CLASSIFICATION OF DAIRY BACTERIA. 153 
Ps. sapolactica Eichholz, An acid, non-liquefying Pseudomonas (soapy). 
This organism was sent by Weigmann and was stated by him to produce soapy- 
tasting milk. When studied by us this latter character was not apparent. We 
have found an identical organism (not soapy) in New York city milk, and twice 
in Middletown. The Middletown culture was found in great quantities in 
some milk that had been preserved at 1° for several weeks. A very closely 
allied organism was sent us from Geneva by Harding, which we have called 
variety A. 
Morphology.—Size, .8u-1.74 x .74-.84. No chains, no spores, no capsules, 
Gram stain negative. 
Gelatine colony.—A round, raised, smooth, homogeneous, entire colony, of. 
agray color. In itmus gelatine, in some cases, the colony becomes acid. 
Gelatine stab.—A filiform needle growth, and a flat surface. 
Agar streak,—Filiform, thick, smooth, opaque, white, moist, moderately 
luxuriant. 
Fermentation tubes.—Dextrose only is rendered acid. There is no gas or 
closed arm growth in any sugar bouillon, 
Bouillon.—A sediment, decided turbidity, and a ring-like pellicle. 
Milk.—Is rendered alkaline, at least after several days, but there is no other 
change. 
Potato.—A slight growth, linear, thin, contoured, brownish in color, moist. 
Potato not discolored. 
Grows rather better at 37° than at 20°. Aerobic. 
Variety A,—Is acid in all three sugar bouillons, curdles milk and shows no 
potato growth. 
Il. Liquefying. 
Ps. lactis ananan.s, This was originally described in 1899. Several cul- 
tures from milk in Middletown, and New York, and Storrs, have been found 
agreeing with this in all points except in the presence of the banana smell upon 
potato. The following more complete description was from a culture isolated 
more recently from milk in Middletown: 
Morphology.—Size, .8u-1.2p x .5¢. Forms chains, no spores and no capsules. 
Gram stain negative. 
Gelatine colony.—A very rapid liquefier, producing a granular pit; not 
characteristic. 
Gelatine stab,—Liquefes rapidly; either stratiform or infundibuliform. 
Agar streak.—Spreading, flat, smooth, creamish to brown color, rather 
luxuriant, and sometimes slightly viscous. 
Fermentation tubes.—No acidity nor gas in any sugar bouillon. One culture 
showed growth in the closed arm, but the others did not. 
Bouillon.—A granular sediment, and a decided flocculent turbidity, but no 
pellicle. The liquid is sometimes but not always greenish. 
