In the great prominence of the supra-orbital ridges which has been observed in some pre-historic human skulls, a likeness to the corresponding feature in anthropoids has been traced. And indeed there is such a likeness, especially to the female chimpanzee, in the well-known Neanderthal skull, which is very dolichocephalic, with prominent supra-orbital arches, only divided from each other by a shallow depression. In the same skull the development of the supra-orbital ridges is related to that of the frontal sinuses. In this pre-historic specimen--which, by the kindness of Professor Schaafhauser, I was able to examine closely at the congress of anthropologists at Berlin in 1880--the forehead retreats in a marked manner towards the flattened region of the crown. De Quatrefages and Hamy say that the skull is both flattened and long (dolichoplatycephalic). The temporal ridges are not only very marked, but they approach each other in the region of the coronal arch (Fig. 35). This also occurs in the adult female chimpanzee, as well as in the young male gorilla, in the aged female orang, and in the gibbon. [Illustration: Fig. 35.--The Neanderthal skull. A. In profile. B. A front view.] It may here be observed that our men of science differ widely in opinion respecting the origin and ethnological significance of the Neanderthal skull, of which I will cite only a few instances. Pruner regards it as the skull of an idiot.[34] Virchow considers the specimen, and the similar one from Kailykke in the Copenhagen Museum, as an altogether individual formation,[35] a typical form modified by disease,[36] in other words, a pathological skull.[37] King regards the skull as one belonging to one of the primitive races.[38] Schaaffhauser has, indeed, endeavoured to make an artistic portrait of such a primitive man. Spengel holds that skulls which are “Neanderthaloid” in form are to be found chiefly in Europe.[39] If Huxley says decidedly that the Neanderthal skull can by no means be regarded as the remains of a human being which was a link between man and apes. At most this discovery only proves the existence of a man whose skull reverted in some respects to the simian type, just as a carrier or tumbler pigeon may sometimes display the plumage of their original ancestor, the rock-pigeon (_Columbia livia_). And although the Neanderthal skull is more like that of the ape than any other human skull with which we are acquainted, yet it is by no means so isolated as it at first appears, but is rather the ultimate expression of a series which may be gradually traced back from the highest and most fully developed type of human skulls. On the one side it approximates to the flattened Australian skulls, from which other Australian forms gradually lead to skulls which rather resemble the type afforded by the Engis skull. On the other side, it is still more closely allied with the skulls of certain ancient races which were either contemporaries or successors of