¥ CLASSIFICATION OF DAIRY BACTERIA. 181 
Fermentation tubes.—All three sugars show acidity, gas, and closed arm 
growth. 
Bouillon.—An amorphous sediment, a slight turbidity, and a granular pel- 
licle. 
Miik.—Is rendered acid and curdled, but with no visible signs of digestion. 
It develops a cheesy odor. 
Potato.—The growth is very scanty and white; potato discolored. 
A second culture of the same differed in showing digestion of the milk and a 
more luxuriant growth on potato. 
Grows at both 20° and 37.° Facultative anaerobic. 
Bacillus ( Proteus) vulgaris (Hauser), This is not uncommon in milk. 
The characteristics are as follows: 
Morphology.—Size, 1.2u-4 x .6u. Forming long chains. It shows no spores 
nor capsules, and does not accept Gram stain. 
Gelatine colony.—Very characteristic, showing irregular amoeboid processes, 
the so called ‘‘proteus type’. 
Gelatine stab,— Begins to liquefy in twelve hours, with liquefaction complete 
in a few days. Saccate. 
Agar streak.—Luxuriant, moist, slimy, glistening, translucent. 
Fermentation tubes.—Not determined, but dextrose is doubtless acid and gas 
is produced. 
Milk.—Rendered acid and curdles at 20°. Is subsequently digested, becom- 
ing yellowish. 
Potato,—A luxuriant, yellowish-white and slimy growth. 
B. lactis diffususn.s. A pink Bacillus, 
Morphology.—A motile rod. Size, 14x .64-.gu. No chains. 
Gelatine colony.—Diffuse appearing as a faint cloud made up of microscopic 
colonies. To the naked eye it appears like 4 mold; 3mm. in diameter, then 
liquefying. 
Gelatine stab.—A napiform liquefaction, with a cloudy pink liquid. Below 
the surface it is orange-red. 
Agar streak.—A luxuriant, pink, moist, smooth growth. 
Fermentation tubes.—Probably acid without gas. 
Bouillon.—A sediment and a turbidity but no pellicle. The sediment is red. 
Milk,—Becomes acid and curdles after several days. No other change. 
Potato.—A luxuriant, bright pink growth. No discoloration. 
Grows at 20° and 37°. Aerobic. , 
B. lactis cochleatusn. s. A non-gas-producing, peritrichic bacillus, without 
spores. This has been observed twice. One culture was sent us from Geneva 
by Harding and a second was found in milk in Middletown. The following 
description is from the Geneva culture. The points where our own differ from 
it are indicated by brackets. 
