t column passing downward and forward from the fetlock
joint to the ground. A small accessory bone, the navicular, or
"shuttle," bone, lies crosswise in the foot between the wings of the
coffin bone and forms a part of the joint surface of the latter. The
short pastern projects about 1-/2 inches above the hoof and extends
about an equal distance to it. (See also page 395.)

The pastern and the coffin bone are held together by strong fibrous
cords passing between each two bones and placed at the sides so as not
to interfere with the forward and backward movement of the bones. The
joints are therefore hinge joints, though imperfect, because, while the
chief movements are those of extension and flexion in a single plane,
some slight rotation and lateral movements are possible.

The bones are still further bound together and supported by three long
fibrous cords, or tendons. One, the extensor tendon of the toe, passes
down the front of the pasterns and attaches to the coffin bone just
below the edge of the hair; when pulled upon by its muscle this tendon
draws the toe forward and enables the horse to place the hoof flat upon
the ground. The other two tendons are placed behind the pasterns and are
called flexors, because they flex, or bend, the pasterns and coffin bone
backward. One of the tendons is attached to the upper end of the short
pastern, while the other passes down between the heels, glides over the
under surface of the navicular bone, and attaches itself to the under
surface of the coffin bone. These two tendons not only flex, or fold up,
the foot as the latter leaves the ground during motion, but at rest
assist the suspensory ligament in supporting the fetlock joint.

The foot-axis is an imaginary line passing from the fetlock joint
through the long axes of the two pasterns and coffin bone. This
imaginary line, which shows the direction of the pasterns and coffin
bone, should always be straight--that is, never broken, either forward
or backward when viewed from the side, or inward or outward when
observed from in front. Viewed from one side, the long axis of the long
pastern, when prolonged to the ground, should be parallel to the line of
the toe. Viewed from in front, the long axis of the long pastern, when
prolonged to the ground, should cut the hoof exactly at the middle of
the toe.

Raising the heel or shortening the toe not only tilts the coffin bone
forward and makes the hoof stand steeper at the toe, bu