210 OUTLINES OF EQUINE ANATOMY. 



sorius, becoming attaclied firmly to tlie posterior surface of 

 the superior extremity of the olecranon ; inferiorly it blends 

 with the faschia of the arm and with flexor metacarpi 

 internus, the tendinous band so formed becoming firmly 

 attached to the superior margin of trapezium, and to the 

 annular ligament of the knee. 



Flexores pedis perforansand perforatus. — Attached to the 

 infero- posterior part of the ridge running upwards from 

 the inner condyle of the humeiiis and to the capsular liga- 

 ment of the elbow-joint, are numerous muscular fasciculi, 

 comprised mainly of four masses which run down the pos- 

 terior surface of the radius and inferiorly combine, three 

 of them forming the perforans tendon, the other the per- 

 foratus ; the first is triangular in shape, being concave on 

 its posterior surface for the reception of the second. To 

 the inner margin of each tendon runs a part of the supe- 

 rior suspensory ligament, that to perforatus being the 

 widest and strongest. Here the tendons of radialis and 

 nlnaris accessorius blend with that of perforans. The 

 tendons of perforans and perforatus with the metacarpal 

 artery, vein, and nerves run together in a synovial sheath, 

 separated from that of flexor metacarpi internus by a fibrous 

 layer from the annular ligament. This sheath superiorly 

 is bounded by the superior suspensory ligament, extends 

 downwards for about four inches, terminating inferiorly 

 opposite the heads of the small metacarpal bones, where it 

 is bounded by the subcarpal ligament, a diffused layer of 

 ligamentous fibres which arises from the inferior part of 

 the annular ligament, where it immediately invests the pos- 

 terior surface of the small bones of the knee, and runs 

 mainly to the perforans tendon, though a few of its fibres 

 run on either side of that tendon to perforatus. Perforans 

 is said to form a sheath for perforatus at the back of the 

 knee, this is hardly correct ; it forms the anterior part of 

 an imperfect sheath which is laterally composed of superior 

 suspensory ligament, and another layer of the annular 

 ligament of the knee, but between the two tendons is a 

 synovial sheath, which on the outer side communicates with 

 the former sheath, but does not extend so far inferiorly 



(by one and a haK inches), though superiorly it extends as 

 far up as the superior part of the inferior third of the 

 radius. We must temporarily defer the examination of the 

 xemaining portion of these tendons. 



