DESCRIPTION OF SPECIES. 



559 



On the surface of agar the cocci 

 form a greyish-white band, which 

 turns brown at the periphery, and 

 later is all dark or orange-yellow. 

 On potato the growth is brown. 

 They occur in nasal mucus. 

 Micrococcus tetragenus ver- 

 satilis (Sternberg and Pinlay). — 

 Cocci varying in size from -5 to 1-5 

 fji, in tetrads -and irregular groups. 



Colonies are circular and lemon- 

 yellow in colour. 



Inoculated in the depth of gela- 

 tine there is very scanty develop- 

 ment along the line of puncture, 

 and the gelatine is liquefied in the 

 form of a cup near the surface. 

 At the bottom of the liquefied 

 gelatine a viscid, pale-yellow mass 

 accumulate^. 



On the surface of agar a thick, 

 viscid, yellow layer is formed along 

 the line of inoculation, which gradu- 

 ally extends over the entire sur- 

 face. The colour varies from cream- 

 yellow to lemon-yellow, and the 

 surface is moist and shining. 



On potato there is a, similar 

 growth. 



They were isolated from the 

 skin of patients suffering from 

 yellow fever, from mosquitoes after 

 attacking these patients, and from 

 the air. 



Micrococcus ureee liquefaciens 

 (Fliigge). — Cocci spherical, 1-25 to 

 2 fi in diam., singly, or in chains 

 of three to ten elements, or in 

 irregular groups. 



Colonies appear in two days 

 as small white points. They have 

 sharply defined edges and a granular 

 surface. The gelatine gradually 

 liquefies, and the edges of the colo- 

 nies become irregular. 



The cocci inoculated in the depth 

 of gelatine produce a continuous 

 white line along the track of 

 the needle. Finally, the whole of 

 the gelatine liquefies, and appears 

 as a whitish-turbid fluid with a 

 thick whitish-yellow deposit at the 

 bottom. 



They were obtained from urine. 

 Micrococcus versicolor 

 (Flugge). — Small cocci, in pairs 

 and in masses. 



White colonies develop in twenty- 

 four hours ; after two days they are 

 yellowish, with sharp contours of 

 yellowish-green colour, and finely 

 granular. The superficial colonies 

 form flat deposits, 2(3 mm. in size, 

 increasing to 10 mm. after four or 

 five days. 



On the surface of gelatine the 

 cocci form a shining layer with a 

 greenish or bluish shimmer like 

 mother-of-pearl. 



Inoculated in the depth of gela- 

 tine the' growth is composed of 

 spherical yellowish colonies, and 

 on the free surface they form an 

 iridescent film. 



They occur in the air. 

 Micrococcus violaceus (Schrs- 

 ter). — Cocci or elliptical cells, de- 

 scribed as uniting into violet-blue 

 gelatinous spots, which again unite 

 to form larger patches. 



The colonies on gelatine are violet 

 in colour. 



Inoculated in the depth of gela- 

 tine the growth is scanty in the 

 track of the needle. 



On the surface of gelatine they 

 form a bluish-yiolet layer, and the 

 same on agar and potato. 



They were observed on boiled 

 potatoes exposed to the air, and are 

 also found in water. 



Micrococcus viticulosus (Katz). 

 — Oval cocci 1 ju in width, and 1-2 /i 

 in length, in masses, but without 

 formation of much gelatinous ma- 

 terial. 



The superficial colonies are quite 

 different in appearance from the 

 deep colonies. From the deep 

 colonies fine hairlike tendrils are 

 thrown off from a centre, forming 

 a very delicate and extensive net- 

 work. The threads are found to 

 consist of zoogloea masses, irregular 

 in size, arranged like strings of 

 beads. The colonies which are ex- 

 posed to the air form a thin layer, 

 of muddy-white gelatinous sub- 

 stance, which rapidly spreads, some- 

 times sending out hairlike processes 

 into the depth of the gelatine. 



Inoculated in the depth of gela- 

 tine a delicate feather-like growth 

 occurs along the track of the needle, 



