112 SECTIONAL ADDRESSES 



The same arguments apply to the negritoes, and lead us to accept an 

 Asiatic cradleland. 



What was the relation of Africa, Australasia, and America to the 

 Eurasian land-mass during the later Ice Ages — when we may surely 

 picture these earlier racial migrations as occurring ? Surely something 

 like this. The easiest of access was Africa, for only the Red Sea — 

 probably much less of a barrier then — separated that region of deserts 

 and savannas from the South Asiatic cradleland. 



Australasia was the next most accessible. During the Ice Ages no 

 doubt the broad low area of Sunda Land with the almost dry Bali-Timor 

 ridge led man to the large low ' Sahul Land ' and so to Australia (Griffith 

 Taylor 1937). In the Interglacial period both Sunda Land and Sahul Land 

 were drowned as the result of the filling of the oceans by the melting 

 ice caps. Hence we may postulate that Australia and Melanesia were, on 

 the whole, much harder to reach than was Africa in those early days. 



As regards America, all migrations must pass via north-east Siberia. 

 In the Ice Ages this was covered with an ice cap (Griffith Taylor 1930) 

 which would definitely discourage migrations. During inter-glacials 

 the Behring route might be quite feasible — and doubtless during such 

 a period a few tribes of Australoids or kindred folks reached America. 

 Possibly during the close of the Wurm Ice Age the Eskimo reached 

 America while their congeners, late Palasolithic man, were reaching 

 Western Europe. The main migrations into America seem to have 

 occurred in the warmer periods (say of the Achen retreat of the ice, or 

 between the Buhl and Gschnitz minor advances of the ice in Europe) 

 some ten to twenty thousand years ago. 



Now, assuming these geographical relations, what should we expect 

 to find } Primitive man was thrust out of south central Asia (primarily 

 by climatic changes leading to greater cold or aridity) and would know 

 nothing of the outlying areas. He would, no doubt, move off in several 

 directions (to south, south-west or south-east) more or less equally. 

 Thus the greater proportion of the earliest (Negro) migrations would 

 inevitably reach Africa (the easiest outlet, on the whole), while a smaller 

 number would reach Melanesia by circumventing the very difficult 

 tangle of mountains in south-east Asia and crossing the * stepping 

 stones ' of the East Indies ; and, if fortunate enough, making use of the 

 alternately open and drowned corridors of Sunda and Sahul Lands. 

 This ' paired ' dispersion to west and east is illustrated in Fig. 7. 



As millennia passed the more accessible lands of Africa would fill up, 

 and Australia would receive a much larger proportion of later (Australoid) 

 migrations. Finally as the latest migrants were thrust from Asia, the 

 American corridor became available — and this is why we find so large 

 a proportion of the last or Alpine-Mongolian Race in the New World. 

 A glance at the arrangement of the zones (Fig. 7) will show that this 

 series of migrations is fully corroborated. 



C 4. Scandinavian Climate. 



Let us now consider the environmental conditions somewhat more in 

 detail. In the first place the migrations were probably extremely slow, 



