14 
The Colorado Experiment Station 
7. Plain Milk. 
No visible change takes place in the milk in 30 days; there is 
no peptonization, no coagulation; the reaction becomes 
neutral to phenolphthalein after 40 days. Reaction after 1 
day, +12, after 2 days, +10, after 4 days, +8, after 10 
days, +5, after 20 days, +2. The medium is unchanged 
in color; there is no curd formation and no peptonization 
at the expiration of 30 days. 
8. Litmus Milk. 
No change observed until the sixth day when the litmus appears 
somewhat lighter in color; by the seventh day it becomes 
bluer and by the fourteenth day it is intense blue. At the 
end of twenty days, it has the same deep blue color; there 
is no curd formation and no peptonization at the expiration 
of 30 days. There is no reduction of the litmus at any time. 
9. Gelatin Colonies. Eight days old. 
GROWTH, slow, 20° C. 
FORM, round. 
ELEVATION, slightly convex. 
EDGE, undulating. 
LIQUEFACTION, none after twenty days. 
10. Agar Colonies. Five days old. 
GROWTH, slow at 2 5° C. Fine white colonies visible to the 
eye after 4 8 hours. 
FORM, round. 
SURFACE, smooth, glistening, concentrically ringed. 
ELEVATION, convex. 
EDGE, entire to undulate; flattened sides. 
INTERNAL STRUCTURE, more coarsely granular and denser at 
the center becoming more finely granular and less dense at 
the margin. 
CHROMOGENESIS, grayish white, Engine Color No. 12. 
SIZE, medium, average 1.5 m.m. 
11. Glycerine Agar. Agar stroke. 
GROWTH, at 27°-28° C., slight in 24 hours; moderate in 4S 
hours. 
FORM OF GROWTH, filiform becoming more or less papillate 
with age. 
ELEVATION OF GROWTH, slightly convex. 
LUSTER, glistening. 
TOPOGRAPHY, smooth. 
OPTICAL CHARACTERS, translucent. 
CHROMOGENESIS, grayish white, Engine Color No. 12. 
ODOR, none. 
CONSISTENCY, butyrous. 
MEDIUM, very light fluorescent green on the third day; not as 
deep a green as nutrient agar. 
12. Alfalfa Agar. Agar stroke. 
GROWTH, slight growth in water of condensation at base of 
stroke atfer 5 days; slight along line of inoculation in 12 
days. 
FORM OF GROWTH, filiform. 
ELEVATION OF GROWTH, slightly convex. 
LUSTER, glistening. 
TOPOGRAPHY, smooth. 
OPTICAL CHARACTERS, nearly opaque. 
CHROMOGENESIS, Green Yellow Tint No. 2. Growth studded 
with fine black particles as if sprinkled with pepper. 
