een the heads of the
gastrocnemius.

On removing next the adipose substance and lymphatic glands, we expose
the popliteal vein and artery. The relative position of these vessels
and the posterior tibial nerve, may now be seen. Between the heads of
the gastrocnemius, the nerve, H, giving off large branches to this
muscle, lies upon the popliteal vein, G, where this is joined by the
posterior saphena vein. Beneath the veins lies the popliteal artery, F.
On tracing the vessels and nerve from this point upwards through the
popliteal space, we find the nerve occupying a comparatively superficial
position at the mesial line, while the vessels are directed upwards,
forwards, and inwards, passing deeply, as they become covered by the
inner flexor muscles, C D, to the place where they perforate the tendon
of the adductor magnus on the inner side of the lower third of the
femur.

The popliteal artery, F, Plate 66, being the continuation of the
femoral, extends from the opening in the great adductor tendon at the
junction of the middle and lower third of the thigh, to the point where
it divides, in the upper, and back part of the leg, at the lower border
of the popliteus muscle, L, into the anterior and posterior tibial
branches. In order to expose the vessel through this extent, we have to
divide and reflect the heads of the gastrocnemius muscle, E E, and to
retract the inner flexors. The popliteal artery will now be seen lying
obliquely over the middle of the back of the joint. It is deeply placed
in its whole course. Its upper and lower thirds are covered by large
muscles; whilst the fascia and a quantity of adipose tissue overlies its
middle. The upper part of the artery rests upon the femur, its middle
part upon the posterior ligament of the joint, and its lower part upon
the popliteus muscle. The popliteal vein, G; adheres to the artery in
its whole course, being situated on its outer side above, and posterior
to it below. The vein is not unfrequently found to be double; one vein
lying to either side of the artery, and both having branches of
communication with each other, which cross behind the artery. In some
instances the posterior saphena vein, instead of joining the popliteal
vein, ascends superficially to terminate in some of the large veins of
the thigh. Numerous lymphatic vessels accompany the superficial and deep
veins into the popliteal space, where they join the lymphatic bodies,
which here lie in the course of