NATURALIZATION OF FISHES. 181 



very little the first summer ; the second season they spawn 

 and breed, as in their native waters, but if the ponds are 

 not refreshed by an overflow of the river every two or 

 three years, the waters lose the chemical condition neces- 

 sary to the reproduction of fish, from a continued infusion 

 of decayed vegetable matter, and the lakes become barren, 

 until another overflow of the mighty river comes rushing 

 through, clearing them of foul, and filling them with fresh 

 water; and restocking them at the same time with fish, and 

 most numerously with percoids. 



" Below its junction with the Ohio, the Mississippi has 

 made, in the course of time, many a " cut off," forcing its 

 way in times of flood, across the neck of a peninsula or a 

 bend, in seeking a more direct course, and leaving con- 

 siderable bodies of water, of a horse-shoe shape, as the old 

 channel closes. These are fed by the annual or occasional 

 overflow of the river, and their waters refreshed and re- 

 stocked with fish, as just described. Bruin Lake, opposite 

 Grand Gulf, Mississippi, is a water of this kind, and is said 

 to contain bass (or as they are there called trout) of im- 

 mense size. I have been told by an angler, that he has 

 taken there, in a day's fishing, thirty of these fish, whose 

 aggregate length was sixty feet." 



In naturalization, care is required that predatory fishes 

 are not introduced into waters with more valuable species ; 

 black bass, for instance, should not inhabit waters where 

 the young of salmon and shad are reared. We occasion- 

 ally find through the country, pig-headed individuals who 

 have introduced pike into ponds which were well stocked 

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