3io Suppuration 



and Streptococcus brevis (chains of from four to ten), have been 

 described by v. Lingelsheim,* but do not hold as separate species. 



The streptococcus is not motile and does not form spores. 



Staining. The organisms stain well with ordinary aqueous 

 solutions of anilin dyes and by Gram's method. 



Isolation. The streptococcus can be isolated from pus contain- 

 ing it by plating or by the inoculation of a mouse or rabbit, from 

 whose blood it may easily be secured after death. 



Cultivation. The organism grows at both the room temperature 

 and that of incubation, its best and most rapid development being 

 at about 37C. 



. Colonies. Upon gelatin plates very small, colorless, translucent 

 colonies appear in from twenty-four to forty-eight hours. When 

 superficial, they spread out to form flat disks about 0.5 mm. in 

 diameter. The microscope shows them to be irregula nd granular, 

 to have a slightly yellowish color by transmitted lig , and to have 

 a frayed-out appearance around the edges, due to projecting chains 

 of the cocci. No liquefaction of the gelatin occurs. 



Gelatin Punctures. In gelatin puncture cultures no liquefaction 

 is observed. The minute spheric colonies grow along the whole 

 length of the puncture and form a slightly opaque granular line. 



Fig. no. Streptococcus colonies on serum agar (From Hiss and Zinsser, 

 "Text-Book of Bacteriology," D. Appleton & Co., Publishers). 



Agar-agar. Upon agar-agar a delicate transparent growth de- 

 velops slowly along the line of inoculation. It consists of small, 

 colorless, or slightly grayish transparent colonies which do not readily 

 coalesce. 



Blood-serum. The growth upon blood-serum resembles that upon 

 agar-agar. The colonies are small, white, discrete, and do not affect 

 the medium. 



Potato. The streptococcus does not seem to grow well upon 

 potato, the colonies being invisible. 



Bouillon. In bouillon the cocci develop slowly, seeming to prefer 

 a neutral or feebly alkaline reaction. The medium remains clear, 



* "Zeitschrift fur Hygiene," 1891, Bd. x, p. 331; 1892, xn, p. 308. 



