BOOK OF NATURE LAID OPEN. 147 



lific powers of the finny tribes have been found suffi- 

 cient for keeping up a constant supply, and making 

 up for every waste, yet there will always be found 

 a requisite number of hungry mouths to devour the 

 overplus. A single Pike has been known to devour 

 one hundred Roaches in three days. Whatever is 

 possessed of life, seems the most desirable food of 

 fish. Some of the smallest feed upon worms and 

 spawn; others, wh^e mouths are large, seek larger 

 prey, it matters not of what kind, or whether it is or 

 is not of their own species. Those with the largest 

 mouths pursue almost every thing that has life ; and 

 often meeting each other in fierce opposition, the fish 

 with the largest swallow comes off victorious by de- 

 vouring its antagonist. 



In regard to the particular construction of fishes, 

 we will briefly remark, that the Whale has often oc- 

 casion to ascend to the surface of the water for the 

 fmrpose of breathing, and it has a tail peculiarly con- 

 structed to enable it to do so. His coat of blubber 

 may be absolutely necessary to make his body equi- 

 ponderate in the water, and to keep his blood warm; 

 while in the absence of offensive weapons he is pos- 

 sessed of extraordinary agility, and by a stroke of 

 his tail can deal destruction to his pursuer. The 

 strength of this fish lies chiefly in the tail. A boat 

 has been cut down, from the top to the bottom, by 

 means of this formidable instrument, though the gun- 

 nel on the top was of tough wood. Another has had 

 the stern-post, three inches thick, cut off smooth, 



