
50 «STORRS AGRICULTURAL EXPERIMENT STATION. 
stab, while No. 89 does not, and No. 125 curdles milk more slowly, not curd- 
ling for two weeks, while No. 89 curdles in six days. 
Both have been used for ripening cream, but produce butter with a markedly 
sour taste. 
While this species is very common, it is rarely abundant enough to produce 
much influence upon the milk. It can therefore hardly be regarded as a dis- 
tinctive dairy bacterium. 
No. 208. (Extremely common.) J. lactis aerogenes. (?) 
Probably identical with J. acid: /actict (Grotenfeld) and &. a. and 4. of 
Guilleleau, and Vo. § of Eckels. 
This is one of the most common species found in milk and cream. It is not 
only almost always found, but is also usually very abundant. Sometimes it 
appears to be the cause of the spontaneous souring of milk, since in some 
samples it is the only acid bacillus found. This is unusual, however, for 
though very common, it is usually far outnumbered by No. 206 and No. 202. 
It is also very variable in its physiological characters, as explained on page 24, 
but the many different cultures which I have studied have in general the 
following characters. ~ 
Morphology; size, .74 by 1m, with rounded ends. 
Gelatin plate; deep colonies, opaque and oval. (Litmus gelatin turned very 
red.) Sometimes lobate, as if made up of many colonies. Surface colonies 
may be large (2 mm.), white, opaque beads, which may contain a gas bubble 
(dextrose gelatin). Sometimes they form projecting colonies, growing up from 
the surface of the gelatin to the height of 1.5 mm., though not more than 
-5 mm. in diameter. Sometimes they are like 2. cof colonies, only more 
luxuriant. 
Gelatin stab; abundant needle growth and a thick, white surface growth. 
Agar; white, moist, glistening and semi-transparent. Abundant. 
Potato; a creamy white, abundant, not folded growth. Moist. 
Milk; at 20° rendered strongly acid, but commonly not curdling. Some cul- 
tures do curdle. At 35° curdles milk two to four days into a soft curd. In all 
cases the milk is strongly acéd. There is a typical sour milk odor. 
fermentation tube; grows strongly in closed arm and in bulb, and produces 
é 
much gas, 
This includes Nos. 16, 53, 56, described in previous publications (Storrs 
Expt. Sta. Rep., 1890 and 1894). 
The next two organisms belong to the 7yphosus type (Fuller) which ferment 
milk sugar, but produce no gas. 
No.-107. (Rare.) 
Morphology; size, .6u to .8u by 1.3m. 
Gelatin plate; a thin, transparent, spreading colony, elevated into irregular 
ridges, becoming a centimeter in diameter, or larger. 
_ Gelatin stab; an abundant needle growth, with a thin, transparent, spread- 
ing, irregular surface growth. Hardly visible, 
Agar and potato; not characteristic. 
