of the inner face is the _Cutigeral Groove_. This cavity has been mentioned
before as accommodating the coronary cushion, whose shape and general
contour it closely follows, being widest and deepest in front, and
gradually decreasing as it proceeds backwards. It is hollowed out at the
expense of the wall, and shows on its surface numberless minute openings
which receive the papillæ of the coronary cushion.

At the bottom of the internal face, at the point where the toe joins the
sole, will be noted the before-mentioned inverted V-shaped prominence.
Its position will be clearly understood when we say that it gives the
appearance of having been forced there by the pressure of the toe-clip of
the shoe. This will be noted again when dealing with the sole.

_The Inferior Border_ of the wall offers little to note. It is that portion
in contact with the ground, and subject to wear. A point of interest is its
union with the sole. This will be noticed in a foot which has just been
pared as a narrow white or faint yellow line on the inner or concave face
of the wall at its lower portion. It marks the point where the horny leaves
of the wall terminate and become locked with corresponding leaves of the
circumference of the sole.

_The Superior Border_ follows closely the line marked by the perioplic ring
and the groove separating the latter from the coronary cushion.

_The Extremities_ of the wall are formed by the abruptly reflected portions
of the wall at the heels. Termed by some the 'Inflexural Nodes,' they are
better known to us as the '_Points of the Heels_.'

2. THE SOLE.--The sole is a thick plate of horn which, in conjunction
with the bars and the frog, forms the floor of the foot. In shape it is