168 SALMONIA. 



introduced them into the river at Long- 

 stock, above Stockbridge. They were for 

 two or three years very abundant in that 

 part of the river; but they gradually de- 

 scended, and though they multiplied greatly, 

 there are now scarcely any above Stock- 

 bridge. There were, four years ago, many 

 in the river just below; but this year there 

 are very few found there, and the great pro- 

 portion that remains is found below Hough- 

 ton. I ought to mention, that the water is 

 particularly fitted for them, and they become 

 larger in this river than in their native place, 

 the Avon, some of them weighing between 

 3 and 41bs. The trout, in all its habits of 

 migration, runs upward, seeking the fresh 

 and cool waters of mountain sources to 

 spawn in : the grayling, I believe, has never 

 the same habit of running up stream; I 

 never saw one leaping at a fall, where trout 

 are so often seen. Their large back fin 

 seems intended to enable them to rise and 

 sink rapidly in deep pools ; and the slender 

 nature of the body, towards the tail, renders 

 them much more unfit for leaping cataracts 



