268 OUTLINES OF EQUINE ANATOMY. 



funiculus running from gastrocnemius internus, and forms 

 a loop through which plantaris runs. This band, plan- 

 taris, and gastrocnemius externus, together become inserted 

 into the point of the hock, after playing over a bursa. 

 About opposite the superior j)art of the inferior third of 

 the tibia the tendon of gastrocnemius internus, which has 

 been hitherto placed in front of the externus, winds from 

 within oidivards around the externus tendon, on which it 

 plays through the medium of a synovial sheath, 



Plantaris is a fleshy muscle, apparently too long for its 

 situation, running from the superior part of the fibula to 

 become inserted as above described into the superior part 

 of OS calcis. The aponeurosis of the lowest head of 

 triceps abductor femoris sends downwards a broad band of 

 white fibrous tissue ; some of the muscular fibres of biceps 

 rotator tibialis terminate in tendinous structure, which 

 blends with the above ; a little lower down this band 

 receives fibres from gastrocnemius internus. About an 

 inch and a half above the point of the hock it bifurcates, 

 one division running on to the inner, the other to the outer 

 surface of the point of os calcis, from Avhich they pass to 

 the dilated portion of the tendon of gastrocnemius in- 

 ternus, which forms the cap of the hock, which they serve 

 to prevent from dislocation, being assisted by some liga- 

 mentous fibres which run directly from the cap to the bone. 

 Gastrocnemius internus arises from the fossa at the 

 postero-external part of the femur, between the two heads 

 of the gastrocnemius externus. It passes over the posterior 

 part of the stifle joint, and after sending some tendinous 

 structure to the fibrous band running to the hock, 

 becomes tendinous, winds round the tendon of the external 

 gastrocnemius muscle from within outwards, and then, 

 widening, forms a cap for the point of os calcis, which is 

 retained in position in the above-mentioned manner by two 

 fibrous bands, and which plays over a large synovial bursa ; 

 continuing downwards it is termed the perforatus tendon, 

 and exactly corresponds to that of the fore extremity. 



Popliteus is attached inf eriorly to a triangular roughened 

 surface, situated on the inner part of the postero-superior 

 region of the tibia ; its fleshy fibres converge, forming a 

 tendon which runs in an outward direction over the surface 

 of the capsular ligament of the stifle-joint within its external 

 lateral ligament (lubricated with synovia), to become 



