flower feeders before the middle of the Secondary period. Several of the
asserted cases have broken down.

Your long letter has stirred many pleasant memories of long past days, when
we had many a discussion and many a good fight.


LETTER 399. TO J.D. HOOKER.
Down, August 21st, 1881.

I cannot aid you much, or at all. I should think that no one could have
thought on the modification of species without thinking of representative
species. But I feel sure that no discussion of any importance had been
published on this subject before the "Origin," for if I had known of it I
should assuredly have alluded to it in the "Origin," as I wished to gain
support from all quarters. I did not then know of Von Buch's view (alluded
to in my Historical Introduction in all the later editions). Von Buch
published his "Isles Canaries" in 1836, and he here briefly argues that
plants spread over a continent and vary, and the varieties in time come to
be species. He also argues that closely allied species have been thus
formed in the SEPARATE valleys of the Canary Islands, but not on the upper
and open parts. I could lend you Von Buch's book, if you like. I have
just consulted the passage.

I have not Baer's papers; but, as far as I remember, the subject is not
fully discussed by him.

I quite agree about Wallace's position on the ocean and continent question.

To return to geographical distribution: As far as I know, no one ever