CLASSIFICATION OF DAIRY BACTERIA. 133 
Morphology.—Size, 1.84 x 5u4-1.24. Sometimes long chains are formed. 
There are no spores and the Gram stain is irregular, commonly negative, but in 
two cultures was positive. 
Gelatine colony.—Small, round, moderately thick, entire or irregular margin, 
white. Litmus gelatine colony is not acid and sometimes distinctly alkaline. 
Sometimes green. ‘The colonies of different cultures show considerable varia- 
tion which may indicate different varieties. Our data, however, at present do 
not warrant us in separating them. 
Gelatine stab.— A needle growth and a spreading, moderately abundant sur- 
face. 
Agar streak.—Moderate to luxuriant, linear, smooth, white, moist. 
Fermentation tubes.—Dextrose acid, and sometimes lactose and saccharose. 
Bouillon.—A sediment and turbidity, and frequently, though not always, a 
pellicle. 
Milk. — Alkaline, or no change in reaction, no digestion nor other change. 
Potato,—Scanty to luxuriant, white, spreading. One culture was wrinkled. 
Grows at both 20° and 37°, though better at 20°. Aerobic. 
The variations given above are large and we feel that this group should be 
broken up. But the different variations mentioned cross each other so much 
that we have as yet been unable to divide them into any definite varieties. As 
more cultures accumulate and give us more information we believe it will be 
possible to recognize some sharply distinct types, but at present we leave them 
together. The variations which we have found fail to group themselves, and if 
we should try to make varieties we should be obliged to recognize nearly as 
many as we have isolated individual cultures. 
This type of lactic bacteria is very common. It appears constantly in milk in 
this vicinity as well as in New York state, and in cheese. It does not seem to 
be, however, so vigorous as the typical lactic organism, and is apparently not 
the cause of ordinary sour milk. 
_ Bact. lactis ubiquitum. This organism we have not especially studied since 
its description in 1899. We reinsert here the description then given: 
Morphology.—Size, 1.2¢-1.4u x .8u. Long chains are formed; spores are 
developed and also a capsule. 
Gelatine colony.—Round, capitate, smooth, entire, white, the outer edge 
thinner and lighter. 
Gelatine stab.—A needle growth and a rather thick irregular surface growth. 
Agar streak.—A luxuriant, white surface growth, developing irregular frost- 
like or feather outgrowths. Moist, smooth. 
_ Fermentation tubes.—Not determined, but probably acidity is produced, at 
least in dextrose and lactose, and there is no gas. 
Bouillon.—A sediment and turbidity, but no pellicle. 
Milk.—Rendered acid and is curdled after several days. No digestion. 
Potato.—A luxuriant growth, transparent, spreading, white, glistening. 
Grows well at both 20° and 37°. Aerobic. 
