If one wants to know what birds are about, especially the larger, more cautious species, let him get under cover near a tall dead oak or walnut, standing alone in the middle of open fields. Such a tree is the natural rest and lookout for every passer. Here come the hawks to wait and watch; here the sentinel crows are posted while the flock pilfers corn and plugs melons; here the flickers and woodpeckers light for a quick lunch of grubs, to call for company or telegraph across the fields on one of the resonant limbs; here the flocking blackbirds swoop and settle, making the old tree look as if it had suddenly leaved out in mourning—leaves black and crackling; and here the turkey-buzzards halt heavily in their gruesomely glorious flight.

With good field-glasses there is no other vantage-ground for bird study equal to this. Not in a day's tramp will one see so many birds, and have such chances to observe them, as in a single hour, when the sun is rising or setting, in the neighborhood of some great, gaunt tree that has died of years or lonesomeness, or been smitten by a bolt from the summer clouds.

"The sentinel crows are posted."

II

Nature's prodigality and parsimony are extremes farther apart than her east and west. Why should she be so lavish of interstellar space, and crowd a drop of stagnant water so? Why give the wide sea surface to the petrels, and screw the sea-urchins into the rocks on Grand Manan? Why scatter in Delaware Bay a million sturgeon eggs for every one hatched, while each mite of a paramecium is cut in two, and wholes made of the halves? Why leave an entire forest of green, live pines for a lonesome crow hermitage, and convert the rottenest old stump into a submerged-tenth tenement?

Part of the answer, at least, is found in nature's hatred and horror of death. She fiercely refuses to have any dead. An empty heaven, a lifeless sea, an uninhabited rock, a dead drop of water, a dying paramecium, are intolerable and impossible. She hastens always to give them life. The succession of strange dwellers to the decaying trees is an instance of her universal and endless effort at making matter live.