The =gastrocnemius= arises on the rough lines above the condyles of the
femur. The heads of origin each contain a bone about the size of a
pea—the sesamoid of Vesal—which articulates with the corresponding
condyle of the femur. The tendon comports itself as in the horse.
The =superficial digital flexor= has a large round belly. It arises in
common with the outer head of the gastrocnemius from the external rough
line and Vesalian sesamoid bone, and from the aponeurosis of the vastus
externus. The tendon winds around that of the gastrocnemius, passes over
the tuber calcis (where it is arranged as in the horse), and divides
below the tarsus into two branches. Each of these divides into two
branches which end as in the fore limb. The outer and inner branches
detach slips to the suspensory ligaments of the large digital pad.
Muscle-fibers often occur in the tendon in the metatarsal region.
[Illustration: