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2,24                 PA THOGENIC BA CTERIA.

bacilli in the milk of cattle affected with tuberculosis. It
does not seem necessary that tuberculous ulcers shall be
present in the udders; indeed, the bacilli have been
demonstrated in considerable numbers in milk from
udders without tubercular lesions discoverable to the
naked eye.

The meat from tuberculous animals is less dangerous
than the milk, because the meat is nearly always cooked
before being eaten, while the milk is generally taken
uncooked. The bacilli enter the intestinal lymphatics,
sometimes produce lesions immediately beneath the mu-
cous membrane, and lead later on to the formation of
ulcers ; but generally they first involve the mesenteric
lymphatic glands. The thoracic duct is sometimes af-
fected, and from such a lesion it is easy to understand the
development of a general miliary tuberculosis. The oc-
casional absorption of tubercle bacilli by the lacteals, and
their entrance into the'systemic'circulation and subse-
quent deposition in the brain, bones, joints, etc., are sup-
posed to explain primary lesions of these tissues.

Infection is said also to take place occasionally through
the sexual apparatus. In sexual intercourse tubercle
bacilli from tuberculous testicles may be discharged into
the female organs, with resulting tuberculous lesions.
The infection in this way generally is from the male to
the female, primary tuberculosis of the testicle being
much more common than primary tuberculosis of the
uterus or ovaries.

While most probably rare, in comparison with the
preceding, wounds also are avenues of entrance for the
tubercle bacilli. Anatomical tubercles are not uncom-
mon upon the hands of anatomists and pathologists,
most of these growths being tuberculous in character.
An interesting fact concerning these dermal lesions
is the exceedingly small number of bacilli which they

The macroscopic lesions of tuberculosis are too familiar
to require a description of any considerable length. They