probable that throughout the Miocene, man's ancestors were still simian. All we know of them is that certain fossil apes found by Dr. Pilgrim in the foothills of the Himalayas reveal curious little peculiarities of structure that serve to identify them in his opinion as members of the group of anthropoids from which the Hominidae were eventually derived probably not until the latter part of the Pliocene (G. E. Pilgrim, "New Siwalik Primates," Records of the Geological Survey of India, xlv., 1915). But whether or not Dr. Pilgrim is justified in his claim that the newly discovered Miocene ape which he has called Sivapithecus is the ancestor of man or not, it is quite certain that in Miocene times the region of the Siwalik Hills was a great breeding-ground of anthropoid apes, and that the great variety of species and genera which were evolved there included the ancestors not only of the orangs, the chimpanzees and gorillas, but also of the human family. The ancestors of the chimpanzees and gorillas spread west with man's forerunners and reached not only Africa, where their descendants have sur- vived until the present day, but also Europe where the fossilized remains of Dryopithecus are widespread. In the course of its wanderings between northern India and Africa human char- acteristics emerged in one of these simian forms.
The outstanding difference between the earliest member of the human family and his simian cousin was the fact that his brain had developed a little further than the ape's, so that he was able to learn to perform acts of a higher degree of skill not only with his hands but with his vocal muscles. He had acquired the power not merely of a fuller appreciation of the symbolism of sound, but also of arbitrarily imitating sounds and of creating a vocal symbolism whereby he could learn from his fellows and communicate his ideas to them. It was the enormously enhanced power of acquiring knowledge and profiting from the experience of his fellows that differentiated man from the apes; and the peculiar features of the endocranial casts of the fossils Pithecan- thropus and Eoanthropus suggest that the acquisition of the power of speech may have been an essential part of the process of making a man from an ape.
If India has provided us with new light on the place and time of the separation of man's ancestors from the other apes, Egypt has revealed the origin of the anthropoids. It was in 1901 that Dr. C. W. Andrews, of the British Museum, discovered that the Egyptian Fayum was a veritable museum of hitherto unknown fossil ancestors of several mammalian Orders. His prediction that important monkeys would be found there has been fully realized by the discovery of the very primitive Cata- rhine Parapithecus and an anthropoid ape, Propliopithecus (M. Schlosser, " Beitrage zur Kenntniss der Oligozanen Landsauge- tiere aus dem Fayum [Aegypten]," Beitriigezur Pal. u. Geol. Oster- reich-Ungarnsu. d. Orients, Bd.xxiv., 1911). The discovery of a diminutive anthropoid as early as the beginning of the Oligocene period prepares us for the fact that it presents many signs of not distant kinship with the peculiar Eocene Tarsioidea, a Sub-Order of Prosimiac, one of whose members, the Spectral Tarsier, stall survives to-day in the forests of Borneo, Java and certain other islands of the Malay Archipelago. For some years intensive studies have been made of the anatomy and embryology of this remarkable creature (see, for example, " the Discussion of the Zoological Position and Affinities of Tarsius," Proc. Zool. Soc. London, 1919, published Feb. 1920); and these investigations have shed a great deal of light upon the factors that brought the Primates into being and in one group of the Order initiated further changes, especially in the cultivation of stereoscopic vision and all that it entailed in the stimulation of brain-growth, which ultimately culminated in the emergence of human powers of foresight and discrimination (see Presidential Address to the Anthropological Section of the British Association, 1912).
Fossil Remains of Extinct Members of the Human Family. The conclusion to which the study of man's ancestry had led investigators, that the brain led the way in the emergence of human characters, received a dramatic confirmation in 1912, when the late Mr. Charles Dawson and Dr. Smith Woodward announced that the former had discovered (in a patch of gravel
alongside the path leading to Barkham Manor, the residence of Mr. Charles Kenward, near Piltdown in Sussex) fossilized fragments of the skull of a palaeolithic member of the human family quite unlike anything known hitherto (C. Dawson and A. Smith Woodward, " On the Discovery of a Palaeolithic Skull and Mandible in a Flint-bearing Gravel overlying the Wealden (Hastings Beds) at Piltdown, Fletching (Sussex)," Quarterly Journal of the Geological Society, vol. Ixix. (1913) and vol. Ixx. (1914) ; the best photographs of these highly signif- icant specimens will be found in A Guide to the Fossil Remains of Man in the Department of Geology and Palaeontology in the British Museum, first issued in 1915). Sufficient of the cranium was recovered to restore the whole of the brain case; and it is im- portant to remember that, although a lively altercation was provoked in 1913 as to the proper way of reconstructing the skull, there never was any real doubt as to the form of the brain case on the part of those who were studying the actual fossils, because these display the anatomical details which leave no room for any doubt on the points at issue. The interesting fea- ture of the cast of the interior of the cranium is the demonstra- tion it affords that this extremely primitive " Dawn Man, " Eoanthropus Dawsoni, as Dr. Smith Woodward has called him, had a brain which fell definitely within the range (so far as size is concerned) of variation of modern men's brains. But it dis- played some remarkable deficiencies, more especially in the singularly poor development of those frontal, parietal and temporal areas, the noteworthy expansion of which is the fundamental distinctive character of the human brain. Perhaps the most interesting feature of the endocranial cast of the Piltdown man is the remarkable localized overgrowth of that particular part of the brain (the posterior part of the superior temporal convolution) which in modern man is intimately associated with the appreciation of the acoustic symbolism of speech. As a somewhat analogous boss is found on the endo- cranial cast of Pithecanthropus, the fossilized remains of which were found nearly thirty years ago in Java by Dr. Eugen Dubois, it affords grounds for the view that the acquisition of speech may have been one of the essential elements in the transforma- tion of an ape into a man.
It is of fundamental importance to realize that, in spite of its size, the endocranial cast of Eoanthropus reveals these in- dubitable traits of an extremely early phase in the attainment of human characters; and the brain was contained in a skull of a peculiarly distinctive type. For so simian is the form of the jaw that many anatomists and palaeontologists refuse to admit that it is human, and claim that a hitherto unknown chimpanzee expired at Piltdown in Pleistocene times on the same spot as Eoanthropus and that the former left its jaw and the latter its skull. This view is widely held, but chiefly by non-British anatomists (see, for example, M. Ramstrom, " Der Piltdown Fund," Geol. Inst. of Upsala, vol. xvi., 1919) who have never studied the actual fossils. Had they done so they would have realized that, in spite of its form, both the mandible itself and the teeth lodged in it display undoubted human characters. Moreover the cranium also reveals much more primitive fea- tures than is commonly supposed by those who have not seen and handled it. In fact there is no reason for withholding assent to the view that this remarkable cranium, which formerly lodged a brain of extremely primitive character, once formed part of the same individual whose jaw had not yet lost all the marks of the ape.
A vast amount of writing has accumulated since 1912 with reference to this remarkable skull, but most of this literature is irrelevant and misleading, as the authors have not seen the material about which they write and have no adequate realiza- tion of the true state of affairs.
As to the age of the Piltdown skull, precise information is lacking. It was found in an ancient river bed along, with rolled teeth of Pliocene elephants and rhinoceros that had been washed out of some older geological formation, and unrolled teeth of early Pleistocene hippopotamus and beaver and the base of the antler of a red deer. From a consideration of all the evidence it
