182 STORRS AGRICULTURAL EXPERIMENT STATION. 
Morphology.—Size, 1.8u-34x.7¢-.9#. No chains, no spores, no capsules. 
Gram stain positive. [Negative.] 
Gelatine colony.—A curiously’ lobed colony, cochleate, rather slowly liquefying. 
Litmus gelatine is not acid. The colony is quite characteristic. [A simple 
lobed, slowly liquefying colony, not cochleate. ] 
Gelatine stab.—Begins to liquefy in three days, stratiform. 
Agar streak.—Linear or spreading, thin, moist, opaque, white or gray, not 
luxuriant. [Yellowish, luxuriant. ] 
Fermentation tubes.—Dextrose and saccharose acid, lactose not acid. No gas 
nor closed arm growth. 
Bouillon.—Sediment and turbidity, but no pellicle. 
Milk.—Made alkaline and curdled at 37°. Subsequently digested, with a 
prominent odor. 
Potato.—Very scanty, white. [Luxuriant, gray-white, with potato dis- 
colored. | 
Grows better at 37° than at 20°. Aerobic.- 
B. lactis Robertiin.s. A non-gas-producing, acid-forming peritrich. Found 
only once. 
Morphology.—Size, 1.54x.5u-.84. No chains, no spores, no capsule, and 
Gram stain negative. 
Gelatine colony.—A dense, white colony, very slowly liquefying, Is not acid 
on itmus gelatine, but forms a pit colony. 
Gelatine stab.— A slow liquefier, stratiform, with a clouded liquid. 
Agar streak.—Filiform, thin or thick, smooth, contoured, white, luxuriant. 
Fermentation tubes,—Dextrose rendered acid, but no other change in any of 
the sugar bouillons. 
Bouillon.—A flocculent sediment, a turbidity, and a ring formed pellicle. 
Mitk,—Acid and curdled, but without digestion. The milk develops an odor. 
Potato.—A luxuriant, thick, moist, white growth. Potato may be discolored. 
Grows at 20° and 37°; better at 20°. Aerobic. 
ACID GAS PRODUCERS. 
The gas-producing Bacteria and Bacilii constitute, with the exception of the 
Bact. lactis acidi group, the most important dairy organisms. To this group 
belong many of the most mischievous dairy bacteria, Among them are those 
that spoil large quantities of cheese by the production of the trouble known as 
swelling. Sometimes great quantities of cheese are utterly ruined by the devel- 
opment of gas bubbles. The gas bacteria, also, sometimes spoil butter, and 
‘they are generally undesirable. Whereas the non-acid-producing bacteria are 
commonly the dairyman’s friends, at least so far as relates to butter and cheese 
making, the gas-producing bacteria are universally his enemies. In their rela- 
tion to milk problems they thus form a group by themselves. In their sys- 
tematic relations they belong to different divisions; some of them are Bacteria, 
