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 Madeiran, 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.
LETTER 368. J.D. HOOKER TO CHARLES DARWIN. Kew, Monday [August 6th, 1866].
Again thanks for your letter. You need not fear my not doing justice to your objections to the continental hypothesis!
Referring to page 344 again (368/1. "Origin of Species," Edition III., pages 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."), 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 Newfoundland "than to Madeira," but "than Madeira is to said places."
With regard to the Madeiran 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 are most rare with us, even the kinds that abound on the opposite side of Thames.
So with shells, we have literally none--not a Helix even, though they abound in the lanes 200 yards off the Gardens. Of the 89 Dezertas insects [only?] 11 are peculiar. Of the 162 Porto Santan 113 are Madeiran and 51 Dezertan.
Never mind bothering Murray about the new edition of the "Origin" for me. You will tell me anything bearing on my subject.
LETTER 369. J.D. HOOKER TO CHARLES DARWIN. Kew, August 7th, 1866.
Dear old Darwin,
You must not let me worry you. I am an obstinate pig, but you must not be miserable at my looking at the same thing in a different light from you. I must get to the bottom of this question, and that is all I can do. Some cleverer fellow one day will knock the bottom out of it, and see his way to explain what to a botanist without a theory to support must be very great difficulties. True enough, all may be explained, as you reason it will be--I quite grant this; but meanwhile all is not so explained, and I cannot accept a hypothesis that leaves so many facts unaccounted for. You say the temperate parts of N. America [are] nearly two and a half times as distant from the Azores as Europe is. According to a rough calculation on Col. James' chart I make E. Azores to Portugal 850, West do. to Newfoundland 1500, but I am writing to a friend at Admiralty to have the distance calculated (which looks like cracking nuts with Nasmyth's hammer!)
Are European birds blown to America? Are the Azorean erratics an established fact? I want them very badly, though they are not of much consequence, as a slight sinking would hide all evidence of that sort.
I do want to sum up impartially, leaving the verdict to jury. I cannot do this without putting all difficulties most clearly. How do you know how you would fare with me if you were a continentalist! Then too we must recollect that I have to meet a host who are all on the continental side-- in fact, pretty nearly all the thinkers, Forbes, Hartung, Heer, Unger, Wollaston, Lowe (Wallace, I suppose), and now Andrew Murray.