osely to its wall. Death is produced usually by
the pressure and interference of the aneurism with adjoining organs or
by rupture. In worm aneurism we usually find large thrombi within the
aneurismal dilatation of the artery, which sometimes plug the whole
vessel or extend into the aorta. Portions of this thrombus, or clot, may
be washed away and produce embolism of a smaller artery. The effect in
either case is to produce anemia of the intestinal canal, serous or
bloody exudation in its walls, which leads to paralysis of the intestine
and resultant colicky symptoms.

_Treatment._--The only treatment advisable is to extirpate or ligate the
tumor above and below.

RUPTURE OF AN ARTERY.

Endarteritis, with its subsequent changes in the walls of arteries, is
the primary cause of rupture in the majority of instances. The rupture
may be partial, involving only one or two coats, and will then form an
aneurism. If complete, it may produce death when it involves a large
vessel, especially if it is situated in one of the large cavities
permitting an excessive escape of blood. Rupture may be produced by
mechanical violence or accident.

_Symptoms._--In fatal rupture, associated with profuse bleeding, the
animal becomes weak, the visible mucous membranes become blanched, the
breathing hurried or gasping, pupils dilated, staggering in gait,
syncope, death. When the hemorrhage is limited the symptoms may not
become noticeable; if it is near the surface of the body a round or
diffuse swelling or tumor may form, constituting a hygroma. If the
rupture is associated with an external wound, the bleeding artery should
be ligated, or where a bandage is applicable, pressure may be applied
by tight bandaging. As a secondary result of rupture of an artery we may
have formation of abscess, gangrene of a part, etc.

_Treatment._--When rupture of a deep-seated artery is suspected, large
doses of fluid extract of ergot may be given to produce contraction of
the blood vessels. Tannin and iron are also useful. The animal should be
allowed to have as much water as he desires. Afterwards stimulants and
nourishing feed are indicated.

THROMBUS AND EMBOLISM.

By thrombosis is generally understood the partial or complete closure of
a vessel by a morbid product developed at the site of the obstruction.
The coagulum, which is usually fibrinous, is known as a thrombus. The
term "embolism" designates an obstruction caused by any body detached
a