CHAPTER I ANCESTRY OF THE ANTHROPOID APES--PLIOCENE CLIMATE, FORESTS, AND LIFE OF WESTERN EUROPE--TRANSITION TO THE PLEISTOCENE, OR AGE OF MAN--THE FIRST GLACIATION, ITS EFFECTS ON CLIMATE, FORESTS, AND ANIMAL LIFE--THE PREHUMAN TRINIL RACE OF JAVA--THE EOLITHS OR PRIMITIVE FLINTS--THE SECOND GLACIATION--THE HEIDELBERG, EARLIEST KNOWN HUMAN RACE--THE THIRD GLACIATION The partly known ancestors of the anthropoid apes and the unknown ancestors of man probably originated among the forests and flood-plains of southern Asia and early began to migrate westward into northern Africa and western Europe. As early as Oligocene times a forerunner of the great apes (_Propliopithecus_), most nearly resembling the gibbons, appears in the desert bordering the Fayum in northern Egypt. Early in Miocene times true tree-living gibbons found their way into Europe and continued throughout the Pliocene in the forms known as _Pliopithecus_ and _Pliohylobates_, the latter being a true gibbon in its proportions; it ranged northward into the present region of Germany. Another ape which early reached Europe is the _Dryopithecus_; it is found in Miocene times in southern France; the grinding-teeth suggest those of the orang, the jaw is deep and in some ways resembles that of the Piltdown man. A third ape (_Neopithecus_) occurs in the Lower Pliocene near Eppelsheim, in Germany, and is known only from a single lower molar tooth, which recalls the dentition of _Dryopithecus_ and more remotely that of _Homo_. In the Pliocene of the Siwalik hills of Asia is found _Palæopithecus_, a generalized form which is believed to be related to the chimpanzee, the gorilla, and the gibbon; the upper premolars resemble those of man. None of these fossil anthropoids either of Europe or of Asia can be regarded as ancestral to man, although both _Neopithecus_ and _Dryopithecus_ have been placed in or near the line of human ancestry by such high authorities as Branco and Gaudry. When _Dryopithecus_ was first discovered by Lartet, Gaudry(1) considered it to be by far the most manlike of all the apes, even attributing to it sufficient intelligence for the working of flints, but fuller knowledge of this animal has shown that some of the living anthropoids are more manlike than _Dryopithecus_. This animal is closely related to the ancestral stock of the chimpanzee, gorilla, and orang. The jaw, it is true, resembles that of the Piltdown man (_Eoanthropus_), but the grinding-teeth are much more primitive and there is little reason to think that it is ancestral to any human type.[N] [Illustration: FIG. 16. The gibbon is primitive in its skull and dentition, but extremely specialized in the adaptation of its limbs to arboreal life. Photograph from the New York Zoological Park.]