Camouflage 189 



postembryonic metamorphoses by nearly all of the 

 other animals of the sea. Indeed, I may add that the 

 more metamorphosis Is studied, the more It becomes 

 divested of Its aspect of marvel, though Its absorbing 

 Interest, of course, never diminishes; for reduced to Its 

 simplest terms, metamorphosis Is development. Those 

 features which excite our wonder usually do so because 

 of the extraordinary or strange contrasts they present; 

 that is to say, development, always gradual and orderly 

 in its course. Is sometimes, however, revealed only as 

 If it were an occasional occurrence, consequently giving 

 the Impression that Its progress Is marked by sudden 

 transitions from one peculiar phase to another. As I 

 have said, our flatfish swims vertically when hatched. 

 Soon It starts to rest Itself obliquely on the bottom, and 

 the eye on the lower side commences to turn upward. 

 As growth continues, this eye gradually moves with Its 

 socket around the forehead accompanied by a twisting 

 of the skull until eventually both eyes and both sockets 

 are more or less approximated on the upper side. By 

 this time the fish has assumed its characteristic flat 

 position. But the end is not yet. The full-grown flat- 

 fish Is an Inhabitant of the deeper and darker waters; 

 it Is only the young and Immature animal which I find 

 frequenting the shallow bottom of my tide pool. There- 

 fore, before Its growth will have been finally completed, 

 it will have changed its bright sand-colored coat to 

 one of a hue more somber and In keeping with the sur- 

 roundings of Its adult home. 



Now the capacity for color resemblance that inheres 

 in our flounder Is clearly of a decided advantage. Were 

 it not so endowed. It would become the prey of count- 



