DESCRIPTION OF SPECIES. 



551 



to 1*5 p. in diam., in pairs and in 

 tetrads. 



Colonies white. 



Inoculated in the depth of gela- 

 tine the cocci produce a granular 

 filament, changing in two or three 

 days to liquefaction in the form of 

 a funnel ; later, a wrinkled mem- 

 brane floats on the surface of the 

 liquid. 



In milk they produce lactic acid. 



They were isolated from butter 

 which had turned cheesy. 



Micrococcus aerogenes (Miller). 

 Oval cocci. 



Colonies are dark and regular in 

 contour, but have a peculiar spotted 

 appearance. 



Inoculated in the depth of gela- 

 tine a brownish-yellow growth 

 occurs along the track of the needle, 

 and on the free surface a white 

 button-like elevation. After a time 

 the gelatine is slowly liquefied. 



On agar a yellowish- white pulpy 

 layer forms, and a similar growth 

 appears on potato. 



They resist the action of acids, so 

 that the presence of gastric juice 

 does not impede their develop- 

 ment. 



They were obtained from the 

 intestine. 



Micrococcus agilis (Ali-Cohen). 

 Cocci 1 /x in diam., singly, in 

 pairs, tetrads, and in chains. They 

 are motile, and possess flagella. 



Inoculated in the depth of gela- 

 tine they grow in the track of the 

 needle, and produce, after two or 

 three weeks, liquefaction or excava- 

 tion of the jelly. 



On agar and potato the growth 

 is pink. 



They occur in water. 



Micrococcus agilis citreus 

 (Menge). Cocci in pairs, chains 

 and masses. They are motile, and 

 each coccus possesses a single fla- 

 gellum. 



Colonies appear surrounded by 

 clouded gelatine. 



Inoculated in the depth of gela- 

 tine there is a scanty growth in the 

 track of the needle, and on the sur- 

 face a bright yellow patch. 



On agar they form a yellow layer, 



which is viscid, and may be drawn 

 out in long threads. 



In broth they produce cloudiness 

 and a viscous deposit. 



The growth on potato is bright 

 yellow. 



Milk is not coagulated. 



They were isolated from an in- 

 fusion of peas. 



Micrococcus albus liquefaciens 

 (Besser). Large cocci in chains and 

 in masses. They are anaerobic. 



Colonies on agar exhibit concen- 

 tric rings of different shades of 

 brown. 



Inoculated in the depth of gela- 

 tine they produce liquefaction in 

 the track of the needle. 



They occur in mucus from the 

 nose. 



Micrococcus amylivorus (Bur- 

 rill). Oval cocci, 1 to 1'4 p. long, 

 7 n broad, singly, in pairs, and rarely 

 in fours, never in chains, are found 

 embedded in an abundant mucilage 

 which is very soluble in water. 



They have been described as pro- 

 ducing the so-called " fire blight " 

 of the pear tree and other plants. 



Micrococcus aquatilis (Bolton). 

 Small cocci in masses. 



Colonies circular, prominent, and 

 pure-white. 



Inoculated in the depth of gela- 

 tine, there is a white growth in the 

 track of the needle and also on the 

 free surface. 



On agar the growth is white. 



They occur in water. 



Micrococcus aquatilis invisi- 

 bilis (Vaughan). Cocci oval. 



Colonies brown. 



In gelatine there is a slight 

 growth in the track of the needle, 

 and a more abundant growth on 

 the free surface. 



On agar they form a white film. 



On potato the growth is in- 

 visible. 



They occur in water. 



Micrococcus aurantiacus 

 (Cohn). Cocci spherical or oval, 

 1-3 to 1-5 p. in diam., singly, in pairs, 

 and in groups. 



Colonies orange-yellow. 



Inoculated in gelatine they form 

 minute colonies in the track of the 



