Appreciates MJB's address [Rep. BAAS 38 (1868): 83–7]. Has had great respect for MJB's knowledge since his undergraduate days at Cambridge.
Agrees that Pangenesis gemmules probably do not develop into free cells, but penetrate other cells in a manner analogous to fertilisation, and modify their development.
Down. | Bromley. | Kent. S.E.
Sep 7 1868
My dear Sir
I am very much obliged to you for having sent me your Address (which however I had read in the Gard. Chron.) for I thus gain a fair excuse for troubling you with this note to thank you for your most kind & extremely honorable notice of my works.
When I tell you that ever since I was an under-graduate at Cambridge I have felt towards you the most unfeigned respect, from all that I continually heard from poor dear Henslow & others of your great knowledge & original researches, you will believe me when I say that I have rarely in my life been more gratified than by reading your address; tho' I feel that you speak much too strongly of what I have done. Your notice of Pangenesis has particularly pleased me, for it has been generally neglected or disliked by my friends; yet I fully expect that it will some day be more successful. I believe I quite agree with you in the manner in which the cast off atoms or so-called gemmules probably act; I have never supposed that they were developed into free cells, but that they penetrated other nascent cells & modified their subsequent development. This process, I have actually compared with ordinary fertilization. The cells thus modified, I suppose—cast off in their turn modified gemmules, which again combine with other nascent cells, & so on. But I must not trouble you any further.
Accept my cordial thanks & with sincere respect Pray believe me my dear Sir | yours very faithfully | Charles Darwin
- f1 6353.f1Berkeley delivered the opening address to the biology section at the meeting of the British Association for the Advancement of Science in Norwich in 1868 (Berkeley 1868). The copy of the address sent to CD by Berkeley is in DAR 226.1: 27; CD's copy of the Gardeners' Chronicle, 29 August 1868, including the speech on page 920, is in the Cory Botanic Garden, Cambridge. Neither copy is annotated.
- f2 6353.f2Berkeley noted CD as `the greatest observer of our age', and after offering a criticism of pangenesis (see n. 4, below), wrote: `We must still take it as a compendium of an enormous mass of facts, comprised in the most marvellous manner within an extremely narrow compass' (Berkeley 1868, pp. 86, 87). In defending pangenesis from charges of materialism, Berkeley ended with the following tribute to CD (ibid., p. 87):
I feel assured that the members of this Association will conclude with me in bidding this great and conscientious author God-speed, and join in expressing a hope that his health may be preserved to enrich science with the results of his great powers of mind and unwearied observation.
- f3 6353.f3John Stevens Henslow taught both Berkeley and CD at the University of Cambridge, where Berkeley was an undergraduate from 1821 to 1825 and CD from 1828 to 1831 (see Correspondence vol. 1, Walters and Stow 2001, and ODNB s.v. Berkeley, Miles Joseph).
- f4 6353.f4Commenting on CD's theory of pangenesis (see Variation 2: 357--404), Berkeley gave his opinion that CD `laid too much stress on free-cell formation' and that it was more probable that the `molecules' (particles or gemmules) responsible for the transmission of hereditary characters were capable of exercising an influence analogous to that exercised by the contents of the pollen-tube or spermatozoid on the embryo sac or ovum than that these particles should themselves develop into cells (Berkeley 1868, p. 87).