r of inflammatory udder troubles known as garget
or mammitis. In most of these, the physical appearance of the milk is so
changed, and often pus is present to such a degree as to give a very
disagreeable appearance to the milk. Pus-forming bacteria (staphylococci
and streptococci) are to be found associated with such troubles. A
number of cases of gastric and intestinal catarrh have been reported as
caused by such milks.[103]

DISEASES TRANSMISSIBLE TO MAN THROUGH INFECTION OF MILK AFTER
WITHDRAWAL.

Milk is so well adapted to the development of bacteria in general, that
it is not surprising to find it a suitable medium for the growth of many
pathogenic species even at ordinary temperatures. Not infrequently,
disease-producing bacteria are able to grow in raw milk in competition
with the normal milk bacteria, so that even a slight contamination may
suffice to produce infection.

The diseases that are most frequently disseminated in this way are
typhoid fever, diphtheria, scarlet fever and cholera, together with the
various illy-defined intestinal troubles of a toxic character that occur
in children, especially under the name of cholera infantum, summer
complaint, etc.

Diseases of this class are not derived directly from animals because
cattle are not susceptible to the same.

~Modes of infection.~ In a variety of ways, however, the milk may be
subject to contaminating influences after it is drawn from the animal,
and so give opportunity for the development of disease-producing
bacteria. The more important methods of infection are as follows:

_1. Infection directly from a pre-existing case of disease on premises._
Quite frequently a person in the early stage of a diseased condition may
continue at his usual vocation as helper in the barn or dairy, and so
give opportunity for direct infection to occur. In the so-called cases
of "walking typhoid," this danger is emphasized. It is noteworthy in
typhoid fever that the bacilli frequently persist in the urine and in
diphtheria they often remain in the throat until after convalescence. In
some cases infection has been traced to storage of the milk in rooms in
the house where it became polluted directly by the emanations of the
patient.[104] Among the dwellings of the lower classes where a single
room has to be used in common this source of infection has been most
frequently observed.

_2. Infection through the medium of another person._ Not infrequently
another ind