long description of the treatment of the varieties of capped
elbow I have thus far omitted any mention of one method which is
practiced and commended by not a few. I refer to the use of setons,
introduced through the tumor. My own experience and the observation of
many failures from this method led me to abandon it.

CAPPED KNEE.

The passage of the tendons of the extensor muscle of the cannon, as it
glides in front of the knee joint, is assisted by one of the little
bursae before mentioned, and when this becomes the seat of dropsical
collection a hygroma is formed and the knee is "capped." Though in its
history somewhat analogous to the capped elbow, there are points of
difference between them. Their development may prove a source of great
annoyance from the fact of the blemish which they constitute.

_Cause._--The capped knee presents itself under various conditions. It
is sometimes the result of a bruise or contusion, often repeated,
inflicted upon himself by a horse addicted to the habit of pawing while
in the stable and striking the front of the stall with his knees.
Another class of patients is formed of those weak-kneed animals which
are subject to falling and bruising the front of the joint against the
ground, the results not being always of the same character.

_Symptoms._--The lesion may be a simple bruise, or it may be a severe
contusion with swelling, edema, heat, and pain. The joint becomes so
stiff and rigid that it interferes with locomotion and yet under careful
simple treatment the trouble may disappear.

Again, instead of altogether passing off, the edema may diminish in
extent, becoming more defined in form and may remain as a swelling on
the front part of the knee. Resulting from the crushing of small blood
vessels, this is necessarily full of blood. The swelling is somewhat
soft, diffuse, not painful, more or less fluctuating, and after a few
days becomes crepitant under the pressure of the hand.

Instead of being filled with blood the swelling may be full of serum, as
often occurs when violence, though perhaps slight, has been frequently
repeated. In that case the swelling is generally well defined, soft, and
painless, with more or less fluctuation, and it may even become
pendulous. In other cases the swelling may be of an acute, inflammatory
nature, with heat and pain, accompanied with stiffness of the joint.
This leads to the formation of an abscess. Whatever the nature of these
swellings