

EXTERNAL FORM. . Ixxxi 



The movements of the external ear are effected by a set of 

 small muscles in contact with them on the upper part of the 

 head. By their means the external ear is erected, depressed, 

 or rotated, so that it may collect the sounds as they come 

 from different points ; and the spirit and temper of the ani- 

 mal may frequently be judged of by the movements of these 

 organs. 



Various muscles are employed in the movement of the eyes 

 and eyelids. Some of them are within the sockets, and vary 

 the position of the globe, so as to suit the relative position 

 of external objects. 



A set of muscles are connected with the movements of 

 the jaws, the mouth, and the nostrils. These cover the 

 maxillary bones, form the cheeks, and, stretching to a circu- 

 lar muscle which surrounds the mouth, form the lips. By 

 means of these muscles the jaws are moved upon one another 

 with great force, the nostrils are dilated to admit the air into 

 the trachea, and the varied movements of the lips are pro- 

 duced. In the horse of high breeding the nostrils are dilated, 

 and the muzzle is delicate. 



Another numerous class of muscles, which are internal, 

 are connected with the varied movements of the tongue. 

 They produce the actions connected with deglutition, and the 

 inflexions of the voice. 



The bones of the neck are enveloped in a vast mass of 

 muscles, subservient to the numerous motions of the head 

 and neck. They stretch from the head to the chest, and their 

 expansion therefore indicates power of the fore-extremities/ 



The chest and abdomen are covered with muscles, several 

 of them flat, and expanded over a large surface. Some lie 

 beneath the shoulder-blade, and are otherwise connected with 

 it, retaining it in its place, and, aided by several muscles of 

 the neck, producing those changes of position which are re- 

 quired by the motions of the fore -limbs. Along the back 

 extend very powerful muscles, producing the necessary flexure 

 of the back ; and some pass along the inner side of the ver- 



