52 STORRS AGRICULTURAL EXPERIMENT STATION. 
From these tables the following significant points are to be 
noted: 
Milk kept at ro°.—1. ‘The development of bacteria did not 
become noticeable for about 80 hours, although there was pre- 
vious to this a slight increase. After this period a more rapid 
development was noticed. The chief growth of bacteria from 
about 60 hours until 120 hours was in the increase of Group 
IV. After 120 hours this group remained practically constant 
in numbers until about 190 hours when there was a noticeable 
decline, both in percentage and in actual numbers, shown best 
in plate II. 
2. The lactic species of Groups I. and II. could not be 
properly differentiated in these plates, and while the tables 
show the separation of the two as well as it could be made, 
they are combined in the percentage numbers and also in Plate 
II. These typical lactic bacteria increased very slowly for 
about 120 hours, after which the increase in the two species 
was much more rapid, and finally the unusual number of 1,600,- 
000,000 per cubic centimeter was found at about the 241st 
hour. In spite of these enormous numbers of lactic bacteria, 
the milk was not curdled at this time nor until the 280th hour, 
at which time the number of lactic bacteria had fallen off nearly 
one-half. The break in the curve at 265 hours (Plate II.) is 
doubtless an error. 
3. Group III., Bactertzum aerogenes, increased with consid- 
erable regularity in this experiment, although there was a 
slight decline at the end, and the percentage never became 
very high. The same was true of the liquefying bacteria. 
4. The milk kept at 10° showed exceptionally high num- 
bers of bacteria, for rarely does the number reach 1,000,000- 
ooo before curdling takes place, and in this case the number 
rose to 1,836,000,000. 
It will be noticed that Group II. appeared only in the later 
analyses and in a few of the first analyses. Whether this is 
due to the fact that this group develops only in old milk, or to 
the fact that it is only a modified form of Group I, we have not 
decided. 
