Page:The Scientific Monthly vol. 3.djvu/169

Rh ENVIRONMENT OF TEE APE MAN 163

The BeuYerian flora^ as it has been called^ appears to indicate a climate about like that of southern Prance of the present time, but with a more abundant rainfall. It was richer in species than the present flora of central Europe and the number of arborescent forms was greater, both relatively and absolutely, comprising fifty per cent, of the determined forms. A somewhat similar Pliocene flora was described some years ago from the Altai Mountains' in Central Asia. In the latter region were found sequoias, alders, oaks, beeches and tulip trees of North American character associated with oriental beeches, walnuts and maples, as well as with various other trees now characteristic of Mediterranean Europe.

These late Pliocene floras are frequently spoken of as cosmopolitan floras and in the sense that throughout the whole Holarctic region there was not then the geographical differentiation that is displayed by the existing floras this term is true. It does not mean that the semi-arid plains of Algiers had identical species with the forested glades of south- em France or that the tropical forests of Indo-China were identical with those of the Asiatic steppes, but there were no well-marked provinces — in Portugal, Prance, Italy and the Altai we recognize the familiar types like the Sassafras, Magnolia and Tulip tree, which to-day are con- fined to southeastern Asia or southeastern North America.

This in brief was the setting in which were inaugurated those climatic changes so striking in their results, but probably not nearly so extreme in their actual changes, that resulted in covering so much of Europe and North America with a continental ice sheet many feet in thickness. This was also the setting of that event, great from our human standpoint, when somewhere in the orient the ape-like ancestors of man passed the intangible bound that separated apedom from incipient manhood, for in the older Pleistocene of the island of Java we find the oldest known fossil remains of such an ape man, the Pithecanihrofus erectus of Du- bois, associated with the bones of a large contemporary fauna ; and the foliage, fruits and wood of the valley forest in which these remote an- cestors of ours dwelt.

The exact age of the strata containing the remains of Pithecwnthro^ pus is of the greatest importance and on this point as well as on the questions of the environment and climate the fossil flora is much more definite and conclusive than the associated vertebrate and invertebrate fossils. Let us then endeavor to picture the surroundings of the ape man and the animals and plants that spread with him into Java from the river valleys of the Brahmaputra and Irawadi, two thousand miles or more to the northwest, and something of the geography and topog- raphy of the lands through which they wandered.

The Pleistocene was in general a time of receding oceans and broad- land connections. Some think that this fall in sea-level was due to the

s Schmalbaiisen, J., ''Pakeont.," Bd. 33, 1887, pp. 181-216, pi. 18-22.

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