EXTERNAL FORM. ]xxi 



Of the domesticated animals, that whose form and proper- 

 ties have excited the greatest observation and interest, is 

 the Horse, whether designed for the exercise of the powers 

 of speed, for the bearing of burdens and drawing of loads, or 

 tor any other use to which he is adapted. 



In the Horse, as in all the mammiferous animals, there is 

 the long chain of distinct bones termed vertebrae, which, 

 bound together by joints, cartilage, and ligaments, consti- 

 tute the vertebral or spinal column. Each vertebra has a 

 perforation through it, so that, when the whole vertebrae are 

 connected together, there is a continued canal passing along 

 the interior. Besides the perforation for forming this canal, 

 each vertebra has exterior projections, two lateral, termed 

 transverse processes, and one upwards, termed the spinous 

 process, the latter forming that sharp elevation of bones 

 which commences with the withers, and extends along the 

 back. At the anterior termination of the spinal column is 

 the cranium, connected with which are -the jaws and other 

 bones of the face. The bones of the face consist of two divi- 

 sions, the first, the lower jaw in one large piece ; the second, 

 the upper maxillary bones, and various other pieces united 

 together. In the sockets of the bones of both jaws are in- 

 serted the teeth. These consist of 6 incisor teeth in each 

 jaw, that is, of 12 incisors, or, as they are called, nippers ; of 

 2 canine teeth or tusks in each jaw, one on each side of the 

 incisors, that is, of 4 canine teeth ; and next to these, and 

 at a distance from them, of 6 molar or grinding teeth on both 

 sides of each jaw, that is, of 24 molar teeth in all. The dis- 

 position of the teeth, the organs of mastication, may be re- 

 presented thus : 



Molar. Canine. Incisor. Canine. Molar. 



Upper jaw, .6 1 6 1 6 



Under jaw, .6 1 6 1 6 ' 



in all 40 teeth, the canine teeth being generally wanting in 

 the female. 



The cranium is composed of ten distinct pieces, namely, 

 the two frontal bones which form the forehead, the temporal 



