228 MYOLOGY. 



carpal and annular ligaments ; the second is formed by the car- 

 tilaginous pad clothing the great sesamoid bones, the posterior 

 face of their inferior, and their annular ligaments, the latter 

 being very adherent to the perforatus tendon, which it covers, 

 and is continued both upwards and downwards, being attached 

 to the phalanges by three fibrous bands on each side. The 

 synovial membranes lining these sheaths, and reflected on the 

 tendons, are very large, and project considerably above and 

 below, each forming an upper and a lower cul-de-sac ; the lower 

 one of the sesamoidean sheath reaching that formed by the mem- 

 brane of the coffin joint, and also the superior one of the navicular 

 sheath. 



Action. — To flex the pastern and fetlock joints, and assist in 

 flexing the carpus. The superior check ligament enables it to act 

 as an unyielding brace to the joints below during rest. 



FLEXOR PEDIS PEEFORANS. 



( Flexor- Profundus — Epicondylo-phalangeu s . ) 



(Fig. 81. c c.) 



This muscle is situated between the preceding one and the 

 radius; it is long, tendinous at its origin, with a round fleshy 

 belly, much larger than that of the perforatus, and ending, above 

 the carpus, in a funicular tendon. This tendon passes through 

 the posterior carpal sheath, then through a sheath partly formed 

 by the perforatus tendon below ; it is joined by the tendons of 

 the accessory flexors, and half-way down the metacarpus by the 

 inferior carpal or check ligament, a strong fibrous band which 

 is continuous with the posterior carpal ligament. The tendon 

 then passes through the sesamoidean sheath anteriorly to the per- 

 foratus tendon, and then between the terminal slips of the latter, 

 over the supero-posterior part of the os coronse, when it expands, 

 the expanded part being termed the plantar aponeurosis; it 

 passes thence over the navicular bone, and its synovial capsule, 

 to the solar aspect of the pedal bone. 



Origin. — In common with the perforatus from the epicondyle. 



Insertion. — To the semilunar ridge on the solar aspect of the 

 OS pedis. 



Relation. — Posteriorly with the perforatus ; anteriorly with 

 the radialis accessorius and the radius. Connected with the 

 terminal portion of the tendon, we may remark that the synovial 



