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live of design in their peculiar formation. Thus, 

 while the front teeth of the former have uniform- 

 ly broad cutting edges, which, meeting like the 

 blades of a pair of pincers, are precisely adapted 

 to nipping off the herbs on which they feed, the 

 back teeth are, as I have just observed, equally 

 adapted to grinding these herbs, and reducing 

 them to a pulp, the copious flow of saliva in the 

 mean time contributing to the same end. In 

 carnivorous quadrupeds, on the contrary, both 

 the front and back teeth are more or less point- 

 ed ; and, while they are obviously incompetent 

 either to bite off blades of grass or other herbs 

 on which the graminivorous tribes subsist, or to 

 grind them to a pulp if bitten off, are excellently 

 calculated, the former to seize, and the latter, to 

 rend and tear the flesh of other animals, which, 

 being in general already more moist than herbs, 

 requires a less copious admixture of saliva to re- 

 duce it to the requisite consistence. 



We come next to the principal organs, which 

 are subservient to the digestion of the food in 

 the several tribes of animals. 



By this process, the crude alimentary matters 

 taken by the mouth, which are, in their original 

 state, quite unfit to be received into the blood- 

 vessels, undergo important changes, and are 

 adapted to be converted ultimately into blood. 

 The simplest form of digestive organs in animals, 

 appears to be that by which alimentary matters, 

 having been absorbed by the surface, undergo 



