from many sides, and requires for its cultivation knowledge derived from sciences so diverse, and requiring such different mental attributes and systems of training, as scarcely ever to be found combined in one individual. This will become perfectly evident when we consider the various factors or elements which constitute the differential characters of the groups or races into which mankind is divided. The most important of these are:
1. Structural or anatomical characters, derived from diversities of stature, proportions of different parts of the body, complexion, features, color and character of the hair, form of the skull and other bones, and the hitherto little-studied anatomy of the nervous, muscular, vascular, and other systems. The modifications in these structures in the different varieties of man are so slight and subtile, and so variously combined, that their due appreciation, and the discrimination of what in them is essential or important, and what incidental or merely superficial, require a long and careful training, superadded to a preliminary knowledge of the general anatomy of man and the higher animals. The study of physical or zoological ethnology, though it lies at the basis of that of race, is thus necessarily limited to a comparatively few original investigators.
2. The mental and moral characters by which different races are distinguished are still more difficult to fathom and to describe and define, and, although the subject of much vague statement, as there are few people who do not consider themselves competent to give an opinion about them, they have hitherto been rarely approached by any strictly scientific method of inquiry.
3. Language.—The same difficulties are met with in the study of language as in that of physical peculiarities, in the discrimination between the fundamental and essential and the mere accidental and superficial resemblances; and in proportion as these difficulties are successfully overcome will the results of the study become valuable instead of misleading. Though the science of language is an essential part of ethnology, and one which generally absorbs almost the entire energies of any one who cultivates it, its place in discriminating racial affinities is unquestionably below that of physical characters. Used, however, with due caution, it is a powerful aid to our investigations, and, in the difficulties with which the subject is surrounded, one which we can by no means afford to do without.
4. The same may be said of social customs, including habitations, dress, arms, food, as well as ceremonies, beliefs, and laws, in themselves fascinating subjects of study, placed here in the fourth rank, not as possessing any want of interest, but as contributing comparatively little to our knowledge of the natural classification and affinities of the racial divisions of man. When we see identical and most strange customs, such as particular modes of mutilation of the body, showing themselves among races the most diverse in character and
