still around us the realm of the unknown; yet not only are daily aggressions made upon it, but science has advanced so far as to render it certain that there is no department or object in the universe, which is not comprehended in this system of mutual fitnesses, harmonies, and uses. Now consider the relation of organized being to this system. What is an organ? It is the capacity of perceiving, choosing, and utilizing a fitness. The rootlets of the tree by the river-side perceive the adjacent water, elongate themselves toward it, in a drought make convulsive and successful efforts to reach it; while the corolla of the heliotrope perceives the calorific rays, and turns toward their source in the heavens. The organs of the plant select from the elements around it such substances as are fitted to feed its growth, and appropriate them to its use, even though they be found in infinitesimal proportions, in masses of alien substance. In all this there is a semi-self-consciousness, corresponding, not indeed to the action of mind, but to that of the spontaneous life-processes in intelligent beings. The animal carries us a step higher. His instincts are an unerring knowledge of fitnesses and uses within his sphere. He seeks what is fitted, shuns what is unfitted to his sustenance and growth, is never deceived when left to his own sagacity, and fails only when brought into anomalous relations with the superior knowledge of man. He lives, merely because he is conscious of the fitnesses of nature, and yields up his life to a stronger beast, in accordance with those same fitnesses--beneficent still--by which all realms of nature are kept fully stocked, yet never overstocked, with healthy and rejoicing life. The fitness which thus pervades and unifies the entire creation, man as an animal perceives, as a living soul recognizes and comprehends; and to his consciousness it is an imperative law, obeyed always with self-approval, disobeyed only with self-condemnation. Of disobedience he alone is capable, yet he but partially. In order to live, he must obey in the vast majority of instances; still more must he obey, if he would have society, physical comfort, transient enjoyment of however low a type; and the most depraved wretch that walks the earth purchases his continued being by a thousand acts of unintended yet inevitable obedience to one of voluntary guilt. Man's law--the law which, in violating or scorning it, he cannot ignore or evade--is the very same fitness which runs through all inorganic nature, and which the semi-conscious tree, shrub, or flower, the imperfectly self-conscious bird, fish, or beast uniformly obeys.