WOUNDS 215 
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.—tThis 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. 
(ce) 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 that the penetrating object has gone deeper. 
It may be distinguished from puncture of the plantar 
aponeurosis alone by the fact that there is an excessive 
discharge of synovia from the wound. This, as it escapes, 
is at first clear and straw-coloured. Later it becomes 
cloudy and flaked with pus, and shows a tendency to 
coagulate in yellowish clots. 
Pain and accompanying fever is most marked, much 
