Sends a list of queries for AG.
Asks whether AG can supply specimens for illustrations [for Descent]. Hopes Mr Ford will do the drawings.
Down. | Beckenham | Kent. S.E.
Sep. 21 1869
My dear Dr Günther
I am going to beg, I hope for the last time, a great deal of assistance from you. I enclose a whole string of queries, but most of these may be answered by a few words written after them. My only excuse for troubling you so much is that four-fifths of the facts which I give, are quoted from you & your works. To save you as much trouble as possible, I enclose an envelope directed.
In the second place, you most kindly offered to help me about
illustrations. I now enclose a list somewhat different from my
original one. Will you look it over, as some of the drawings
cannot be made, unless you can supply the specimens. Mr Ford
Pray forgive me for asking so many favours & | believe me | yours sincerely obliged | Ch. Darwin
(1) In my notes from y
(2) Agassiz writes to me that certain chromids, as Pomotis, Hygrogonus &c sit on their nest; do you happen to know whether it is the male, or the female, or indifferently both sexes, which thus sit?
(3) I understood you to say that the female of Solenostoma is brighter coloured than the male; is this the case, for you do not say so in the Fishes of Zanzibar? Do you believe Kaup's statement that the males have marsupial sacks & carry the eggs? What must I say on this head?
(4) Is it known whether any Lizards utter any sound during their courtship?
(5) You gave me cases, with Lizards, of the dorsal crest being confined to the males; & other cases in which the crest was larger in the males than in the female; Now are there other cases in which the dorsal crest is equally developed in both sexes?
(6) Chamælio bifurcus. What is its native Country? Is it brightly coloured, especially the projections on the head of the male?
(7) Chamælio owenii. What is its native Country? Is it brightly coloured?
Has the female any rudiment of the triple horn? Is the horn in the male flexible or rigid?
Is the triple horn formed by the modification of one or more scales?
(8) Can you remember whether any amphibian or reptile is marked with true ocelli of bright colours; that is a spot of colour surrounded by a ring of another colour?
(9) With Lizards are the males generally or often or rarely larger than the females?
- f1 6903.f1CD cited Günther extensively on fishes, amphibians, and reptiles in Descent (see Descent 2: 9--10, 12, 18--19, 22, 30, 33--4, 37). He made particular use of Günther's descriptive catalogue of central American fish (Günther 1864--6), and his monograph on the reptiles of British India (Günther 1864). There is an annotated copy of Günther 1864 in the Darwin Library--Down (see Marginalia 1: 352). An annotated copy of Günther 1864--6 is in the unbound pamphlet collection in the Darwin Archive--CUL.
- f2 6903.f2CD had discussed the illustrations for Descent with Günther during a visit to London in March 1868. See Correspondence vol. 16, letter to Albert Günther, 23 March  and n. 2.
- f3 6903.f3The enclosed list has not been found. CD had enclosed a slip (also not found) in the letter to Albert Günther of 23 March  (Correspondence vol. 16).
- f4 6903.f4George Henry Ford.
- f5 6903.f5CD originally planned to include material on the expression of emotions in Descent.
- f6 6903.f6CD refers to Günther 1864--6, p. 485. Mollienesia petenensis (now Poecilia petenensis) is the peten molly.
- f7 6903.f7See Correspondence vol. 16, letter from Louis Agassiz, 22 July 1868. The former family Chromidae includes the present families Cichlidae and Pomacentridae (Pauly 2004). Pomotis is a now invalid genus that included species now recognised as sunfishes as well as some cichlids. Hygrogonus is now Astronotus.
- f8 6903.f8CD refers to The fishes of Zanzibar (Playfair and Günther 1866), p. 137; Solenostoma is now Solenostomus).
- f9 6903.f9Günther had reported Johann Jakob Kaup's observation in Playfair and Günther 1866, p. 138.
- f10 6903.f10In his letter of 19 December 1867 (Correspondence vol. 15), Günther wrote that in lizards with a dorsal crest, the feature was more developed in the male.
- f11 6903.f11CD refers to Chamaeleo bifurcus (now Furcifer bifidus, the two-horned chameleon).
- f12 6903.f12CD refers to Chamaeleo owenii (now Chamaeleo oweni, Owen's three-horned chameleon).