In the winter Lutra had imperceptibly acquired the habit of swimming and diving across-stream, just as an old fox, when hunting in the woods, quarters his ground systematically across-wind, and so detects the slightest scent that may be wafted on the breeze. Nature had been specially kind to her; she was fashioned perfectly, and in the river reigned supreme. Her body was long, supple, and tapering; her brown fur was close and short, so that the water never penetrated to her skin and her movements were not retarded as they would have been had she possessed the loose, draggling coat of an otter-hound. She seemed to glide with extraordinary facility even against a rapid current. Her skin was so tough that on one occasion when, by accident, she was carried down a raging rapid and thrown against a jagged rock, a slight bruise was the only result. Her legs were short and powerful, her toes webbed, and her tail served the purpose of a rudder. Nostrils, eyes, and ears--all were small and water-tight, and set so high on the skull that, when she rose to breathe, little more than a speck could be seen on the surface, unless she felt it safe to raise her head and body further for the sake of ease in plunging deep.
When Lutra was nine months old she caught her first salmon; and, though the fish was only a small "kelt," returning, weak from spawning, to the sea, the capture was a fair test of the cub's prowess and daring. It happened thus. She was walking up the river-bed one boisterous night, when she saw a dark form hovering close to the surface in the middle of a deep pool. Her eyes, peculiarly fitted for watching objects immediately above, quickly detected the almost motionless fish. The eyes of the salmon were also formed for looking upwards, and so Lutra remained unnoticed by her prey. She stole around the hovering fish, that the bubbles caused by her breathing might make no noticeable disturbance as they rose to the surface, and then, having judged to a nicety the strength of the stream, paddled with almost imperceptible motion towards the salmon. Before the fish had time to flee it was caught in Lutra's vice-like jaws and borne, struggling desperately and threshing the water into foam, to the bank. There the otter-cub killed her victim by severing the vertebræ immediately behind its gills.