OSTEOLOGY OF THE HORSE. 75 



same bones, above and below. — The long inferior sesamoid liga- 

 ment protects this articulation behind, and the extensor tendon 

 forms a broad defence to it in front: indeed, both these parts are 

 so knitted in texture with the capsular membrane, that they ap- 

 pear to form the principal strength of it. 



Coffin-joint. — The condyloid prominences constituting the 

 inferior extremity of the coronet bone, are received into a bi-concave 

 hollow formed by the upper surfaces of the coffin and navicular 

 bones, although in an inconsiderable degree by the latter. The 

 articulation is secured by — 1st, The capsular membrane, which 

 inwraps the cartilaginous surfaces, and becomes inserted around 

 their boundaries. In front, it is interwoven with the extensor 

 tendon ; behind, it is greatly strengthened by connexion with the 

 tendo perforans. 2d, Three pairs of ligaments of the coffin bone. 

 a, First pair pass from the superior edges of the alae of the coffin 

 bone upon the sides of the coronet bone, and are fixed about its 

 middle. /», Second pair are stretched from the extremities of the 

 aloe, also to the coronet bone, and are inserted below and behind 

 the first. Third pair s\i\mg irova i\\Q sides of the coronal pro- 

 cess, and run to be fixed to the cartilages. 3f/, Four liga- 

 ments, two single and one pair, belonging to the navicular 

 bone, a, Superior ligament, extending from the upper and 

 posterior part of the bone to the tendo perforans. b. Inferior li- 

 gament, a very broad one, occupying the entire lower edge of the 

 bone, and thence passing into the coffin bone, just above the in- 

 sertion of the long flexor tendon, c, The tivo lateral ligaments, 

 fixing the lateral extremities of the shuttle to the sides of the co- 

 ronet bone. 



The coffin ligaments are slight in comparison to those of the pas- 

 tern and fetlock, because the coffin bone, from its situation within 

 the hoof, is not liable to dislocation. 



Section II. 

 MUSCULAR SYSTEM. 



OF THE MUSCLES. 



The fleshy parts of the body prove on dissection to be naturally 

 divisible into numerous compact masses, assuming various forms 

 and sizes, constituting so many distinct and separate muscles, 

 whose number may be estimated at about 312. The majority of 

 the muscles possess tendons or sinews, which are to be re- 

 garded as component parts of (rather than appendages to) them. 

 The symmetry of the entire body is preserved by each half pre- 



