1843—1882] INSULAR FLORAS 485 



think, in N. America ; but docs not occur in the Azores, where Letter 367 

 it is replaced by one that is of a decidedly American type. 



This tells heavily against the doctrine that joins Atlantis 

 to America, and is much against your trans-oceanic migration 

 — for considering how near the Azores are to America, and 

 in the influence of the Gulf-stream and prevalent winds, it 

 certainly appears marvellous. Not only are the Azores in 

 a current that sweeps the coast of U. States, but they are 

 in the S.W. winds, and in the eye of the S.W. hurricanes ! 



I suppose you will answer that the European forms are 

 prepotent, but this is riding prepotency to death. 



R. T. Lowe has written me a capital letter on the 

 Madciran, Canarian, and Cape Verde floras. 



I misled you if I gave you to understand that Wollaston's 

 Catalogue said anything about rare plants. I am worked 

 and worried to death with this lecture : and curse myself as 

 a soft headed and hearted imbecile to have accepted it. 



J. D. Hooker to C. Darwin. Letter 36S 



Kew, Monday [Aug. 6th, 1 866]. 



Again thanks for your letter. You need not fear my not 

 doing justice to your objections to the continental hypothesis ! 



Referring to p. 344 l again, it never occurred to me that 

 you alluded to extinction of marine life : an isthmus is a 

 piece of land, and you go on in the same sentence about 

 " an island," which quite threw me out, for the destruction 

 of an isthmus makes an island ! 



I surely did not say Azores nearer to Britain and New- 

 foundland " than to Madeira," but " than Madeira is to 

 said places." 



With regard to the Madciran coleoptera I rely very little 

 on local distribution of insects — they are so local themselves. 

 A butterfly is a great rarity in Kew, even a white, though we 

 are surrounded by market gardens. All insects arc most rare 

 with us, even the kinds that abound on the opposite side of 

 Thames. 



1 Origin of Species, Ed. ill., pp. 343-4: "In some cases, however, 

 as by the breaking of an isthmus and the consequent irruption of a 

 multitude of new inhabitants, or by the final subsidence of an island, the 

 extinction may have been comparatively rapid.' 



