158 STORRS AGRICULTURAL EXPERIMENT STATION. 
Potato.—A luxuriant, spreading, thin, white growth. Potato discolored. 
{Thick.] 
Grows better at 20° than at 37° Facultative anaerobic. 
Ps. lactis varians n.s. An acid-producing, white monotrich, This organ- 
ism, incompletely described in 1899, is now more completely described from 
recently isolated cultures that are probably the same. ‘They are quite common 
_and have been found in abundance in milk that had been preserved for several 
weeks at I°. 
Morphology.—A rod, forming chains; the individual elements Im-1.4u x .8p. 
No spores, no capsules. Gram stain negative. 
Gelatine colony. —A round, flat or umbilicate, smooth, rugose colony, of a 
slight brown, yellow or cream-brown color, producing a slow liquefaction. 
Gelatine stab,—Stratiform or infundibuliform. The liquefaction % slow, and 
one culture produced a dry pit without liquefaction. 
Agar Streak.—Filiform, raised, smooth, opaque, white and moderately 
luxuriant. 
Fermentation tubes.—Usually acid in dextrose but not in other sugar bouillons. 
No gas nor closed arm growth in any bouillon. 
Boutllon.—A sediment, an abundant turbidity, and a membranous pellicle. 
Milk,—Rendered slightly acid and curdled at 20°, but not at 37° No 
visible digestion, but a prominent odor. 
Potato.—Somewhat variable. It may be thin, spreading, smooth and gray- 
brown, or more luxuriant, varying from white to brown. 
Grows better at 20° than at 37°, though there is a slight growth at 37°. 
Aerobic. 7 
Variety A.—One culture of this organism differs from the above description 
in the following points: Size, 1¢x.5. Liquefies rapidly, beginning in one 
day. The colony forms a granular liquefying pit. Saccharose bouillon acid 
and shows growth inclosed arm. Milk rendered alkaline, curdled, and digested. 
A luxuriant, thick growth on potato. 
Here belong, probably, Gorini’s 8. actdificans presamigenes casei and 
Griiber’s Ps. fragagariae //, (Cent. f. Bact. II., XIV., 122), neither of which 
is thoroughly described. Griiber’s organism is not sufficiently described for 
identification. Gorini’s has the following characters: 
B, acidificans presamegemus casei Gorini. (Rev. gen. d’lait, III., 505.) 
Morphology.—Size, 8u-top. x 24 (?) Produces spores and stains by the Gram 
method. Though not distinctly stated, this is probably monotrichic. 
Gelatine colony.—A round, white, filamentous, irregular colony, which lique- 
fies gelatine. 
Agar streak.—A luxuriant, white growth, 
Lrermentation tubes.—Dextrose bouillon is rendered acid and shows closed 
arm growth. 
Bouillon,—A sediment, turbidity, and pellicle are produced. 
