202 C.-E. A, WiNSLOW AND AnNE F. RoGERS 



The third of our types, like the second, has not previously been 

 distinguished from the genus Micrococcus; it appears, however, 

 to shov^r its own definite individuality, and to belong with the Para- 

 coccaceae, although it approaches the saprophytic cocci in certain 

 characters. We suggest the name Alhococcus for this genus, which 

 includes those organisms of which M. pyogenes (Ros.) Mig. is a 

 type. They produce a more vigorous surface growth than the strep- 

 tococci, with a clear white pigment, and ferment carbohydrates, 

 producing a fair amount of acid. They are also distinguished from 

 the Metacoccaceae by the general tendency of their morphology and 

 staining reactions, and by their habitat. In our series we have 23 

 cultures of this type. All without exception were obtained from the 

 body or from the air, none from water or earth. All without excep- 

 tion show a good surface growth, white pigment, and division into 

 groups and rarely chains, but never packets. Sixteen were uni- 

 formly Gram positive and only two uniformly Gram negative. The 

 average acidity in dextrose broth was 0.7 per cent normal, and 

 in lactose broth o . 5 per cent normal. Only three cultures showed 

 an acidity lower than o . 2 per cent, and only one culture an acidity 

 over 1 . 5 per cent in dextrose. Lactose results, as usual, were more 

 variable, nine cultures falling below o . 2 per cent acid, and one above 

 1.5 per cent. Nitrates were reduced by three cultures and gelatin 

 liquefied by 14. The four species which we have previously call- 

 ed M. pyogenes (Ros.) Mig., M. rhenanus Mig., M. candicans 

 Fliigge, and M. canescens Mig., should belong to this new genus, 

 being distinguished, as before, by their relation to acid and 

 gelatin. The reduction of nitrates may furnish a basis for the 

 establishment of other species. 



The fourth of the general groups which have appeared in this 

 study is the group of the yellow pigment formers, of which M. lute- 

 us and Sarcina ventriculi are typical — a group which differs in almost 

 all its properties from those previously considered. Organisms of 

 this type are found mainly in earth and water rather than on or in 

 the animal body. They give abundant, to very heavy, growths 

 of a yellow color. They frequently occur in packets, generally decol- 

 orize by Gram, and fail to ferment sugars or ferment them only 

 slightly. They may or may not liquefy gelatin or reduce nitrates. 



