"Zoolog. Generale." Is it not strange that the author, of such a book as the 'Animaux sans Vertebres,' should have written that insects, which never see their eggs, should WILL (and plants, their seeds) to be of particular forms, so as to become attached to particular objects. The other, common (specially Germanic) notion is hardly less absurd, viz. that climate, food, etc., should make a Pediculus formed to climb hair, or wood-pecker, to climb trees. I believe all these absurd views arise, from no one having, as far as I know, approached the subject on the side of variation under domestication, and having studied all that is known about domestication. I was very glad to hear your criticism on island-floras and on non-diffusion of plants: the subject is too long for a letter: I could defend myself to some considerable extent, but I doubt whether successfully in your eyes, or indeed in my own...
CHARLES DARWIN TO J.D. HOOKER. Down [July, 1844].
...I am now reading a wonderful book for facts on variation—Bronn, 'Geschichte der Natur.' It is stiff German: it forestalls me, sometimes I think delightfully, and sometimes cruelly. You will be ten times hereafter more horrified at me than at H. Watson. I hate arguments from results, but on my views of descent, really Natural History becomes a sublimely grand result-giving subject (now you may quiz me for so foolish an escape of mouth)...I must leave this letter till to-morrow, for I am tired; but I so enjoy writing to you, that I must inflict a little more on you.
Have you any good evidence for absence of insects in small islands? I found thirteen species in Keeling Atoll. Flies are good fertilizers, and I have seen a microscopic Thrips and a Cecidomya take flight from a flower in the direction of another with pollen adhering to them. In Arctic countries a bee seems to go as far N. as any flower...
CHARLES DARWIN TO J.D. HOOKER. Shrewsbury [September, 1845].
My dear Hooker,