268 BRITISH FRESH-WATER FISHES 
of May. When they arrive at prime condition their flesh is 
sometimes as red as that of a salmon; at other times it 
remains white, but not necessarily inferior in flavour. The 
cause of this change doubtless is to be found in the food 
of the fish, but the precise agent producing it is unknown. 
The trout is a ravenous feeder, and far from fastidious as 
to the material of its meals ; but, like most fish, for uncertain 
Food of periods and under unknown influences it sometimes 
Trout. refuses all kind of food. Crustaceans, molluscs, 
aquatic larve, minnows, and other small fish, flies, and worms 
are allacceptable in turn. The phenomenon of trout “ coming 
on the rise’’ is one with which fly-fishers are very familiar, 
and for which they keep an eager look-out, because it means 
that swarms of some species of subaqueous larve have suddenly 
and simultaneouely begun to pass from the stage of pupa to 
that of imago, or perfect fly. The trout, which have hitherto 
been preying upon what living animals they could find on the 
bottom or in mid-water, become greatly excited, follow the 
emerging flies to the surface, which is dimpled all over by the 
fish as they suck them down in myriads. This is the fisher- 
man’s opportunity. By casting his counterfeit imitations of 
the prevailing fly deftly, and keeping himself well out of sight, 
he reaps his reward. 
The art of fly-fishing for trout is such a complicated and 
difficult one that it would take a whole volume to describe its 
practice—nay, have not whole volumes, many scores of them, 
already been devoted to the mystery? Therefore I will say 
no more in this place, save that it is the most sportsmanlike 
and delicate way of capturing these pretty fish. The minnow, 
natural or artificial, certainly takes larger trout than can usually 
be tempted to rise to the surface lure; with the worm they 
may be hauled out of flooded streams without the exercise of 
much skill ; but with the artificial fly success is only to be 
scored by the clumsy and inexpert where trout have not yet 
learnt to dread the wiles of men. And how soon they come 
