uter margin of the flexor carpi ulnaris muscle,
K, Plate 16, indicates the locality of the ulnar artery. Both arteries,
I, K, Plate 15, at the wrist, lie beneath the fascia. If either of these
vessels require a ligature in this region of the arm, the operation may
be performed with little trouble, as a simple incision over the track of
the vessels, through the skin and the fascia, will readily expose each.

Whenever circumstances may call for placing a ligature on the ulnar
artery, as it lies between the superficial and deep flexor muscles, in
the region of I L M, Plate 16, the course of the vessel may be indicated
by a line drawn from a central point of the forearm, an inch or so below
the level of the inner condyle--viz., the point F, and carried to the
pisiform bone, T. The line of incision will divide obliquely the
superficial flexors; and, on a full exposure of the vessel in this
situation, the median nerve will be seen to cross the artery at an acute
angle, in order to gain the mid-place in the wrist at Q. The ulnar
nerve, d, Plate 16, passing behind the inner condyle, e, does not come
into connexion with the ulnar artery until both arrive at the place O.
It will, however, be considered an awkward proceeding to subject to
transverse section so large a mass of muscles as the superficial flexors
of the forearm, when the vessel may be more readily reached elsewhere,
and perhaps with equal advantage as to the locality of the ligature.

When either the radial or ulnar arteries happen to be completely divided
in a wound, both ends of the vessel will bleed alike, in consequence of
the free anastomosis of both arteries in the hand.

DESCRIPTION OF PLATES 15 & 16.

PLATE 15.

A. Fascia covering the biceps muscle.

B. Basilic vein, with the internal cutaneous nerve.

C. Brachial artery, with the venae comites.

D. Cephalic vein, with the external cutaneous nerve; d, the median nerve.

E. A communicating vein, joining the venae comites.

F. Median basilic vein.

G. Lymphatic gland.

H. Radial artery at its middle.

I. Radial artery of the pulse.

K. Ulnar artery, with ulnar nerve.

L. Palmaris brevis muscle.

[Illustration: Right arm, showing blood vessels, muscles and other
internal organs.]
Plate 15

PLATE 16.

A. Biceps muscle.

B. Basilic vein, cut.

C. Brachial artery.

D. Median nerve; d, the ulnar nerve.

E. Brachialis anticus muscle; e, the internal condyle.

F. Origin of radial