Comments on GRW's paper [Rep. BAAS (1843): 65–7; Ann. & Mag. Nat. Hist. 12 (1843): 399–412]. CD says by "link" between any two groups he never understood a half-way link, merely one in a long series. Observes that one cannot have a simple species intermediate between two great families. Criticises GRW's use of circles to represent groups, which leads to thinking that groups are of equal value.
Down, Bromley Kent
My dear Waterhouse
I have read your paper with much interest & it has helped to clear my notions
considerably, though I do not think I was one of the very guilty ones, against whom you
write. By the term “link between any two
groups” I never understood (, & I rather doubt, whether many
naturalists meant much more) a half way link, but merely one in a long series. I think
you have done good service in pointing out how rare half-way-links are, if indeed they
exist. If they do exist which I doubt we must, I suspect, look back to ancient
geological periods.— There is one thing to observe namely that one cannot have
a simple species intermediate between two great families, for if such did exist, it
I have one criticism to make about your circles
—that is that I think you are bound to state that they do not necessarily
represent (without you think they do) groups of equal value & though all
touching, the affinities are not necessarily equally strong.— I believe
infinite harm has been done by these circles, which catch the eye as of equal size,
& inevitably lead the mind to suppose they are of equal value— it is
by this artifice, as I believe, the possibility of making the Quinarian system appear
probible has chiefly rested: Moreover it sh
I admire my own impudence in criticising you & doing this I repeat I think you have done good service in pointing that most or all links are not intermediate but fall into to one or other of the two groups,— Are there are not some forms which show alliances to more than two groups? (a case you do not allude to, which surely is real)— as for your wicked circles, I wish they were all d——d together.
Farewell | Yours impudently | C. Darwin
I saw Owen, after you, & he spoke most warmly & cordially about your affairs—
N.B. This is vilely written letter, but I cannot express myself off-hand—
- f1 718.f1The conjectured dates are based on Waterhouse 1843, which appeared in December, and on CD's reference in the postscript to his having seen Waterhouse and Owen. According to CD's Account Book (Down House MS), he travelled to London on 30 November and 14 December.
- f2 718.f2Waterhouse 1843 argues that systematic groups of animals do not blend into one another and that, when species are well enough understood, they can always be assigned unambiguously to one group or another. His article may have been partly directed against evolutionary theories, like that of Lamarck, which postulated intermediate gradations from one systematic group to another.
- f3 718.f3Waterhouse 1843 cites several of Owen's papers; however, CD may also refer to a paper not cited in which Owen commented on the frequent separation of the squamous, petrous, and tympanic portions of the temporal bone in marsupials—a condition that prevails among adult birds and reptiles but not among placental mammals (Owen 1841, p. 383).
- f4 718.f4Waterhouse had argued that the resemblances between a marsupial wombat and true rodents are merely adaptive and thus not genuine affinities (Waterhouse 1843, p. 406).
- f5 718.f5Waterhouse had adopted the procedure, popular among followers of William Sharp MacLeay's quinary system, of representing closely related groups by contiguously placed circles; however, he did not accept all of MacLeay's interpretations for these circles.