230 INTRODUCTION TO ZOOLOGY. 



examples of fishes constructing nests, and evincing a remark- 

 able degree of care and anxiety for their young. The obser- 

 vations of Mr. Couch prove, that, on our own shores, " nests 

 are built, in which the ova are deposited, and over which the 

 adult fish will watch till the young make their escape." On 

 one occasion this gentleman visited daily for three weeks a 

 nest of the Fifteen-spined Stickle-back (Gasterosteus spmacliia), 

 formed of sea-weed and the common coralline, and invariably 

 found it guarded; nor would the old fish quit its post so long 

 as he remained.* 



MEANS OF ESCAPE, DEFENCE, AND ATTACK, In some tribes 

 safety is to some extent secured by the colour of the skin 

 being inconspicuous. It was an old belief, when the real 

 fructification of the ferns was unknown, that the possession 

 of the seed gave supernatural powers of concealment; and 

 hence Shakespeare says: " We have got the fern-seed; we 

 walk invisible." Without possessing the fern-seed, there are 

 certain fishes that enjoy, to some extent, the gift which it 

 was supposed to bestow; and such fishes are living in great 

 abundance on our own shores. I allude to some of the most 

 common flat-fishes. Let any one try to see them as they lie 

 upon the bottom, and he will be convinced it is not an easy 

 matter. When in motion they are of course detected, and 

 occasionally the white side of the body shows for an instant 

 as they glide along; but as soon as they stop, and by the 

 action of the fins have settled down into the sand, they are so 

 similar in colour to the surface on which they rest that they 

 escape detection, unless the eye has watched the movement. 

 All parts of the beach, are not, however, of the same material, 

 and therefore are not of the same colour; but, whatever it 

 may be, the upper surface of the fish exhibits a correspon- 

 dence which is very remarkable. We have seen it of a uniform 

 dark tint, similar to that of the muddy bottom on which the 

 fish had been found; while on others it was of a mottled or 

 pepper-and-salt colour, like the gravel of the little bay in 

 which it had been captured. 



The Flying-fish springing into the air when pursued by the 

 Bonito is an example of a different mode by which danger is 

 avoided. Others, however, do not content themselves with 



* Notes on the Nidification of Fishes, by R. Q. Couch, Esq. published 

 in " The Zoologist," vol. ii. p. 795. 1844. 



