198 RELATIONSHIPS OF THE COCCACE^ 



these respects the group was homogeneous. Three cul- 

 tures showed the gelatin liquefaction and nitrate reduc- 

 tion, characteristic of Gordon's first type. Nine failed 

 to liquefy gelatin or reduce nitrates (Gordon's third type). 

 The other eleven liquefied gelatin but failed to reduce 

 nitrates, and therefore corresponded with the commonest 

 described form of the Staphylococcus pyogenes albus. It 

 is curious that this form, which a survey of pathological 

 literature shows to be well-nigh ubiquitous, was isolated 

 by Gordon in only a few cases. 



It seems certain from the frequency with which the 

 liquefying, non-reducing albococcus has been reported 

 that it should receive recognition as a distinct specific 

 type. It is the form described by Rosenbach as Staphy- 

 lococcus pyogenes albus, now more commonly called 

 M. pyogenes, and it may be characterized under the 

 name Alb. pyogenes as follows: 



i. ALB. PYOGENES (Rosenbach) Winslow. A parasitic 

 coccus, living normally on the surfaces of the human or 

 animal body, or in diseased tissues. Occurs singly, or in 

 pairs, or irregular groups. Generally stains by Gram. Good 

 to abundant white surface growth. Moderate acid produc- 

 tion in dextrose and lactose broth. Nitrates not reduced. 

 Growth best at 37 degrees. Gelatin liquefied, but somewhat 

 slowly. 



Many names have been given to white liquefying 

 cocci; but a study of the published descriptions fails 

 to show any valid characters for their separation. Almost 



