seased animal to man through the medium of infected
milk.

Class II. Bacteria pathogenic for man but not for cattle which are
capable of thriving in milk after it is drawn from the animal.

In the first group the disease produced by the specific organism must be
common to both cattle and man. The organism must live a parasitic life
in the animal, developing in the udder, and so infect the milk supply.
It may, of course, happen that diseases toward which domestic animals
alone are susceptible may be spread from one animal to another in this
way without affecting human beings.

In the second group, the bacterial species lives a saprophytic
existence, growing in milk, if it happens to find its way therein. In
such cases milk indirectly serves as an agent in the dissemination of
disease, by giving conditions favorable to the growth of the disease
germ.

By far the most important of diseases that may be transmitted directly
from animal to man through a diseased milk supply is tuberculosis, but
in addition to this, foot and mouth disease (aphthous fever in
children), anthrax and acute enteric troubles have also been traced to a
similar source of infection.

The most important specific diseases that have been disseminated through
subsequent pollution of the milk are typhoid fever, diphtheria, scarlet
fever and cholera, but, of course, the possibility exists that any
disease germ capable of living and thriving in milk may be spread in
this way. In addition to these diseases that are caused by the
introduction of specific organisms (the causal organism of scarlet fever
has not yet been definitely determined), there are a large number of
more or less illy-defined troubles of an intestinal character that occur
especially in infants and young children that are undoubtedly
attributable to the activity of microorganisms that gain access to milk
during and subsequent to the milking, and which produce changes in milk
before or after its ingestion that result in the formation of toxic
products.

DISEASES TRANSMISSIBLE FROM ANIMAL TO MAN THROUGH DISEASED MILK.

~Tuberculosis.~ In view of the wide-spread distribution of this disease in
both the human and the bovine race, the relation of the same to milk
supplies is a question of great importance. It is now generally admitted
that the different types of tubercular disease found in different kinds
of animals and man are attributable to the development of the same
organism, _Bacil