Fig. 28. Various thigh-bones arranged to shew the alleged similarity between A Orang-utan and B Aurignac man, as also between C Neanderthal and D Gorilla. A and B, while resembling each other, are to be contrasted with C and D. They are referred to as the A/O and N/G groups. (From Klaatsch.)
The further development of the story includes the following propositions. The more primitive and Gorilla-like Neanderthal type is introduced into Europe as an invader from Africa. Then (at a subsequent epoch probably) an Asiatic invasion followed. The new-comers owning descent from an Orang-utan-like forerunner are represented by the Aurignac skeleton and its congeners. In various respects they represented a higher type not only in conformation but in other directions. Having mingled with the Neanderthal tribes, whether by way of conquest or pacific penetration, a hybrid type resulted. Such was the origin of the Cro-magnon race.
The hypothesis has been severely handled, by none more trenchantly than by Professor Keith[50]. A notable weakness is exposed in the attribution to the ancestors of the Orang-utan so close an association to any human ancestral forms, as Professor Klaatsch demands. To those familiar with the general anatomy of the Orang-utan (i.e. the anatomy of parts other than the skeleton) the difficulties are very apparent.
Another effect of the hypothesis is that the so-called Neanderthaloid resemblances of the aborigines of Australia are very largely if not entirely subverted. This would not matter so much, but for the very decided stress laid by Professor Klaatsch upon the significance of those resemblances (cf. Klaatsch, 1909, p. 579, ‘Die Neanderthalrasse besitzt zahlreiche australoide Anklänge’). Again in earlier days, Professor Klaatsch supported a view whereby the Australian continent was claimed as the scene of initial stages in Man's evolution. Finally, up to the year 1908, Professor Klaatsch was amongst the foremost of those who demand absolute exclusion of the Orang-utan and the Gorilla from any participation in the scheme of human ancestry.
Having regard to such facts and to such oscillations of opinion, it is not surprising that this recent attempt to demonstrate a ‘diphyletic’ or ‘polyphyletic’ mode of human descent should fail to convince most of those competent to pronounce upon its merits.
Yet with all its defects, this attempt must not be ignored. Crude as the present demonstration may be, the possibility of its survival in a modified form should be taken into account. These reflections (but not necessarily the theory) may be supported in various ways. By a curious coincidence, Professor Keith, in rebutting the whole hypothesis, makes a statement not irrelevant in this connexion. For he opines that ‘the characters which separate these two types of men (viz. the Aurignac and Neanderthal types) are exactly of the same character and of the same degree as separate a blood-horse from a shire-stallion.’ Now some zoologists have paid special attention to such differences, when engaged in attempts to elucidate the ancestry of the modern types of horse. As a result of their studies, Professors Cossar Ewart and Osborn (and Professor Ridgeway's name should be added to theirs) agree that proofs have been obtained of the ‘multiple nature of horse evolution’ (Osborn). If we pass to other but allied animals, we may notice that coarser and finer types of Hipparion (H. crassum and H. gracile) have been contrasted with each other. A step further brings us to the Peat-hog problem (Torf-Schwein Frage of German writers), and in the discussion of this the more leggy types of swine are contrasted with the more stocky forms. Owen (in 1846) relied on similar points for distinguishing the extinct species of Bovidae (Oxen) from one another. The contrast maybe extended even to the Proboscidea, for Dr Leith Adams believed that the surest test of the limb bones of E. antiquus was their stoutness in comparison with those of E. primigenius. This is the very character relied upon by Professor Klaatsch in contrasting the corresponding parts of the human and ape skeletons concerned. But such analogies must not be pressed too far. They have been adduced only with a view to justifying the contention that the diphyletic scheme of Professor Klaatsch may yet be modified to such an extent as to receive support denied to it in its present form.
D. In commenting upon the hypothesis expounded by Professor Klaatsch, mention was made of its bearing upon the status of the Cro-Magnon race. This is but part of a wide subject, viz. the attempt to trace in descent certain modern European types. It is necessary to mention the elaborate series of memoirs now proceeding from the pen of Dr Schliz[51], who postulates four stocks at least as the parent forms of the mass of European populations of to-day. Of these four, the Neanderthal type is regarded as the most ancient. But it is not believed to have been extirpated. On the contrary its impress in modern Europe is still recognisable, veiled though it may be in combination with any of the remaining three. The latter are designated the Cro-Magnon, Engis, and Truchère-Grenelle types, the last-mentioned being broad-headed as contrasted with all the rest. Of Professor Schliz' work it is hard to express a final opinion, save that while its comprehensive scope (without excessive regard to craniometry as such) is a feature of great value, yet it appears to lack the force of criticism based upon extensive anatomical, i.e. osteological study.
E. The remarkable change in Professor Klaatsch's views on the part played by the anthropoid apes in human ancestral history has been already mentioned. In earlier days the Simiidae were literally set aside by Professor Klaatsch. But although the anthropoid monkeys have gained an adherent, they still find their claim to distinction most energetically combated by Professor Giuffrida-Ruggeri[52]. The latter declares that though he now (1911) repeats his views, it is but a repetition of such as he, following De Quatrefages, has long maintained. In this matter also, the last word will not be said for some time to come.
F. The significance of the peculiar characters of massiveness and cranial flattening as presented by the Neanderthal type of skeleton continues to stimulate research. In addition to the scattered remarks already made on these subjects, two recently-published views demand special notice.
(i) Professor Keith has (1911) been much impressed with the exuberance of bone-formation, and the parts it affects in the disease known as Acromegaly. The disease seems dependent upon an excessive activity of processes regulated by a glandular body in the floor of the brain-case (the pituitary gland). The suggestion is now advanced that a comparatively slight increase in activity might result in the production of such ‘Neanderthaloid’ characters as massive brow-ridges and limb bones. (Of existing races, some of the aborigines of Australia would appear to exemplify this process, but to a lesser degree than the extinct type, since the aboriginal limb bones are exempt.) Professor Keith adopts the view that the Neanderthal type is ancestral to the modern types. And his argument seems to run further to the following effect: that the evolution of the modern from the Neanderthal type of man was consequent on a change in the activity of the pituitary gland.