ia and it is claimed by Fokker[19] that this same property was
found in freshly drawn milk. This peculiarity has also been investigated
by Freudenreich,[20] and Hunziker[21] who find a similar property.

No material increase in germ content takes place in milk for several
hours when chilled to 40 deg.-70 deg. F.; on the other hand an actual,
but usually not a marked decrease is observed for about 6 hours. This
phenomenon varies with the milk of different cows. Nothing is known as
to the cause of this apparent germicidal action. The question is yet by
no means satisfactorily settled, although the facts on which the
hypothesis is based are not in controversy. If such a peculiarity
belongs to milk, it is not at all improbable that it may serve to keep
down the germ content in the udder. Freudenreich[22] found that udders
which were not examined for some time after death showed abundant
growth, which fact he attributed to the loss of this germicidal
property.

The infection of the whole milk can be materially reduced by rejecting
the fore milk, but it is questionable whether such rejection is worth
while, except in the case of "sanitary" dairies where milk is produced
with as low a germ content as possible. The intrinsic loss in butter fat
in the fore milk is inconsiderable as the first few streams contain only
about one-fifth the normal fat content.

~Infection of milk after withdrawal from animal.~ The germ content of the
milk, when it is being drawn from the animal is immediately increased
upon contact with the atmosphere. These organisms are derived from the
surrounding air and the utensils in which the milk is received and
stored. The number of organisms which find their way into the milk
depends largely upon the character of the surroundings. Bacteria are so
intimately associated with dirt, dust and filth of all kinds that
wherever the latter are found, the former are sure to be present in
abundance.

The most important factors in the infection of the milk after withdrawal
are the pollution which is directly traceable to the animal herself and
the condition of the milk utensils. Fortunately both of these sources of
contamination are capable of being greatly minimized by more careful
methods of handling.

~Infection directly from the cow.~ It is a popular belief that the
organisms found in milk are derived from the feed and water which the
cow consumes, the same passing directly from the intestinal tract to the
m