178 



DEGLUTITION OR SWALLOWING. 



general habit of very rapidly eating or rather " bolting " the 

 meals. There is another evil attendant on this practice, that 

 much more food is swallowed than is necessary to supply the 

 wants of the system ; for the sense of hunger is not so readily 

 abated by food which has not been prepared for digestion ; 

 and thus the feeling of satiety is not produced, until the 

 stomach has already received a larger supply than it is well 

 able to dispose of. Imperfect mastication of the food is very 

 apt to occur, in persons who are losing their teeth by old age 

 or decay; and where these are not replaced by artificial means, 

 the next best remedy is to cut the food into very small por- 

 tions, before it is taken into the mouth, and to masticate it 

 there as thoroughly as possible. 



Deglutition. 



192. In the Mammalia, the cavity of the mouth is guarded 

 behind by a sort of moveable curtain, which is known as the 

 veil of the palate (fig. 107); and this hangs down during 



Veil of the palate 



Nose 



Pharynx 



Salivary glands 

 Os hyoides 



Larynx 

 Thyroid gland 



(Esophagus 



mm ma 



Trachea 

 Fig. 107. PERPENDICULAR SECTION OF THE MOUTH AXD THROAT. 



mastication, in such a manner as to prevent any of the food 

 from passing backwards. This partition, which does not exist 



