32 



camping grounds had, therefore, to be revisited, and this 

 must eventually result in the accumulation of large heaps 

 of refuse such as we observe, for instance, in the cave de- 

 posits in Europe. But, as already stated, these heaps of 

 refuse are wanting in the Tasmanian camping grounds, 

 and the only refuse we note axe here and there a few 

 traces of ash or charcoal and stone implements, which are 

 limited to a layer of not more than 6 to 12 incnes from the 

 surface. 



The only accuiuulations of refuse we observe in Tas- 

 mania are the shell heaps along the sea coast and the 

 estuaries of the bigger rivers.. The accumulation of these 

 shell heaps is easily accounted for, and is of no special in- 

 terest"; inasmuch as a large shell heap must collect within 

 a comparatively short, time. (1.) 



If we examine the situation of the shell heaps and 

 the old camping grounds, it becomes at once unquestion- 

 able that both came into existence not previous, but after 

 the present system of drainage hau been established ; in 

 other words, after Tasmania had acquired its present 

 shape, that is to say, become separated from the mainland. 

 So far, I have not seen a single camping site or shell 

 heap which tends to contradict this view. I may be wrong, 

 and others may, perhaps, be discovered, which disprove 

 this view, but all those I have so far examined have been, 

 formed after Tasmania had acquired its present contours 

 and physical features. 



This is, in my opinion, a very important fact, because 

 in conjunction with certain geological evidence it may tend 

 to throw some light on the all-important question of age. 

 We know, and recent investigations have conclusively 

 proved that the highlands of Tasmania were, geologically 

 speaking, in very recent times, covei'ed under vast sheets 

 of ice. The exact area of this glaciation is not known yet, 

 nor is it known to what height above sea level the ice 

 reached. Prof. GregoiT states that on the West Coast 

 glacial deposits are found near Queenstown ; the enormous, 

 boulder beds near Strahan are most probably of glacial 

 origin. With all reserve, I venture to say that to judge 

 from the present scanty evidence the glaciers extended to 

 a much lower sea level in the Western than in the Eastern 

 part of Tasmania. If we assume that all the land above 

 1,200-1,300 feet of the present level was covered under ice 

 during the glacial period, I think we are well withm 

 limits. But even this moderate estimate leaves only a 



(1) A short calculation will easily prove this; assuming every member of a tribe 

 of 50 persons consumes 50 oysters a day, not a very large allowance bv any means, 

 yet this would result in the daily production of SOOO valves, or 1, 825,000 valves 

 per year. Assuming that each valve weighs not more than 1 ounce (a verv low 

 estimate) this tribe would leave a refuse heap weighing 50 tons, being composed 

 of nearly 2 million valves every year. 



