258 



THE ANTIQUITY OF MAN IN TASMANIA. 



the eastern strait has been too short to allow for a mix- 

 ing of these two faunas, even if we assume that the Ade- 

 laidean fauna migrated into the inland sea the moment 

 communication with the western ocean was opened. 



I need hardly to mention that the above figures are 

 based on averages, and though the aggregate may be 

 fairly correct the components may be quite erroneous. 

 For instance, if we take the time since the commence- 

 ment of the volcanic activity till the time when Tasmania 

 became separated from the mainland to be 5,000 years, 

 we may assume that the whole of the volcanic activity 

 was over in, say, 1,000 years, while the balance of 4,000 

 years represented a period of quietness, or better, slow 

 changes. It may also be that the second period of 5,000 

 years which have lapsed since the separation is in fact 

 much shorter, owing to the sea rising quicker during 

 this than during the earlier period. It is, of course, im- 

 possible to go into such questions, which are but vague 

 speculations. We are bound to go by average figures, 

 on which a working theory can be based, but we must 

 not be led astray by factors which may be probable but 

 which cannot be proved. 



10. THE TIME OF THE IMMIGRATION OF THE 

 ABORIGINES INTO TASMANIA. 



The above arguments give us the key to the solution 

 of the problem when the Tasmanian race first arrived 

 on the island. Three facts are absolutely certain, viz.: — 



(a) The immigration must have taken place while 



Tasmania was still connected with the mainland 

 of Australia. 



(b) The immigration must have taken place after the 



disappearance of the gigantic marsupials. 



(c) The immigration must have taken place before 



the appearance of the dingo in Victoria. 



The immigration must therefore have taken place in 

 post-glacial time ; the period that lapsed since the glacial 

 time has been estimated at 60,000 years, which can be 

 divided into two very unequal stages, the earlier lasting 

 50,000, the later 10,000 years. At the beginning of the 

 later period great tectonic and volcanic changes took 



