CLASSIFICATION OF DAIRY BACTERIA. I61 
Agar streak.—A filiform, flat, smooth growth, of a gray-white color, rather 
scanty. , 
Fermentation tubes.—Dextrose is rendered acid, but there is no acidity on 
other sugar bouillons, and there is never any gas or closed arm growth. 
Bouillon.—A sediment, turbidity and a pellicle. 
Milk,— Rendered alkaline, and is curdled at 37°. There is no digestion, but 
an unpleasant odor, 
Potato.—A scanty, flat growth, moist, smooth, of a brownish color. 
Grows better at 20° than at 37° Aerobic. 
B. lactis Isigniin.s. A brown, fluorescent Lophotrich, Found in Isigny 
cheese, comprising 18% of the bacteria in the centre of the cheese. 
Morphology.—Size, .64 x .ou. A rod, occasionally forming chains. Spores 
are developed, capsules are present, and Gram stain is positive. Usually one 
flagellum is present, though sometimes a tuft is seen at one end. 
Gelatine colony.—An extremely rapid liquefier, without any distinct character- 
istic. 
Gelatine stab.—Begins to liquefy in two days, and is complete in twelve days. 
Sacchate or stratiform. 
Agar streak.—Spreading, thin, smooth, luxuriant, translucent white. At 
37° the agar becomes brownish, and at 20° it becomes at first flesh color and, 
later, brown. : 
Fermentation tubes.—Acidity, gas and closed arm growth in all sugar 
bouillons. 
Bouillon.—A sediment and decided turbidity, but no pellicle. 
Milk.—Rendered acid and curdled at both 20° and 37°, but no subsequent 
digestion noticeable. 
Potato.—A luxuriant, thick, smooth growth, of a yellowish color, and a dis- 
colored potato. . 
Grows at both 20° and 37°. Aerobic. 
Il. Liquefying Lophotrichic Bacilli. 
B, lactis fluorescens In. s. A lophotrich producing a smoky fluorescence and 
a green color, 
Morphology.—Size, 8u-1.6ux .4u-.6p. A lophotrichic rod with two or three 
polar flagella. Nochains. Spores developed in the ends of the rods. Gram 
stain negative, and no capsules. 
Gelatine colony.—A round, gray, smooth, white colony, which liquefies into 
a uniformly granular pit. 
Gelatine stab.—Liquefies rapidly, infundibuliform, with a cloudy liquid, full 
of flakes. 
Agar streak, —Luxuriant, filiform, smooth, raised, gray, moist. The agar is 
smoky. 
