of the ilium traced as it proceeds outwards and backwards from this. The boundary line between the front of the thigh and the region of the abdomen is formed by Poupart's ligament, which stretches from the anterior superior spine of the ilium to the spine of the pubis. Its course and position are marked on the surface by a faint groove. By running the finger along this when the thigh is fully extended the ligament may be felt. At its inner end the spine of the pubis should be determined, and then the finger may be carried inwards on the crest of the pubis to the symphysis pubis. The rami of the pubis and ischium, leading downwards and backwards to the tuberosity of the ischium, constitute the upper boundary of the thigh on its internal aspect, and their relation to the surface must therefore be ascertained. Below Poupart's ligament in the extended position of the thigh, there is a faint depression corresponding in position to Scarpa's triangle.

In the dissection of the front of the thigh, the skin is also reflected from the anterior aspect of the knee. The dissector should therefore take the present opportunity of studying the surface anatomy of this articulation. The patella forms a marked prominence in front of the joint. When the limb is extended and the extensor muscles on the front of the thigh are relaxed, the patella will be found to be freely movable when grasped firmly between the finger and thumb. Note its change of position when the leg is flexed on the thigh at the knee-joint. It passes downwards, and comes to lie in front of the interval between the femur and tibia. The patellar surface of the femur can now be felt. The powerful ligamentum patella which passes vertically downwards from the patella to anterior tuberosity of the tibia can be easily distinguished. The massive condyles of the femur should next be studied and compared. The internal condyle is the more prominent of the two, and immediately above its tuberosity the adductor tubercle can be recognised. The articular interval between the condyles of the femur and the head

of the tibia is not visible on the surface, but it can readily be felt by the finger. The three tuberosities of the tibia should likewise be studied, and the position of the head of the fibula on the posterior and lower aspect of the external tuberosity ascertained.

SUPERFICIAL DISSECTION.

This dissection comprises the examination of the following parts:

1. Superficial fascia.

2. Internal saphenous vein, and its several tributaries.

Superficial pudic.

3. Arteries, Superficial epigastric.

Superficial circumflex iliac.

4. Lymphatic glands and vessels.

5. The saphenous opening.

6. Cutaneous nerves.

7. The fascia lata.

8. The bursa patellæ.

Reflection of Skin.—Incisions.—(1) From the anterior superior spine of the ilium along the line of Poupart's ligament to the symphysis pubis; (2) from the inner extremity of this line downwards, round the scrotum, and along the inner aspect of the thigh for four inches; (3) from the lower extremity of this vertical incision transversely outwards, across the front of the thigh, to the outer aspect of the limb (Fig, 4. p. 17).

The quadrilateral flap of skin thus traced out must be raised carefully from the subjacent superficial fascia and turned outwards.

Superficial Fascia.-The fatty superficial fascia which is now exposed is continuous with the corresponding layer on the front of the abdomen, and it is regarded by some anatomists as being composed of two layers. This subdivision we consider needless and artificial. In the lower part of the abdominal wall, above Poupart's ligament, it is true the superficial fascia presents two distinct strata―one a fatty layer continuous over Poupart's ligament, with the superficial fascia on the front of the thigh, and sometimes termed the fascia of Camper; the other, a deeper layer, firm and membranous and devoid of fat, called the fascia

of Scarpa. As this latter fascial stratum is attached to the fascia lata (deep fascia of the thigh), immediately below Poupart's ligament, it is necessary that it should receive some attention.

To demonstrate the fascia of Scarpa the dissectors of the lower limb and abdomen should work in conjunction with each other. A transverse incision should be made through the entire thickness of the superficial fascia on the front of the abdomen, from the anterior superior spine of the ilium to the middle line of the body. On raising the lower edge of the divided fascia the two layers can be easily distinguished. Insinuate the fingers between the fascia of Scarpa and the pearly-looking tendon of the external oblique. Little resistance will be encountered, as it is only bound down by some lax areolar tissue. The fingers can be readily carried downwards behind the fascia of Scarpa as far as Poupart's ligament. Here it will be found that they can force their way no farther. The passage of the hand into the thigh is barred by the blending of the fascia of Scarpa with the fascia lata. At this level therefore it ceases to exist. The fatty superficial layer of Camper, however, as we have said, is continued onwards as the superficial fascia of the thigh.

