

CLASSIFICATION OF DAIRY BACTERIA. 169 
Morphology.—A peritrichic rod. Size, IM-I.5u x .7u-.8u. It forms chains 
but no spores nor capsules, and does not accept Gram stain. 
Gelatine colony.—Round to oval, brown or yellow colonies, with a central 
colony in a liquid pit. The colony is opaque and granular, 4 mm, in diameter 
in 48 hours, and liquefies at the edge; with a cheesy smell. 
Gelatine stab.—A needle growth and a shallow liquefying pit, with no color. 
It then becomes infundibuliform, but no red pigment develops. 
Agar streak.—A luxuriant, opaque growth, with a central wine-red streak, 
and a colorless peripheral zone. Condensation water, dark colored. 
Fermentation tubes.—Not given, but probably produces acid and gas. 
Bouillon.—A sediment and turbidity. There is no pellicle, but there is a 
rose-red color near the surface. 
Milk.—Made acid, and curdled with a cheesy smell and a rose-red color. It 
is subsequently digested into a yellow liquid with a cheesy smell. 
Potato.—A luxuriant, carmine red growth, the pigment appearing at 37° as 
well as at 20°. 
Grows at 20° and 37°, but the color is not so well developed at the higher 
temperature. , 
B. lactis citronus n. s. A lemon-yellow, peritrichic bacillus. This we have 
found but once, in milk fresh from the udder. 
Morphology.—Peritrichic bacillus. Size, 1.5ux.8u. It forms no spores, 
accepts the Gram stain and has evident capsules. No chains are formed. 
Gelatine colony.—A round, convex, smooth, homogeneous, entire, white 
colony, which at liquefaction shows radiation. 
Gelatine stab.—Liquefies, infundibuliform. 
Agar streak.—Filiform, flat, smooth colony, lemon-yellow color, luxuriant. 
Fermentation tubes.—Lactose is rendered acid, but the other sugars are not 
acid. Growth in the closed arm shows in all cases, and no gas is produced. 
Boutllon.—A sediment and an abundant turbidity, but no pellicle. 
Milk.—Becomes acid and-is curdled at both 20° and a7 «Lhe milk 1s) sub- 
sequently digested with an odor, but no color. 
Potato,—Spreads over the potato, thin, lemon-yellow, luxuriant. 
Grows both at 20° and 37°. Facultative anaerobic. 
B. lactis Harrisonii n. s. A slimy milk, yellow bacillus, Isolated by Har- 
rison and described by him. (Rev. gen. d’Lait, 1906). I have ventured to 
name it after him. 
Morphology.—Somewhat irregular. Size, .25u-.75¢ x .3u-34. No chains 
nor spores, and no capsules. It stains by the Gram method. 
Gelatine colony.—Irregular, lobulate, slimy, becoming umbonate. Sinks in a 
pit 3-7 mm. in diameter, from which the whole colony can be removed by a 
needle. 
