it terminates in several divisions which bury themselves in the os pedis.
Before leaving the inner aspect of the pedal wing it supplies a deep branch
to the heel and the villous tissue. Gaining the outer aspect of the
wing, it distributes a further backward branch, which passes behind the
circumflex artery of the pedal bone, and, during its passage in the
preplantar fissure, gives off ascending and descending branches, which
ramify in the laminal tissue.

THE PLANTAR (UNGUAL[A]) ARTERY.--This, the larger of the two terminals
of the digital, may be looked upon as a continuation of the main vessel.
Running along the plantar groove, it gains the plantar foramen. Here it
enters the interior of the bone (the semilunar sinus) and anastomoses with
the corresponding artery of the opposite side. The circle of vessels so
formed is called the _Plantar Arch_ or the _Semilunar Anastomosis_.

[Footnote A: The epithet 'ungual' is added by Chauveau to distinguish
these arteries from the properly so-called plantar arteries--the terminal
divisions of the posterior tibial artery.]

From the semilunar anastomosis radiate two main groups of arterial
branches, an ascending group and a descending one. The _ascending_ branches
penetrate the substance of the os pedis, and emerge by the numerous
foraminæ on its laminal surface. The _descending_ branches, larger in size,
also penetrate the substance of the pedal bone, and emerge in turn from
the foraminæ cribbling its outer surface--in this case the set of larger
foraminæ opening on its inferior edge. Having gained exit from the bone,
their frequent anastomosis, right and left, with their fellows forms a
large vessel following the contour of the inferior edge of the os pedis.
This constitutes the _Circumflex Artery of the Toe_.