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CLASSIFICATION OF DAIRY BACTERIA. I19g 
Milk.—Rendered alkaline. Sometimes there is a curdling and sometimes 
not, but the milk always digests. 
Potato.—Luxuriant, yellow to lemon-yellow, with a discolored potato. 
Grows best at 20°; slightly at 37°. Aerobic. 
This was very abundant in a Camembert cheese sent us from France. It 
differs only slightly from the last described type, being intensely alkaline on 
litmus gelatine, and having a very luxuriant potato growth. The two are 
closely allied and are perhaps the same. 
M. lactis minutissimus. A minute, liquefying Coccus. Has been found but 
once, from milk in Middletown. 
Morphology.—Size, .2u-.34. Gram stain negative. 
Gelatine colony.—Round, thin, smooth, in a clear, liquefying pit. Liquefac- 
tion slow. 
Gelatine stab,—An infundibuliform liquefaction, with a granular layer on the 
surface, or sometimes only a deep, dry pit. 
Agar streak.—Scanty, thin, smooth, yellow to lemon yellow. 
Fermentation tubes.—Lactose is acid; the other sugars are not acid, and no 
gas nor closed arm growth is produced. 
Boutlion.—A sediment and turbidity, but no ote 
Milk.-—No change in the reaction, but the milk is promptly curdled and then 
digested, with a prominent odor. 
Potato.—A white, dry, wrinkled, luxuriant growth. 
Grows best at 20°; slightly at 37°. Aerobic. 
M. lactis aureus An. s. A yellowish, liquefying Micrococcus, This organ- 
ism is very much like J. Jactis varians, and may be the same. (See p. 121.) 
. The only essential difference is the lack of acid production, and on this ground 
we separate them, although we regard them as allies, or identical. This type is 
comparatively rare, while the varians type is very abundant. Certain varia- 
tions from the described type are found in other cultures, and are indicated in 
brackets. 
Morphology.—Size, .8u-14. Gram stain positive. 
Gelatine colony.—A V-shaped colony is formed in a pit suLrounded by a halo. 
It is irregular, globate or entire; later it liquefies. 
Gelatine stab,—A stratiform liquefaction, with a yellow sediment. Liquefac- 
tion begins on the second day and is complete in fourteen days. 
Agar streak,—A luxuriant, brownish-yellow growth. [White with yellowish 
tinge. | . 
Fermentation tubes.—No acidity nor vas is produced. 
Bouillon.—A pellicle and turbidity, with no sediment. [Sediment and no 
pellicle. | 
Milk.—Alkaline and curdled; the milk subsequently digested into a clear 
liquid, with a half inch of sediment. [No digestion. ] 
Potato.—A luxuriant, brownish-yellow growth. 
Grows at both 20° and 37°. Aerobic. 
Two types of yellow cocci, unnamed, described by Freudenreich, belong here. 
