There is something mysterious in loch-fishing, in the tastes and habits of the fish which inhabit the innumerable lakes and tarns of Scotland. It is not always easy to account either for their presence or their absence, for their numbers or scarcity, their eagerness to take or their "dourness." For example, there is Loch Borlan, close to the well-known little inn of Alt-na-geal-gach in Sutherland. Unless that piece of water is greatly changed, it is simply full of fish of about a quarter of a pound, which will rise at almost any time to almost any fly. There is not much pleasure in catching such tiny and eager trout, but in the season complacent anglers capture and boast of their many dozens. On the other hand, a year or two ago, a beginner took a four-pound trout there with the fly. If such trout exist in Borlan, it is hard to explain the presence of the innumerable fry. One would expect the giants of the deep to keep down their population. Not far off is another small lake, Loch Awe, which has invisible advantages over Loch Borlan, yet there the trout are, or were, "fat and fair of flesh," like Tamlane in the ballad. Wherefore are the trout in Loch Tummell so big and strong, from one to five pounds, and so scarce, while those in Loch Awe are numerous and small? One occasionally sees examples of how quickly trout will increase in weight, and what curious habits they will adopt. In a county of south- western Scotland there is a large village, populated by a keenly devoted set of anglers, who miss no opportunity. Within a quarter of a mile of the village is a small tarn, very picturesquely situated among low hills, and provided with the very tiniest feeder and outflow. There is a sluice at the outflow, and, for some reason, the farmer used to let most of the water out, in the summer of every year. In winter the tarn is used by the curling club. It is not deep, has rather a marshy bottom, and many ducks, snipe, and wild-fowl generally dwell among the reeds and marish plants of its sides. Nobody ever dreamed of fishing here, but one day a rustic, "glowering" idly over the wall of the adjacent road, saw fish rising. He mentioned his discovery to an angler, who is said to have caught some large trout, but tradition varies about everything, except that the fish are very "dour." One evening in August, a warm, still evening, I happened to visit the tarn. As soon as the sun fell below the hills, it was literally alive with large trout rising. As far as one could estimate from the brief view of heads and shoulders, they were sometimes two or three pounds in weight. I got my rod, of course, as did a rural friend. Mine was a small cane rod, his a salmon-rod. I fished with one Test-fly; he with three large loch-flies. The fish were rising actually at our feet, but they seemed to move about very much, never, or seldom, rising twice exactly at the same place. The hypothesis was