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Darwin Correspondence Project

From Edward Blyth   18 May 1868

1 Princess Terrace,

May 18/68–

My dear Sir,

I give what replies I can to your various queries.1

1. I am unaware that any gibbon has the laryngeal Sac, with the exception of the siamang, H. syndactylus, peculiar to Sumatra. I think I can safely say that both sexes are equally noisy;2 & the cry, hoc-co, hoc-co, (with modifications in the different species) although much louder, is essentially like that of the chimpanzee, & these animals bear a considerable resemblance to the chimpanzee in visage. I never heard an orang-utan emit a loud cry of any kind.

2. I do not believe that chameleons ever fight, & I do not remember the passage in L. and W. giving an account of a male Anolis fighting.3

3. The two lesser fire-back pheasants, Euplocamus erythropthalmus & its Bornean ally, are remarkable for having wholly black females with well-spurred tarsi, & the crimson on the cheeks is also well developed in the hen bird.4 The Burmese pea-hen (spiciferus) is always conspicuously spurred, & the common or Indian pea-hen is very commonly so—5 I once obtained the skin of a wild jungle-hen with well developed spurs. It is now in the Mus. As. Soc., Calcutta—6 Plumage that of an ordinary jungle-hen.

4. I am tolerably sure that both sexes of storks clatter their beaks, especially as I have seen several of the large Indian adjutants do so at the same time, & the great probability is that they were not all of one sex.7 But I will see further to this.

5. I never heard of male Turnices 8 fighting.

6. In the British larger pied woodpecker, both sexes of the young have a crimson patch (or rather tips to the feathers of) the vertex, whilst the adult male has a crimson occipital crescent, & the old female no red whatever.9

In Buceros nipalensis the old female is wholly black excepting on tail, while the male has the head, neck, and under-parts bright ferruginous.10 In the only nestling-bird I have seen (sex unknown) the colouring was that of the adult male. In our British blackbird & stone-chat the sexes are readily distinguishable in the nest.11 In Palæornis javanicus the nestling male only has the upper mandible coral-red, it being black in the female until the second year or so, when it becomes red as in the male.12 I know of no vividly coloured young birds which are duller when adult, beyond such cases as the barred juvenile plumage of Cuculus canorus, & the stripes of the young emu & analogous cases. There are species of egret-heron in which the young are white & the adults slate-coloured, as A. cærulea & A. asha; others in which there is both a white & a slate-coloured phase at all ages, as A. jugularis (the white phase of which is Herodias Greyi, Gray); and the African A. gularis would appear also to have the same two phases, for I have now by me a dark ash-coloured one in its first plumage, & a purely white adult with dorsal train, that has a portion only of two wing-feathers (a tertiary & one of its coverts) dark ashy.13

In this instance it would appear that the reverse change had taken place to what occurs regularly in A. cærulea & A. asha! But I suspect that both young & adults of A. gularis occur in the white as well as in the slate-coloured phase, and also more or less pied, which does not appear to be the case with jugularis, & Greyi is therefore recognised as distinct by Gould, following McGillivray, whom he quotes in his “Handbook of the Birds of Australia,” Vol 2, p. 309.14

—In the Z. G. there is now a recently captured Ibis rubra retaining some of its dark first feathers, while the rest of its plumage (save the neck) is deep scarlet; shewing that the latter here is not due to age.15 In captivity, at least in this country, the plumage of the Ibis rubra is never of more than a very dilute scarlet.—

By the way, I could never understand why the Plumbago rosea was so named, for in India its flowers are intense crimson, but at Kew I see that its flowers are only roseate.

This plant is a splendid ornament of the Burmese jungles, & its masses of crimson, and the masses of beautiful blue which I have there seen of Eranthemum erectum, do not bear out Wallace’s remark that there is no display in a tropical jungle to compare with an English display of Hyacinthus non scriptus. The fine crimson flowers of Euphorbia jacquiniflora 16 are much more brilliant under a tropical sun, & I could mention other instances,—Euph. Bogiri 17 for one. This however is a digression.

Yours Sincerely, | E. Blyth

CD annotations

3.1 2.... fighting. 3.2] crossed blue crayon
4.1 3.... fighting. 6.1] crossed pencil
4.3 The Burmese … commonly so— 4.5] scored blue crayon
5.1 4. I am … this. 5.3] crossed pencil
7.1 6.... whatever. 7.3] crossed blue crayon
8.1 In … young are white 8.9] crossed pencil
8.13 a dark … dorsal train, 8.14] scored pencil and red crayon
10.1 —In … digression. 12.6] crossed blue crayon
Top of letter: ‘Voice of Gibbon’ pencil | ‘Keep’ blue crayon; ‘1’ blue crayon, circled blue crayon


