"The laws of the development of the brain in the two types, laws which I mentioned before, explain and justify this language; and the laws of which it is the summary are a formal refutation of the comparison which some have attempted to make between the _contracted human brain_, and the _animal brain, however developed_. "6th. The excavations which have been made in intact ancient beds have brought to light skulls of ancient races of man, and these skulls present characteristics which approximate them to the skull of the ape. Does not this pithecoïd stamp, which is very striking on the Neanderthal skull in particular, argue a transition from one type to another, and consequently _filiation_? "This argument is perhaps the only one which has been brought forward with any degree of precision, and it is often recurred to. Is it, on this account, more demonstrative? Let the reader judge for himself. "We may, in the first place, remark that Sir C. Lyell does not venture to pronounce affirmatively as to the high antiquity of the human remains discovered by Dr. Fuhlrott, and that he looked upon them, at the most, as contemporary with the Engis skull, in which the Caucasian type of head was reproduced. "Let us, however, admit that the Neanderthal skull belongs to the remote antiquity to which it has been assigned; what, then, is in reality the significance of this skull? Is it actually a link between the head of the man and that of the ape? And does it not find some analogy in comparatively modern races? "Many writings have been published on these questions, and, as it appears to me, some light has gradually been thrown upon the subject. There is no doubt that this skull is really remarkable for the enormous size of its superciliary ridges, the length and narrowness of the bony case, the slight elevation of the top of the skull. But these features are found to be much less exceptional than was at first supposed, in default of any means of instituting a just comparison; very far, indeed, from justifying the approximation which some have endeavoured to make, this skull is, in all its characteristics, essentially human. Mr. Busk, in England, has pointed out the great affinity which is established, by the prominence of the superciliary ridges and the depression of the upper region, between certain Danish skulls from Borreby and the Neanderthal skull. Dr. Barnard Davis has described the still greater similarities existing between this very _fossil_ and a skull in his collection. Gratiolet forwarded to the Museum the skull of an idiot of the present time, which was almost identical with it in everything, although in slighter proportions, &c. "The following appears to me to be decisive: