Such changes of form as the rudest protozoa show us, are utterly vague--admit of no precise description; and though in higher kinds the movements of the parts are more definable, yet the movement of the whole in respect of direction is indeterminate: there is no adjustment of it to this or the other point in space. In such coelenterate animals as polypes we see the parts moving in ways which lack precision; and in one of the locomotive forms, as a medusa, the course taken, otherwise at random, can be described only as one which carries it toward the light, where degrees of light and darkness are present. Among annulose creatures the contrast between the track of a worm, turning this way or that at hazard, and the definite course taken by a bee in its flight from flower to flower or back to the hive, shows us the same thing; the bee's acts in building cells and feeding larvæ further exhibiting precision in the simultaneous movements as well as in the successive movements. Though the motions made by a fish in pursuing its prey have considerable definiteness, yet they are of a simple kind, and are in this respect contrasted with the many definite motions of body, head, and limbs gone through by a carnivorous mammal in the course of waylaying, running down, and seizing a herbivore; and further, the fish shows us none of those definitely adjusted sets of motions which in the mammal subserve the rearing of young. Much greater definiteness, if not in the combined movements forming single acts, still in the adjustments of many combined acts to various purposes, characterizes human conduct, even in its lowest stages. In making and using weapons and in the maneuverings of savage warfare, numerous movements, all precise in their adaptations to proximate ends, are arranged for the achievement of remote ends, with a precision not paralleled among lower creatures. The lives of civilized men exhibit this trait far more conspicuously. Each industrial art exemplifies the effects of movements which are severally definite; and which are definitely arranged in simultaneous and successive order. Business transactions of every kind are characterized by exact relations between the sets of motions constituting acts, and the purposes fulfilled, in time, place, and quantity. Further, the daily routine of each person shows us in its periods and amounts of activity, of rest, of relaxation, a measured arrangement which is not shown us by the doings of the wandering savage, who has no fixed times for hunting, sleeping, feeding, or any one kind of action.