534 ANATOMY AND PHYSIOLOGY OF THE HORSe’s FOOT. 
the disposition of these vascular arcades, composed as they 
are of ever-varying-sized tubes intertwining closely and 
gracefully with each other, all throwing off an infinite number 
of arborescent filaments which graft themselves on to other 
branches ; and yet, while these are growing less and less in 
dimensions by this strange process of ramification and inter- 
weaving, the aggregate diameter of the whole far exceeds 
by many times that of the parent trunks. This net- 
work encircles the coronary bone, lies closely beneath the 
skin, covers the inside and outside of the lateral cartilages, 
spreads over the flexor tendons behind, forms a junction 
with the vessels from the opposite side and with other off- 
shoots from the principal tubes which go to supply most im- 
portant textures with nutrition, sometimes spreading under a 
dense membranous web of tendons, at other times doubling 
gracefully around it; or monopolising the whole surface of one 
texture by its wide dimensions, and then contracting sud- 
denly to suit the position, form or requirements of another — 
the multiform loops dwindling into a few of greater capacity, 
only to be again opened out widely into a maze of throbbing 
canals apparently bewildering by reason of their tortuosity 
and entanglement, but in reality simply and methodically 
arranged throughout. 
In this way the large artery on each side of the foot 
meanders by a thousand coalescing channels over the exte- 
rior and interior of the organ, till at length it terminates in 
two branches, the larger of which, ensconcing itself in the 
groove on the side of the os pedis, creeps round to one of the 
larger openings in the posterior concavity of that bone, passes 
into the solidly constructed tunnels I have before described, 
and uniting with the analogous vessel of the opposite side, 
constitutes an interosseous semilunar shaped mesh more 
wonderful, perhaps, than those which are not so concealed 
from view. This is broken up into a double series of vas- 
cular tracery minutely wrought, the first ascending to make 
an exit by the multitude of openings on the outside of the 
pedal bone, there again to originate another finely netted 
expansion — the “laminal arteries while the second series 
descend in an eccentric fashion, escape through the larger 
apertures seen on the lower or convex margin of the bone, 
then climb upwards by a crowd of branches (the “ ascending 
laminal arteries ”) to make yet another reticulated covering of 
vessels by meeting each other in cross twigs. This finally 
resolves itself into an artery (called the “ circumflex^), which 
courses along the under edge of the bone, transmitting, as it 
proceeds, a countless number of minute branches to the sole, 
