OSTEOLOGY OF THE HORSE. 67 



The body has the precise shape of a spur; consisting of a 

 semi-circular portion, from the middle of the convex side of which 

 projects a straight part, corresponding to the neck of the spur : 

 this (latter) part, also called the appendix, is surrounded by the 

 root of the tongue, to the fleshy fibres of which both its sides and 

 extremity afford original attachment. The branches, or sides of 

 the spur, are directed backwards, embracing between them the 

 superior border of the thyroid cartilage. The curved part, from 

 which the branches and neck spring, is broader and thicker than 

 elsewhere, and has, laterally, two small articulatory knots with 

 which the short horns are connected. 



The horns are four in number — two long, and two short. 

 2Vie short, or inferior horns, ascend obliquely from their articu- 

 latory connexions with the body, and terminate in two oblong 

 smooth extremities, which form similar joint-like connexions with 

 the long horns. They are flattened on the sides, and their ante- 

 rior borders are sharper than their posterior. They give attach- 

 ment to a pair of the muscles of the tongue. — The long, or superior 

 horns, constitute two long, flattened, thin bones, extending back- 

 wards, in a horizontal direction, from the summits of the inferior 

 horns, with which they are articulated. Each horn presents — 

 two smooth polished surfaces, viz. an internal and an external 

 side ; two borders, an anterior and a posterior, the latter surmounted 

 by a prominent crest; and two extremities : the supero-posterior 

 has a cartilaginous junction with the hyoideal process of the 

 petrous portion of the temporal bone; the infero-anterior, with the 

 short horn. 



This bone gives attachment to the stylo-hyoideus and hyoideus 

 magnus, and also to the pharynx. 



Connexion — With the temporal bone, larynx, pharynx, tongue, 

 and some of the muscles of the neck. 



Development. — In the young animal the body itself is separa- 

 ble into three pieces. 



THE TEETH : 



The instruments for the abscission and manducation of food. 



Number — Forty; disposed in pairs ; twenty in each jaw. 



Conformation — Conoid or oblong ; infixed within distinct alve- 

 oles formed in the maxillae; whence we distinguish, in each tooth, 

 a part without and a part within the socket: to the former portion 

 we give the name of body, and that of face to the wearing surface 

 of it ; the latter is called the root, and the pointed extremity of it, 

 the fatig. 



Structure. — The tooth is composed of two hard substances, 

 distinct from each other in aspect as well as nature; viz. a dense. 



