228 Anatomy of the Rabbit. 



(c) The extensor digitorum longus. Origin: By a flattened 

 tendon from the lateral portion of the patellar surface of the 

 femur. This tendon passes through the capsule of the knee- 

 joint, and the fleshy portion of the muscle lies on the antero- 

 lateral surface of the tibia. Insertion: The distal tendon 

 passes beneath the crural ligament, then beneath the cruciate 

 ligament of the dorsum of the foot, dividing into four por- 

 tions for insertion on all the phalanges of the_digits. - 

 The muscle may be displaced by dividing the crural ligament. 

 The branches of the anteror tibial artery lie behind this muscle, 

 one in a medial position, in contact with the tibia, the other on the 

 peronaei muscles in company with the peroneal nerve. 

 B. Peronaeus group. These muscles arise from the lateral 

 surface of the leg, and are inserted on all surfaces at the lateral side 

 of the foot. The insertion tendons reach the foot from beneath the 

 lateral malleolus. The muscles can be separated after the tendons 

 ar^ released from this position. 

 1(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 fiexor digitorum longus. Insertion : Head of the fourth 

 metatarsal. 



