To the different characters of human complexion, Dr Prichard gives three distinctive terms--the _melanous_ or brunette; the _xanthous_ or blonde; and the _leucous_ or albino; the _melanous_ predominating in the southern countries, the _xanthous_ in the northern. It is observable here, that although the natural divisions of territory with respect to complexion, (supposing climate to have the principal modifying effect upon complexion,) would be the equatorial and polar regions, or the zones of the earth which differ in latitude, yet, with some few exceptions, it is only on the northern side of the equator that the _xanthous_ complexion prevails--the inhabitants of Australia and the South Sea Islands being very generally _melanous_. The distribution of land and water cannot well be conceived to have any influence upon climate which would account for such diversity; it is probably, therefore, a result of long-continued civilization, the covering the body with clothes, and being for the most part sheltered from the direct rays of the sun. The _leucous_ complexion is an abnormal variety, and occurs occasionally in all countries. It proceeds from the absence of the dark colouring matter, or pigment; there appears in this case, however, no difference of anatomical structure, the pigment being sometimes subsequently developed in persons who have been born albinoes. The change from the _xanthous_ to the _melanous_ complexion, is a circumstance of constant occurrence; there are few children born, whose complexion does not darken as they grow up, in many cases undergoing a total change: the passage from dark to fair is rare, but it constantly occurs that _xanthous_, or even _leucous_ children, are born of _melanous_ parents. There is nothing, therefore, in the diversities of complexion which indicates specific diversity in different human races. Of the conformation of the bony fabric in the human race, the formation of the skull is the part of the greatest importance; we shall only therefore briefly notice, as to the other parts of the skeleton, that between the most uncultivated races of men, and those tribes of apes which most nearly approach man, there is a wide difference--the arms of the orang-outang reach to the ankle, and those of the chimpanzee below the knee; the pelvis, or central bony fabric, differ much from those of the human race. With regard to the skull, the value of the distinctions in its form and structure depends upon their connexion with the size and organization of the brain--involving the question, whether this has any, and what, influence upon the powers and habits of the creature. Dr Prichard, as we have already stated, blinks the question of phrenology; though he makes some inferences which prove him to have a general belief in the connexion between mental power and physical formation; nay, further, in the appropriation of different portions of the brain to different faculties.