right and left ureters. These canals terminate in the bladder, an
oval-shaped reservoir for the urine. This organ is situated in the
posterior portion of the abdominal cavity and at the entrance to the pelvic
cavity. Posteriorly, it forms a constricted portion or neck. It is here
that the urethra originates. This canal represents the last division of the
excretory apparatus. In the female, the urethra is short and terminates in
the vulva. In the male it is long and is supported by the penis.

The urine secreted by the kidneys is a body excretion, and consists of
water, organic matter and salts. The nitrogenous end-products, aromatic
compounds, coloring matter, and mucin form the organic matter. The
nitrogenous end-products and aromatic compounds are urea, uric and hippuric
acids, benzoic acid and ethereal sulfates of phenol and cresol. The salts
are sulfates, phosphates and chlorides of sodium, potassium, calcium and
magnesium. The organic and inorganic matter varies with the ration.

The quantity of urine secreted within a given time varies in the different
species and at different times in the same individual. In the horse the
quantity secreted in twenty-four hours varies from twelve to fifteen pints;
in cattle from ten to forty pints; in sheep from one-half to one and
three-quarter pints. The normal color of the urine varies. In the horse it
is yellow or yellowish-red; in cattle and sheep yellowish; and in the dog a
straw yellow. The specific gravity varies with the quantity secreted and
the ration fed. When the quantity of urine secreted is above the average,
the specific gravity is usually low.

THE NECESSITY OF EXAMINING THE URINE.--In diseases of the urinary
apparatus, a careful examination of the urine is very necessary in order to
be able to form a correct diagnosis. In domestic animals it is impractical
to attempt to determine the exact amount of urine passed within a certain