58 STORRS AGRICULTURAL EXPERIMENT STATION, 
Relation to atr. 

Will not grow under mica plate. 
Grows best at about 20-23° C.; at 35°, scarcely any growth;* 
killed by temperature of 60° C. to 10 minutes. 

Temperature. 
Colony on Gelatine.—A smooth, round colony under surface. On surface a 
small, grey, raised bead-like colony, spreading somewhat, reaching size of I mm. 
occasionally. Not characteristic. 
Gelatine Stab Culture.—Slight needle growth. Spreads over surface as a 
moist, white, thick mound, forming a nail growth. Does not liquefy. 
A gar-Agar.—An abundant, white, smooth, glistening layer. 
Potato.—Raised, thick, whitish or slightly yellow-tinged layer. Differing in 
color with amount of moisture. When very moist, is white, but when dry tends 
to a yellowish tinge. Grows profusely. 
Milk, 
becomes slightly translucent and brownish. The reaction is slightly acid. 
After three to four weeks it seems to digest into a translucent mass. It acquires 

Does not curdle either at 20° or 35°. After two to three weeks 
a pleasant aroma. é 
Bouillon.—Very cloudy with heavy scum. After five days scum sinks and 
forms a sediment. Liquid remains cloudy after a month’s growth. 
From the above description it will be noticed that the organism, 
while forming an acid in its growth in milk, is not to be regarded 
as one of the milk-souring organisms. Milk under its influence 
becomes acid, but the acid production is quite slight and the 
milk, under no condition, becomes curdled. .Even when growing 
at a warm temperature the milk remains limpid for weeks, finally 
becoming somewhat brownish. After cultivation of the organism 
for a year or more in the laboratory, its acid-producing powers 
seem to be somewhat greater than at first. | 
This organism has proved the best of all of the many species 
of bacteria thus far studied in its effect upon cream in ripening. 
Preliminary experiments with the organism have already been 
described, and by reference. to Bulletin 12 of this Station it 
will be seen that those experiments, both in the laboratory with 
small lots of butter and in a neighboring creamery, gave promise 
of the possibility of the production of an excellent butter. The 
further continuation of those experiments from the time of the 
publication of Bulletin 12 will be now described. 
METHOD OF EXPERIMENT. iy 
'It may be well first to explain the method of experiment which 
has been found after considerable trial to be, all things con- 
sidered, the most satisfactory. Thus far the organism has been 

* After a year’s cultivation it failed to grow at 35°, although would do so feebly when first 
studied. 


