108 THE POPULAR SCIENCE MONTHLY. 



derer and a vagabond on the face of the waters, leading what the sci- 

 entific men prettily describe as a pelagic existence, and much more 

 frequently met with in the open sea than among the shallows and 

 sand-banks which are to form the refuge of his maturer years. But 

 soon his Wanderjdhre are fairly over : the transparency of early youth 

 fades out with him exactly as it fades out in the human subject : he 

 begins to seek the recesses of the sea, settles down quietly in a com- 

 fortable hollow, and gives up his youthful Bohemian aspirations in 

 favor of safety and respectability on a sandy bottom. This, of course, 

 is all as it should be ; in thus sacrificing freedom to the necessities of 

 existence he only follows the universal rule of animated nature. But, 

 like all the rest of us when we settle down into our final groove, he 

 shortly begins to develop a tendency toward distinct one-sidedness. 

 Lying flat on the sand upon his left cheek and side, he quickly under- 

 goes a strange metamorphosis from the perfect and symmetrical to the 

 lopsided condition. His left eye, having now nothing in particular to 

 look at on the sands below, takes naturally to squinting as hard as it 

 can round the corner, to observe the world above it ; and so effectually 

 does it manage to squint that it at last pulls all the socket and sur- 

 rounding parts clean round the head to the right or upper surface. In 

 short, the young sole lies on his left side till that half of his face 

 (except the mouth) is compelled to twist itself round to the opposite 

 cheek, thus giving him through life the appearance constantly depre- 

 cated by nurses who meet all unilateral grimaces on the part of their 

 charges with the awful suggestion, " Suppose you were to be struck 

 so ! " The young sole is actually struck so, and remains in that dis- 

 tressing condition ever afterward. 



This singular early history of the individual sole evidently recapit- 

 ulates for us in brief the evolutionary history of the entire group to 

 which he belongs. It is pretty clear (to believers, at least) that the 

 prime ancestor of all the flat-fish was a sort of cod, and that his de- 

 scendants only acquired their existing flatness by long persistence in 

 the pernicious habit of lying always entirely on one side. Why the 

 primeval flat-fish first took to this queer custom is equally easy to un- 

 derstand. Soles, turbots, plaice, brill, and other members of the flat- 

 fish family are all, as we well know, very excellent edible fishes. Their 

 edibility is as highly appreciated by the sharks and dog-fish as by the 

 enlightened public of a Christian land. Moreover, they are ill-provided 

 with any external protection, having neither fierce jaws, like the pike 

 and shark ; efficient weapons of attack, like the sword-fish and the elec- 

 tric eel ; or stout defensive armor, like the globe-fish, the file-fish, and 

 the bony pike, whose outer covering is as effectually repellent as that of 

 a tortoise, an armadillo, or a hedgehog. The connection between these 

 apparently dissimilar facts is by no means an artificial one. Fish 

 which possess one form of protection seldom require the additional 

 aid of another : for example, all the electric fish have scaleless bodies, 



