22 



The Probable, Region 



become universally distributed. No tropical region supplied the 

 conditions necessary to produce such changes. In what direction, 

 then, must we look ? 



We have seen that it would be out of all reason, as far as 

 present evidence goes, to suppose that the ape, out of which man 

 sprang, was an inhabitant of America or of the Arctic regions. 

 We have also seen that there is no evidence to show that apes 

 existed farther north than Central Europe, and we have seen 

 that they have been traced to Southern Europe and Northern 

 India in Miocene and Pliocene times. In short, we have seen 

 that there has been a gradual southward distribution of simian 

 life, as of every other form of life, in consequence of the gradual 

 cooling down of the northern zones of our globe. 



The tendency of the steady process of refrigeration was of 

 course to drive all forms of life, by degrees, southward to the 

 tropics, excepting such as should become compulsorily adapted 

 to temperate or cold climates ; and had there been no barriers 

 to this southward distribution in the Old World it is very pro- 

 bable that apes would never have had a fair chance of becoming 

 evolved into manhood. 



But geographical barriers did exist that were, on the one hand, 

 unfavourable for apes moving southward, and so continuing to 

 be apes, and on the other were favourable to their detention in 

 the very region in which they had the best chance of becoming 

 men, if they were to survive at all. What then were those 

 barriers ? 



The principal barrier which prevented the apes from easily 

 moving southwards was, briefly, the enormous extent of sea 

 border on the south of Europe and sub-tropical Asia. On the 

 south of Europe was the Mediterranean, separating Europe from 

 Africa. On the south of sub-tropical Asia was the Arabian 

 sea and its diverging branches, which in Miocene times extended 

 from at least high up the Euphrates valley, down the Persian 

 Gulf, round into the valley of the Indus and the Punjab. The 

 Eed Sea and Gulf of Suez, moreover, then ran into the Mediter- 

 ranean. It is not impossible even that the Jordan valley was 

 then filled with water, extending from the Eed Sea to the 

 Euphrates valley, thereby probably cutting off Arabia from 

 Asia. It is not certain that, in Miocene times, what is now the 

 Strait of Gibraltar was dry land, or that Europe was connected 

 by an isthmus through Italy and Sicily to Africa. But allowing 

 that land connections did exist, both between Gibraltar and 

 Tangier, and between Italy and Tunis, yet there was still a 

 water separation of some five thousand miles extent on its 

 northern border between Europe and Africa, as compared with 

 two bands, of fifty and a hundred miles respectively, of land 



