and their corresponding qualities internally. The shad differs from the salmon in its absolute structure equally with its outward appearance. The whole anatomical arrangement of the horse differs as widely from that of the ass as the outward features vary. And the entire bodily structure of the negro, down to the minutest atom of elementary matter, differs just as widely, of course, as the color of the skin or other external qualities, from those of the white man. It is equally palpable to the reason that the nature of the negro, his instincts, all the faculties of his mind, and all the functions of his body, are pervaded by the same or by relative differences from those of the Caucasian. To suppose otherwise is not to suppose a monstrosity, for, as has been remarked, monstrosities, however wide the departure from the normal standard, are _sui generis_, without any approximation to different beings—but such things are simply impossible. As it is plainly impossible that any being could exist half like or half unlike any other creature, so, too, it is obvious that beings with different structures could not possess the same qualities or manifest the same nature. Can any one imagine an apple with the qualities of the pear or peach, or even of another apple that differed from it in its material structure? Can it be supposed that a lion could ever have the nature of the tiger, or panther, or cat, or of any of the felinæ? Can it be believed that a bull-dog ever manifested the nature of a hound, or that the mastiff or spaniel could be made to exhibit the specific qualities of either? No, indeed. Nature makes no mistakes, nor does the Almighty Master of life permit His creatures to violate or transcend His eternal decrees. It being, therefore, an invariable, indestructible, and eternal law, that the outward qualities are exactly harmonized with the interior structure down to the minutest atom of elementary particles and equally invariable and everlasting that the organism is in harmonious correspondence with the functions, the instincts, in a word, the nature, we are able to understand, with absolute certainty, the _specific_ qualities, and to approach with tolerable certainty the relative differences and actual interval that separate the white and black races. The figures of the plate in the opening of this work indicate these vital and all-important truths.