| 
 
			
			BTW, there has been quite a trade in arctic ivory (etc.) since at least the 18th and aparently somewhat world wide.  I have an Indonesian statue of a rhinoceros made from what is clearly walrus tooth, for instance.  So geography is no barrier to a material being used, or even popular, especially in seagoing cultures.I find the sea/land division idea fascinating.  Somehow seems to link to the tradition of not carrying kris across water?
 |