244 
ANATOMY OF THE HORSE. 
tibia inwards. It will also extricate the capsular ligament from 
being pinched between the bones. * 
flexor pedis. — Tibio-phalangeus . 
Situation .—Postero-external side of the limb. 
Figure .—Fusiform ; elongated : fleshy part, thick. 
Attachment .—Superiorly, to the postero-external side of the 
head of the tibia; to the supero-posterior half of the body of the 
bone, and to the posterior side of the fibula. Interiorly, the ten¬ 
don assumes the name of tendo perforans , and is disposed of in 
a manner so similar to the tendon of the same name in the fore 
extremity as to render any description of its lower attachments 
here quite unnecessary. 
Relations .—Posteriorly, with the plantaris and the gastrocne- 
mii, and also with the posterior tibia 1 bloodvessels; anteriorly, 
w ith the tibia and fibula. Superiorly and internally, w ith the 
flexor accessorius ; externally, with the plantaris and the flexor 
metatarsi. 
Structure .—Superior attachment, both tendinous and fleshy, 
from w hich at the back of the hock proceeds a strong cordiform 
tendon, w hich passes within a groove upon the inner side of the 
os calcis and runs down the posterior part of the leg, where it 
becomes connected with the tendons of the flexor accessorius and 
gastrocnemius internus. With the former of these it unites, and 
the two together form a single tendon; but with the latter, the 
union is only one formed by cellular membrane. This tendon is 
denominated the tendo perforans , in eontra-distinction to that 
derived from the gastrocnemius internus, which (as w T as before 
observed) is styled the tendo perforatus . Both tendons are 
inclosed w ithin the same sheath; and are, in fact, disposed of 
down the leg and foot in a similar manner to what the cor¬ 
responding tendons are in the fore extremity: on which account 
any further detail would prove but recapitulatory. 
Action .—That of the gastrocnemius internus corresponds to 
that of the externus: it extends the hock. But, as it continues 
down the leg through the medium of the tendo perforates, it 
will also flex the fetlock and pastern joints. The flexor pedis 
will prove of some effect in the extension of the hock: although 
its principal operation is upon the foot, which it alone flexes ; and 
at the same time it flexes the pastern and the fetlock. 
flexor pedis accessorius. — Peroneo-phalangeus. 
Situation .—Deep seated : postero-internal part of the leg. 
Figure .—Elongated; fleshy portion pyramidal. 
