342 FASCLE AND MUSCLES OF THE HORSE 
tarsal bone. The tarsal sheath (Vagina tarsea) begins two to three inches (ea. 
5 to 7.5 cm.) above the level of the medial malleolus, and extends about one-fourth 
of the way down the metatarsus. The check ligament resembles that of the fore 
limb, except that it is longer and very much weaker; it may be absent.! The re- 
mainder of the tendon is arranged like that of the thoracic limb. 
Tendon of 
gastrocnemius 
Superficial 
flexor tendon 
— Calcanean 
Tibialis bursa 
anterior 
- Tuber calcis 
Subcutaneous 
thickening 
Synovial 
sheath hy : 
WN Plantar liga- 
| [ ] ment 
F Deep flexor 
tendon 
Tendon of per- 
oneus tlertius 
Tibial tarsal bone 
Wi 
-—— Tarsal sheath 
- Superficial flexor 
| tendon 
Medial tendon of Annular ligament 
tibialis anterior 
Joint cavity 
Joint capsule (tarso- 
Dorsal ligament : 
g metatarsal ligament) 
Central tarsal bone 
Third tarsal bone Fourth tarsal 
Perforating tarsal vein 
Mt. III 
Check ligament 
Suspensory ligament 
Fig. 299.—Saairrau Section or Rriagut Hock or Horse. 
The section passes through the middle of the groove of the trochlea of the tibial tarsal bone, 1, 2, Proximal ends 
of cavity of hock joint; 3, thick part of joint capsule over which deep flexor tendon plays; 4, fibular tarsal bone (sus- 
tentaculum). <A large vein crosses the upper part of the joint capsule (in front of 1). 
Relations—Anteriorly, the tibia and fibula, the popliteus, lateral extensor, 
tibialis anterior, and the tibial vessels; posteriorly, the gastrocnemius, superficial 
flexor, and the tibial nerve; laterally, the fascia, skin, and the soleus; medially, 
the fascia and skin. 
1 This might well be called the tarsal (tendinous) head of the deep flexor. 
