184 MANUAL OF MODERN FARRIERY 



which he meets with upon a road, and the rider 

 may be thrown off when he least expects it ; while 

 a horse that is quite blind will generally resign him- 

 self to the guidance of his rider or driver. 



THE TEETH AND THEIR DEVELOPMENT. 



Mastication in the horse is performed in two 

 ways, namely, by a champing motion, and also a 

 ofrindinof motion. 



At 0, Plate III, fig. I, is the masseter-muscle, 

 which is of great strength, and constituting the 

 cheek ; it has its origin at the superior maxillary 

 bone, under the ridge continued from the zygomatic- 

 arch, Plate viii, ^<g. Z^ f^ f^ ^'^^ inserted into the 

 lower jaw. This acts in conjunction with the 

 temporal muscle in closing the jaw, and in pro- 

 ducing its direct cutting, or champing motion. 



Inside of the lower jaw, on each side, and occupy- 

 ing the entire of the hollowed portion, and opposite 

 the masseter, or cheek-muscles, are the pterygoid- 

 muscles, which proceed from the jaw-bones to those 

 more in the centre of the channel, also shutting the 

 mouth, and likewise by their alternate action giving 

 that grinding motion so necessary in preparing the 

 food of the horse. 



The channel which occupies that portion of the 

 lower jaw between the branches, is of considerable 

 importance in the conformation of the head of the 

 horse. If this part is too wide, it always gives a 

 clumsy, heavy appearance to the face ; and when too 

 narrow, it prevents the animal from bending his 

 head with freedom and grace. Horses with such 

 heads are unpleasant in the hand either of the rider 

 or driver, as they constantly keep pulling and 



