the sole is rare.

Prick sustained at the hands of the smith may, of course, run in either of
the following directions: (1) Directly into the position where the horny
and sensitive laminae interleave; (2) between the sensitive laminae and the
os pedis; (3) into the os pedis itself; (4) the nail may bend excessively
immediately after entering the horn, and so pass either between the horny
and sensitive sole; or (5) between the sensitive sole and the bone.

_Classification_.--Punctured wounds of the foot may be classified as
follows:

_Simple or superficial_ when penetrating no structure of great importance.
For instance, a prick that penetrates to the sensitive sole and is not
driven with sufficient force to seriously injure the os pedis we may regard
as simple. In the same manner a prick to the frog that, although deep, is
mainly concerned with penetrating the plantar cushion may also be classed
as simple.

_Deep or penetrating_ when driven with sufficient force or in such a
direction as to injure structures whose penetration is calculated to give
rise either to serious constitutional disturbance or to permanent lameness.
In this category we may place injuries to the terminal portion of the
perforans, puncture of the navicular bursa, fracture of the navicular bone
and penetration of the pedal articulation, and splintering of the os pedis.

_Symptoms and Diagnosis_.--While discussing the symptoms and diagnosis, we
will still continue to consider our subject under the two headings of (1)
accidental 'gathering' of some foreign body, and (2) pricks inflicted in
the forge.

In a few cases belonging to the former class the veterinary surgeon is
fortunate in obtaining a direct history of the injury. The driver has seen
the animal go suddenly lame, and has examined the foot for the cause.
Either the nail has been found embedded in the horn, or the puncture it has
made detected, and the matter has been reported. The foot is then explored
and the full extent of the injury ascertained.

In many cases, however, it so happens that no evidence of the infliction of
the injury is forthcoming. The momentary lameness occurring at the time of
the prick is unreported at the time by the attendant, and the horse for
a time goes sound. It is not until the changes set up by the subsequent
inflammatory phenomena make their appearance, and lameness results, that
attention is called to the foot. When this happens there has, as a rule,
been