The loch seems to prove that any hill-tarn might be made a good place for sport, if trout were introduced where they do not exist already. But the size of these in Loch Beg puzzles me, nor can one see how they breed, as breed they do: for twice or thrice I caught a fingerling, and threw him in again. No burn runs out of the loch, and, even in a flood, the feeder is so small, and its course so extremely steep, that one cannot imagine where the fish manage to spawn. The only loch known to me where the common trout are of equal size, is on the Border. It is extremely deep, with very clear water, and with scarce any spawning ground. On a summer evening the trout are occasionally caught; three weighing seven pounds were taken one night, a year or two ago. I have not tried the evening fishing, but at all other times of day have found them the “dourest” of trout, and they grow dourer. But one is always lured on by the spectacle of the monsters which throw themselves out of water, with a splash that echoes through all the circuit of the low green hills. They probably reach at least four or five pounds, but it is unlikely that the biggest take the fly, and one may doubt whether they propagate their species, as small trout are never seen there.
There are two ways of enlarging the size of trout which should be carefully avoided. Pike are supposed to keep down the population and leave more food for the survivors, minnows are supposed to be nourishing food. Both of these novelties are dangerous. Pike have been introduced in that long lovely sheet of water, Loch Ken, and I have never once seen the rise of a trout break that surface, so “hideously serene.” Trout, in lochs which have become accustomed to feeding on minnows, are apt to disdain fly altogether. Of course there are lochs in which good trout coexist with minnows and with pike, but these inmates are too dangerous to be introduced. The introduction, too, of Loch Leven trout is often disappointing. Sometimes they escape down the burn into the river in floods; sometimes, perhaps for lack of proper food and sufficient, they dwindle terribly in size, and become no better than “brownies.” In St. Mary’s Loch, in Selkirkshire, some Canadian trout were introduced. Little or nothing has been seen of them, unless some small creatures of a quarter of a pound, extraordinarily silvery, and more often in the air than in the water when hooked, are these children of the remote West. If they grew up, and retained their beauty and sprightliness, they would be excellent substitutes for sea-trout. Almost all experiments in stocking lochs have their perils, except the simple experiment of putting trout where there were no trout before. This can do no harm, and they may increase in weight, let us hope not in wisdom, like the curiously heavy and shy fish mentioned in the beginning of this paper.