of the foot. Here the plantar aponeurosis,
the navicular bursa, the navicular bone itself, or the pedal articulation
may be injured.

Anterior to this position the most serious mischief that can ordinarily
result is stabbing of the os pedis.

Posterior to the position we have named, the only structure to be injured
is the plantar cushion.

Anatomically, then, the inferior surface of the foot may be divided into
three zones, as follows:

_A. Anterior_, extending from the toe to the point of the frog.

_B. Middle_, extending from the point of the frog to the commencement of
its median lacuna.

_C. Posterior_, including everything posterior to the middle zone.

This division of the inferior surface of the foot into zones will be
somewhat of a guide also when describing the complications next to follow:

_(a) Suppuration_.--This is the common complication of most wounds of the
foot. When detected, it calls for immediate surgical interference in the
shape of removal of the horn of the sole or the frog, as the case may be.
This we shall consider further under the treatment.

_(b) Separation of the Horny Frog_.--This is a sequel to pus formation in
the sensitive structures immediately beneath it, and the condition makes
itself apparent by a line of separation between the horn and the skin of
the heel of the injured side.

_(c) Wounding of the Plantar Aponeurosis_.--This occurs when a
moderately-deep penetration of the horn of the middle zone has taken place.
It is always most painful, especially when complicated by necrosis. The
heel is then persistently elevated, and lameness is extreme, in some cases
so severe as to cause the leg to be carried altogether.

In favourable cases the necrosed piece of tendon is sloughed off by the
process of suppuration, and escapes with the discharges from the wound.
There is then an abatement in the symptoms, and recovery is rapid.

Commonly, however, on account of the non-vascularity of the structure of
the tendon, the necrotic spot in it tends to spread. The wound is thus led
to become fistulous in character, and the pus forming within it prevented
from escaping from the original opening. As a result, lameness and fever
persist. There is a gradual increase in the severity of the symptoms, and
later fistulous openings appear in the hollow of the heel.

_(d) Puncture of the Navicular Bursa_.--This results from a prick in
exactly the same position as that last described, and means