CHAPTER I
A Theory[1]
[1] Rewritten from an article in The Field under the heading of “An Unorthodox View of Wet Fly Fishing.”
That a trout or any other fish could possibly mistake a wet fly used in the regular wet fly way for the natural fly of which it is supposed to be an imitation, was always to my mind a very doubtful question; but now it is so no longer. I am sure the fish takes it for something else.
If we consider what would happen to a natural fly which had by some mishap become submerged, we can come to no other conclusion than that it would be carried along by the current, without any power of its own of altering the direction in which it was being moved by the water. Does this ever happen to the sunk fly? I think not. In fishing across and down stream it certainly does not; and even in up stream fishing, in order to keep his line straight, the fisherman must keep a certain amount of tension on it, and very probably draws it through the water with much the same sort of movement he would give it if not fishing up stream.
This movement through the water which is given to the artificial must be absolutely unlike any movement of the natural fly when under the surface; for in the natural fly, if it were not already drowned, the only possible movement would be that of its legs and wings, which, not being intended as a means of progression through the water, and being absolutely unsuitable for that object, would be most unlikely to enable it to do so.
But here a very natural question arises as to what, if not the natural fly, the fish takes the imitation to be? In a communication to the Field in June, 1897, I described, under the heading of “A New Trout Fly,” the imitations of two Corixæ. This seems to be a key to the whole question. The number of insects living in fresh waters, and possessing the power of moving through it, is enormous.
There are between 220 and 230 different species of Water Beetles in our waters. There are also very many different sorts of Heteroptera, including the numerous family Notonectidæ. When we add to these the larvæ of flies and water beetles, the Crustaceans, Hydræ and Water Spiders, we must begin to realise that there are other things than a drowned natural fly for which the fish might mistake its imitation, with the materials of which it is made soaked in and drawn through the water.
The movement of many of these creatures through the water is fairly represented by the movement of the artificial fly in wet fly-fishing; and, when the shade and colour and size of the fly is the same as one of these aquatic creatures, I am sure that the fish takes it, not for a fly, but for one of them. Again, when the enormous number of these aquatic creatures is considered, it is most probable that one or other of the flies tried on any water by the fisherman will come very near in shade, colour, and movement through the water, at any rate, to one of them.
If this conclusion at which I have arrived is correct, as I believe it to be, would it not be wiser to try to imitate, not the natural fly, but some of these numerous aquatic creatures? They are numerous enough, and a large number of them are easy to imitate; but as yet but little has been done, except with regard to the spiders, in this direction. I am also sure that the success of the so-called spider patterns used in wet fly-fishing has been due to quite a different cause to that which those who first used them and those who use them now believe, as these imitations are made from the insect as it appears when out of the water. The spider goes from its nest to the surface of the water and back again by a thread stretched between, and so would hardly move through the water, as its imitation is made to do by the fisherman. Those of the so-called spider-flies which are supposed to represent some of the Ephemeridæ, are, for the reasons I have given before in speaking of flies in general, most unlikely to be mistaken for the natural insect by the trout.
A trout will undoubtedly sometimes take anything moving through the water which simulates life, if it be of a suitable size. This is shown by the manner in which they take the fancy flies; although here again, as one particular pattern of a fancy fly kills better than any other on one particular water, I think that very often this fancy fly is taken by the fish for some creature which is particularly numerous there. At any rate, if the fish only takes the artificial fly because it is apparently something alive and moving, I am sure that he would seize it with much more avidity if it represented one of his aquatic neighbours on which he has been feeding, and if its appearance reminded him of many previous pleasant meals. (Jan. 15, 1898.)[2]