Mr. Darwin justly remarks, that “the belief that there exists in man some close relation between the size of the brain and the development of the intellectual faculties, is supported by the comparison of the skulls of savage and civilised races of ancient and modern peoples, and by the analogy of the whole vertebrate series.”[374] There must, indeed, be a certain agreement between the brain and its intellectual products, and hence the large size of the human brain requires that the mental phenomena of man should be of a vastly superior nature to those presented by the lower animals. Whether, according to the developmental view of the correspondence between human and brute mental faculties, the lower races of man, as compared with animals, really exhibit an intellectual superiority commensurate with the largeness of their brains, may be questioned. Mr. Wallace, indeed, declares that they do not, and he goes so far as to say that “a brain slightly larger than that of the gorilla would, according to the evidence before us, fully have sufficed for the limited mental development of the savage.”[375] This opinion is correct, on the assumption that animal and human mental action is perfectly analogous, and Mr. Wallace would undoubtedly be right in asserting that the savage possesses a brain “quite disproportionate to his actual requirements,” if by this phrase is meant his mere animal wants. But the savage is a man, and the size of brain required by him must be judged of, not by the degree of intellectual action he exhibits, but by its accompaniments—not by quantity, but by quality.