From the facts collected by Dr. Prichard, it appears to follow very distinctly, not only that Human Physiology is extremely mutable, but also that the transitions do not occupy a very long interval of time. Thus Jews are resident in the African Kingdom of Kongo, whose complexions are as black as those of the native Negro population. Again on the borders of Negro-land, different sections of the same tribe, speaking the same language, are, in many instances, found variously approaching to or diverging from the Negro standard of colour and physiognomy, according to the latitude or elevation, or other physical features of their respective locations; instances in which the separation—and therefore the physiological differences—must have been recent—for languages change too rapidly to preserve the features of identity or even of a close affinity for a period of long duration! The descendants of the Arabs who overran the North of Africa in comparatively modern times furnish another example; they do not differ in physiognomy from the Berbers, the original inhabitants of the same regions. From these and similar facts it must be inferred—not only that the existing varieties of Human Physiology form no objection to the opinion that the different populations of the Globe are descended from one stock—the same facts lead also to the conclusion, that—with relation to the earliest eras in the History of our species—Physiological peculiarities must be entirely rejected as evidence, either of a specific connexion or of a specific difference between individual races of men, a principle admitting of many highly interesting applications, of which an example will now be offered.