MUSCLES OF THE PELVIC LIMB 



381 



condyles of the 



of the lateral face of the tibia and the fibula. Its tendon accompanies that of 

 the lateral extensor over the lateral malleolus, and ends on the proximal end of the 

 fifth metatarsal bone. 



The soleus is absent. (It is present and large in the cat.) 



The gastrocnemius arises from the rough lines above the 

 femur. The origin of each head contains a sesamoid 

 bone about the size of a pea (Os sesamoideum m. gas- 

 trocnemii), which articulates with the corresponding 

 condyle of the femur. The tendon comports itself as 

 in the horse. 



The superficial digital flexor has a large round 

 belly. It arises in common with the lateral head of 

 the gastrocnemius from the lateral rough line and sesa- 

 moid bone, and from the aponeurosis of the vastus 

 lateralis. The tendon winds around that of the gas- 

 trocnemius, passes over the tuber calcis (where it is 

 arranged as in the horse), and divides below the tarsus 

 into two branches. Each of these divides into two 

 l^ranches which end as in the forelimb. The lateral 

 and medial branches detach slips to the suspensory 

 ligaments of the large digital pad. Muscle-fibers 

 often occur in the tendon in the metatarsal region. 



The deep digital flexor has two heads. The large 

 lateral head, the flexor hallucis longus, arises from the 

 posterior surface of the tibia and fibula, filling the in- 

 terosseous space. The small medial head, flexor digi- 

 talis pedis longus, also arises from the tibia and fibula; 

 its tendon passes through the groove on the medial 

 malleolus, inclines backward in its descent over the 

 tarsus, and joins that of the large head below the 

 tarsus. The common tendon detaches a branch to 

 the large digital pad and terminates as in the forelimb. 



The tibialis posterior is a very small but distinct 

 muscle, which arises on the proximal part of the fibula. 

 The delicate tendon accompanies that of the flexor 

 longus and ends on the medial ligament of the tarsus. 



The tendon of origin of the popUteus contains a 

 small sesamoid bone. 



The adductors of the second and fifth digits, the 

 lumbricales, and the interossei are arranged as in the 

 thoracic limb. 



The quadratus plants arises on the lateral surface 

 of the distal end of the fibular tarsal bone and on the 

 lateral tarsal ligament, passes downward and inward, 

 and terminates on a thin tendon which fuses with that 

 of the deep flexor. 



The abductor digiti quinti is a very small muscle 

 which consists of two parts. One of these is a tendin- 

 ous slip which extends from the plantar surface of the 

 proximal part of the fibular tarsal bone to the head of 

 the fiith metatarsal bone; the other part arises from 



the medial surface of the fibular tarsal bone (or from the tendinous part) and ends 

 on the first phalanx of the fifth digit. 



In case the skeleton of the first digit is well developed, there are three muscles 



Fig., 327. — Muscles of Leg and 

 Foot of Dog; Lateral View. 

 a. Quadriceps femoris; h, gas- 

 trocnemius, lateral head; c, super- 

 ficial digital flexor; '/, deep digital 

 flexor; e, peroneus longus; /, ten- 

 don .of lateral extensor;' g, peroneus 

 brevis; /(, long digital extensor; h', 

 h", h'", tendons of preceding; i, 

 tibialis anterior; /:, extensor brevis; 

 Z, slips from interossei (m); 1, lateral 

 condyle of femur; 2, patella; 3, 

 tibia; Jf, tuber calcis; 5, 6, annular 

 ligaments. (After EUenberger, in 

 Leisering's Atlas.) 



