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CLASSIFICATION OF DAIRY BACTERIA. 165 
Grows both at 20° and at 37°, but better at 37°. Aerobic. 
One culture of this organism which we have found, spread over the surface of 
a gelatine stab as a thick felt, but on potato it produced no growth. The 
characteristic rhizoid colony, however, leads us to place it here. 
B. lactis Colchesteriin. s. A yellow, rhizoid, peritrichic bacillus. 
Morphology.—Size, 1v-.2ux.74-.9u, forming short chains. It accepts the 
Gram stain, and has an evident capsule, but produces no spores. 
Gelatine colony.—A rhizoid colony is produced that looks exactly like a mold. 
- Gelatine stab.—There is a needle growth and a surface growth. 
Agar streak.—Mold-like colonies are formed which extend under the surface 
of the agar. The growth is luxuriant and of a yellow color. Frequently with 
an iridescence. 
fermentation tubes.—No acidity, gas, nor growth in closed arm in any sugar 
bouillon. 
Bourlion.—An abundant sediment, a slight turbidity, but no pellicle. 
Milk.—No action on milk. — 
Potato.—A thin, yellow growth, not widely spreading. 
‘ Grows at both 20° and 37°. Aerobic. 
Only a single culture of this organism has been found in milk, from Col- 
chester, Conn. It is readily distinguished from other bacilli by its mold-lke 
colony, and its yellow color. : 
B. lactis nebulusn.s. A smoky bacillus. 
; M orphology.—A very small rod. Size, .8ux .3u4. It forms chains, is actively 
motile, produces no spores, and does not accept Gram stain. 
Gelatine colony.—A thick, contoured;smooth colony of a yellow color. On 
Litmus gelatine a plain white colony is formed, not characteristic. 
_ Gelatine stab.—An abundant needle growth and a transparent surface 
growth. . 
Agar streak.—A luxuriant, rather thick, smooth growth, opaque, white. The 
agar shows a smoky fluorescence. 
fermentation tubes.—Neither acidity, gas, nor growth in closed arm in any 
sugar bouillon. 
Bouillon.—An abundant, amorphous sediment, and a slight turbidity, with a 
pellicle on the surface. 
Milk.—No action. 
Potato.—A thin, scanty, white growth. 
~ Grows better at 20° than at 37°. Aerobic. 
Two cultures have been found which we have carefully studied and regarded 
as probably the same. One of them was isolated in 1895 and the other in 1903: 
The former did not produce the smoky fluorescence in agar, nor did it produce 
a pellicle on bouillon. In other respects they were the same. 
