92 AMERICAN FISHES 



aad as the purifying influences of the springs are gaining upon the cor- 

 rupt and stagnant qualities of the pond, the fishes are likewise becoming 

 brighter and better. In the course of a few more years, it is probable 

 that they will be scarcely distinguishable from the finely-formed and 

 finely-colored fish of Snedecor's or Carman's streams, at Islip and Fire- 

 place. 



Doubtless, other causes besides the influence of light, have their 

 effect both upon the app ;arance and the flavor of the Trout ; we have 

 seen that. their color is affected by the shell-fish, or even the larvae of 

 flies, on which they feed ; we have also seen that they increase in 

 weight, size, and fatness, according as they are nourished with worms, 

 with small fry, or with water-flies ; and no one in his senses can doubt, 

 I imagine, that if these fish which have obtained scarlet spots, and 

 become golden-finned and golden-bellied by feeding on shell-fish, or 

 crustaceous-cased insects, were confined upon a regimen of dew-worms 

 or May-flies, they would gradually relapse into their original coloring. 



Nor can it be supposed, I think, judging from all analogy, but that 

 the Gillaroo Trout, kept permanently in situations where it could never 

 find either shell-fish, or any hard edible substances, would gradually 

 lose the distinctive hardness of its stomach, as well as its characteristic 

 coloring. The probability is, that the young fry of a finger's length, 

 spoken of by Sir Humphrey, would lose the distinction individually ; 

 and I do not at all conceive it likely that the characteristic would sur- 

 vive through two generations from the largest adult. 



While I am writing on this point, I will cite a fact, though it belongs 

 with greater propriety to the history of another fish, the Greatest Lake 

 Trout, Salmo Amethystus, when describing which, it will be noticed 

 more fully. This is simply that in the same lakes, Huron and Superior, 

 this same fish exists in three different states of color, so totally dissimilar, 

 that it is supposed by the French inhabitants of the shores, to be three 

 distinct fishes, and is known by three distinct names, according to the 

 situations in which it is found, and by which its coloring is evidently 

 affected. 



Drawings of the fish in two of these stages are now lying before me, 

 and will be presented to my readers under the proper head ; here, it 

 will be sufficient to state that, but for the shape of the head and gill- 

 covers, the form of the fins and the number of the fin-rays, things not 



