermidis since it was Gordon's work which 

 first made its characteristics clear. Our forms of this series 

 agree with those of Gordon in generally coagulating milk and 

 generally failing to peptonize the clot; though the agreement is 

 by no means very close. Several cultures which came to us as 

 St. ureae belong in this group. They acidify milk and produce 

 ammonia. 



The second type in abundance in our study, and the type found 

 most commonly on the skin after St. epidermidis by Gordon, is 

 the form which ferments lactose but fails to liquefy gelatin, iden- 

 tified by the Winslows as Alb. Candidas and now to be called 

 St. candidus (group 2 of table 10). Our strains, however, re- 

 duced nitrate and generally clotted milk which Gordon's type did 

 not. Three strains sent in to the Museum collection as M. 

 ietragenus all belong to this group. None of them reduce ni- 

 trates and results are variable in milk and in regard to ammonia 

 production. 



Finally the third form found commonly in the present study 

 resembles Gordon's fjrm characteristic of the scalp, which neither 

 ferments lactose nor liquefies gelatin. This is the type for which 

 Kligler suggested the name ATbococcus candicans, and which should 

 be called St. candicans (group 4 of table 10). Our strains how- 

 ever differed from Gordon's in failing to peptonize casein or fer- 

 ment mannitol and in fermenting maltose. 



Two of the strains in this group came to us originally as M . 

 neoformans, both being alkaline in milk with variable results in 

 regard to nitrate reduction. 



The lactose-negative gelatin-positive type of white pigment 

 producers appears in our study, as in that of Gordon, to be a 



