a2 STORRS AGRICULTURAL EXPERIMENT STATION. 
due almost wholly to the growth of lactic bacteria. These 
considerations lead us to believe that the ripening is not 
wholly a factor of acid bacteria, but upon this matter we 
recognize more experimentation is needed. 
GENERAL SUMMARY. 
We may now give a general summary of the conclustons which 
were drawn from the long series of experiments above detailed in 
regard to the actual bacteriological development that occurs during 
the normal ripening of cream. 
I. Milk as itis drawn from the cow contains great quantities 
of bacteria; most of these are miscellaneous forms of liquefying 
bacteria and other non-acid species. At the outset the number of 
acid bacteria ts very small, 
2. All species of bacteria increase during the setting of the 
mulk for the separation of the cream. 
3. fora few hours the alkaline bacteria and the others which 
have here been included under the head of Miscellaneous increase 
guite rapidly, while the lactic bacteria are hardly evident. 
g. After about twelve hours the lactic bacteria have increased 
so much as to be as numerous as the others, and from this time on 
they continue to increase with great rapidity until a maximum ts 
reached at about forty-eight hours, after this the numbers grad- 
wally decrease and they finally practically disappear. 
5. Lhe ripened cream contains prodigious numbers of bacteria, 
larger numbers than are known in any other natural medium. 
They are, however, nearly all lactic bacteria. 
6. After the first twelve hours all species of bacteria except 
the two lactic species decrease in relative numbers and finally ab- 
solutely disappear. 
7. Lhe two common species, Nos. 206 and 202, increase regu-— 
larly from the beginning of an experiment until the maximum. 
No. 208 ts always present in considerable quantity and during 
the ripening increases in numbers though not increasing in pro- 
portion. 
8. TLhecream which ts received by a creamery ts already partly 
ripened, as indicated by the tmmense numbers of bacteria tt con- 
tains. All of the changes which occur in the cream under the 
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