(4) The distribution of the implements finds a weak spot in the defences of the eolithic partisans. It is alleged that eoliths are almost always flints: and that they occur with and among other flints, and but rarely elsewhere. Palaeoliths (of flint) also occur among other flints, but they are not thus limited in their association. This distinction is admitted by some at least of the supporters of the ‘artefact’ nature of the eoliths, and the admission certainly weakens their case.
The question is thus far from the point of settlement, and it may well continue to induce research and discussion for years to come. That a final settlement for the very earliest stages is practically unattainable will be conceded, when the earliest conditions are recalled in imagination. For when a human being first employed stones as implements, natural forms with sharp points or edges would be probably selected. The first early attempts to improvise these or to restore a blunted point or edge would be so erratic as to be indistinguishable (in the result) from the effects of fortuitous collisions. While such considerations are legitimately applicable to human artefacts of Oligocene or Miocene antiquity, they might well appear to be less effective when directed to the Pleistocene representatives where signs of progress might be expected. Yet Professor Rutot (1911) does not distinguish even the Pleistocene Reutelian from the Oligocene (eolithic) forms. If, on such evidence as this, early Pleistocene Man be recognised, Oligocene Man must needs be accepted likewise. Professor Rutot's mode of escape from this difficult position is interesting and instructive, if not convincing. It is effected by way of the assumption that in regard to his handiwork, Man (some say a tool-making precursor of Man) was in a state of stagnation throughout the ages which witnessed the rise and fall of whole genera of other mammals. That this proposition is untrue, can never be demonstrated. On the other hand, the proposition may be true, and therefore the unprejudiced will maintain an open mind, pending the advent of more conclusive evidence than has been adduced hitherto.
CHAPTER V
HUMAN FOSSILS AND GEOLOGICAL CHRONOLOGY
In the preceding Chapter, the remains of Palaeolithic Man were studied in relation to the associated animals (especially mammals), and again (so far as possible) in connection with the accompanying implements. In the comparison of the different types of implement, evidence was adduced to shew that certain forms of these are distinctive of corresponding geological horizons. Of the three series, (1) human remains, (2) mammalian remains, (3) stone implements, the first two, (1) and (2), have been compared as well as (1) and (3). A comparison between (2) and (3) has now to be instituted. And this is of interest, for mammalian remains have been found in the presence of implements where no human bones could be discovered. Moreover the expectation is well founded, whereby the mammalian fauna will prove to supply information unobtainable from either human skeletons or implements by themselves. That information will bear upon the climatic conditions of the different phases which mark the geological history of Man. And in this way, a more perfect correlation of the past history of Man with the later geological history of the earth may be fairly anticipated.
In Chapter IV, use was frequently made of the expression ‘southern,’ ‘temperate’ or ‘sub-arctic,’ in connection with the various groups of mammals mentioned in Table A. And while the geological period is limited, during which these investigations are profitably applicable, yet the matter is one of no small importance. For the very fact that the fauna can be described in one case as ‘southern’ in character, in another as ‘temperate,’ suggests some variation of climate. And the relation of the history of Man to the great variation of climate implied in the expression ‘Glacial Period,’ may be reasonably expected to receive some elucidation from this branch of study. It will be noticed that Man himself is at present comparatively independent of climate, and even in earlier times he was probably less affected than some other animals. But while the importance of these studies must be recognised, it is also very necessary to notice that as elsewhere so here the difficulties are great, and pitfalls numerous.
It is no part of the present work to attempt a history of the stages through which opinion passed in developing the conception embodied in the phrase ‘Ice-Age.’ Long before that idea had been formulated, the presence of animal remains both in cave and alluvial deposits was a matter of common knowledge. The late Professor Phillips is believed to have been the first to make definite use of the terms ‘pre-glacial’ and ‘post-glacial’ in reference to the later geological formations (1855). And to the pre-glacial era that geologist referred most of the ossiferous caves and fissures.
But in 1860, this, the accepted view, was overthrown by the late Dr Falconer[40] at least so far as the caves (with the exception of the Victoria Cave) then explored in Britain were concerned. In the same year, the post-glacial position and antiquity of various brick-earths and gravels of the Thames valley were considered to have been definitely established by the late Professor Prestwich. It is very important to note in this connection, that the palaeontological evidence of those brick-earths was nevertheless held to indicate pre-glacial antiquity and thus to contradict the evidence of stratigraphy. The method employed in the latter mode of enquiry consisted in ascertaining the relation of the boulder-clay to certain deposits distinguished by their fauna, the Mollusca being especially employed in the identifications. Boulder-clay seems, in this country, to have been taken as the premier indication of the glacial period; it was supposed to be a submarine deposit formed during a submergence of large parts of these islands in the course of that period. That the late Sir Charles Lyell dwelt upon the problems of the boulder clay should also be recalled, for he expressly recounts how constantly it proved a barrier marking the extreme limit to which the works of Man could be traced. Implements or even bones had been found in the drift and above the boulder-clay, but not below.
For a while no attempt seems to have been made to subdivide the boulder-clay or to question its exact identity over all the area occupied by it. Yet such a subdivision might have resulted in explaining the contradiction or paradox (curiously analogous to that propounded by Mr Hinton in 1910, cf. p. [102] supra) just mentioned as existing between the age to be assigned to the Thames river-drift upon (a) stratigraphical evidence (‘post-glacial’), and (b) palaeontological evidence (‘pre-glacial’).
That there might be several deposits of the boulder-clay with intervening strata, does not appear to have been suggested. The Glacial period was long regarded as one and indivisible. By some able geologists that view is still held.