Indeed, it has been found that many of the songs of birds are sung in certain of the keys; while a learned musical writer has produced a book in which are printed many samples of the music often sung by birds. In very recent times it is stated, too, that birds have been taught to sing some of the popular tunes of the day; this being accomplished by placing a bird in a room for a while, allowing it to hear no other bird, and only the tune to be learned. Professor Brown of Aiken, S.C., has mocking-birds which he has taught to sing such songs as "The Star-spangled Banner" and "Yankee Doodle." These birds were to be taken to the Centennial Exhibition, to there exhibit their marvellous skill. A writer in "The Monthly Reader" thus speaks of that pretty singer the bullfinch:-- "I heard a lady cry out to a little bird in a cage, 'Come, Bully, Bully, sweet little Bully Bullfinch, please give us just one more tune.' "And then, to my surprise, the little bird whistled the tune of 'Yankee Doodle' as well as I could have done it myself. "The lady then told me about the bird. It was a bullfinch. She had bought it in the little town of Fulda, in Germany, where there are schools for teaching these birds to sing. "When a bullfinch has learned to sing two or three tunes, he is worth from forty to sixty dollars; for he will bring that price in London or Boston or New York. "To teach them, the birds are put in classes of about six each, and kept for a time in a dark room. Here, when their food is given them, they are made to hear music. And so, when they have had their food, or when they want more food, they will sing, and try to sing a tune like that they have just heard; for perhaps they think it has something to do with what they eat." But as, in presenting these examples of the musical teachableness of the "feathered songsters," I am entering the domain of music as an art, I will not further digress. Certain it is, too, that these delightful musicians of Nature do not require the aid of the skill of man; nor is it desirable, for the sake of musical effect at least, that their own wild, free, and glad-hearted warblings should be changed. They are better as they are, affording as they do a pleasing contrast, and adding freshness and variety to the many other forms of music. Some one, dwelling upon the charming beauty of bird-music, has expressed in words of very excusable rapture the following unique wish:-- "Oh! had I but the power To set the proper words To all your glorious melodies, My sweet-voiced birds, When words and dainty music Would each to each belong, Together we might give the world A _perfect_ song."