MIGRATION OF FISHES. 173 



after a sudden and violent storm, cast on the eastern 

 coast of Scotland. That might naturally be expected : 

 the soft structure of a young fish cannot be supposed 

 capable of resisting the tumbling and lashing of that 

 broken water, which can tear asunder beams of oak 

 and bolts of iron. When the fish is in the deep, it 

 is safe from those casualties ; but even whales, that 

 sometimes leave their distant haunts, and visit the 

 British seas, are unable to contend with the surge, and 

 thus they are wrecked, cast on shore, and left by the 

 tide. We are not aware of any instance where that has 

 taken place, except upon low and shelving beaches, or 

 where the fish has got entangled among rocks and been 

 left dry or aground at low water. Thus we find that, 

 though the provisions of nature are abundant, they are 

 never superfluous : the animal that can live and move 

 in the water, which is a homogeneous element, is unable 

 to sustain the conflict of air, sea, and earth in a storm. 

 The migration of fishes is even a more curious matter 

 than that of birds, especially in those that alternately 

 visit salt and fresh water. The water is their atmo- 

 sphere the element from which they elaborate the air 

 necessary for their life and growth ; and any change of 

 air, even nearly as great as the change from salt water 

 to fresh, would be fatal to any land animal with which 

 we are acquainted. Change of temperature in the ele- 

 ment which they breathe, is that which land animals 

 can endure best, while fishes are adapted to bear a 

 change in the composition. The former are protected 

 against variations of temperature, by the heat of their 

 bodies being, in general, greater than that of the air ; 

 for, when the air is warm, they suffer and pant, pro- 

 Q 3 





