SALMONIDJE. 91 



the Trout of America is a lighter colored, brighter, gayer, and more 

 gorgeous creature than his European kinsman. And, farther yet, we 

 shall find that in the purest and most limpid streams, in the lakes which 

 to the most transparent waters add the sunniest expanse, the brightest 

 and most beautiful Trout are taken ; while in black boggy waters, or 

 in forest-embowered rivers, the colors of the fish are rather dim and 

 dusky. 



This is not, however, merely a matter of theory and analogy, for 

 experiments have been actually tried on this point, and with perfect 

 success. Mr. Agassiz assures me that he has repeatedly known very 

 brilliant and gaily-colored fish, taken in clear and sunshiny waters, and 

 transferred to neighboring pools or streams of totally different charac- 

 ter, to begin to fade and lose the intensity of their colors, sensibly, 

 within a very few hours, and aftei: a few days or weeks, to be entirely 

 undistinguishable from the native fish of the place. 



This accounts, at once, for the facts so often stated, and seemingly 

 so inexplicable, of two lakes communicating with each other by a com- 

 mon channel, and containing two distinct varieties of Trout, one beau- 

 tiful, and excellent upon the table, the other dark-colored and ill-tasted, 

 the two varieties never beingknown to intermingle, or to exchange from 

 one to the other water. 



The explanation of this apparent phenomenon is, that the change pro- 

 duced by passing from the dark and peat-soiled waters of the one lake, 

 to the limpid element of the other, in the fish, is so rapid, that they 

 assimilate themselves almost instantaneously, in outward appearance, 

 to the fish into whose society they have emigrated. 



The lakelet, known as Stump-pond, on the northern side of Long 

 Island, which, as its name indicates, is filled with thebuttsof dead trees, 

 and saturated with vegetalble matter, has been for many years -famous, 

 or I should rather say infamous, for the ugliness, want of brilliancy, 

 and indifferent quality in a culinary point of view, of its Trout, as com- 

 pared with those of the bright and transparent mill-ponds and rivulets 

 of the south side. No one, however, has ever thought of erecting them 

 into a species, or of designating them as Salmo Stumppondicus, seeing 

 clearly the cause and effect ; and lo ! now of late years, as the cause 

 is passing away with the process of time, the effect is also disappearing ; 

 as the vegetable matter is decaying, being absorbed, and swept away, 



