lexor tendons in company with the external plantar nerve.

_The Interosseous Vein_.--This is an irregular vessel running up between
the suspensory ligament and the posterior face of the large metacarpal
bone.

F. THE NERVES.

THE PLANTAR NERVES.--These are two in number, and are distinguished as
Internal and External.

THE INTERNAL PLANTAR NERVE lies behind and in close contact with the great
metacarpal artery during that vessel's course down the region of the
cannon. A point of interest is that it gives off at about the middle of
the cannon a branch which bends obliquely downwards and behind the flexor
tendons to join its fellow of the opposite side--namely, the external
plantar. This it joins an inch or more above the bottom of the splint bone.
Measured in a straight line, this is about 2-1/2 inches below its point
of origin. Near the fetlock, at the level of the sesamoids, the internal
plantar nerve ends in several digital branches.

THE EXTERNAL PLANTAR NERVE.--This holds a position to the outside of the
metacarpal region, analogous to that of the internal plantar nerve on
the inside of the limb, running down on the external edge of the flexor
tendons. Unlike the internal nerve, it is accompanied by a single vessel
only, the external metacarpal vein, behind which it lies. At the level of
the sesamoid bones it divides, as does the _internal_ nerve, into three
main branches--the digital nerves.

[Illustration: FIG. 15.--THE VEINS AND NERVES OF THE FOOT. 1, The digital
vein; 2, its main tributaries, draining the podophyllous plexus, and
concurring to form the digital; 3. the digital artery (the main trunk only
of this is shown, in order to show its relationship with the vein and
nerve); 4, the plantar nerve, with its three branches--(_a_) the anterior
digital, (_b_) the middle digital, (_c_) the posterior digital; 5, the
podophyllous plexus; 6, superficial portion of the coronary plexus; 7, the
peripheral or circumflex vein of the toe.]

THE DIGITAL NERVES.--These are distinguished as Anterior, Middle, and
Posterior.

_The Anterior Branch_ descends in front of the vein, distributing cutaneous
branches to the front of the digit, and terminating in the coronary
cushion.

_The Middle Branch_ descends between the artery and the vein, and freely
anastomoses with the two other branches. It terminates in the coronary
cushion and the sensitive laminae.

_The Posterior Branch_.--This is the largest of the three, a