266 NATURAL THEOLOGY. 



like those of a saw : but, corresponding with the 

 boldness and voracity of the animal, we see a 

 provision for their rapid renewal. 



It is interesting to see how the same class of 

 parts may be modified, and yet retain their origi- 

 nal destination of supplying the stomach with 

 food, and preparing it for digestion. What teeth 

 could we suppose suited for the whale? Now the 

 largest species of whale feed upon a small mol- 

 luscous animal which abounds in the northern 

 ocean. The teeth are here, we may say, con- 

 verted into a substance like horn ; with which we 

 are familiar under the name of whalebone. They 

 consist of plates of this whalebone attached to the 

 upper jaw, and placed in rows on the outer mar- 

 gins. Their loose edges terminate in a fringe, as 

 if the plates were split and teased into shreds ; 

 and this is undoubtedly for the purpose of retain- 

 ing the small fry, while the water is drained 

 through their interstices. 



In this curious apparatus there is, of course, no 

 necessity for great strength in the jaw, nor for 

 very powerful muscles to move them. The head 

 of the animal needs not, therefore, be denser in 

 its texture, nor less buoyant than the rest of the 

 body. What would be required if any of the 

 species had jaws or teeth at all corresponding 

 with their size? They could not lie horizontally: 

 their head would, from its weight, be tK?pressed, 

 and their tail elevated towards the suria e of the 

 water. We need not, however, straiii ur inge- 



