43 



Kuro Siwo passes far to the westward of" the westernmost iskxnd, and 

 between it and the wanii current a broad strip of water, with a temperature 

 of 35° Fahrenlieit, intervenes. This is strikingly evident in the founa of 

 shoal water about Attn, where Arctic forms prevail almost exclusively. The 

 strait between Kamchatka and the Commander's Islands is, at its narrowest 

 part, one hundred and twenty nautical miles wide ; and, between them and 

 Attn, it is two hundred and twenty miles wide. Between the Commander's 

 Islands and the end of the Aleutian chain is a great gulf of fovu- thousand 

 fathoms in depth, cutting off the fauna of Asia from that of America, except 

 such portion as has spread from the Arctic along the shores southward 

 on both sides of Bering Sea. I have been thus explicit in stating the 

 physical features of the region, because they have a very important bear- 

 ing on the subject of migration, and are iisually wholly ignored in ethno- 

 logical papers which treat of that topic. 



Shell-heaps are found on nearly all the islands of the Aleutian group. 

 They are most abundant and extensive in the islands east of Unalashka, 

 and on the few islands from Amchitka eastward, which are less high and 

 rugged than the others; or on those where the greater amount of level land 

 is to be found. The two necessaries for a settlement a])pear to have been 

 a stream of water or a spring, and a place where canoes could land with 

 safety in rough Aveather. Where these are both wanting, shell-heaps are 

 never found, and rarely when either is absent. The favorite spots appear 

 to have been on narrow necks of land, across which an easy portage could 

 be made from one body of water to another. Safety from hostile attacks 

 also governed the selection of village-sites, and hence the mouths of streams 

 abounding with salmon, but offering no protection, were seldom made a 

 place of settlement. The earliest inhabitants, however, appear to have 

 been less particular in this respect than their more modern successors. 



On the islands west of Amchitka, shell-heaps are less abundant, the 

 shores being less fully provided with food and drift-wood, and less acces- 

 sible for canoes. 



We observed shell-heaps in the following localities: 



Attu Island. — 1. At the head of Chichagoff Ilarboi', east of the present 

 village ; ex:tent about three acres and a half; the shell-heaps covered with 



