372 POPULAR SCIENCE MONTHLY. 



into consideration, we concluded that the differentiation of the human 

 species took place during tertiary times. Eeasoning in like manner 

 from the geographical situation of the discovery, we may suppose Indo- 

 Malaysia to have been the cradle-land of mankind. The assumption is 

 further substantiated by the fact that this tropical region is still the 

 home of many of the higher apes, and was probably the point of de- 

 parture for the dispersion of the other anthropoids. If we turn, now, 

 to the evidences of quaternary culture we shall find a multitude of 

 human relics buried in the pleistocene or post-pleistocene deposits 

 of every continent of the globe. The widespread diffusion of these re- 

 mains proves beyond peradventure the existence of man in every 

 quarter of the earth at the beginning of the prehistoric epoch. 

 Obviously, then, the descendants of the pliocene precursor must have 

 wandered far and wide from the original abode during the long geolog- 

 ical era that elapsed between the pliocene and post-pleistocene periods. 

 It is incumbent on us, therefore, to determine how this migratory 

 movement was effected. Close upon the problem of the differentiation 

 of the human species comes, in other words, that of the dispersion of 

 mankind over the face of the earth. 



Subjectively speaking, there were evidently no difficulties in the 

 way. The human prototype was, as we know, structurally fitted to 

 walk, and his omnivorous manner of life must in itself have led him 

 further and further forth in search of subsistence. In so far as physical 

 capacity and psychic motive are concerned we may, therefore, think of 

 the pliocene precursor as an ambulatory, omnivagant animal. It is 

 only when objective conditions are taken into account that obstacles 

 appear to arise. Granting primeval man's ability and desire to wander, 

 how are we to imagine he endured the vicissitudes of climate that met 

 him on the march? and how are we to suppose he crossed the seas that 

 separate the several continents? Before the great antiquity of the 

 human race was assured, it was necessary to assume an almost miracu- 

 lous power of adaptation on man's part, and furthermore to endow 

 him, somewhat inconsequently, with an innate knowledge of naviga- 

 tion; but now that science has succeeded in tracing man's ancestry 

 back to tertiary times, we may more logically accept the explanation 

 that geology affords. Instead of proceeding upon the presumption 

 that the climate and configuration of the earth was then as it is now, 

 we must reckon with the geological changes that have since occurred 

 and work out our conclusions accordingly. In so doing we shall find 

 that during these early ages of his existence on earth, environmental 

 infiuences opposed no insuperable barriers before the dispersive pro- 

 pensities of man. 



If, as we have supposed, the prototype was differentiated from the 

 apes in Indo-Malaysia during the pliocene period, and arrived in re- 