But it is necessary to study more closely the line along which the fascia of Scarpa unites with the fascia lata. Its direction does not correspond with that of Poupart's ligament; it is more nearly horizontal. Internally the union takes place along the line of Poupart's ligament; but as it is traced outwards, it will be seen to fall somewhat below the ligament. When urine is effused under the superficial fascia of the anterior abdominal wall, this attachment of the fascia of Scarpa prevents its passage downwards in front of the thigh.

Dissection.In the superficial fascia blood-vessels, glands, lymphatic vessels, and nerves are embedded, and these must now be dissected out. First look for the large internal saphenous vein. It will be found extending up the thigh a little way internal to the middle line of the limb. Trace it upwards till it reaches a point about two inches from

Poupart's ligament. At this point it dips through the deep fascia, and joins the femoral vein. It is not desirable to define the opening in the fascia lata through which it passes until a later stage of the dissection. Several tributaries join the internal saphenous vein at this point, and these should be dissected along with the small superficial arteries of the groin which accompany them.

The large lymphatic glands of the groin must also be dissected out from the fatty tissue in which they lie. In doing this care must be taken to preserve as many of the minute thread-like lymphatic vessels which enter and leave the glands as possible. A small artery and vein should also be traced to each gland.

Superficial Inguinal Vessels.-Three minute arteries, termed the superficial epigastric, the superficial external pudic, and the superficial circumflex iliac, pierce the deep fascia below Poupart's ligament, and radiate from each other for the supply of the glands and integument of the groin. They all spring from the femoral artery immediately after it enters the thigh.

The superficial external pudic comes forward through the cribriform fascia (a thin fascial layer, which is spread over the saphenous opening), and runs inwards and upwards across the spermatic cord. It supplies the skin of the scrotum and penis.

The superficial epigastric turns upwards and leaves the thigh by crossing Poupart's ligament about its middle. It is distributed chiefly to the skin on the front of the abdomen.

The superficial circumflex iliac is very minute, and courses upwards and outwards along Poupart's ligament towards the anterior superior spine of the ilium.

The veins which accompany these arteries converge towards the saphenous opening and join the internal saphenous vein near its termination.

Lymphatic Glands and Vessels.-The disposition of the lymphatic glands into two groups will now be evident—an upper inguinal group along the line of Poupart's ligament, and a lower femoral group, which extends for a short way down the thigh along the line of the internal saphenous vein.

In a spare subject, or better still, in a dropsical subject,

the general arrangement of the lymphatic vessels may also be made out. To the femoral group of glands proceed the vessels of the lower limb; to the inguinal glands go the lymphatic vessels from the genitals, perineum, and the surface of the abdomen. These are termed the afferent vessels. In addition to these, numerous vessels pass between the various glands and connect them with each other. The lymphatic vessels which lead the lymph away from the glands are called the efferent vessels. A large number of these pass through the saphenous opening, others pierce the deep fascia. They join the glands which lie in relation to the femoral and external iliac arteries.

Dissection. It requires an experienced dissector to display in a satisfactory manner the saphenous opening, or, in other words, the aperture in the deep fascia through which the saphenous vein passes to join the femoral vein. Begin by removing the lymphatic glands. In doing this bear in mind that the crural branch of the genito-crural nerve pierces the fascia lata in the middle line of the thigh about an inch or so below Poupart's ligament. Take care also of the two divisions of the middle cutaneous nerve, which make their appearance in the same line about three inches below Poupart's ligament.

To define the saphenous opening, the dissector should commence by cautiously removing the superficial fascia from the fascia lata over the upper parts of the adductor longus and pectineus muscles. The deep fascia at this point is called, the pubic portion of the fascia lata, and as it is cleaned, from within outwards, it will be observed to recede gradually from the surface and to be continued behind the femoral vessels. The clearly-defined inferior cornu of the saphenous opening will now be brought into view, curving under the internal saphenous vein, and blending with the pubic portion of the fascia lata. The cribriform fascia, a thin and imperfect layer which is spread over the aperture, must be removed so as to display the outer boundary of the opening. In doing this take great care of the subjacent sheath of the femoral vessels to which it is more or less firmly attached. certain extent this dissection is artificial, seeing that the cribriform fascia is merely a continuation inwards of the outer lip of the opening. The outer boundary is usually very much broken up by the superficial branches of the femoral artery which pierce it, and its definition is a matter of some difficulty. In a spare subject, however, the line of demarcation between the cribriform fascia and the iliac portion of the fascia lata may be distinguished.

To a

1 This is the name which is given to that part of the fascia lata which lies external to the opening.