ed in loose cellular and adipose tissue. The femoral vein, O, is
on the same plane with the artery near Poupart's ligament; but from this
place downwards through the thigh, the vein gradually winds from the
inner to the back part of the artery; and when both vessels pass under
cover of the sartorius, they enter a strong fibrous sheath, V, derived
from the tendons of the adductor muscles upon which they lie. The artery
approaches the shaft of the femur near its middle; and in this place it
may be readily compressed against the bone by the hand. The anterior
crural nerve, P, dividing on the outer side of the artery, sends some of
its branches coursing over the femoral sheath; and one of these--the
long saphenous nerve--enters the sheath and follows the artery as far as
the opening in the great adductor tendon. The femoral artery, before it
passes through this opening into the popliteal space, gives off its
anastomatic branch. The profundus branch, N, springs from the outer side
of the femoral artery usually at a distance of from one to two inches
(seldom more) below Poupart's ligament, and soon subdivides. [Footnote]
The femoral artery in a few instances has been found double.

[Footnote: The ordinary length of each part of the main artery is stated
on the authority of Mr. Quain. See "Anatomy of the Arteries," &c. ]

The main artery of the lower limb may be exposed and tied in any part of
its course from the aorta to the popliteal space. But the situation most
eligible for performing such an operation depends of course upon
circumstances, both anatomical and pathological. If an aneurism affect
the popliteal part of the vessel, or if, from whatever cause arising, it
be found expedient to tie the femoral above this part, the place best
suited for the operation is that where the artery, W, first passes under
cover of the sartorius muscle. [Footnote] For, considering that the
vessel gives off no important branch destined to supply any part of the
thigh or leg between the profundus branch and those into which it
divides below the popliteal space, the arrest to circulation will be the
same in amount at whichever part of the vessel between these two points
the ligature be applied. But since the vessel in the situation specified
can be reached with greater facility here than elsewhere lower down; and
since, moreover, a ligature applied to it here will be sufficiently
removed from the profundus branch above, and the seat of diseas