AUSTRALIAN QUATERNARY CLIMATES AND MIGRATION 11 



south-east right down the whole course of the River Finke for a distance of 400 



miles. 



And again, in discussing the improbability of the aborigines 

 being only long enough in Australia to increase to their number 

 when the white man came, he stales: 



.... we know that in many tribes even in good country, a balance between 

 numbers and food resources is maintained by infanticide and sometimes by 

 abortion. In times of severe drought in the drier parts of the continent, 

 infanticide is apt to be practised temporarily in the interests of the adults 

 without any thought of the future of the group. 



These quotations indicate how dependent the aborigines were 

 on the fertility of a region and its implied food resources but 

 that, even witli fertility in their Australian environment, a 

 balance between numbers and the food available had to he main- 

 tained. For a former tropical rain-l'orest people to favour the 

 arid belt for habitation is unthinkable; their first contact with it 

 would be a deterrent. As Marett (1938) says: 



.More especially inhospitable is the arid type of desert, more so even than 



the frozen type of tundra; lack of rain being the physical scourge that man lias 

 to fear most, Nay, as a cause of migration on a grand scale desiccation is 

 perhaps more effective than any cultural influence . . . 



Taylor's estimate (1927) of the aridity in northern Australia 

 during the Pleistocene Ice Ages applies also to the arid belts 

 during the Postglacial period : 



We may picture much more repellent conditions in the north during the 

 Pleistocene Ice Ages than ohlain today. These may well have prevented any 

 higher race from following the aborigines into Australia. 



From the standpoint of subsistence, the fertile tracts with their 

 relative sufficiency of food and water, were the first to be occupied. 

 These were. 15,000 years ago when the t ropical rain-forest reached 

 Australia, the coastal corridor and the rainfall-reliability 

 lxdt which covered the south-east, a narrow avenue at the bead of 

 the Great Australian Bight, south-west Australia, and the western 

 coastal corridor. It also extended at this time as far west as 

 Lake Eyre and a triangle (Fig. 13) converging from the head 

 of the Bight on the west, and Grafton on the east, subtended at 

 the north by Georgetown in Queensland. 



This triangle embraced part of the bake Eyre basin, western 

 New South Wales, and a large part of inland Queensland. From 

 the aspect of climate and fertility, it may be assumed that it 

 formerly enclosed an area carrying a relatively large population 

 of aborigines in small tribal areas, but now, as if is wholly within 

 the arid bell, it is sparsely peopled and the tribal areas are Large 

 such as EUrin mentions in referring to the Aranda. Some of its 



