CLASSIFICATION OF DAIRY BACTERIA. r75 
Gelatine colony.—A rapidly liquefying colony, cloudy and sometimes showing 
a nueleus, but not characteristic. 
Gelatine stab.—Begins to liquefy in one day, infundibuliform; complete in 
8 to 10 days. 
Agar streak.—Luxuriant, capitate, smooth or contoured, gray, moist, com- 
monly viscous. 
Fermentation tubes.—Grows in the closed arm; produces gas in dextrose and 
saccharose and in some cases in lactose. No acidity is developed. [One 
culture shows gas in saccharose only. ] 
Bouillon.—A sediment, a strong turbidity, and a ring-formed pellicle. 
Mitk.—Either unchanged in reaction, or rendered slightly alkaline; is curdled 
both at 20° and 37°; is always digested more or less completely and always 
shows the presence of gas bubbles. The odor is variable, in some cases being 
that of decay and in others that of cheese. 
Potato.—Spreading, raised, contoured, gray, moist, luxuriant, with a dis- 
colored potato. 
Grows at 20° and abundantly at 37° +‘ Facultative anaerobic. 
We have isolated this organism from milk from several sources. It is quite 
similar to B. megatherium of Du Bary. 
B. lactis tetragenesn.s. A rhizoid iquefying bacillus.—The original culture 
of this organism was sent me by Weigmann and isolated from cheese. The 
characteristics below were determined by us from Weigmann’s culture. Later 
we found apparently the same organism in milk here. The points where our 
new culture differed from that of Weigmann are indicated in brackets. 
Morphology.—A large rod, not forming chains. Size, 34x .74[2.5ux 1.4m]. 
No spores, no Gram stain, but a capsule is evident. 
Gelatine colony.—A rhizoid or proteus-like colony, of large size, slowly lique- 
fying. It is not acid in “tmus gelatine. 
Gelatine stab.—Begins to liquefy in one day [three days], liquefaction strati- 
form. At first an arborescent needle track. [Not arborescent.] 
Agar streak.—A filiform, flat or raised, smooth, gray growth, moderately 
luxuriant, moist. 
Fermentation tubes.—No action upon any sugar bouillon. 
Bouillon.—A slight turbidity and a tenacious pellicle is formed, but no sedi_ 
ment. [Sediment without pellicle. ] 
Milk.—No change in reaction, or a slight alkalinity. Milk is curdled at the 
bottom, at 37°, and is subsequently slightly digested, with a faint pinkish color. 
[Yellowish.] 
Potato.—A luxuriant, wide spreading, thin, contoured growth, of a gray 
color, with a discolored potato. [Growth is slight. ] 
Grows at 20° and 37° [Growth at 37° slight.] Aerobic. 
“B. lactis distortus nu. s. This resembles 7y. distortus of Duclaux. 
Morphology.—Size, 34x .74. Chains are formed, but no spores or capsules. 
The Gram stain is positive. 
