120 FISH CULTURE. 



seek it, or giving themselves the trouble to come 

 to the top. Colonel Whyte also mentioned a fact 

 somewhat of this nature, some time since, in the 

 Field. He related, that wishing to improve the 

 size and condition of his fish in a small lake, he 

 cast into it a bushel of the small Crustacea, which 

 are often found on water-weeds. These increased 

 rapidly, and as they did so his trout increased in 

 size and improved in condition wonderfully ; but it 

 is also fair to say, that they became much shyer of 

 rising to the fly. Probably the reason why the fish 

 sometimes rise well to flies, and not at others, in 

 lakes like those of Donegal (which are by no means 

 few), is owing to the fact that the abundance of 

 caddis at the bottom may be undergoing some trans- 

 formation, into flies perhaps, which ascend rapidly to 

 the top of the water, and the trout are thus led in 

 pursuit of them to the top of the water, where the 

 insects rest, and are easily captured. If anglers, 

 being aware of this fact, made some little study of 

 entomology, so far as to know about the time when 

 these insects undergo their transformations, they 

 might not be induced to seek such lakes so often in 

 vain. In the instance I have noted the lake is deep, 

 and the water dark ; and the fish at the bottom, engaged 

 with ground food, do not see the flies at the top. 



