Comments on the great extent of variations and on the acknowledgment of the new idea of greater female variety.
Expresses belief that the glacial period did affect the tropics, though HWB's arguments have confounded him.
Poses a series of questions concerning sexual selection.
Down Bromley Kent
I have read your papers with extreme interest & I have carefully read every word of them. They seem to me to be far richer in facts on variation, & especially on the distribution of varieties & subspecies, than anything which I have read. Hereafter I shall reread them, & hope in my future work to profit by them & make use of them. The amount of variation has much surprised me. The analogous variation of distinct species in the same regions strikes me as particularly curious. The greater variability of female sex is new to me. Your Guiana case seems in some degree analogous, as far as plants are concerned, with the modern plains of La Plata, which seem to have been colonised from the north, but the species have been hardly modified.—
I have been particularly struck with your remarks on the Glacial period. You seem to me to have put the case with admirable clearness
& with crushing force. I am quite staggered with the blow & do not know
what to think. Of late several facts have turned up leading me to believe more firmly
that the Glacial period did affect the Equatorial Regions; but I can make no answer to
your argument; & am completely in a cleft stick. By an odd chance I had only a
few days ago been discussing this subject, in relation to plants, with
There are many perplexing points, temperate plants seem to have migrated far more than animals— Possibly species may have been formed more rapidly within Tropics than one would have expected. I freely confess that you have confounded me: but I cannot yet give up my belief that the Glacial period did to certain extent affect the Tropics.—
Would you kindly answer me 2 or 3 questions if in your power.— When species (A) becomes modified in another region into a well marked form (C), but is connected with it by one (or more) gradational form (B,) inhabiting an intermediate region; does this form (B) generally exist in equal numbers with (A) & (C), or inhabit an equally large area?— The probability is that you cannot answer this question: though one of your cases seem to bear on it.—
In Butterflies, in which the sexes are differently coloured, is the male or female most
beautiful in our eyes? Do you know in Tropics any strictly nocturnal moths with
gaudy colours? As with Birds, have you ever noticed that female butterflies make any
selection of the male with which they copulate? Do several males
pursue same female? Are butterflies attracted by gay colours, as it has been asserted
Dragon-flies are. Any authentic facts on the courtship of Butterflies would be most
thankfully received & quoted by me. But I can see how very improbable it
is that anything sh
You will, I think, be glad to hear that I now often hear of naturalists accepting my views more or less fully: but some are curiously cautious in running risk of any small odium in expressing their belief.
With cordial thanks & respect | Believe me my dear Sir | Yours sincerely | C. Darwin
(Have you received copy of new Edit. of Origin?)
- f1 3100.f1Bates 1861a was printed in two separate issues of the Transactions of the Entomological Society of London for 1861.
- f2 3100.f2See Bates 1861a, pp. 352--3. See also letter from H. W. Bates, 18 March 1861. CD took Bates's work into account in the revisions he made to the discussion of the mundane glacial period in the fourth edition of Origin (Origin 4th ed., p. 451).
- f3 3100.f3Letter to J. D. Hooker, 18 March .
- f4 3100.f4See CD's note transcribed following the letter.
- f5 3100.f5See letter from H. W. Bates, 18 March 1861 and n. 7.
- f6 3100.f6For Bates's replies to CD's questions, see the letter from H. W. Bates, 28 March 1861. CD cited Bates on many of these points in the fourth edition of Origin (Origin 4th ed., pp. 502--6). He also referred in Descent to Bates's published account of his studies of the natural history of the Amazon region (Bates 1863).
- f7 3100.f7The third edition of Origin was published in April 1861.
- f8 3100.f8The note is in DAR 50 (ser. 6): 26.