CHAPTER I. 



CLASSIFICATION OF THE FLAT-FISHES. 



It is a matter of general knowledge and experience that the various kinds of flat- 

 fishes resemble one another and differ from all other fishes in these conspicuous 

 features : that their form is very flat, that one side is coloured and the other of a pure 

 opaque white, and that there are two eyes on the coloured side and none on the white 

 side. It is further generally known, from the observation of such fishes in the living 

 state in aquaria, that when alive they are usually resting on the white side at the 

 bottom of the water, sometimes gliding gently over the ground, sometimes burying 

 themselves in the sand, which is the material on which they are accustomed to live, 

 and only occasionally rising up from the bottom and swimming in a horizontal position 

 through the water. The common sole is also as a rule recognised by everybody as a 

 particular kind of flat-fish, being readily distinguished by its gently curved outline, 

 especially by the regular, almost semicircular, shape of the snout, and by the dull 

 brown colour of its upper side after death. 



But this is only true of the sole as it is usually seen by the majority of people, that 

 is in its adult condition. Ordinary habits of observation are not sufficient to dis- 

 tinguish the sole in its very young condition from other kinds of flat-fishes : only 

 naturalists are able to separate the kinds from one another among individuals from 

 one to three inches in length. Even fishermen, who might be supposed to have 

 unusual opportunities of comparing different kinds of fishes, but who, as a matter of 

 fact, have usually no leisure and no superfluous energy to devote to accurate and 

 minute observation, constantly mistake various kinds of flat-fishes in their young stages 

 for young soles. The reason of this is not that the young fishes between one and 

 three inches long differ in their characters from full-grown specimens, but simply that 

 the characteristic features are on a much smaller scale, and therefore are not seen 

 without attentive observation. 



Untrained powers of observation are also unable to compare the degree of difference 

 between one kind of flat-fish and another. The plaice and flounder are named 

 independently ; but a fish which resembles the plaice and flounder far more closely 

 than it does the sole is sold under the name of merry-sole in Devonsliire and lemon- 

 sole in London. This may be partly due to an inclination to enhance its value in the 



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