_The functions of the blood_ are to nourish the body tissues; furnish
material for the purpose of the body secretions; supply the cells of the
body with oxygen; convey from the tissues injurious substances produced by
the cellular activity; and destroy organisms that may have entered the body
tissues. The cellular and fluid portions of the blood are not always
destructive to disease-producing organisms. In certain infectious diseases,
the fluid portion of the blood may contain innumerable organisms, and
destruction of the blood cells occurs.

_In inflammation_ of tissue the circulation of the blood in the inflamed
part undergoes certain characteristic changes. At the beginning there is an
increase in the blood going to the part. This is followed by a slowing of
the blood stream in the small vessels, and the collecting of the blood
cells in the capillaries and veins. These circulatory changes are followed
by the migration of the blood cells, and the escape of the fluid portion of
the blood into the surrounding tissue. The character of the above
circulatory changes depends on the extent of the injury to the tissue.

PALPITATION.--This disturbance in domestic animals seems to be purely
functional. It may occur independent of any organic heart disease. A highly
nervous condition, excitement, over-exertion, debility from disease and the
feeding of an improper ration are the common causes.

The heart beats are so violent and tumultuous as to shake the body, and be
noticed when standing near the animal. The heart sounds are louder than
normal and the pulse beats small and irregular. It may be differentiated
from spasm of the diaphragm by determining the relationship of the heart
beats to the abrupt shocks observed in the costal and flank regions.

_The treatment_ consists in keeping the animal quiet and avoiding any