MICROCOCCUS TETRAGENUS. 171 



>nly a forma depauperata from long culture) ( from 0. 5 /u to 0. 8 fi ) ; other- 

 rise it corresponds in all particulars. According to Leube's descrip- 

 tion (Virch. Arch. 100, p. 560), the Micr. ureae is entirely identical 

 lorphologically with the Micr. candicans (0.8 //); the colonies in gel- 

 bin plates at times present sectorial cracks, old cultures have an in- 

 ipid, pasty smell. Any statement regarding the growth on potato is 

 jking. 



Microccocus aquatilis (Mead Bolton). 



We are not familiar with this organism. It is common in the water 

 Gottingen (Z. H. I, 94), and is characterized by " very small" 



idividuals. The colonies in gelatin plates present something of 

 Lial streaks and circular lines, so that rhomboid spaces occur. Fur- 



ler characteristics are not given by Bolton. The organism is able to 

 >w in distilled water. According to Schroter's insufficient descrip- 

 ion, it may perhaps be identical with the Micr. candidus Cohn. 

 Also the porcelain coccus of Escherich from the intestine ( " Darm- 

 kterien," p. 90) appears similar ; it measures only 0.3 //. 



Micrococcus tetragenus (Koch and Gaffky). 



(Plate 7.) 



Synonyms. — Micr. tetragenus septicus Boutron, Micr. 

 jtragenus albus Boutron. 



Principal Literature. — Koch and Gaffky, "Mitteil. a. d. Gesundh.," 

 ii, 42 ; Langenbeck's "Arehiv," Bd. 28, 500 ; Boutron's "These 

 le Paris" contains a monograph upon the organism, Reference in C. 

 \ xvi, 971 ; Teissier, "Arch, de med. exp.," vin, 14. 



Microscopic Appearance. — Roundish or somewhat 



>val cocci, usually lying in pairs or fours. 1 The size is 



miewhat variable. Not infrequently one sees but little 



characteristic cell arrangement in a microscopic prepara- 



ion, made from a culture. In the animal and human body 



le arrangement in tetrads is regular, and a rather thick 



instained gelatinous capsule surrounds the tetrad. In 



actions stained by Gram's method the capsule may be 



counterstained with eosin. 



Relation to Oxygen. — Grows well with oxygen, and 

 not so well without. 



Requirements as to Temperature and Nutrient 



x We have found, on one occasion, in old cultures in hay decoction 

 typical sarcina forms. Unfortunately the observation was not followed 

 further. Contamination is not excluded. 



