In Nature nothing is unclean; her chemistry meets and appropriates all, even when we flee or faint. Our physical well-being forces upon us the conception of the clean and the unclean, but in the processes of the Nature that sustains us both are one. We are adjustable creatures. We are neither sugar nor salt, neither round nor square, neither iron nor lead; we yield and we resist, we melt and we freeze. We are as adjustable and as adaptive as the leaves of the forest. The firmly woven texture of the leaf, its mobile stem, the flexible branch to which it clings, make it secure against the ordinary vicissitudes to which it is subject. Man is the most adaptive of all creatures; he is as local as the turtle, and as cosmopolitan as the eagle. All climes, all conditions of wet and dry, of plain and mountain, of sea and shore, of island and continent, are his. His home is the world. Lately he has conquered the air with forces of the earth. Will he yet conquer the ether with forces of the air? Already the ether conveys his messages, but no mechanical contrivance of his can yet lay hands upon it. Let me again say that by the Natural Providence I mean the general beneficence of Nature, the blind, undiscriminating, uncalculating, inevitable beneficence which brought us here and keeps us here, and makes it good for us to be alive, despite the vicissitudes and the occasional apparently lesser phases of malevolence to which we are subject. The changing seasons, the fertile soils, the rains, the dews, the snows, the blue skies, the green earth, the flowing streams, the gentle winds, in fact all the conditions that make life possible and permanent, are expressions of this beneficence. The whole movement of evolution, with all its dark and forbidding phases, is an expression of it. Allow time enough and the turbid stream flows itself clear, and the stream of evolution is fast losing, has lost, most of its terrible and repellent features. At its flood, in earlier geologic times, one may say that its waters were charged with the elements of huge, uncouth, and terrible forms which have been mostly eliminated; the current has cleared and purified as it advanced; the dragons and monsters have nearly disappeared; the reptiles have receded and left the fowl and birds; the saurians are gone, and in their stead we have the more comely and useful forms of mammalian life. From our human point of view--and we can have no other--creation has refined. The tide of life is still like a river that has its noisome and unlovely margins, but how has it cleared and sweetened since Permian and Jurassic times! The scale of animal life has changed, less bone and muscle and more nerve and brains, less emphasis laid upon size and more upon wit. Only in the insect world are the dragons and monsters, and the carnival of blood and slaughter, repeated. In the shade of a summer tree, or in a clover-field, one may see minute creatures pursuing or devouring