"This is really the way in which a true disciple of Darwin must reason, even if he solely took into account the external morphological characteristics and the anatomical characteristics which are the expression of the former in the adult animal.
"Will it be said that when the degree of organisation manifested in the anthropomorphous apes had been once arrived at, the organism underwent a new impulse and became adapted for walking? This would be, in fact, adding a fresh hypothesis, and its promoters would not be in a position to appeal to the organised gradation presented by the quadrumanous order as a whole on which stress is laid as leading to the conclusion against which I am contending: they would be completely outside Darwin's theory, on which these opinions claim to be based.
"Without going beyond these purely morphological considerations, we may place, side by side, for the sake of comparison, as was done by M. Pruner-Bey, the most striking general characteristics in man and in the anthropomorphous apes. As the result, we ascertain this general fact—that there exists 'an inverse order of the final term of development in the sensitive and vegetative apparatus, in the systems of locomotion and reproduction' (Pruner-Bey).
"In addition to this, this inverse order is equally exhibited in the series of phenomena of individual development.
"M. Pruner-Bey has shown that this is the case with a portion of the permanent teeth. M. Welker, in his curious studies of the sphenoïdal angle of Virchow, arrived at a similar result. He demonstrated that the modifications of the base of the skull, that is, of a portion of the skeleton which stands in the most intimate relation to the brain, take place inversely in the man and ape. This angle diminishes from his birth in man, but, on the contrary, in the ape it becomes more and more obtuse, so as sometimes to become entirely extinct.
"But there is also another fact which is of a still more important character: it is that this inverse course of development has been ascertained to exist even in the brain itself. This fact, which was pointed out by Gratiolet, and dwelt upon by him on various occasions, has never been contested either at the Société d'Anthropologie or elsewhere, and possesses an importance and significance which may be readily comprehended.
"In man and the anthropomorphous ape, when in an adult state, there exists in the mode of arrangement of the cerebral folds a certain similarity on which much stress has been laid; but this resemblance has been, to some extent, a source of error, for the result is attained by an inverse course of action. In the ape, the temporo-sphenoïdal convolutions, which form the middle lobe, make their appearance, and are completed, before the anterior convolutions which form the frontal lobe. In man, on the contrary, the frontal convolutions are the first to appear, and those of the middle lobe are subsequently developed.
"It is evident that when two organised beings follow an inverse course in their growth, the more highly developed of the two cannot have descended from the other by means of evolution.
"Embryology next adds its evidence to that of anatomy and morphology, to show how much in error they are who have fancied that Darwin's ideas would afford them the means of maintaining the simial origin of man.