Before concluding, reference should be made to certain facts connected with the development of the brain and the human organism generally, which at first sight seem to be quite irreconcilable with the notion of man’s derivation from the ape, even under the conditions I have proposed. Thus, M. Pruner Bey has shown that in man and the anthropomorphous apes there exists “an _inverse order_ of the final term of development in the sensitive and vegetative apparatus, and in the systems of locomotion and reproduction.” The same inverse order is exhibited in the development of individual organs. Thus it is, says Pruner Bey, with a portion of the permanent teeth; Welcher makes a similar remark as to the modifications of the base of the skull in relation to the sphenoidal angle of Virchow; and Gratiolet points out an analogous fact in the development of the brain. The language of the great French anatomist is very precise. He says: “With man and the adult anthropormorphous apes there exists a certain resemblance in the mode of arrangement in the cerebral folds which has imposed on some persons and on which they have strongly insisted. But this result is attained _by an inverse process_ (_marche inverse_). In the monkey the temporosphenoidal convolutions which form the middle lobe appear and perfect themselves before the anterior convolutions which form the frontal lobe. With man, on the contrary, the frontal convolutions appear the first, and those of the middle lobe show themselves the last.” In referring to these facts, M. de Quatrefages declares that “when two organised beings follow an inverse course in their development, the more highly developed of the two cannot have descended from the other by means of evolution.”[401] If by evolution is meant simple descent under the influence of natural selection and modification of external conditions, this conclusion is certainly correct. It is true that, contrary to the opinion expressed by Gratiolet, that “the human brain differs the more from that of the monkey the less it is developed, and an arrest of development can only exaggerate this natural difference.”[402] M. Carl Vogt declares that the human brain may, under certain conditions, not only externally resemble that of the higher apes, but also that the superior portion of it (_parties voûtées_) in microcephalic idiots is really developed after the simian type,[403] the skull itself having both simian and human elements.[404] But does not the fact that the lower part of the microcephalic skull, and the portion of the brain which is the earliest developed, are formed on the human type, amply justify the assertion of Gratiolet that “the microcephale, however degraded, is not a brute, but only a modified man?” Is it not evident, moreover, that however highly an ape brain may be developed, it could not become like that of a man, at least by descent with natural selection? It is different, however,