THE FOOT. 287 



bursa), after covering tlie antero-superior part of the iiife- 

 rior jDortion of the tendon on reaching the superior broad 

 ligament above, is reflected over its posterior surface as 

 far as the bone, while from below it is reflected upwards 

 over the posterior surface of the inferior broad ligament 

 centrally, and laterally comes in contact with the stellate 

 ligament. 



The blood-vessels and nerves of the foot have been already 

 noticed, but we may here repeat that each metacarpal or 

 metatarsal nerve just above the fetlock breaks up into 

 three divisions, which pass downwards over the lateral 

 surface of the joint, in company with the plantar vein and 

 artery. The anterior division runs forwards to suj^ply the 

 structures in front of the joint. 



The middle division or anterior plantar nerve, crossing 

 the artery from behind forwards, runs to the coronet, 

 during the first part of its course situated behind the 

 artery and vein. 



The posterior division or posterior plantar nerve is 

 situated behind the artery, and accompanies it to the pos- 

 terior part of the foot, sending off fibres to accompany 

 many of its branches ; this nerve is divided in the " Zo^y " 

 operation of neurotomy. The inferior extremity of the 

 metacarpal nerve before division is involved in the " high" 

 operation. 



The flexor tendons must now be examined. 



While passing through the sesamoid groove at the back 

 of the fetlock the perforatus tendon extends round the per- 

 forans, and thus forms a sheath for it, which is deficient 

 anteriorly, so that the theca between the tendons com- 

 municates with the sesamoid bursa. From the supero- 

 lateral angles of os suffraginis portions of white fibrous 

 tissue run to the posterior surface of the perforatus tendon, 

 which shortly after bifurcates one of its divisions runnino- 

 to each extremity of the posterior fibro-cartilaginous sur- 

 face of OS coronge. Between the divisions the perforans 

 tendon runs, playing over the fibro-cartilaginous surface ; 

 to its posterior surface run white fibrous tissue layers from 

 the infero-lateral parts of os suffraginis ; thus reinforced it 

 receives some white and yellow elastic fibres from the 

 superior margin of the navicular bone (superior broad 

 ligament) which run to its anterior surface. It then plays 

 over the inferior surface of os naviculare, through the 



