152 Anatomy of the Rabbit. 



(a) The peronaeus longus (p. primus). Origin: Lateral condyle 

 of the tibia and head of the fibula. Insertion: End of the 

 reduced first metatarsal. The tendon crosses the plantar 

 surface of the foot, passing around the distal end of the 

 cuboid bone. 



The muscle should be divided. 



(b) The peronaeus brevis (p. secundus). Origin: Lateral 

 condyle of the tibia and corresponding surface of the shaft; 

 also the crural interosseous ligament joining the tibia and 

 fibula. Insertion : Tuberosity of the base of the fifth meta- 

 tarsal. 



(c) The peronaeus tertius. Origin: The head of the fibula and 

 the crural interosseous ligament, fused with the extensor 

 digitorum longus. Insertion : Head of the fifth metatarsal, 

 and distally, united with the tendon of the extensor digitorum 

 longus, on the phalanges of this digit. 



(d) The peronaeus quartus. Origin: The fibula and the inter- 

 osseous ligament, fused with the peronaeus brevis and with the 

 extensor digitorum longus. Insertion: Head of the fourth 

 metatarsal. 



C. Flexor group. The muscles arise from the medial and lateral 

 condyles of tibia and femur (the flexor digitorum sublimis from the 

 posterior surface of the tibia). They lie behind the axis of the tibia, 

 and are inserted both on the heel and on the plantar surface of the foot. 



(a) The triceps surae comprises : 



(1) The gastrocnemius. Origin: in two portions: 



Caput laterale: Lateral condyles of tibia and femur and 



related femoral sesamoid. 



Caput mediale: Medial condyle of the femur and its sesamoid. 



(2) The soleus: Origin: Head of the fibula. 



Insertion: Through the Achilles' tendon (tendo calcaneus). The 

 latter passes over the posterior end of the tuber calcanei, and 

 is attached to its ventral surface. The tendon is covered by 

 that of the plantaris muscle. 



The small saphenous artery and vein lie at the posterior margin of the 

 lateral head of the gastrocnemius in company with the lesser saphenous 

 nerve. 



(b) The plantaris. Origin: Lateral condyle of the femur and 

 associated sesamoid. Insertion: The tendon passes over 

 the heel to the plantar surface of the foot, and divides in four 

 parts for insertion on the second phalanges of the four 

 developed digits. 



The two muscles should be divided. 

 c) The popliteus. Origin: Lateral condyle of the femur: The 

 tendon passes through the capsule of the knee-joint. The 

 muscle contains the tibial sesamoid. It crosses the pos- 

 terior surface of the tibia obliquely, and is inserted on the 

 proximal portion of its posteromedial angle. 



