To Charles Lyell   31 [October 1859]1

Wells Terrace. Ilkley Otley Y.

Monday 31st

My dear Lyell

That you may not misunderstand how far I go with Pallas & his many disciples, I shd. like to add that, though I believe that our domestic Dogs have descended from several wild forms, & though I must think that the sterility which they would probably have evinced if crossed before being domesticated, has been eliminated, yet I go but a very little way with Pallas & Co. in their belief in the importance of the crossing & blending of the aboriginal stocks: you will see this briefly put in first chapter.—2 Generally with respect to crossing, the effects may be diametrically opposite: if you cross two very distinct races, you may make (not that I believe such has often been made) a third & new intermediate race. But if you cross two exceedingly close races or two slightly different individuals of the same race, then in fact you annul & obliterate the differences.— In this latter way I believe crossing is all-important; & now for 20 years I have been working at flowers & insects under this point of view.— I do not like Hooker’s terms centripetal & centrifugal; they remind me of Forbes’ bad term of Polarity.—3

I daresay selection by man would generally work quicker than natural selection; but the important distinction between them is that man can scarcely select except external & visible characters, & secondly he selects for his own good; whereas under nature characters of all kinds are selected exclusively for each creature’s own good, & are well exerrcised: but you will find all this in Ch. IV.—

Although the Hound—Greyhound & Bull-dog may possibly have descended from 3 distinct stocks, I am convinced that their present great amount of difference is mainly due to the same causes, which have made the breeds of pigeons so different from each other, though these breeds of pigeons have all descended from one wild stock. So that the Pallasian doctrine, I look at, as of but quite secondary importance.

In my bigger book I have explained my meaning fully;4 whether I have in the abstract, I cannot remember.—

Yours affect— | C. Darwin

1
Dated by the relationship to the letter from Charles Lyell, 28 October 1859.
2
Origin, pp. 19–20.
3
Edward Forbes’s principle of ‘polarity’ was intended to describe the existence in the fossil record of two very prolific eras: one early in geological time, called by Forbes the Palaeozoic era, and one just before the present, called the Neozoic era. According to Forbes, the number of genera diminished after the Palaeozoic, increasing again at the start of the Neozoic (Browne 1983 and Rehbock 1983). CD had earlier remarked: ‘“Polarity” makes me sick’ (Correspondence vol. 5, letter to J. D. Hooker,7 July [1854]).
4
CD refers to the first two chapters on ‘Variation under domestication’ intended for his big book on species. They were later expanded into Variation. He also discussed the doctrine concerning the domestication of animals espoused by Pyotr Simon Pallas in the conclusion to chapter 9 on hybridism (see Natural selection, p. 462).

Manuscript Alterations and Comments

1.1 That] ‘T’ over ‘t’
1.2 our domestic] interl
1.3 several] after del ‘more than’
1.4 probably] interl
1.4 if crossed … domesticated] above del ‘at first’
1.4 been] after del interl ‘probably’
1.5 in the] after del ‘th’
2.4 of all kinds] interl
3.1 possibly] interl
3.3 mainly] interl

Please cite as “DCP-LETT-2513,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-2513