intricate and compact, and the attractive power by which they are united exhibits a greater arid more subtle cohesion. Then, the animal kingdom, still composed of the same essential matter, shows a still more compact structure, still more perfect forms ; and its parts are bound by higher powers of attraction, which even resist the attractions of the lower spheres, till man, finally, the summit of all the kingdoms, though made up of the same materials, walks abroad the most complex and concentrated of all structures, the most harmonious and beautiful of all forms. The progress of nature, therefore, from one kingdom to another, from a lower rank in creation to a higher, consists in a gradual passage from a loose and irregular organization to one more complicated and concentric.
Again, if you take any of the natural kingdoms separately, to consider the relative rank of its different members, we shall find the distinction of degree marked by the same principle. In the mineral region, for instance, the grain of sand may be regarded as one of its lowest forms, and the crystal one of the highest; because the former exhibits no traces of organization; while the latter splits into regular mathematical figures, thereby showing a tendency, or mute prophecy, of an organic arrangement of parts.
So, in the vegetable kingdom, mosses and lichens, which are found growing loosely upon the rocks, are among the simplest, and therefore lowest, elements of it; while among the highest is the firm-knit and lordly oak, whose organization has given it a grace of outline which painters envy, and a strength of structure that defies the blasts of a hundred years. Or take, finally, the animal kingdom, with its first rude specimens of animals, almost formless, almost without parts and without powers as the oyster; and ascend gradually through worms, reptiles, fishes, birds, quadrupeds, up to man, do we not find one invariable character of progress all along the ascent, in the increasing compactness, delicacy, and finish of the organization?
But further: even in the growth of the individual members of any one of these kingdoms, this fact is strikingly exemplified. The bird, for example, begins in the lowest phases of
