Evidence of the location of the early evolution of man in Asia and in the geologically recent submerged area toward the southeast is afforded by the fossil deposits in the Siwalik hills of northern India; where the remains of primates have been found which were either ancestral or closely related to the four genera of living anthropoids and where we may confidently look for remains of the earliest human forms; and by the discovery in Java, which in Pliocene times was connected with the mainland over what is now the South China Sea, of the earliest known form of erect primate, the Pithecanthropus. This ape-like man is practically the “missing link,” being intermediate between man and the anthropoids and is generally believed to have been contemporary with the Günz glaciation of some 500,000 years ago, the first of the four great glacial advances in Europe.

One or two species of anthropoid apes have been discovered in the Miocene of Europe which may possibly have been remotely related to the ancestors of man but when the archæological exploration of Asia shall be as complete and intensive as that of Europe it is probable that more forms of fossil anthropoids and new species of man will be found there.

Man existed in Europe during the second and third interglacial periods, if not earlier. We have his artifacts in the form of eoliths, at least as early as the second interglacial stage, the Mindel-Riss, of some 300,000 years ago. A single jaw found near Heidelberg is referred to this period and is the earliest skeletal evidence of man in Europe. From certain remarkable characters in this jaw, it has been assigned to a new species, Homo heidelbergensis.

Then follows a long period showing only scanty industrial relics and no known skeletal remains. Man was slowly and painfully struggling up from a culture phase where chance flints served his temporary purpose. This period, known as the Eolithic, was succeeded by a stage of human development where slight chipping and retouching of flints for his increasing needs led, after vast intervals of time, to the deliberate manufacture of tools. This Eolithic Period is necessarily extremely hazy and uncertain. Whether or not certain chipped or broken flints, called eoliths or dawn stones, were actually human artifacts or were the products of natural forces is, however, immaterial for man must have passed through such an eolithic stage.

The further back we go toward the commencement of this Eolithic culture, the more unrecognizable the flints necessarily become until they finally cannot be distinguished from natural stone fragments. At the beginning, the earliest man merely picked up a convenient stone, used it once and flung it away, precisely as an anthropoid ape would act to-day if he wanted to break the shell of a tortoise or crack an ostrich egg.

Man must have experienced the following phases of development in the transition from the prehuman to the human stage: first, the utilization of chance stones and sticks; second, the casual adaptation of flints by a minimum amount of chipping; third, the deliberate manufacture of the simplest implements from flint nodules; and fourth, the invention of new forms of weapons and tools in ever increasing variety.

Of the last two stages we have an extensive and clear record. Of the second stage we have in the eoliths intermediate forms ranging from flints that are evidently results of natural causes to flints that are clearly artifacts. The first and earliest stage, of course, could leave behind it no definite record and must in the present state of our knowledge rest on hypothesis.

II
PALEOLITHIC MAN

With the deliberate manufacture of implements from flint nodules, we enter the beginning of Paleolithic time and from here on our way is relatively clear. The successive stages of the Paleolithic were of great length but are each characterized by some improvement in the manufacture of tools. During long ages man was merely a tool making and tool using animal and, after all is said, that is about as good a definition as we can find to-day for the primate we call human.

The Paleolithic Period or Old Stone Age lasted from the somewhat indefinite termination of the Eolithic, some 150,000 years ago, to the Neolithic or New Stone Age, which began about 7000 B. C.