CLASSIFICATION OF DAIRY BACTERIA. 123 
We have found this only once. Kriiger apparently found the same in milk 
and butter. His organism differed from ours in digesting milk. The salmon 
color gives it independent rank. 
The white, liquefying, acid-producing cocci form another series of extremely 
common Bacteria, with a long list of variations. As already mentioned, they 
pass, by imperceptible grades, into the yellow acid cocci, and should, perhaps, 
be united with them. These white cocci appear identical in cultural characters 
with Staph. pyogenes albus, a culture of which, when compared side by side, 
showed no essential differences. Staph. mastitis albus of Guillebau seems also 
to be essentially the same, as well as four different varieties of white cocci de- 
scribed by Freudenreich. (A/zlch2tg. 1905, pp. 628 and 643.) These white 
cocci are extremely common in milk, in the udder, in the dust of the stable, 
and have been found in many samples of milk here and elsewhere. Among the 
many variations some are quite striking, and we have, therefore, endeavored to 
separate the various strains studied in groups, as follows: 
M, lactis albidus n. s. 
Morphology.—Micrococci. Size, .6u-1.24. Stains by Gram method. 
Gelatine colony.— An opaque colony, usually white, and soon liquefying. It 
is not characteristic. On Utmus gelatine it is sometimes acid and sometimes 
not acid. 
Gelatine stab,—Liquefies in from one to three days, infundibuliform. Some- 
times a dry pit is formed, which may liquefy after several days. 
Agar streak.—A moderately luxuriant, smooth, white growth; not very thick. 
Fermentation tubes,—All sugars are rendered acid but no gas is formed, and 
there is usually no closed arm growth. (One culture did not produce acid or 
grow in bouillon.) 
Bouillon.—A sediment and turbidity, but no pellicle. 
Milk,—Usually rendered acid, and may or may not curdle. Curdling is 
more common, however, than not curdling. The milk is digested, except in 
those cultures that do not liquefy gelatine. One culture, however, liquefies 
gelatine, but does not curdle milk. 
Potato.—A moderate growth, white to yellow; not characteristic. 
Grows at 20° and 37°. Facultative anaerobic. 
To this type belongs the white cocci of Guillebau and Freudenreich. 
Variety A.—This differs from type Variety A chiefly in producing a snow- 
white growth on agar. Two cultures were studied, one of which produced a 
snow-white colony in gelatine, and the other lacked snow-white color. One of 
the two was snow-white on potato, while the other produced a thin, scanty 
growth. In all other respects they resemble the type. 
Variety B.—This is separated from the others by its more anaerobic charac- 
ter, as shown by growth in the closed arms of the fermentation tubes. The 
colonies on litmus gelatine are acid; the agar growth is scanty, as is also the 
growth on potato. This was foundon Cheddar cheese and Camembert cheese. 
Variety C.—Distinguished from the others chiefly by not making milk acid 
and by not curdling. One culture of this variety renders the milk alkaline, 
