THE FOOT. 461 
cellular tissue. It gradually becomes thinner as it descends upon the 
pedal bone, and ends in puckers or folds, which are continuous with those 
of the lamine, and are not even separable from them by maceration. ‘The 
lamine thus continuing upon the pedal bone, consist of about five hundred 
parallel folds or plaits, plentifully supplied with blood, and forming a 
secretory surface, which aids the coronary substance to form the horn. 
They lie upon an elastic substratum of fibrous periosteum, which is of great 
service in taking off the jar from the foot in its battering upon hard roads, 
for it appears that the weight of the body is suspended from these plates, 
and not carried wpon the sole. The lamin are continuous at the toe with 
the sensible sole, which is a vascular membrane covering the floor of the 
pedal bone, and secreting the horny 
sole. In the centre of the posterior 
part of this is the sensible frog, 
which is of nearly the same shape 
as the horny frog, and is still more 
liberally supplied with blood than 
the sensible sole. 
THE ARTERIES supplying these 
vascular structures with blood, and 
the veins taking it back, are of 
creat importance, and doubly so be- 
cause it is in these vessels that an 
operation is often performed in in- 
flammation of the foot, calculated 
to afford relief by a local abstrac- 
tion of blood. Commencing with 
the large metacarpal artery, which 
is the continuation of the radial 
below the knee, we find it descend- 
ing by the side of the tendo-perfo- 
ratus under the posterior-annular 
ligament. Immediately above the 
fetlock joint it splits into three 
branches ; the middle one passing 
to the deep parts of the leg, and 
the two others, forming the plantar 
arteries, descend on each side the 
posterior joint to the postero-lateral Fre. 5.—Vview or Vessets oF THE Foor, tNJECTED. 
parts of the coronary substance. 
Here they divide into two leading 
portions, the anterior running 
round to meet its fellow of the 
opposite side, and giving off with 
it a complete fringe of vessels, which are displayed in the accom- 
panying representation of an injected preparation of the foot. The 
branches uniting in front of the foot and encircling the coronary ligament 
are called the superior coronary circle. The posterior division of the 
plantar artery gives off, opposite the pastern joint, the artery of the frog, 
which descends obliquely inwards through the substance of the sensible 
frog, and divides into two branches within it, after which it supplies the 
whole of that substance with numerous vessels, and then goes on to the 
sole, to which it gives off a number of radiating branches. After giving 
f the artery of the frog, the plantar artery ends posteriorly in the lateral 
GGa2 
. Plantar vein. 
. Plantar artery. 
. Branches to the coronary substance and lamin. 
. Posterior division of plantar artery. 
. Perpendicular branch. 
. Anastomosis with opposite planter artery. 
Dorp OO be 
