CHANGE OF COLOUR IN TROUT. 105 



shallows and sandbanks during the night time. Occasionally 

 in the moonlight we catch a glimpse of the mallards as they 

 rise from some little stream or ditch which runs into the bay, 

 or we see a rabbit hurrying up at our approach, from the sea- 

 weed, which he had been nibbling. 



In this way, with very little trouble, and often much 

 nearer home, I can generally reckon on getting some few 

 brace of wild ducks in the winter; shifting my place of 

 ambush according to the weather, the wind, &c., changes in 

 which cause the birds to take to different feeding-places. 



Trout are not nearly so tender a fish as is generally 

 supposed. At the farm-yard here they have two trout, 

 about six inches or more in length, living in the wooden 

 trough out of which the cart horses drink. They were 

 caught in the river in August, and throughout all the 

 severe frost have lived, and apparently continued in good 

 condition, although sometimes in passing I have seen the 

 water in the trough so firmly frozen, and the ice ap- 

 parently reaching so low, that the trout had scarcely room to 

 swim. When fresh water is put in they always come to the 

 place where it is poured, and seem to look for any particles 

 of food or any insects that may come in with -it. They feed 

 on worms which the boys often bring them, and which they 

 take immediately, without fear. The change of colour in 

 fish is very remarkable, and takes place with great rapidity. 

 Put a living Hack burn trout into a white basin of water, and 

 it becomes, within half an hour,* of a light colour. Keep the 

 fish living in a white jar for some days, and it becomes 

 absolutely white ; but put it into a dark-coloured or black 

 vessel, and although on first being placed there the white- 

 coloured fish shows most conspicuously on the black -ground, 

 in a quarter of an hour it becomes as dark-coloured as the 

 bottom of the jar, and consequently difficult to be seen. No 

 doubt this facility of adapting its colour to the bottom of the 

 water in which it lives, is of the greatest service to the fish 

 in protecting it from its numerous enemies. All anglers 

 must have observed that in every stream the trout are very 

 much of the same colour as the gravel or sand on which they 

 live : whether this change of colour is a voluntary or involun- 

 tary act on the part of the fish I leave it for the scientific to 

 determine. 



* In the case of some fish the change is perceptible in five minutes. 



