A small elongated muscle placed behind the one last described on the outer side of the leg.

Origin. - From the outer part of the fibula and the external lateral ligament of the stifle.

Insertion. - The tendon of the peroneus in its downward course passes over a groove on the outer and lower extremity of the tibia or leg-bone, thence over the outer side of the hock-joint, where it is contained in a canal and invested by a synovial sheath. On emerging from its enclosure it passes obliquely forward and joins the tendon of the extensor pedis in the middle of the canon.

Action. - To assist the last-named muscle.