of the head, and the widened space between, represent the Mongolian form; while it is only as the child advances to maturity, that the oval face, the arched forehead, and the marked features of the true Caucasian, become perfectly developed.” {307a} _The leading characters_, _in short_, _of the various races of mankind_, _are simply representations of particular stages in the development of the highest or Caucasian type_. The Negro exhibits permanently the imperfect brain, projecting lower jaw, and slender bent limbs, of a Caucasian child, some considerable time before the period of its birth. The aboriginal American represents the same child nearer birth. The Mongolian is an arrested infant newly born. And so forth. All this is as respects form; {307b} but whence colour? This might be supposed to have depended on climatal agencies only; but it has been shewn by overpowering evidence to be independent of these. In further considering the matter, we are met by the very remarkable fact that colour is deepest in the least perfectly developed type, next in the Malay, next in the American, next in the Mongolian, the very order in which the degrees of development are ranged. _May not colour_, _then_, _depend upon development also_? We do not, indeed, see that a Caucasian fœtus at the stage which the African represents is anything like black; neither is a Caucasian child yellow, like the Mongolian. There may, nevertheless, be a character of skin at a certain stage of development which is predisposed to a particular colour when it is presented as the envelope of a mature being. Development being arrested at so immature a stage in the case of the Negro, the skin may take on the colour as an unavoidable consequence of its imperfect organization. It is favourable to this view, that Negro infants are not deeply black at first, but only acquire the full colour tint after exposure for some time to the atmosphere. Another consideration in its favour is that there is a likelihood of peculiarities of form and colour, since they are so coincident, depending on one set of phenomena. If it be admitted as true, there can be no difficulty in accounting for all the varieties of mankind. They are simply the result of so many advances and retrogressions in the developing power of the human mothers, these advances and retrogressions being, as we have formerly seen, the immediate effect of external conditions in nutrition, hardship, &c., {309} and also, perhaps, to some extent, of the suitableness and unsuitableness of marriages, for it is found that parents too nearly related tend to produce offspring of the Mongolian type,—that is, persons who in maturity still are a kind of children. According to this view, the greater part of the human race must be considered as having lapsed or declined from the original type. In the Caucasian or Indo-European family alone has the primitive organization been improved upon. The