170 STORRS AGRICULTURAL EXPERIMENT STATION. 
Gelatine stab.—Outgrowths from the needle track. In two weeks it sinks 
into a pit 4 mm. deep, and there is no further change. 
Agar streak,—Luxuriant, viscous and dull, at first shiny, later dry; citron 
yellow; spreading. 
Fermentation tubes.—Not described, but apparently no acid and no gas. 
Bouillon,—A turbidity, sediment, and*a ring pellicle. 
Milk.—Rendered alkaline, but neither curdled nor digested. It is turned 
yellow and becomes slimy. 
Potato.—A luxuriant growth, spreading and intensely yellow. 
Grows at 20° and at 37°. Aerobic. 
B. lactis fluorescens IV. n.s. A fluorescent, liquefying bacillus. 
Morphology.—Size, 2.5¢-3.34 X .gu-1.5m@. Forming chains. It produces 
central spores, accepts the Gram stain, and shows an evident capsule. 
Gelatine colony.—A granular colony with a central nucleus, liquefying almost 
immediately. 
Gelatine stab.—Liquefying rapidly, infundibuliform. 
Agar streak.—Filiform, flat, contoured, opaque, yellowish, moist, and later, 
wrinkled. The agar shows a yellow-green fluorescence. 
Fermentation tubes.—All three tubes show growth in closed arm; dextrose 
alone being acid. No gas produced. 
Bouillon.—A flocculent sediment, turbidity, and pellicle. The liquid is 
yellow at the top. 
Milk.—Rendered alkaline, is curdled at 37°, and is subsequently completely 
digested, both at 20° and 37° _—It becomes yellow to orange in color. 
Potato.—Spreads completely over the potato, rather thin and yellow, luxuriant. 
Grows both at 20° and at 37” _Is facultative aerobic. 
Variety A.—Found in milk in Colchester. Differs from the last in the fol- 
lowing points. Size, 1.54x.6. Gram stain is negative. The flagella are 
extremely long and numerous, and protrude from very thick capsules. Gelatine 
stab shows a greenish growth, which later becomes yellow. Yellow pigment is 
not produced on agar or on potato. There are no wrinkles on agar and no 
growth in the closed arm of fermentation tubes. 
The differences between these two varieties are considerable, and are perhaps 
sufficient to require recognition under separate names. At present, however, 
we leave them together. 
« 
B. lactis niger (Gorini) n. ». A black liguefying bacillus, This organism, 
which was sent us from Geneva by Harding, is almost identical with Ps. lactis 
niger of Gorini. See p. 154. The latter, however, is monotrichic, while this 
is peritrichic. The other differences are very slight. 
Morphology.—Size, 2u-3.54x.g4. Long chains are produced. The organ- 
ism.stains with the Gram method, produces no spores and shows no capsules. 
