12 THE EXTERIOR OF THE HORSE 



organ is composed of a thin piece of cartilage covered with mucous mem- 

 brane. It is capable of being projected over the surface of the eye, and by 

 its thin edge may be made to sweep away any foreign matter that may 

 accidentally fall upon it. Deep pressure applied to the upj^er lid with the 

 finger, as shown in fig. 8, will cause the haw to protrude. 



The Cheeks. — The cheeks form the greater portion of the side of 

 the tace. They extend from the temples and throat above to the angles 

 of the mouth below. In front they reach to a vertical line drawn down- 

 ward from the outer corner of tlie eye to the nostrils, and behind extend 

 along the posterior edge of the lower jaw. The upper part of the cheek is 

 broad and flat, and corresponds to the expanded portion of the lower jaw- 

 bone. The inferior portion is narrower, loose in its arrangement, and more 

 distensible. In the groove dividing the two parts are lodged the main 

 blood-vessels of the face, as well as the duct of the parotid gland by which 

 saliva is carried to the mouth. 



POSTERIOR SURFACE OF THE HEAD 



The posterior surface of the head embraces the intermaxillary sj^ace, 

 the chin, and the chin groove. 



Intermaxillary Space. — The intermaxillary space is enclosed 

 within the two branches of the lower jaw, which bound it laterally. 

 Above and below it is limited by the throat and chin respectively. It 

 corresponds to the under surface of the tongue, and gives lodgment to the 

 submaxillary lymphatic glands. The latter, which lie on the inner side of 

 the broad portion of the jaw-bone immediately beneath the skin, are 

 specially interesting to the horseman on account of the enlargement they 

 undergo in glanders, strangles, nasal gleet, and other diseases affecting 

 the nostrils. 



The Chin (fig. 2). — The chin is the prominence situated above and 

 behind the lower lip, and the chin groove ajDpears as a transverse depression 

 above it. 



2. UPPER ASPECT OF THE BODY— TOP-LINE 



The Neck. — The neck comprises the cervical portion of the spine, and 

 the muscles attached thereto, as well as a broad elastic ligament running 

 through the centre of its entire length. In front it supjDorts the head, 

 where it concurs to form the poll, and lower down is united to the throat. 

 Behind, the neck joins on to the shoulders, the withers, and the breast. 

 The superior arched border constitutes the cervical crest (fig. 1), the curve 

 of which varies in different races of horses, and in diff'erent members of the 

 same race. In stallions it is specially marked in all breeds. 



