CLASSIFICATION OF DAIRY BACTERIA. I3I 
fermentation tubes.—Dextrose acid, lactose and saccharose slightly acid; no 
gas nor closed arm growth. 
Bouillon.—No visible growth. 
Milk.—Very slightly alkaline, no curdling and no digestion. 
Potato.—Spreading, thin, smooth, yellow. 
Grows better at 20° than at 37°. Aerobic. 
This organism was sent me by Gorini from Italy. Another, which seemed 
to be identical, was found in milk here, the only points of difference being a 
luxuriant potato growth and a slight sediment in bouillon. A very similar cul- 
ture was sent by Harding, differing only in having a somewhat dry, wrinkled 
growth on agar. .We regard the three as identical. 
Another culture is very closely related to this, but es in enough par- 
ticulars to lead us to regard it as a separate variety. 
Variety A.—This organism was found here on Camembert cheese and 
another culture was sent us by Gorini. It differs from the above described 
type only in the following points: Size, .gu-1.5#x.5u. Gram stain positive, 
grows well in bouillon, with a sediment. Milk distinctly alkaline. Color of a 
lemon instead of an orange yellow. 
Variety 6.—This organism, sent by Harding, differs from the type in pro- 
ducing a rather more orange color, a turbidity and sediment in bouillon, and in 
making milk distinctly acid, but not curdling it. 
Bact. lactis synxanthum.—A culture of this organism, several years old, was 
sent me by Harrison. It had completely lost its power of producing yellow 
pigment. Below are given its characters as made out by us, and in brackets 
the characters as originally described where they differ from those observed. 
Morphology.—sSize, .8u@-.Qux1.24-24. No spores, no chains. A capsule is 
evident. Gram stain is negative. [Gram stain positive, motile. | 
Gelatine colony.—Round, capitate, smooth, homogeneous, entire, opalescent, 
gray, moist. [Luxuriant, gray, yellow.] On /tmus gelatine transparent, white 
colonies. 
Gelatine stab,—A needle growth and a raised surface growth. 
Agar streak.—Luxuriant, filiform, raised, smooth, opaque, porcelain white. 
Slightly viscous. [A yellow pigment, soluble in water. ] 
Fermentation tubes.—All three bouillons are acid, but there is no gas nor 
closed arm growth. 
Boutllon.—A sediment, slight turbidity, and a ring-formed pellicle. 
Milk.—Becomes acid but does not curdle nor digest. [Alkaline, and digests 
to a bright yellow color. | . 
Potato.—Filiform, raised, contoured, sebaceous, gray, luxuriant; potato 
discolored. 
Grows at both 20° and 37°. Aerobic. 

These organisms show how decidedly characters which are relied upon to dis- 
tinguish types may disappear after long cultivation, and naturally throws doubt 
upon all classifications based upon physiological properties. If an organism 
originally isolated because of its power of producing red pigment lose this power 
absolutely, and if. one which produces a brilliant yellow color loses this property, 
we naturally ask whether any physiological properties are constant. 
