My dear Falconer

On my return home yesterday I found your letter and MS. which I have read with extreme interest.² Your note and every word in your paper are expressed with the same kind feeling which I have experienced from you, ever since I have had the happiness of knowing you.³ I value scientific praise, but I value incomparably higher such kind feeling as yours. There is not a single word in your paper to which I could possibly object: I should be mad to do so; its only fault is perhaps its too great kindness. Your case seems the most striking one which I have met with of the persistence of specific characters. It is very much the more striking as it relates to the molar teeth, which differ so much in the species of the genus, and in which consequently I should have expected variation. As I read on, I felt not a little dumb-founded, and thought to myself that whenever I came to this subject, I should have to be savage against myself; and I wondered how savage you would be. I trembled a little. My only hope was that something could be made out of the B-o-g N. American forms, which you rank as a geographical race;⁴ and possibly hereafter out of the Sicilian species.⁵ Guess then my satisfaction when I found that you yourself made a loophole which I never of course could have guessed at; and imagine my still greater satisfaction at your expressing yourself as an unbeliever in the eternal immutability of species.⁶ Your final remarks on my work are too generous; but have given me not a little pleasure.⁷ As for criticisms, I have only small ones: when you speak of “moderate range of variation”,⁸ I cannot but think that you ought to remind your readers (though I daresay previously given) what the amount is, including case of the American Bog Mammoth. You speak of these animals as having been exposed to vast range of climatal changes from before to after the Glacial period;⁹ I should have thought from analogy of sea-shells, that by migration (or local extinction when migration not possible) these animals might and would have kept under nearly the same climate.

A rather more important consideration, as it seems to me, is that the whole Proboscidean Group may, I presume, be looked at as verging towards extinction: anyhow the extinction has been complete as far as Europe and America are concerned. Numerous considerations and facts have led me in the Origin to conclude that it is the flourishing or dominant members of each order which generally give rise to new races, sub-species and species;¹⁰ and under this point of view I am not at all surprised at the constancy of your species. This leads me to remark that the sentence at the bottom of p. 60 is not applicable to my views, though quite applicable to those who attribute modification to the direct action of the conditions of life.¹¹ An elephant might be more individually variable than any known quadruped (from the effects of the conditions of life or other innate unknown causes), but if these variations did not aid the animal in better resisting all hostile influences, and therefore making it increase in numbers, there would be no tendency to the preservation and accumulation of such variations, i.e., to the formation of a new race. As the proboscidean group seems to be from utterly unknown causes a failing group in many parts of the world, I should not have anticipated the formation of new races.

You make important remarks versus natural selection,¹² and you will perhaps be surprised that I do to a large extent agree with you. I could show you many passages, written as strongly as I could in the Origin, declaring that Natural Selection can do nothing without previous variability; and I have tried to put equally strongly that variability is governed by many laws, mostly quite unknown. My title deceives people, and I wish I had made it rather different.¹³ Your phyllotaxis will serve as example; for I quite agree that the spiral arrangement of a certain number of whorls of leaves (however that may have primordially arisen; (and whether quite as invariable as you state?)) governs the limits of variability, and therefore governs what natural selection can do.¹⁴ Let me explain how it arose that I laid so much stress on Natural Selection, and I still think justly: I came to think from Geographical Distribution &c. &c. that species probably change; but for years I was stopped dead by my utter incapability of seeing how every part of each creature (a wood-pecker or swallow for instance) had become adapted to its conditions of life. This seemed to me and does still seem the problem to solve, and I think natural selection solves it, as artificial selection solves the adaptation of domestic races for man’s use. But I suspect that you mean something further,—that there is some unknown law of evolution by which species necessarily change; and if this be so, I cannot agree.¹⁵ This, however, is too large a question even for so unreasonably long a letter as this.

Nevertheless just to explain by mere valueless conjectures how I imagine the teeth of your elephants change; I should look at the change, as indirectly resulting from changes in the form of the jaws, or from development of tusks, or in case of the “primigenius” even from correlation with the woolly covering; in all cases natural selection checking the variation. If indeed an elephant could succeed better by feeding on some new kinds of food, then any variation of any kind in the teeth, which favoured their grinding power would be preserved. Now I can fancy you holding up your hands and crying out what bosh! To return to your concluding sentence; far from being surprised, I look at it as absolutely certain that very much in the Origin will be proved rubbish; but I expect and hope that the frame-work will stand.¹⁶

I had hoped to have called on you on Monday evening, but was quite knocked up.¹⁷ I saw Lyell yesterday morning; he was very curious about your views, and as I had to write to him this morning I could not help telling him a few words on your views.¹⁸ I suppose you are tired of the Origin and will never read it again; otherwise I should like you to have the 3rd edit., and would gladly send it rather than you should look at the 1st or 2nd editions.¹⁹

With cordial thanks for your generous kindness, believe me | My dear Falconer | Very truly yours | Ch. Darwin