"_Study the warbler while you may: how long he will inhabit the Kentucky forest no one can tell. As civilisation advances upon the forest, the wild species retreat; when the forest falls, the wild species are gone. Every human generation during these centuries has a last look at many things in Nature. No one will ever see them again: Nature can never find what she has once lost: if it is gone, it is gone forever. What Wilson records he saw of bird life in Kentucky a hundred years ago reads to us now as fables of the marvellous, of the incredible. Were he the sole witness, some of us might think him to be a lying witness. Let me tell you that I in my boyhood--half a century later than Wilson's visit to Kentucky--beheld things that you will hardly believe. The vast oak forest of Kentucky was what attracted the passenger pigeon. In the autumn when acorns were ripe but not yet fallen, the pigeons filled the trees at times and places, eating them from the cups. Walking quietly some sunny afternoon through the bluegrass pastures, you might approach an oak and see nothing but the tree itself, thick boughs with the afternoon sunlight sparkling on the leaves along one side. As you drew nearer, all at once, as if some violent explosion had taken place within the tree, a blue smoke-like cloud burst out all around the treetop--the simultaneous explosive flight of the frightened pigeons. Or all night long there might be wind and rain and the swishing of boughs and the tapping of loosened leaves against the window panes; and when you stepped out of doors next morning, it had suddenly become clear and cold. Walking out into the open and looking up at the clear sky you might see this: an arch of pigeons breast by breast, wing-tip to wing-tip, high up in the air as the wild geese fly, slowly moving southward. You could not see the end of the arch on one horizon or the other: the whole firmament was spanned by that mighty arch of pigeons flying south from the sudden cold. Not all the forces in Nature can ever restore that morning sunlit arch of pigeons flying south. The distant time may come, or a nearer, when the Kentucky warbler will have vanished like the wild pigeon: then any story of him will be as one of the ancient fables of bird life._" * * * * * "_The rocks of the earth are the one flooring on which every thing develops its story, then either disappears upon the stillness of the earth's atmosphere or sinks toward the silence of its rocks. Of the myriad forms of life on the earth the bird has always been the one thing nearest to what we call the higher life of the human species._