But we must not pause too long among these smaller groups of birds, for the multitude of perching birds, which form nine-tenths of the whole bird kingdom, await us with their delicate nests and their happy family life. Ah! now we are really coming to nature’s feathered favourites, for what can be sweeter than the song of the nightingale, the skylark, or the thrush? or more touching than the fact that the young ones learn from their father the loving notes; that they, in their turn, may be able to woo and win some gentle mate to share their nests and bring up their young ones? It is for this that they have gained that wonderful singing instrument which they have deep down in their throat. For they do not produce their sounds as we do, just below the back of the mouth, but at the lower end of the windpipe, just where it divides into two branches, one going to each lung. There, where the rush of the air is strongest, is found a complicated apparatus, moved by a whole set of muscles, upon which the little fellow plays, and seems never to be exhausted, so much air has he in all parts of his body. And as the song pours through the windpipe there again he can help to give it its soft mellow tones, for while in hoarse-crying birds, like the sea birds and the waders, this tube is long and stiff, in the sweet singing birds it is short, and the bony rings composing it are thin and far apart, with soft delicate membrane between them, which can be shortened or lengthened to modulate the tones. And so we hear them in the springtime pouring forth their full tide of song to tempt a young wife to come and help them to build a nest; or, in the full pleasure of success, trilling out their delight in the warm bright sunshine, and calling on all the world to be as happy as they.