A careful watcher will see the birds teach these things, and many others as interesting. But no one will see anything unless he is quiet, and does not frighten them. THE BIRD GROWN UP XI THE BIRD'S LANGUAGE WHEN the bird is grown up, there are many other interesting things to know about him,--one is, whether he can talk. It is plain to those who have studied the ways of birds, that they are able to tell things to each other, and many writers have said plainly that birds have a language. If you notice birds in cages, you will find that when two or more of a kind are in the same room, you will hear little chirps and twitters and other notes, not at all like their song. But if one is alone in a room, he hardly makes a sound except when singing. Then see a robin out of doors. He is less afraid of us than most birds, and easiest to watch. If something comes up on him suddenly, he gives a sharp note of surprise. If a cat appears, he has another cry which every one can understand, a word of warning to all. If everything is quiet and his mate is near, he will greet her with some low, sweet notes. When a partridge mother sees danger, she gives one call, which all her brood know, and at once run and hide. When the hen speaks to her chicks, they know well whether it means to come to her, or to run away. Of course birds do not use our words. When it is said that the quail says "Bob White," it is meant that his call sounds like those words. To some the notes sound like "more wet." One may call it almost anything, like "all right" or "too hot." You will read in books about birds, that a certain warbler says "Witches here," or that the white-throated sparrow says "Old Sam Peabody," and other birds say still different things. The writer means that the words remind one of the bird's notes, and so it is useful to know them, because it helps you to know the bird when you hear him. I have many times seen birds act as if they were talking to each other. You can often see the city sparrows do so. There is nothing in a bird's ways that we like so well as his singing. And in all the many species of birds in the world, no two sing exactly alike, so far as I can find out. You may always know a bird by his song. A robin does not sing like a thrush or a catbird. And what is more, not one of the sounds he utters is like those made by any other bird. If you know him well, whatever noise he makes, you will know at once that it is a robin. But there is something still more curious about it. No robin sings exactly like another robin. When you come to know one bird well, you can tell his song from any other bird's. Of course, all robins sing enough alike for one to know that it is a robin song, but if you listen closely, you will see that it is really different from all others. Persons who have kept birds in cages have noticed the same thing.