The Watch of a Swan

I read somewhere that a swan, snow-white, In the sun all day, in the moon all night, Alone by a little grave would sit   Waiting, and watching it. Up out of the lake her mate would rise, And call her down with his piteous cries Into the waters still and dim:—   With cries she would answer him. Hardly a shadow would she let pass Over the baby’s cover of grass; Only the wind might dare to stir   The lily that watched with her. Do I think that the swan was an angel? Oh, I think it was only a swan, you know, That for some sweet reason, wingëd and wild,   Had the love of a bird for a child.