The world of fishes is the world of silence. Men say, "Dumb as a fish."
The world of insects is the world of night. They are all light-shunners. Even those, which, like the bee, labour during the day-time, prefer the shades of obscurity.
The world of birds is the world of light—of song.
All of them live in the sun, fill themselves with it, or are inspired by it. Those of the South carry its reflected radiance on their wings; those of our colder climates in their songs; many of them follow it from land to land.
"See," says St. John, "how at morning time they hail the rising sun, and at evening faithfully congregate to watch it setting on our Scottish shores. Towards evening, the heath-cock, that he may see it longer, stands on tiptoe and balances himself on the branch of the tallest willow."
Light, love, and song, have for them but one meaning. If you would have the captive nightingale sing when it is not the season of his loves, cover up his cage, then suddenly let in the light upon him, and he recovers his voice. The unfortunate chaffinch, blinded by barbarous hands, sings with a despairing and sickly animation, creating for himself the light of harmony with his voice, becoming a sun unto himself in his internal fire.
I would willingly believe that this is the chief inspiration of the bird's song in our gloomy climates, where the sun appears only in vivid flashes. In comparison with those brilliant zones where he never quits the horizon, our countries, veiled in mist and cloud, but glowing at intervals, have exactly the effect of the cage, first covered, and then exposed, of the imprisoned nightingale. They provoke the strain, and, like light, awaken bursts of harmony.
Even the bird's flight is influenced by it. Flight depends on the eye quite as much as on the wing. Among species gifted with a keen and delicate vision, like the falcon, which from the loftiest heights of heaven can espy the worm in a thicket—like the swallow, which from a distance of one thousand feet can perceive a gnat—flight is sure, daring, and charming to look at in its infallible certainty. Far otherwise is it with the myopes, the short-sighted, as you may see by their gait; they fly with caution, grope about, and are afraid of falling.
The eye and the wing—sight and flight—that exalted degree of puissance which enables you incessantly to embrace in a glance, and to overleap, immense landscapes, vast countries, kingdoms—which permits you to see in complete detail, and not to contract, as in a geographical chart, so grand a variety of objects—to possess and to discern, almost as if you were the equal of God;—oh, what a source of boundless enjoyment! what a strange and mysterious happiness, scarcely conceivable by man!