Prehistoric man

by W. L. H. Duckworth

Professor Dubois assigned the bones to one and the same skeleton, and for this he has been severely criticised. Apart from arguments affecting the geological age of the specimens, the question of their forming part of a single individual is very momentous. For if two skeletons are represented, one may be human, while the other is that of an ape. It is admitted that the larger bones were separated by a distance of forty-six feet. By way of meeting this criticism, it is submitted that the distance is by no means so great as to preclude the possibility of the common and identical origin of the various bones. Moreover it is at least curious that if two skeletons are here represented, no further remains should have been detected in the immediate vicinity.

The fact that the thigh-bone might easily have passed as that of a man, while the skull-fragment is so divergent from all modern forms as to be scarcely human, is of great interest. The contrast between the indications provided by the two bones was remarked at once. Some writers, rejecting certain other evidence on the point, then drew the inference that the human thigh-bone had been evolved and had arrived at the distinctive human condition in advance of the skull. The importance of this conclusion lies in the fact that the human thigh-bone bears indications of an erect attitude, while the form of the skull gives guidance as to the size of the brain, and consequently to some extent provides a clue to the mental endowment of the individual. Whether the erect attitude or the characteristic brain-development was first obtained by man has been debated for many years. In this case, the evidence was taken to shew that the assumption of the erect attitude came as a means of surmounting the crux of the situation. Thenceforth the upper limb was emancipated entirely from its locomotor functions. Upon this emancipation followed the liberation of jaws and mouth from their use as organs of prehension. Simultaneously the mechanism whereby the head is attached to the neck and trunk became profoundly modified. This alteration gave to the brain an opportunity of growth and increase previously denied, but now seized, with the consequent accession of intellectual activity so characteristic of the Hominidae.

The story thus expounded is attractive from several points of view. But while possessing the support of the Javan fossil remains, it is not confirmed in the embryonic history of Man, for there the growth of the brain is by far the most distinctive feature. Nor did those who adopted this opinion (in 1896), take into account all the characters of the ancient human remains even then available. For the evidence of those remains points to an order exactly the reverse of that just stated, and it indicates the early acquisition of a large and presumably active brain. And now that additions have been lately made to those older remains (other than the Javan bones), the same ‘reversed’ order seems to be confirmed. On the whole therefore, the soundest conclusion is that following a preliminary increment of brain-material, the erect attitude came as a further evolutionary advance.

But to return from this digression to the objections against the Pithecanthropus erectus, it must now be explained that the very contrast between the thigh-bone and the skull-cap in respect of these inferences, has been used as an argument against the association of these bones as part of one skeleton.

The objection may be met in two ways at least. For instance, the thigh-bone may yet possess characters which lessen its resemblance to those of recent men, but are not recognised on a superficial inspection. Careful investigation of the thigh-bone seems to shew that such indeed is the case (indeed the human characters are by some absolutely denied). But together with this result comes the discovery that the characters of straightness and slenderness in the shaft of the bone from which the inference as to the erect attitude was largely drawn, do not give trustworthy evidence upon this point. In fact, a human thigh-bone may be much less straight and less slender than that of arboreal animals such as the Gibbon, the Cebus monkey, or the Lemurs (especially Nycticebus). The famous Eppelsheim femur is straighter than, and as slender as that of Pithecanthropus. It was regarded at first as that of a young woman, but is now ascribed to an anthropoid ape. And in fact, even if the skull-cap and thigh-bone of Pithecanthropus should be retained in association, it seems that the title ‘erectus’ is not fully justified.

Another method of rebutting the objection is based on the suggestion that Pithecanthropus is not a human ancestor in the direct line. Thus to describe an uncle as a parent is an error not uncommon in palaeontology, and it was treated leniently by Huxley. To my mind this position can be adopted without materially depreciating the value of the evidence yielded by the conjoint remains, provided only that their original association be acknowledged. Should this assumption be granted, the claims put forward on behalf of his discovery by Professor Dubois seem to be justified. On the other hand, should the association of skull-cap and thigh-bone be rejected, the former has not lost all claim to the same position. For the most recent researches of Professor Schwalbe[3] of Strassburg, and the further elaboration of these by Professor Berry[4] and Mr Cross[5] of Melbourne, support Professor Dubois' view. And though the objections may not have been finally disposed of, a review of the literature called forth by Professor Dubois' publications will shew a slight margin of evidence for, rather than against his view.

The Heidelberg or Mauer Jaw[6].

Professor Dubois' Javanese researches were carried out in the years 1891 and 1892. Fifteen years separate the discovery of the Pithecanthropus erectus from that of the second great find mentioned in the introductory paragraph of this chapter. This period was by no means barren in respect of other additions to the list of human fossils. But the other results (including even the finds at Taubach) are regarded as of subsidiary importance, so that their consideration will be deferred for the present. In 1907 a lower jaw, known now as the Heidelberg or Mauer jaw, was discovered by workmen in the sand-pit of Mauer near Heidelberg.

The Mauer jaw is indeed a most remarkable specimen. The first general outcome of an inspection of the photographs or of the excellent casts (which may now be seen in many museums) is a profound impression of its enormous strength (Figs. 2, 13, and 15c). By every part of the specimen save one, this impression is confirmed. This massiveness, together with the complete absence of any prominence at the chin, would have caused great hesitation in regard to the pronouncement of a decision as to the probable nature of the fossil. The one paradoxical feature is the relatively small size of the teeth. All of these have been preserved, though on the left side the crowns of four have been removed by accident in the process of clearing away some adherent earth and pebbles. The net result shews that the teeth are actually within the range of variation provided by human beings of races still extant, though commonly regarded as ‘primitive,’ if not pithecoid (such as the aboriginal race of Australia). Yet these teeth are implanted in a jaw of such size and strength as render difficult the reference of the specimen to a human being.