CLASSIFICATION OF DAIRY BACTERIA. 173 
Bouillon.—A sediment, turbidity, and pellicle. 
Milk,—Rendered alkaline, curdled and digested at both 20° and 37° 
Potato.—A spreading, raised, gray, dry, or moist, luxuriant, wrinkled growth. 
Some cultures are yellowish and thin. 
Grows well at 20° and 37°. Aerobic. 
Variety A.—Differs in the following points from the type. Size, 2.5ux .5u. 
Gram stain negative; colony with a radiate pit which is later gyrose; agar 
streak shows no wrinkling; potato discolored, a bluish-black. 
Variety B.—Size, 3.54x.9u. Gram is negative; liquefaction is so slow that 
it hardly occurs on gelatine plate, the colony being round, smooth, raised, en- 
tire, translucent, yellowish; a slow infundibuliform liquefaction; acid is produced 
in dextrose and saccharose, and a closed arm growth in lactose and saccharose; 
on potato the growth is yellow. 
Here belong several of the forms of 7ythothrix of Duclaux, (turgidus, fili- 
formis, urophalum, ) and also B. Bernensis, found in Emmenthaller cheese. 
At this place should be included 7. vergwla of Duclaux, found in cheese, 
and B. mesentericus of Fliigge, neither of which is sufficiently described to be 
clearly identified, as equivalent to any of the organisms which we have already 
described. 
B. lactis Cromwelhii n. ». Producing a slimy jelly on potato. This has been 
found but once, but its peculiar potato growth demands special recognition. 
Morphology.—Size, 1u-.6u. Forming chains. Spores are developed and also 
acapsule. Flagella not definitely made out but probably peritrichic. 
Gelatine colony.— An opaque colony, in a pit, at first somewhat lobate and 
then breaking into opaque granules as the liquefaction increases. 
Gelatine stab,—At first a-dry crateriform pit, with later a liquefaction and a 
scum, 
Agar streak.—Luxuriant, opaque, white, with a thin edge; the whole subse- 
quently becoming yellow. 
Bouillon.—A sediment, turbidity, and a pellicle, with a tinge of reddish or 
brown color. : 
Milk.—Rendered alkaline, curdled, and digested at both 20° and 37°; may 
digest without curdling. The milk becomes nearly transparent in 12 days. A 
yellow scum sometimes forms, but soon sinks to the bottom. 
Potato.—A moist, slimy, jelly develops all over the potato, extremely profuse. 
White or yellowish-brown color. 
Grows at both 20° and 37°. Aerobic. 
B. janthinus (Zopt.), violaceus (Macé), A violet bacillus. We have never 
found this, but it is said to occur in milk occasionally. Its description is not 
complete, as follows: 
Morphology.—Size, 2M-5&X .4u-.5h. It forms chains and spores and stains 
by the Gram method. Flagella not described. 
