he preceding in that all appearance of lung tissue
had disappeared from the diseased mass. Only on the exterior the lung
tissue could be recognized, although even there it had been largely
converted into very dense, whitish connective tissue inclosing the fungoid
growth. In the other case the external form of the lung and the shape and
outline of the lobules were preserved, but the lung tissue itself was not
recognizable as such. In the case first mentioned the changes were still
less marked, and actinomycosis would not have been suspected by a simple
inspection. These few illustrations suffice to show that actinomycosis of
the lungs may appear under quite different forms, and that the nature of
the disease can be accurately determined only by finding the fungus itself.
Rarely actinomycosis attacks the body externally in places other than the
head and neck. Crookshank describes the case of a bull in which the flank
was attacked and subsequently the scrotum became diseased. A large portion
of the skin of the flank was destroyed and covered with a leathery crust.
When this was pulled away the pus beneath it showed the actinomyces grains
to the naked eye.

Actinomycosis may also involve the udder, the spermatic cord of castrated
animals, the vagina, and, when it becomes generalized, the brain, liver,
spleen, and muscular tissue.

Actinomycosis may in some cases be confounded with tuberculosis. The
diagnosis does not offer any difficulties, since the presence of the
actinomyces fungus at once removes any existing doubts. As has already been
intimated, these grains, simulating sulphur balls, are visible to the naked
eye, and their nature is readily determined with the aid of a microscope.

The course of the disease is quite slow. As the tumors grow they may
interfere with the natural functions of the body. According to their
situation, mastication, rumination, or breathing may be interfered with,
and in this way the animal may become emaciated. Actinomycosis of the
jawbones leads to destruction of the teeth and impedes the movements
necessary to chewing the feed. Similarly, when the disease attacks the soft
parts of the head obstructions may arise in the mouth by an inward growth
of the tumor. If tumors exist in the pharynx they may partially obstruct
the movements necessary to breathing, or close the air passages and cause
partial suffocation. Actinomycosis of the tongue, in interfering with the
many and varied movements o