Sometimes, on a midsummer's eve, one goes out to fish all night; and then, whether the water be a lake or it be a stream, an interesting movement by the trout is invariably noticeable. They may have been scared from their places in moderate shallows during the day; but when night has fallen, and they cannot see far into the dusk, they congregate in waters which, in some cases, are hardly more than enough to cover them. Often at that time they come freely at large flies, and at a black moth as readily as at a white one. That is not because they are then indifferent as to their food. It is because colour gradually lapses as the light wanes. If you sit in a garden after sundown, all the hues in it will slowly, slowly, fade, until the laurels, which were green in the light, are dark; until a rose cannot be distinguished from a lily ; until, indeed, there is left only a general blackness. That is not because you cannot see the colours. It is because the colours are not there to see. Colours are light, light in subtle distributions among matter ; and when the light goes, colours also gradually cease to be. That is why in the darkening a black fly is as good as a white one. In the eyes of the trout there is no difference., Each is only a thing which moves, and therefore seems to live, dimly seen. There is a greater wonder to be pondered by the water-side at night. Why are the fish, among which there may be salmon and sea-trout, gathered so closely in the shallow bays ? Is it for warmth ? I do not think so : the deeps, even at midsummer, would be warmer still. I hesitate over my own conjecture ; but it may be given. I think that the fish have come in, out of the current if the water is a stream, to be free from pressure if it is a lake, to bed. There is always a time in any night when the fish ignore the flies. They will take a gentle, or a worm, it is true ; but why ? A fish snaps at the bait, I think, only when, chancing to run against him, the sunken tackle rouses him from sleep.