160 UPLAND AND MEADOW. 



assumes what we may call an " inanimate" position, and, 

 with a variety of colors streaking and spotting its sides, 

 has much the appearance of a bit of dead grass, a twig, 

 or a caddis-worm. Often such unnatural positions will 

 be retained for many minutes, or until some object suita- 

 ble for food comes within reach, when it darts at and 

 seizes it with the rapidity and certainty of a pike. Now, 

 in all such cases, there is great and constant changing 

 of color. Often the tints deepen until the fish appears 

 to be inky-black, then pale, until, from above, we can 

 scarcely detect the fish. Such changes, of course, are 

 very significant, and can only be explained as being ser- 

 viceable to the fishes in rendering them inconspicuous, 

 both to their enemies and to the wandering animal-life 

 on which they prey. In precisely what way the ex- 

 treme variations from very dark to pale are service- 

 able is not yet known, so far as I am aware ; but the fact 

 itself can scarcely be used to the disadvantage of the 

 main proposition, that the color and its changeablencss 

 are of benefit to the fish, and are under the animal's con- 

 trol. 



During the early spring, when the vigor of these 

 fishes is at its maximum, the coloration is more pro- 

 nounced in every particular; and the continual chang- 

 ing from dark to light, and vice versa^ as seen in con- 

 nection with its other habits, shows plainly that it is as 

 much under control as are the folding and spreading of 

 a peacock's tail. 



The cyprinoids, or "shiners," known collectively as 

 minnows, roach, and dace, so many species of which are 

 conspicuously colored at least at one time of the year, 



