ment in the arts of working stone and bone, to which he gives the names of the Moustier epoch, the Solutré epoch, and the La Madelaine epoch, from the stations which best typify each stage of primitive culture. M. Broca has shown that, between the time when the Moustier cave was inhabited by troglodytes and the time when the La Madelaine cave was similarly inhabited, the valley of the Vézère had undergone a denudation to the depth of twenty-seven metres; while from the date of the La Madelaine cave to our own time the denudation was only four or five metres. In other words, the interval between the two epochs was far greater than the interval between the last of them and our own times.
As to the drift-men, the few bones attributed to them are so singularly and suspiciously like those of neolithic times that it seems very unsafe to build any definite conclusion upon them. Accordingly, when Professor Dawkins tells us that "the river-drift man first comes before us endowed with all human attributes, and without any signs of a closer alliance with the lower animals than is presented by the savages of to-day," I think we must venture to suspend judgment for the present. Seeing that a later skull, like that of Neanderthal, is strikingly ape-like in one most important particular, is considerably lower in general type than that of the lowest living savage, and (as Professor Huxley has shown) is rather nearer the chimpanzee than the modern European in outline, it seems hazardous to conclude on very dubious evidence that a still earlier race had skulls as well formed as those of the neolithic Iberians. The least doubtful cases are acknowledged to be identical in character with the far later Cro-Magnon remains (belonging to the latest cave age), which in itself is enough to rouse considerable suspicion. So many supposed palæolithic skeletons, like the "fossil man" of Mentone, have turned out on further examination to be neolithic or later, that it is unwise to base conclusions upon them, when those conclusions clearly run counter to the general course of evolution.
With regard to the previous history of the human race, we can only guess at it by the analogy of the other higher mammalia. But late researches have all gone to show that the general progress of mammalian development has been singularly regular. If we apply this analogy, and couple it with the other known and observed facts, we may be able still further to bridge over the gap between man and his anthropoid progenitor. As Professor Huxley remarks, "The first traces of the primordial stock whence man has proceeded need no longer be sought, by those who entertain any form of the doctrine of progressive development, in the newest tertiaries; they may be looked for in an epoch more distant from the age of the Elephas primigenius than that is from us."
The bifurcation of the European placental mammals begins in the Eocene; and it is to the Eocene that we must look for the earliest