, the outer quarter
more curved than the inner, and the outer half of the sole wider than
the inner. The weight falls largely into the inner half of the hoof. In
motion the hoof is moved in a circle. From its position on the ground it
breaks over the inner toe, is carried forward and inward close to the
supporting leg, thence forward and outward to the ground, which the hoof
meets first with the outer toe. Horses that are toe-wide
("splay-footed"--toes turned outward) show all these peculiarities of
hoof-form and hoof-flight to a still more marked degree and are
therefore more prone to "interfere" when in motion.

_A hoof of the base-narrow position_ is awry, but not to so marked a
degree as the base-wide hoof. The inner wall is usually a little more
slanting than the outer, the inner half of the sole wider than the
outer, and the inner quarter more curved than the outer. The outer
quarter is often flattened and drawn in at the bottom. The weight falls
largely into the outer half of the hoof. In motion the hoof breaks over
the outer toe, is carried forward and outward at some distance from the
supporting leg, thence forward and inward to the ground, which it
generally meets with the outer toe. The foot thus moves in a circle,
whose convexity is outward, a manner of flight called "paddling." A
base-narrow horse, whose toes point straight ahead, frequently
"interferes," while a toe-narrow (pigeon-toed) animal seldom does.

_A regular hoof_ (fig. 5b), viewed from one side, has a straight
foot-axis inclined to the horizon at an angle of 45 deg. to 50 deg.. The weight
falls near the center of the foot and there is moderate expansion of the
quarters.

_An acute-angled hoof_ (fig. 5a) has a straight foot-axis inclined at
an angle less than 45 deg. to the horizon. The weight falls more largely in
the back half of the hoof and there is greater length of hoof in contact
with the ground and greater expansion of the heels than in the regular
hoof.

_Upright or stumpy hoof._--In the upright or stumpy hoof (fig. 5c) the
foot-axis is straight and more than 55 deg. steep. The hoof is relatively
short from toe to heel, the weight falls farther forward, and there is
less expansion of the heels than in the regular hoof.

_Wide and narrow hoofs._--Finally, there are wide hoofs and narrow
hoofs, dependent solely upon race and breeding. The wide hoof is almost
circular on the ground surface, the sole but little concave, the frog
large,