"Man and apes in general," says M. de Quatrefages, "present a most striking contrast--a contrast on which Vicq-d'Azyr, Lawrence, and M. Serres have dwelt in detail for some considerable time past. The former is a _walking animal_, who walks upon his hind legs; all apes are _climbing animals_. The whole of the locomotive system in the two groups bears the stamp of these two very different intentions; the two types, in fact, are perfectly distinct. "The very remarkable works of Duvernoy on the 'Gorilla,' and of MM. Gratiolet and Alix on the 'Chimpanzee,' have fully confirmed this result as regards the anthropomorphous apes--a result very important, from whatever point of view it is looked at, but of still greater value to any one who wishes to apply _logically_ Darwin's idea. These recent investigations prove, in fact, that the ape type, however highly it may be developed, loses nothing of its fundamental character, and remains always perfectly distinct from the type of man; the latter, therefore, cannot have taken its rise from the former. "Darwin's doctrine, when rationally adapted to the fact of the appearance of man, would lead us to the following results: "We are acquainted with a large number of terms in the Simian series. We see it branching out into secondary series all leading up to anthropomorphous apes, which are not members of one and the same family, but corresponding superior _terms_ of three distinct families (Gratiolet). In spite of the secondary modifications involved by the developments of the same natural qualities, the orang, the gorilla, and the chimpanzee remain none the less fundamentally mere _apes_ and _climbers_ (Duvernoy, Gratiolet, and Alix). Man, consequently, in whom everything shows that he is a _walker_, cannot belong to any one of these series; he can only be the higher term of a distinct series, the other representatives of which have disappeared, or, up to the present time, have evaded our search. Man and the anthropomorphous apes are the final terms of two series, which commence to diverge at the very latest as soon as the lowest of the apes appear upon the earth. "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.