672 



Genus 3. Micrococcus (Ilallier) Cohn. 



Facultative parasites or saprophytes. Cells 

 in plates or irregular masses (never in long 

 chains or packets). Acid production variable. 



Under this genus, thirteen species may be 

 distinguished, by the three properties of lique- 

 faction, acid production and chromogenesis, 

 their characters being indicated in tabular 

 form below. 



Gelatin Liquefied. 

 Acid. Nos-Acid. 

 Yellow. ..it/, aureus (R03 ) Mig. M. orbicularis (Ravtnel) 

 While.. ..M. pyogenes (Ros.) Mig. M. rhenanus Mig. 

 Red M. ruseus FHigge. M. fulvus Cohn. 



Gelatin not Liquefied. 

 Acid. NonAcid. 

 Yellow. ..3/. luteus (Schroter) Cohn. 31. oc/iracc!<« Rosen- 

 thal. 



White.. ..jV. candicans Flugge. M. canescens Mig. 

 Red iV. cinnabareiii Flugge. 



M. urece Cohn. Ammoniacal fermentation of urine pro- 

 duced. Gelatin not liquefied. 



M. (Elhebius Trevisan. Ammoniacal fermentntion of 

 urine produced. Gelatin liquefied. 



Genus 4. Sarcina (Goodsir). 



Saprophytes or facultative parasites. Divi- 

 sion under favorable conditions, in three 

 planes, producing regular packets. Sugars as 

 a rule not fermented. 



Under Sarcina are eleven species, eight of 



which are grouped as follows : 



Gelatin Liquefied. Gelatin not Liquefied. 



Yellow .S'. snbflava Eavenel. S. venlriculi Goodsir. 



White S. Candida Lindner. S. puimonum Virchow. 



Red S. rosacea Lindner. S. incaniata Gruber. 



Brown S. cervina .Stub. S. fnsca Gruber. 



In addition three somewhat aberrant species 

 must be recognized — 8. aurantiaca Tliigge, a 

 yellow liquefying chromogen, which unlike the 

 other members of the group, has the power to 

 coagulate milk, with 8. agilis (Ali-Cohen) 

 Mig. and 8. tetragenus (Mendoza), Mig., re- 

 spectively red, and yellowish-white, motile 

 forms. From study of the literature and a 

 few cultures of supposedly motile forms we are 

 inclined to believe that all the truly motile 

 cocci may be classed under these two heads. 



Genus 5. Ascococcus (Cohn). 

 Generally saprophytic. Cells imbedded in 

 large irregularly lobed masses of zoogloea, in 

 presence of carbohydrates. Acid usually 

 formed. 



Two species are distinguished, A. mesen- 



[N. S. Vol. XXI. ^o. 5-39. 



feroides Cienkowski, a non-liquefying form, 

 and A. mucilaginosus Migula, a liquefier. 



The characters of the species tentatively de- 

 fined above are still somewhat artificial and 

 may be subject to revision and modification 

 when our studies are complete. It is prob- 

 able that the liquefaction of gelatin can not 

 bear any very direct relation to phylogeny, 

 since in every genus except Diplococcus, and 

 in each subdivision of a genus, a liquefying 

 and a non-liquefying form occur parallel to 

 each other. 



Synonymy will be discussed in our full com- 

 munication later; but we have strictly followed 

 the rules of priority as recognized in other- 

 fields of systematic biology. 



In reviewing our genera a serial arrange- 

 ment is at once apparent. Diplococcus is 

 strictly parasitic, and commonly produces only 

 aggregates of two cells. Streptococcus, also 

 normally parasitic, thrives better, though still 

 not luxuriantly, on artificial media and its 

 typical growth-form is a chain. Micrococcus 

 includes both pathogenic and non-pathogenic 

 forms but all grow abundantly on gelatin and 

 agar, in rather large irregular cell aggregates, 

 while some province acid and some alkalies in 

 milk. Sarcina shows further development in 

 the same direction, its growth form being 

 larger and produced by three planes of divi-. 

 sion, its saprophytic habit being more marked, 

 (no truly pathogenic forms known to exist), 

 with the power of acid production generally 

 wanting. Ascococcus, in spite of its slight 

 acid production and chain formation, appears 

 on the whole to form the extreme of this series, 

 since its entirely saprophytic existence and 

 large vegetative growth-forms are far removed 

 from the pathogenic micrococci. The genera 

 above defined seem to mark the important 

 transition stages beginning with such strict 

 parasites as D. Weichselhaumii and ranging 

 through the intermediate forms of Strep- 

 tococci, Micrococci and Sarcinse to the sapro- 

 phytic Ascococcus mesenteroides at another 

 extreme. We believe that these genera have 

 true phylogenetic significance and represent 

 real groups of organisms having, natural 

 affinities. C.-E. A. Winslow, 



Anne F. Eogers. 



SCIENCE. 



