The Life and Letters of Charles Darwin – Day 146 of 188

Charles Darwin to J.D. Hooker.

Down, August 5th [1856].

…I quite agree about Lyell’s letters to me, which, though to me interesting, have afforded me no new light. Your letters, under the geological point of view, have been more valuable to me. You cannot imagine how earnestly I wish I could swallow continental extension, but I cannot; the more I think (and I cannot get the subject out of my head), the more difficult I find it. If there were only some half-dozen cases, I should not feel the least difficulty; but the generality of the facts of all islands (except one or two) having a considerable part of their productions in common with one or more mainlands utterly staggers me. What a wonderful case of the Epacridae! It is most vexatious, also humiliating, to me that I cannot follow and subscribe to the way in which you strikingly put your view of the case. I look at your facts (about Eucalyptus, etc.) as damning against continental extension, and if you like also damning against migration, or at least of enormous difficulty. I see the ground of our difference (in a letter I must put myself on an equality in arguing) lies, in my opinion, that scarcely anything is known of means of distribution. I quite agree with A. De Candolle’s (and I dare say your) opinion that it is poor work putting together the merely possible means of distribution; but I see no other way in which the subject can be attacked, for I think that A. De Candolle’s argument, that no plants have been introduced into England except by man’s agency, [is] of no weight. I cannot but think that the theory of continental extension does do some little harm as stopping investigation of the means of dispersal, which, whether negative or positive, seems to me of value; when negatived, then every one who believes in single centres will have to admit continental extensions.

…I see from your remarks that you do not understand my notions (whether or no worth anything) about modification; I attribute very little to the direct action of climate, etc. I suppose, in regard to specific centres, we are at cross purposes; I should call the kitchen garden in which the red cabbage was produced, or the farm in which Bakewell made the Shorthorn cattle, the specific centre of these species! And surely this is centralisation enough!

I thank you most sincerely for all your assistance; and whether or no my book may be wretched, you have done your best to make it less wretched. Sometimes I am in very good spirits and sometimes very low about it. My own mind is decided on the question of the origin of species; but, good heavens, how little that is worth!…

[With regard to “specific centres,” a passage from a letter dated July 25, 1856, by Sir Charles Lyell to Sir J.D. Hooker (‘Life’ ii. page 216) is of interest:

“I fear much that if Darwin argues that species are phantoms, he will also have to admit that single centres of dispersion are phantoms also, and that would deprive me of much of the value which I ascribe to the present provinces of animals and plants, as illustrating modern and tertiary changes in physical geography.”

He seems to have recognised, however, that the phantom doctrine would soon have to be faced, for he wrote in the same letter: “Whether Darwin persuades you and me to renounce our faith in species (when geological epochs are considered) or not, I foresee that many will go over to the indefinite modifiability doctrine.”

In the autumn my father was still working at geographical distribution, and again sought the aid of Sir J.D. Hooker.

Post a Comment

Your email is never published nor shared. (To tell the truth I don't even really care if you give me your email or not.)