spread upwards towards the abdomen, and, to a less extent,
downwards into the thigh. Sometimes a constriction occurs across the
sac at the level of Poupart's ligament.

The pressure exerted on the nerves and veins of the lower extremity
causes pain, congestion, and oedema of the limb. Rupture may take place
externally, or into the cellular tissue of the iliac fossa.

These aneurysms have to be diagnosed from pulsating sarcoma growing from
the pelvic bones, and from an abscess or a mass of enlarged lymph glands
overlying the artery and transmitting its pulsation.

The method of treatment that has met with most success is ligation of
the common or external iliac, reached either by reflecting the
peritoneum from off the iliac fossa (extra-peritoneal operation), or by
going through the peritoneal cavity (trans-peritoneal operation).

#Gluteal Aneurysm.#--An aneurysm in the buttock may arise from the
superior or from the inferior gluteal artery, but by the time it forms a
salient swelling it is seldom possible to recognise by external
examination in which vessel it takes origin. The special symptoms to
which it gives rise are pain down the limb from pressure on the sciatic
nerve, and interference with the movements at the hip.

Ligation of the hypogastric (internal iliac) by the trans-peritoneal
route is the most satisfactory method of treatment. Extirpation of the
sac is difficult and dangerous, especially when the aneurysm has spread
into the pelvis.

#Femoral Aneurysm.#--Aneurysm of the femoral artery beyond the origin of
the profunda branch is usually traumatic in origin, and is more common
in Scarpa's triangle than in Hunter's canal. Any of the methods already
described is available for their treatment--the choice lying between
Matas' operation and ligation of the external iliac.

Aneurysm of the _profunda femoris_ is distinguished from that of the
main trunk by the fact that the pulses beyond are, in the former,
unaffected, and by the normal artery being felt pulsating over or
alongside the sac.

In _aneurysmal varix_, a not infrequent result of a bullet wound or a
stab, the communication with the vein may involve the main trunk of the
femoral artery. Should operative interference become necessary as a
result of progressive increase in size of the tumour, or progressive
distension of the veins of the limb, an attempt should be made to
separate the vessels concerned and to close the opening in each by
suture. I