Part 108

The =supinator= has been found by Arloing and Lesbre, but is usually absent in the pig.

The =pronator teres= is a small muscle which lies on the internal lateral ligament of the elbow. It arises from the internal epicondyle of the humerus, and reaches about to the middle of the inner border of the radius.

The =flexor carpi internus= is well developed. It arises on the flexor epicondyle of the humerus, and is inserted into the third metacarpal bone.

The =flexor carpi medius= is narrow and has no ulnar head.

The =flexor carpi externus= (M. extensor carpi ulnaris) is covered by a thick, tendinous band, which extends from the extensor epicondyle to the accessory carpal bone and outer aspect of the carpus. The tendon of the muscle perforates this band in the distal part of the forearm and ends on the proximal end of the fifth metacarpal bone.

The =superficial digital flexor= has two bellies. The tendon of the =superficial head= passes down behind the posterior annular ligament of the carpus (bound down by a special annular ligament), forms a ring at the fetlock for a tendon of the deep flexor, and ends by two branches on the second phalanx of the =fourth digit=. The tendon of the =deep head=, after detaching a slip to the tendon of the deep flexor, passes down with the latter (for which it forms a ring), and ends on the =third digit=.

The =deep digital flexor= has three heads—humeral, ulnar, and radial. The common tendon divides into four branches, the larger central pair ending on the third phalanges of the principal digits, the smaller pair on the accessory digits. The latter are bound down by a peculiar spiral band. There is no check ligament.

The =lumbricales= are represented by bundles which extend from the deep flexor tendon to the tendon of the deep head of the superficial flexor.

The third and fourth =interossei= are present. Each sends two slips to the corresponding sesamoid bones and extensor tendon.

There are =flexors=, =adductors=, and =abductors= of the =second= and =fifth digits=.

MUSCLES OF THE PELVIC LIMB

SUBLUMBAR MUSCLES

The =psoas minor= is intimately united with the psoas major in front, and has a long small tendon which ends on the psoas tubercle. It has no thoracic part.

The =psoas major= is large and rounded. It begins at the last rib.

The =quadratus lumborum= is well developed, and extends forward as far as the twelfth rib.

MUSCLES OF THE HIP AND THIGH

The =tensor fasciæ latæ= is broad, and its fleshy part reaches almost to the patella.

The =gluteus superficialis= has a sacral head only; it blends with the biceps femoris.

The =gluteus medius= has a small lumbar part which does not extend so far forward as in the horse. The deep part (Gluteus accessorius) is pretty clearly marked.

The =gluteus profundus= is extensive, reaching nearly to the external angle of the ilium.

The =biceps femoris= has a narrow origin from the sacro-sciatic ligament and tuber ischii. It ends below like that of the ox.

The =semitendinosus= resembles that of the horse.

The =semimembranosus= has two insertions as in the ox.

The =sartorius= has two heads of origin, between which the external iliac vessels are situated. The inner arises from the tendon of the psoas minor, the outer one from the iliac fascia.

The =graciles= are united at their origin even more than in the ox.

The =pectineus= is well developed and is flattened from before backward.

The =adductor= shows no division and is partially fused with the gracilis. It ends on the femur just above the origin of the gastrocnemius.

The =quadratus femoris= is large.