in the comparative absence of controversy excited by its discovery. This must not be ascribed to any lack of ardour on the part of archaeologists. More probable is it that with the lapse of time, the acceptance of an evolutionary interpretation of the origin of man has gained a wider circle of adherents, so that the claims of even so sensational a specimen as this, are sifted and investigated with a judicial calm much more appropriate and certainly more dignified than the fierce outbursts occasioned by some of the earlier discoveries.

It remains to institute brief anatomical comparisons between the Mauer jaw and those of the highest apes on the one hand, and of the most primitive of human beings on the other.

(a) Of the three larger anthropoid apes available for comparison, it is hard to say which presents the closest similarity. The Gibbons do not appear to approach so nearly as these larger forms. Among the latter, no small range of individual variations occurs. My own comparisons shew that of the material at my disposal the mandible of an Orang-utan comes nearest to the Mauer jaw. But other mandibles of the same kind of ape (Orang-utan) are very different. The chief difficulty in assigning the possessor of the Mauer jaw to a pithecoid stock has been mentioned already. It consists in the inadequate size of the teeth. In addition to this, other evidence comes from the results of an examination of the grinding surfaces (crowns) of the molar teeth. These resemble teeth of the more primitive human types rather than those of apes. Finally the convergence of the two rows when traced towards the canine or eye-tooth of each side, points in the same direction.

(b) If the apes be thus rejected, the next question is, Would the Mauer jaw be appropriate to such a cranium as that of Pithecanthropus? I believe an affirmative answer is justifiable. It is true that an excellent authority (Keith[7]) hesitates on the ground that the mandible seems too massive for the skull, though the same writer recognises that, in regard to the teeth, the comparison is apt. This is a difficult point. For instance the H. moust. hauseri (cf. Chapter II) has a mandible which is far ‘lower’ than the capacity of the brain-case would lead one to expect. Therefore it seems that the degree of correlation between mandible and capacity is small, and to predict the size of the brain from evidence given by the jaw is not always safe. It is to be remembered that special stress was laid by Professor Dubois (cf. p. 4) on the fact that the teeth of Pithecanthropus when compared with the skull-cap are inadequately small, if judged by the ape-standard of proportion. The characters of the teeth, in so far as upper and lower molars can be compared, present no obstacle to such an association, and in fact provide some additional evidence in its favour. The crucial point seems therefore to be the massiveness of the jaw. With regard to this, the following remarks may be made. First, that the skull-cap of Pithecanthropus is on all sides admitted to shew provision for powerful jaw-muscles. And further, in respect of actual measurements, the comparison of the transverse width of the Javanese skull-cap with that of the Mauer jaw is instructive. For the skull-cap measures 130 mm. in extreme width, the jaw 130 mm. The association of the two does not, in my opinion, make an extravagant demand on the variability in size of either part. A curious comparison may be instituted between the Mauer jaw and the corresponding bone as represented by Professor Manouvrier (cf. Dubois[8], 1896) in an attempted reconstruction of the whole skull of Pithecanthropus. Professor Manouvrier's forecast of the jaw differs from the Mauer specimen chiefly in regard to the size of the teeth, and the stoutness of the ascending ramus. The teeth are larger and the ascending ramus is more slender in the reconstruction than in the Mauer specimen.

(c) Passing from the consideration of Pithecanthropus to that of human beings, the general results of the comparisons that can be made will shew that the gap separating the jaw of Mauer from all modern human representatives is filled by human jaws of great prehistoric antiquity.

The progress of an evolutionary development is accordingly well-illustrated by these specimens. And although Homo heidelbergensis is seen to be separated from his modern successors by great differences in form as well as a vast lapse of time, still the intervening period does provide intermediate forms to bridge the gulf. Not the least interesting of many reflections conjured up by the Mauer jaw, is that this extraordinary form should be met with in a latitude so far north of that corresponding to the Javanese discoveries. This difference, together with that of longitude, suggests an immense range of distribution of these ancestral types. Some of their successors are considered in the next chapter.

CHAPTER II
PALAEOLITHIC MAN

The fossil remains described in the preceding chapter possess good claims to that most interesting position, viz. an intermediate one between Mankind and the more highly-developed of the Apes.

From such remarkable claimants we turn to consider fossil bones of undoubted human nature. Of such examples some have been regarded as differing from all other human types to such an extent as to justify their segregation in a distinct species or even genus. Yet even were such separation fully justified, they are still indubitably human.

In the early phases of the study of prehistoric archaeology, the distinction of a ‘stone age’ from those of metals was soon realised. Credit is due to the present Lord Avebury[9] for the subdivision of that period into the earlier and later parts known as the Palaeolithic and Neolithic stages. At first, those subdivisions possessed no connotation of anatomical or ethnical significance. But as research progressed, the existence of a representative human type specially characteristic of the palaeolithic period passed from the stage of surmise to that of certainty. Yet, although characteristic, this type is not the only one recognisable in those early days.

In the following pages, some account is given of the most recent discoveries of human remains to which Palaeolithic antiquity can undoubtedly be assigned. The very numerous works relating to prehistoric man are full of discussions of such specimens as those found in the Neanderthal, at Spy, Engis, Malarnaud, La Naulette or Denise.

That some of these examples are of great antiquity is inferred from the circumstances under which they were discovered. The evidence relates either to their association with extinct animals such as the Mammoth, or again the bones may have been found at great depths from the surface, in strata judged to have been undisturbed since the remains were deposited. One of the earliest discoveries was that of the Engis skull; the differences separating this skull from those of modern Europeans are so