536 ANATOMY AND PHYSIOLOGY OF THE HORSE’S FOOT. 
climbing as they do through the meshes of a fibrous frame- 
work (which has been named the reticulum processigerum ) 
overlaying the anterior aspect of the os pedis. From their 
situation and their relations to a peculiar structure which 
will be examined immediately, this network has been called 
the “ podophyllous” or “ laminal plexus.” Extending to the 
coronet, and encircling the junction of the second and third 
phalanges, the circumference of the cartilages, and the coro- 
nary cushion, like a close and evenly twined wreath, this 
mesh, augmented by some veins from the inner parts of the 
foot, is designated the “ coronary plexus.” This covers the 
upper part of the pedal and the whole of the coronary bone, 
the lateral cartilages, and the heels of the plantar cushion, 
looking in some preparations not unlike the thick clus- 
tering tubers of some aquatic plant, the central ramuscules 
standing much closer than those at the sides. The latter, 
which envelope the outer and inner aspects of the cartilages, 
are very numerous and large. All these ramifications con- 
verge on and open into a large sinuous vein that sur- 
rounds the upper surface of the pastern, and this again empties 
itself into the digital vein, which ascends the limb along 
with the artery, one on each side. 
In the interior of the os pedis, the deep-seated veins follow 
pretty closely the distribution of the arteries, entering the 
semilunar sinuses, often communicating with each other, and 
spreading themselves over the internal structure of the bone. 
As before mentioned, however, they differ from the arteries 
in remaining isolated from the superficial veins — those which 
wind and twist over the external surface in such a surprising 
manner. Above, they proceed to augment the volume of the 
coronary plexus. 
Lymphatic vessels of the Foot . — Sharing to some extent in the 
nutritive operations carried on in the horse's foot, we cannot 
leave the consideration of the apparatus destined for the accom- 
plishment of these without bestowing a glance at the vessels 
which convey that colourless fluid whose exact nature or uses are 
as yet debatable, the “ liquor lymphse,” from the foot and limb 
into the circulation. Though the actual presence of these canals 
within the lower cavity of the hoof has not, so far as I am 
aware, been positively ascertained or directly demonstrated, 
yet there can be no doubt as to their existence in this region. 
It is certain that a large plexus or network of lymphatics 
extends itself in the cellular tissue and beneath the skin 
enveloping the large and small pastern bones, some of whose 
principal branches are plainly visible to the naked eye, and 
that these empty themselves, following the course of the 
