CHAP, vi.] LAMPKEYS. 63 



some of the stones from the distance of two feet against the 

 current and rolling them to the place with evident difficulty, 

 that the lampreys must have some good reason which induces 

 them to take this trouble. It is a great pity that the habits of 

 fish and animals living in water are so difficult to observe with 

 any degree of exactness. 



