Mr Stark oti Changes in the Colour of Fishes. 331 



may be traced to the protection which they thus secure from 

 the attacks of their enemies ; and it affords another beautiful 

 instance of the care displayed by Nature in the preservation of 

 all her species. 



May not the changes of colour observed in these fishes de- 

 pend much upon the same cause as the changes which take 

 place in the colour of the chameleon, and for which no very sa- 

 tisfactory account has yet been given ? When crawling on 

 plants, the keenest eye cannot detect its presence, as being diffe- 

 rent in colour from the exact shade of the leaves. 



Not having been on the sea-coast this summer, I have not yet 

 had an opportunity of repeating these experiments on the sea- 

 'fishes, though, from analogy, I have no doubt that the same 

 changes of colour will be found to take place in them. In fact, 

 I have often observed on our flat sandy coasts, that the flounders 

 were so very much the colour of the sand, that, unless they 

 moved, it was impossible to distinguish them frcftn the bottom 

 on which they lay. I have noticed the same with regard to 

 the eel in the muddy pools and places where these animals 

 are usually found. 



It may perhaps be worth while to mention, that the food of 

 my minnows in winter consisted of fibres of beef or mutton ; 

 and this, with flies, generally formed their summer food. With 

 this they were generally retained in health and activity ; but I 

 have never been able to keep them ahve above three yeeirs, 

 which I take to be about the average duration of life in the 

 minnow. 



In the stickleback, the loche, and the minnow, when full 

 grown, and I suppose arrived at the extremity of age, I have 

 often observed, some days previous to death, the tail extremity 

 to lose its flexibility, and to become covered with a kind of 

 mould or conferva-hke substance to the height of two or three 

 lines, and that this substance or growth gradually crept along 

 towards the middle of the fish, the rigidity of the parts still in- 

 creasing till they died. Is this the natural death of fishes ? 



15. Brown's SauAEE, 1 

 23(/ August 1830. J 



y2 



