



CLASSIFICATION OF DAIRY BACTERIA. 35 
Gelatin plate; colonies I mm. in diameter, of a light pink color. Under a 
low power they show a nucleus with a lighter zone. Upon the surface the 
edges are thin and the center raised. 
Gelatin stab, there is a slight needle growth anda slight surface growth, 
which is pink. 
Agar and potato; a moist, thick, not widely spreading, pink layer. 
Bouillon, after a few days a pinkish sediment makes its appearance. The 
liquid is cloudy, with no scum. 
Milk, no curdling takes place. Reaction becoming slightly alkaline, with 
no digestion. After two weeks a very slight pinkish tinge is noticed in the 
milk, which becomes quite decided in a month. Later a pink scum forms, and 
the milk becomes somewhat slimy. 
The. distinctive characteristic of this species is the fz color produced, 
which shows in the gelatin colony, in the gelatin stab growth, in the growth on 
agar and potato, and in the sediment in the bouillon. 
No. 115. (Somewhat common.) Aactllus ruber lactis. (n. sp.) 
Morphology; a rod .ou by 2u to 4u in length, occasionally forming long bent 
chains. 
Gelatin plate; a white opaque bead, .7 mm. in diameter, formed on the sur- 
face of the gelatin, coarsely granular and broken around the edge. Gelatin 
liquefies rapidly, with a central mass and an outer granular zone, which is 
broken and lobed at first. Later the outer zone becomes clear as it expands, 
and the inner mass is broken into fragments. | 
Gelatin stab; a shallow funnel formed, with a thin liquid layer of gelatin 
over the whole surface of the tube, which gradually deepens. A dense sedi- 
ment appears in a clear liquefied gelatin, but no scum. 
Agar, a thick, coarsely folded growth, which may be at first yellow, but 
later pzzk. . 
Potato; smooth, thick, glistening growth, with a decidedly Zzxzk or salmon 
tinge. A very striking characteristic. 
Milk; curdled in 4 days at body temperature. The curd is soft and alka- 
line, and soon digests into a colorless liquid. At 20° the milk does not curdle, 
but digestion occurs. When used for ripening cream it produces a good 
flavored butter, with a pleasant aroma, though neither taste nor smell are 
those of typical butter. 
No; 151.” (Rare;) 
Morphology, Bacillus .64 by .7“ to 1.24, blunt ends. 
Gelatin plate; surface colony round, semi-transparent, liquefying gelatin 
slowly, with an orange pink color. 
Gelatin stab, slight needle growth, with slow liquefaction. A slightly cloudy 
liquid is produced, with a thin scum. 
. Agar; moist, salmon pink growth. 
Potato, a moist, light orange growth, which later becomes deeper and shows 
“various shades, from orange to a brilliant red, 
Milk, no effect for 10 days, except a slight pink scum around edge and a 
pink tinge to milk. Then it curdles into a soft curd, which later digests into 
an orange colored liquid. Is alkaline. 