No letter containing CD’s queries has been found. However, see the letter to T. H. Huxley, [before 18 May 1868].
Blyth refers to Hylobates syndactylus. CD cited Blyth for this information in Descent 2: 276–7.
Anoles (Anolis) are a genus of lizards of the iguana family (OED). CD discussed the pugnacity of Anolis cristatellus in Descent 2: 32, quoting from an article in Land and Water, July 1867, p. 9. Anolis cristatellus, the crested anole, is now Ctenonotus cristatellus (ITIS (internet resource), consulted 27 September 2005).
CD cited Blyth for information on the spurs of Euplocamus erythropthalmus in Descent 2: 46. Euplocamus erythropthalmus and its Bornean ally are now the crestless firebacks, Lophura erythrophthalma erythrophthalma (Malay peninsula and Sumatra) and L. e. pyronota (Borneo). See Birds of the World 2: 536.
The Burmese peafowl (Pavo spiciferus) is now P. mutatus spicifer. In Descent 1: 290, n. 28, CD stated that in the common peafowl, Pavo cristatus, the male alone possessed spurs.
Blyth had been curator of the Museum of the Asiatic Society, Calcutta, from 1841 to 1862 (ODNB).
Blyth refers to the greater or lesser adjutant storks (now Leptoptilos dubius and L. javanicus), both found in India.
Turnices: i.e. Turnix, the buttonquail genus.
Blyth refers to Dendrocopos major, the great spotted woodpecker (Birds of the world 7: 484–5).
Buceros nipalensis is now Aceros nipalensis, the rufous-necked hornbill (Birds of the world 6: 511).
The Eurasian blackbird (Turdus merula), and the common stonechat (Saxicola axillaris). CD mentioned the colouring of young blackbirds and stonechats (which he called Saxicola rubicola), amongst other birds, in Descent 2: 219–20 and n. 49, citing Blyth for information on the stonechat.
CD cited Blyth for this information in Descent 2: 179. For Palaeornis javanicus (this is no longer a recognised species name), see Jerdon 1862–4, 1: 262–3: according to this account, the females differ from the males only in having a black bill ‘at first’, which changes to red in ‘old or fully adult females’. The species is probably that now known as the moustached parakeet, Psittacula alexandri, although these are said to have a ‘pale red bill in very young birds’ (Forshaw and Cooper 1989).
CD mentioned the coloration of Ardea caerulea, A. asha, and A. gularis in Descent 2: 231 and n. 58 and 232; see also Descent 2: 214 n. 37. Ardea caerulea is now Egretta caerulea, the little blue heron (Birds of the world 1: 411). Ardea asha is now Egretta garzetta schistacea, the western reef heron (Birds of the world 1: 412, Hancock and Kushlan 1984, p. 129). Ardea jugularis is probably now Egretta sacra, the eastern reef egret. Ardea gularis is now Egretta garzetta gularis, also known as the western reef heron (Birds of the world 1: 412, UNEP/WCMC (internet resource), consulted 29 September 2005). All these species are morphic, including in juveniles, that is, there are dark, white, and mixed variants. In a list annotated by CD (DAR 84.1: 110), Blyth described Ardea species, including A. jugularis, as having two different phases at all ages; however, he refined his conclusion regarding A. gularis.
Blyth refers to John Gould, William Macgillivray, and J. Gould 1865.
Blyth refers to the Zoological Gardens in Regent’s Park, London. The scarlet ibis (now Eudocimus ruber) was presented to the Zoological Society of London on 2 May 1868 (Proceedings of the Zoological Society of London (1868): 642).
Euphorbia jacquiniiflora is a synonym of Euphorbia fulgens, the scarlet plume. Blyth refers to Alfred Russel Wallace.
Euphorbia bojiri, sometimes known as the crown-of-thorns plant.


Birds of the world: Handbook of the birds of the world. By Josep del Hoyo et al. 17 vols. Barcelona: Lynx editions. 1991–2013.

Descent: The descent of man, and selection in relation to sex. By Charles Darwin. 2 vols. London: John Murray. 1871.

Gould, John. 1865. Handbook to the birds of Australia. 2 vols. London: the author.

ITIS: Integrated Taxonomic Information System.

Jerdon, Thomas Claverhill. 1862–4. The birds of India; being a natural history of all the birds known to inhabit continental India, with descriptions of the species, genera, families, tribes, and orders, and a brief notice of such families as are not found in India, making it a manual of ornithology specially adapted for India. 2 vols. in 3. Calcutta: the author.

ODNB: Oxford dictionary of national biography: from the earliest times to the year 2000. (Revised edition.) Edited by H. C. G. Matthew and Brian Harrison. 60 vols. and index. Oxford: Oxford University Press. 2004.

OED: The Oxford English dictionary. Being a corrected re-issue with an introduction, supplement and bibliography of a new English dictionary. Edited by James A. H. Murray, et al. 12 vols. and supplement. Oxford: Clarendon Press. 1970. A supplement to the Oxford English dictionary. 4 vols. Edited by R. W. Burchfield. Oxford: Clarendon Press. 1972–86. The Oxford English dictionary. 2d edition. 20 vols. Prepared by J. A. Simpson and E. S. C. Weiner. Oxford: Clarendon Press. 1989. Oxford English dictionary additional series. 3 vols. Edited by John Simpson et al. Oxford: Clarendon Press. 1993–7.


Replies to CD’s queries regarding sexual differences in gibbons’ voices, chameleon behaviour, and the occurrence of spurs in pheasants and peahens. Discusses sexual differences in structure and habit within certain bird species.

Letter details

Letter no.
Edward Blyth
Charles Robert Darwin
Sent from
London, Princess Terrace, 7
Source of text
DAR 83: 148, DAR 84.1: 107–8, 111
Physical description
8pp †

Please cite as

Darwin Correspondence Project, “Letter no. 6180,” accessed on 28 September 2021,

Also published in The Correspondence of Charles Darwin, vol. 16