THE LIPS. 186 



proper head of this is received, and with which it forms a joint. 

 The ridges at either end of this cavity ai-e very low, to allow more 

 latitude of motion, and admit of the grinding action by which rumi- 

 nation is principally characterized. The muscle, being inserted so 

 near to the joint, acts with great mechanical disadvantage ; but it is 

 sufficiently powerful for every purpose that is required. 



THE CHEEKS. 



The outer walls of the mouth are the cheeks and lips. The cheeks 

 consist principally of muscle, (the masseter and the buccinator 

 muscles.) They are covered externally by the skin, and lined by 

 the membrane of the mouth. There is considerable glandular sub- 

 stance in their composition, and these glands have distinct openings 

 into the mouth, and assist in supplying it with moisture. 



THE LIPS. 



The lips form the anterior opening of the mouth ; they close it, 

 and assist in gathering and retaining the food. They consist of mus- 

 cular, glandular, and cellular texture ; and of much, in the upper lip 

 especially, condensed substance almost resembling cartilage. The 

 muscles give them the power of motion, and particularly that of 

 forcibly seizing and compressing the food. This is especially neces- 

 sary in the ox, because there are no upper front teeth, and for this 

 purpose also the cartilaginous matter was added to them, and most 

 of all to the upper lip. Simple muscular substance would be too 

 yielding to retain the grass, when it is to be forcibly separated from 

 the stalk or root. On account of this peculiar function of the upper 

 lip of the ox, it is wide and flat, in order that it may be brought 

 better into contact with herbage, and gather it in sufficient quantities. 



Being so much employed for this purpose, there is a want of 

 feeling about the lips of cattle, very diflferent from acute sensitiveness. 

 His muzzle is to be continually in contact with the ground, among 

 smooth and rough herbage — things pleasing and annoying ; and 

 therefore all acute feeling is withheld from him, and, consequently, 

 he is rarely seen using his lips as substitutes for hands, and forming 

 his opinion of the objects around him by the indications which they 

 afford him. 



The excess of glandular substance in the lips of the ox is easily 

 accounted for. They not only afford their share of the natural mois- 

 ture of the mouth, but are, from situation, form, and use, exposed to 

 various nuisances. Insects continually crawl about the muzzle, and 

 dirt and gravel accumulate on it. If the grass is to be firmly held 

 between the pad in the upper jaw and the teeth in the lower, and 

 the upper lip must materially assist in the firmness of the grip, it 



