122 STORRS AGRICULTURAL EXPERIMENT STATION. 
These variations clearly run into AZ. /actis aureus on one hand and &M. éactis 
albidus on the other, so that a sharp separation is impossible. This corre- 
sponds to M/ic. Z. of Barthel and is probably everywhere distributed. 
This organism is‘not only common in this country but it appears to be com- 
mon in Europe as well, several described forms doubtless belonging to the 
type, for example, Stad/-luftbacterium JZ, of Koning and others. Koning’s 
Stall-luftbacterium IZ., which he regards as different, shows such slight varia- 
tions from this that it also comes within the limits that may properly be regarded 
as covered by our MW. lactis varians. 
M. lactis varians A.—Under this head we recognize two cultures derived 
from milk fresh from the udder, agreeing with the type in all points except the 
following: 
Acid is produced in dextrose only. 
Milk is not rendered acid, although it may be curdled and digested. 
We do not think this is sufficiently different to constitute a new type, but 
tabulate it here separately. 
M., lactis giganteusn.s, An extremely large, iquefying Coccus. 
Morphology.—Size, 1.44-3.54. A micrococcus which accepts the Gram stain. 
Its peculiarity is the very large size which the coccus sometimes reaches—3.5u 
in diameter. 
Gelatine colony.—A clear, liquefying pit, which is slightly cloudy and white. 
Litmus gelatine is not acid. 
Gelatine stab.—Begins to liquefy in one day, infundibuliform. 
Agar streak,—A moderately luxuriant, smooth growth, of an orange color. 
Fermentation tubes.—All sugar bouillons are made acid, but there is no gas. 
nor closed arm growth. 
Bouillon.—A sediment, but no turbidity nor pellicle. 
Milk.—Rendered acid and digested into a yellow liquid at both 20° and 37°. 
Potato.—A scanty, beady, brownish growth. 
Grows at both 20° and 37°. Aerobic. 
This agrees with the last in its physiological properties, but the extraordinary 
size of the cells is so peculiar that we have given it independent rank. 
M, lactis rugosus n. >. A salmon-yellow Coccus. Perhaps M. acidi lactici of 
Kriiger. 
Morphology.—Size, 1u¢-1.2u. Gram stain irregular; micrococcus. 
Gelatine colony.— A liquefying pit, with a clear centre and a ring of granular 
matter; white. 
Gelatine stab.—A slow liquefier, crateriform or stratiform. 
Agar streak.—A salmon-yellow growth, luxuriant and viscous, wrinkled, 
with a dull surface and a salmon-yellow color. 
Bouillon.—A sediment, turbidity, and a ring-like pellicle. 
Milk.—Rendered acid and curdled, with an orange color and a sour odor; 
no digestion. 
Grows well at 20° and 37°. Aerobic. 
