TEETH OF ANIMALS. 267 



nuity ot say what would be required ; for Nature 

 has demonstrated how this defect is to be reme- 

 died. The spermaceti whale, which has teeth, 

 has also cavities in its head filled with a material 

 much lighter than water, the spermaceti; and this 

 counterpoises the weight of the teeth and jaws, 

 and restores the equilibrium of this cetaceous ani- 

 mal. 



We have, perhaps, said enough on this part of 

 our subject. But as we have seen how strangely 

 the teeth vary, to be adapted to their office of 

 cutting and grinding, we may observe that they 

 are sometimes adapted to different purposes. 



The common classification of the teeth is into 

 incisors, canine, and molar or grinding teeth. Let 

 us take our example from the canine teeth. In 

 man, they are of great length and strength : their 

 fangs project deep into the upper jaw ; they are 



The figure of the lower jaw of the Tiger. 



