THE FASCIAE OF THE LEG. 257 



The adductor magnus consists of two parts, which are as a rule quite distinct. The 

 anterior and superior portion, which is often described as a separate muscle under the name of 

 adductor minimus, arises from the body of the pubis and the ischio-pubic rami : its fibres form 

 a thin layer which is inserted into the femur from the lower border of the quadratus femoris 

 to the upper end of the linea aspera, and sometimes for a short distance along that line. The 

 posterior and inferior portion, much the larger, arises from the ischial ramus internal to the 

 foregoing-, and from the ischial tuberosity by a strong tendon which descends on the posterior 

 aspect of the muscle for the upper third of the length of the thigh. The fibres springing 

 from the fore part of this origin and the outer side of the tendon pass obliquely to the linea 

 aspera below the insertion of the superior portion, and to the upper part of the internal supra- 

 condylar line ; while those proceeding from the hinder part of the mass and the inner border 

 of the tendon descend on the inner side of the opening for the femoral vessels to the condylar 

 insertion. 



Relations. This muscle is in contact in front with the long and short adductors, the 

 vastus internus, the obturator nerve, and the profunda artery, behind with the hamstring 

 muscles, gluteus maximus, and great sciatic nerve, internally with the gracilis and sartorius 

 muscles, superiorly with the obturator externus and quadratus femoris muscles ; and along the 

 line of attachment to the femur it is pierced by the femoral and perforating arteries. 



Varieties. The adductor muscles are so closely related that their varieties may be 

 oonveniently considered together. The pectineus is sometimes divided more or less completely 

 into two parts, which receive their nerves from different sources, viz., the inner from the 

 obturator, and the outer from the anterior crural. This division occurs naturally in many 

 animals. The muscle has also been seen attached to the capsule of the hip-joint, or even 

 inserted into it. The adductor longus may be double, or it may extend as far as the knee with 

 its tendon of insertion inseparable from that of the adductor magnus. Its outer border may 

 be continuous with, or receive a slip from, the adjacent edge of the pectineus. The adductor 

 brer is is frequently found divided into two or three parts, or it may be incorporated with the 

 adductor magnus. The adductor magnus varies in the degree of its segmentation. Its condylar 

 part has been found distinct from the rest of the muscle, a condition which is usual in apes. 

 On the other hand, the muscle has been found with its upper part completely united to the 

 quadratus femoris. 



Nerves. The adductor muscles as a whole are supplied by the obturator nerve (2, 3, 4 1), 

 but the adductor magnus likewise receives a branch from the great sciatic, and the pectineus 

 has regularly a branch from the anterior crural, while an offset to it from the obturator nerve 

 is only occasionally present. 



Actions. All these muscles adduct the thigh. In addition to this action, the pectineus, 

 adductor longus and adductor brevis' are accessory flexors of the hip, while the strong part 

 of the adductor magnus springing from the ischial tuberosity aids in extending that joint. 

 The gracilis also flexes the knee and rotates the leg inwards. The adductors, acting with 

 their opponents the gluteal muscles, balance the body upon the femur in walking, and the 

 adductor magnus supports the pelvis and steadies the hip- joint in standing. 



THE MUSCLES AND FASCL3E OF THE LEG. 



FASCIJE. The aponeurosis of the leg invests the muscles closely, but is not 

 continued over the subcutaneous surfaces of the bones. It is thus intimately united 

 with the periosteum over the head and the anterior and inner borders of the tibia, the 

 head of the fibula, and the inner and outer malleoli. It is thicker on the front of 

 the leg than behind, especially at the upper parfc, where it is very dense and gives 

 origin to the subjacent muscles. Posteriorly it is continuous with the fascia lata on 

 the back of the thigh, and near the knee it receives accessions from the tendons of 

 the biceps externally, and the sartorius, gracilis and semitendinosus internally. Over 

 the popliteal space it consists of strong transverse fibres, which bind together the 

 muscles of the outer and inner sides, and it is perforated at the lower part of the space 

 by the external saphenous vein ; lower down it becomes much thinner over the gas- 

 trocnemius muscle. From the deep surface of the fascia intermuscular septa are 

 ent inwards, and give origin to the adjacent muscles : on the outer side two of these 

 pass inwards to be attached to the anterior and external borders of the fibula, and 

 thus separate the peroneal muscles from those of the front and back of the leg res- 

 pectively ; and in front there is one septum, confined to the upper third of the leg, 

 between the tibialis anticus and extensor longus digitorum muscles. 



Beneath the gastrocnemius and soleus muscles on the back of the leg, a deep 



