140 _ ALIMENTARY ORGANS. 



THE MOUTH. 



A. "In comparing the different animals," says 

 Dr. Paley, " I know no part of their structure which 

 exhibits greater variety, or in that variety a nicer ac- 

 commodation to their respective convenience, than that 

 which is seen in the different formation of their mouths. 

 Whether the purpose be the reception of aliment mere- 

 ly, or the catching of prey, the picking up of seeds,- the 

 cropping of herbage, the extraction of juices, the suc- 

 tion of liquids, the breaking and grinding of food the 

 taste of that food, together with the respiration of air, 

 and in conjunction with the utterance of sound ; these 

 various offices are assigned to this one part, and in 

 different species, provided for, as they are wanted by 

 its different constitution. In the human species, for- 

 asmuch as there are hands to convey the food to the 

 mouth, the mouth is flat, and by reason of its flatness 

 fitted only for reception. Whereas the projecting 

 jaws, he. of the dog and his affinities, enable them 

 to apply their mouths to snatch and seize the object 

 of their pursuit. 



The full lips, the rough tongue, the corrugated cartil- 

 aginous palate, the points and ridges in the roof of the 

 mouth, directed backwards, which assist grazing ani- 

 mals in swallowing their food, the broad cutting teeth 

 of the ox, the deer, the horse and the sheep, qualify 

 this tribe for browsing upon their pasture. The retiring 

 under jaw of the swine works in the grounds, after 

 the protruding snout, like a prong or ploughshare, 



