The predominance of the cerebral nervous system and of intelligence in childhood, which is here under consideration, together with the decline of it in riper age, receives important illustration and confirmation from the fact that in the species of animals which stands nearest to man, the apes, the same relation is found in a striking degree. It has by degrees become certain that the highly intelligent orang-outang is a young pongo, which when it has grown up loses the remarkable human look of its countenance, and also its astonishing intelligence, because the lower and brutal part of its face increases in size, the forehead thereby recedes, large cristæ, muscular developments, give the skull a brutish form, the activity of the nervous system sinks, and in its place extraordinary muscular strength develops, which, as it is sufficient for its preservation, makes the great intelligence now superfluous. Especially important is what Fréd. Cuvier has said in this reference, and Flourens has illustrated in a review of the "Histoire Naturelle" of the former, which appeared in the September number of the "Journal des Savans" of 1839, and was also separately printed with some additions, under the title, "Résumé analytique des observations de Fr. Cuvier sur l'instinct et l'intelligence des animaux," p. Flourens, 1841. It is there said, p. 50: "L'intelligence de l'orang-outang, cette intelligence si développée, et développée de si bonne heure, décroit avec l'âge. L'orang-outang, lorsqu'il est jeune, nous étonne par sa pénétration, par sa ruse, par son adresse; l'orang-outang, devenu adulte, n'est plus qu'un animal grossier, brutal, intraitable. Et il en est de tous les singes comme de l'orang-outang. Dans tous, l'intelligence décroit à mesure que les forces s'accroissent. L'animal qui a le plus d'intelligence, n'a toute cette intelligence que dans le jeune âge." Further, p. 87: "Les singes de tous les genres offrent ce rapport inverse de l'âge et de l'intelligence. Ainsi, par exemple, l'Entelle (espèce de guenon du sous-genre des Semno-pithèques et l'un des singes vénérés dans la religion des Brames) a, dans le
