GENERAL MORPHOLOGY AND PHYSIOLOGY 45 



media. Cells normally in pairs of flattened cells. Gram-negative. 

 Fermentative powers low. Growth fairly abundant on serum media, 

 usually whitish or yellowish. 



The type species is Neisseria gonorrhoea Trevisan. 



2. Streptococcus. Rosenbach, 1884, emended Winslow and Rogers, 

 1905. Synonyms: Sph&rococcus Marpmann 1885, not Sph&rococcus 

 Agardh 1821; Perroncitoa Trevisan 1889; Babesia? Trevisan 1889; 

 Schuetzia Trevisan 1889; Lactococcus Beijerinck 1901; Hypnococcus Bet- 

 tencourt et al. 1904; Myxokokkus Gonnermann 1907, not Myxococcus 

 Thaxter 1892; Melococcus? Amiradzibi 1907; Diplostreptococcus Lingels- 

 heim 1912. 



Chiefly parasites. Cells normally in short or long chains (under un- 

 favorable conditions, sometimes in pairs and small groups, never in large 

 packets). Generally stain by Gram. Capsules and zooglea often formed. 

 On agar streak, effused translucent growth, often with isolated colonies. 

 In stab culture, little surface growth. Sugars fermented with formation 

 of large amount of acid. Generally fail to liquefy gelatin or reduce nitrates. 



Type species is Streptococcus pyo genes Rosenbach. 



3. Staphylococcus. Rosenbach, 1884. Synonyms: Micrococcus Cohn 

 1872 em. Migula 1894; Botryomyces Bollinger 1888; Botryococcus Kitt 1888, 

 not Botryococcus Kuetzing 1849; Galactococcus Guillebeau; Bollingera 

 Trevisan 1889; Gaffkya Trevisan 1885; Pyococcus Ludwig 1892; Carpho- 

 coccus Hohl 1902; Aurococcus Winslow and Rogers 1906, Indolococcus 

 Jensen 1909; Liquidococcus Jensen 1909; Peptonococcus Jensen 1909; 

 Enterococcus? (Thiercelin) Rougentzoff 1914. 



Parasites. Cells in groups and short chains, very rarely in packets. 

 Generally stain by Gram. On agar streak good growth, of orange color. 

 Sugars fermented with formation of moderate amount of acid. Gelatin 

 often liquefied very actively. 



Type species is Staphylococcus aureus Rosenbach. 



4. Albococcus. Winslow and Rogers, 1905. Differs from Staphylo- 

 coccus in forming more abundant surface growth of porcelain white color, 

 and in fact that liquefaction of gelatin when present is less vigorous. 



Tribe 2. Micrococcea. Trevisan. Facultative parasites or sapro- 

 phytes. Thrive best under aerobic conditions. Grow well on artificial 

 media, producing abundant surface growths. Planes of fission often at 

 right angles; cell aggregates in groups, packets or zooglea masses. Gen- 

 erally decolorize by Gram. Pigment yellow or red. 



5. Micrococcus. Cohn, 1872, emended Winslow and Rogers, 1905. 

 Synonyms: Micros phara Cohn 1872, not Microsph&ra Leveille 1851; 

 Pediococcus Balcke 1884; Merista Van Tieghem 1884, not Merista (Banks 

 and Soland) Cunningham 1839; Planococcus Migula 1894; Urococcus 



