392 REASON FOR DISTRIBUTION, [ciiAPr 



the same general habits, occupying analogous situations, 

 and obviously filling the same place in the natural economy 

 of this archipelago, that strikes me with wonder. It may 

 be suspected that some of these representative species, at 

 least in the case of the tortoise and of some of the birds, 

 may hereafter prove to be only well-marked races ; but this 

 would be of equally great interest to the philosophical 

 naturalist. I have said that most of the islands are in sight 

 of each other ; I may specify that Charles Island is fifty 

 miles from the nearest part of Chatham Island, and thirty- 

 three miles from the nearest part of Albemarle Island. 

 Chatham Island is sixty miles from the nearest part of 

 James Island, but there are two intermediate islands 

 between them which were not visited by me. James Island 

 is only ten miles from the part of Albemarle Island, but the 

 two points where the collections were made are thirty-two 

 miles apart. 1 must repeat, that neither the nature of the 

 soil, nor height of the land, nor the climate, nor the general 

 character of the associated beings, and therefore their action 

 one on another, can differ much in the different islands. 

 If there be any sensible difference in their climates, it must 

 be between the windward group (namely Charles and 

 Chatham Islands), and that to leeward ; but there seems 

 to be no corresponding difference in the productions of 

 these two halves of the archipelago. 



The only light which I can throw on this remarkable 

 difference in the inhabitants of the different islands, is, 

 that very strong currents of the sea running in a westerly 

 and W.N.W. direction must separate, as far as transported 

 by the sea is concerned, the southern islands from the 

 northern ones ; and between these northern islands a strong 

 N.W. current was observed, which must effectually separate 

 James and Albemarle Islands. As the archipelago is free 

 to a most remarkable degree from gales of wind, neither 

 the birds, insects, nor lighter seeds, would be blown from 

 island to island. And lastly, the profound depth of the 

 ocean between the islands, and their apparently recent 

 (in a geological sense) volcanic origin, render it highly 

 unlikely that they were ever united : and this, probably, 

 is a far more important consideration than any other, 

 with respect to the geographical distribution of their 

 inhabitants. Reviewing the facts here given, one is 

 astonished at the amount of creative force, if such an 

 expression may be used, displayed on these small, barren, 



