146 



THE BONES. 



Calcaneum, or Calcis (Figs. 98, 99, 100, 101).— A bone vertically elongated, 

 flattened on both sides, and presenting two faces, two borders, and two extremities. 



The extwnal face is smooth and nearly plane. The internal face is excavated 

 into a ghding groove to form the tarsal groove, in which passes the tendon of 

 the perforans. The anterior border is slightly concave. The posterior border is 



Fig. 99. 



TARSUS OF THE HORSE. 



INTERNAL ASPECT. 



1, Calcis; 2, astragalus (first and second bones of the 

 upper row) ; 3, cuboid ; 4, scaphoid ; 5, cuneiform 

 magnum; 6, vascular canal bet>veen the cuboid, 

 scaphoid, and cuneiform magnum ; 7, smooth sur- 

 face for the tendon of the gastrocnemius; 8, surface 

 for insertion of latter ; 9. smooth surface for the 

 tendon of the perforans ; 10, anterior extremity of 

 the tibia; 11, superior extremity of the large meta- 

 tarsal bone. A, Bones of the upper row. B, Bones 

 of the lower row. T, Tibia. M, Metatarsus. 



ANTERO-EXTERNAL ASPECT. 



Calcis ; 2, astragalus ; 3, cunei- 

 form magnum ; 4, scaphoid ; 5, 

 cuboid ; l3, cuneiform parvum ; 7, 

 superior extremity of large meta- 

 tarsal bone ; 8, superior extremity 

 of inner small metatarsal bone. 

 A, Bones of the upper row. B, 

 Bones of the lower row. T, Tibia. 

 M, Metatarsus. 



thicker, straight, and rugged. The superior extremity, shghtly enlarged, con- 

 stitutes the summit of the calcaneum, and is divided into three parts : a middle, 

 which gives attachment to the tendon of the gastrocnemius : the other, the 

 anterior, is a smooth surface on which this tendon rests when the foot is much 

 flexed ; the third, altogether posterior, also constitutes a gliding surface for the 



