DESCRIPTION OF SPECIES. 



551 



to lo fi 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 /i 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 liquefacieus 

 (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 fi long, 

 •7 fi 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- 

 Mlis (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 aurautiacus 

 (Cohn). — Cocci spherical or oval, 

 1-3 to 15 ^ in diam., singly, in pairs, 

 and in groups. 



Colonies orange-yellow. 



Inoculated in gelatine they form 

 minute colonies in the track of the 



