This prevalence of life at the same time is as Nature would have it—the one acting as food for the other. The beat of unseen pinions is heard above, but no object visible—some night-haunting bird flying off to its feeding ground. Through the short night summer snipe whistle and wail. Newly-arrived crakes call from the meadows, and a disturbed lapwing gets up crying from the green cornstalks. Maybe the disturber was the hare whose almost human cry now comes from the thorn fence. For it the corn sprouts have come for the last time, and soon it will be in the poacher's wallet. A loud splash comes from the water, and a great black trout has sucked down its prey. This is a large-winged night-fly. That first splash is a token of more abundant night food, and soon the reach boils. Every speckled trout is "on its feed." How we long for the pliant, sympathetic rod! Then, ye lusty trout, how would the undefinable thrill rush at intervals up our arm! But our mission to-night is not this. The herons scream, the wood-owls hoot, and—what is that other night sound? The crescent moon shows a bit of light at intervals; soon masses of cloud intervene.
A faint whistle, unlike that of any bird, comes up stream, and although imperceptible the dark, still water is moved. The trout cease to rise. The whistle comes nearer, and then a rustle is heard. The osier beds are stirred, and some long dark object makes its way between the parted stems. A movement would dispel the dark shadow, and which in turn would divide the dark water and take it silently away. The otters have reconnoitered, and all is safe. They come paddling down stream, and, arriving at the pool, stop, tumble and frolic, rolling over and over, and round and round, and performing the most marvellous evolutions you could possibly conceive. They swing on the willow spray, and dash with lightning velocity at a piece of floating bark, tumble with it, wrestle with it, and go through a hundred wonderful movements. They are motionless, then begin to play, and so continue for nearly an hour, when, as if suddenly alarmed, they rush down stream to their fishing grounds, and leave us cold and benumbed. We plod through the meadow beneath the moon and stars, chilled to the marrow by the falling dew.
Otters are still abundant on the banks of most northern streams, as also among the rocks and boulders of the coast-line. Human invasion drives them from their haunts, although, where waters remain unpolluted, they not unfrequently pass up the rivers by towns and villages during the still night. On the margins of the more secluded tarns of the fells, otters, too, are yet found. Fitted for an aquatic existence, the structure of the otter beautifully exhibits the provisions suitable to its mode of life. On land it can travel swiftly, though the water is its best element. Immersed in this, its coat appears smooth and glossy. In pursuing its prey it performs the most graceful movements, doubling and diving so rapidly that it is difficult to follow its evolutions. When fishing, its object is to get beneath the object pursued, as, from the construction of its eyes, which are placed high in the head, it is better enabled to secure its prey. This it seldom fails to do, its whole structure, as already remarked, greatly facilitating its movements in the water. Its uniform dusky brown coat has, like all aquatic creatures, a soft under-fur with long hair above.
The otter generally takes possession of a natural cavity, a drain, or a hole made by the inundation of the stream. The entrance is usually under water, and inclines towards the bank. Situations where the latter is overhung with bushes and with tall water plants in the vicinity are generally chosen. From this the young, when three or four weeks old, betake themselves to the water. If captured now they may easily be domesticated. One of our friends has to-day a young otter, which he leads about in a leash. At Bassenthwaite a man and his son trained a pair of otters to fish in the lake. They would return when called upon, or follow their master home when the fishing was over. The males in spring fight desperately, and once, when hidden, we witnessed a fight which lasted an hour, and so engrossed did the combatants become that we approached and, taking the part of the lesser, shot its aggressor.
And now a word as to the food of the otter. That it destroys fish we are not about to deny. But this liking for fish has become such a stereotyped fact (?) in natural history that it is glibly repeated, parrot-like, and so continues until most readers have come to accept it. The otter destroys but few fish, using the word in its popular acceptation. What it destroys are for food, and not out of love of killing. The greater part of its diet consists of fresh-water crayfish, thousands of which it destroys, and it is for these that long journeys are so frequently made. This does not apply to the pairing season; the wanderings have then another end. Many miles in a night are traversed for these crustaceans, the beds of mountain and moorland streams being tracked to their source, almost every stone on the way being examined. At least upon two occasions have we found the remains of the moor-hen after an otter's meal.
CHAPTER IV.
COURIERS OF THE AIR
The power of flight being almost exclusively the characteristic attribute of birds, it is somewhat strange that even the most eminent naturalists should be silent upon it. And yet this is almost universally so. Those who mention the speed of flight do so upon the most insufficient evidence, as witness Michelet's statement that the swallow flies at the rate of eighty leagues an hour. Roughly this gives us a thousand miles in four hours; but assuredly, even in its dashes, the swallow does not attain to anything like this speed. The Duke of Argyll is rather under than over the mark when he computes the speed at more than a hundred miles an hour. Here, however, the mechanism of flight in the swallows is carried through an ascending scale, until in the swift it reaches its highest degree of power both in endurance and facility of evolution. Although there are birds which may, and probably do, attain to a speed of one hundred and fifty miles an hour, this remarkable rate is not to be looked for in any of the birds of the swallow kind. There is something fascinating in the idea of eliminating time and space, and with this attribute popular fancy has in some measure clothed the swallows. At the greater rate of speed indicated above the swallow might, as has been stated, breakfast round the Barbican, and take its mid-day siesta in Algiers. This, however, is a popular myth. In their migrations swallows stick close to land, and never leave it unless compelled; they cross straits at the narrowest part, and are among the most fatiguable of birds. From this it will be seen that although swallows may possess considerable speed, they have no great powers of sustained flight or endurance. These attributes belong, in the most marked degree, to several ocean birds.
Any one who has crossed the Atlantic must have noticed that gulls accompany the ship over the whole distance; or, at least, are never absent throughout the voyage. The snowy "sea swallows," as the terns are called, seem quite tireless on the wing; though the petrels and albatross alone deserve the name of oceanic birds. Sir Edwin Arnold, in an account of his voyage to America, writes as follows of the sea-swallows: "Every day we see playing round the ship and skimming up and down the wave-hollows companies of lovely little terns and sea-swallows, the latter no larger than thrushes. These fearless