382 THE MUSCLES OF THE DOG 



which are homologous with those of the "same digit in the forehmb. These are 

 the abductor hallucis, adductor hallucis, and flexor hallucis brevis. 



The principal bursee and syno^dal sheaths of the muscles of the leg and foot are as follows: 

 The tibialis anterior has a bursa under its tendon at the tarsus. A pouch of the synovial membrane 

 of the stifle joint underlies the tendon of origin of the extensor digitalis longus, and is partially 

 reflected upon the superficial face of the tendon; the tendons of insertion are provided with a 

 synovial sheath which begins at the end of the muscular part and extends to the proximal part of 

 the metatarsus. The tendons of the lateral digital extensor and peroneus brevis have a common 

 synovial sheath at the distal end of the leg and proximal part of the tarsus. The tendon of the 

 peroneus longus has a syno^dal sheath which begins an inch or more above the lateral malleolus 

 (in a good-sized dog) and extends about to the middle of the tarsus; another sheath [envelops the 

 tendon to the point where it bends round to the plantar surface of the hock; a bursa lies between 

 the tendon and the joint capsule and fourth tarsal bone, and communicates with the joint cavity. 

 A bursa underhes the terminal part of the tendon of the peroneus brevis. There is a bursa in 

 front of the distal part of the tendon of the gastrocnemius; it extends an inch or more (in large 

 dogs) above the tuber calcis. A bursa underhes the superficial flexor tendon at the tarsus; in large 

 dogs it extends about an inch above and below the tuber calcis. The tendon of the tibialis posterior 

 has a synovial sheath at the distal end of the leg. The tendon of the flexor digitalis longus has a 

 synovial sheath which begins a httlc above the medial malleolus and extends to the junction with 

 the tendon of the flexor hallucis. The tarsal sheath of the flexor hallucis begins (in large dogs) 

 about an inch and a half above the level of the medial malleolus and extends to the distal end of 

 the tarsus; it communicates with the tibio-tarsal joint cavity. The synovial apparatus in the 

 distal part of the hmb resembles that of the forelimb. 



