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Darwin Correspondence Project

From Robert Goodwin Mumbray   18 January 1864

R. Goodwin Mumbray’s | Pharmaceutical Laboratory | Richmond Hill S.W.

January 18. 1864


In common with most readers I feel much interested in your valuable contributions on “The origin of species”—especially as regards Hybrids—1

Bechstein states that the Hybrids of the Finches—(Canary &c) propagate—2

With a view to testing the correctness of this statement I last spring put together in a large Cage a male Chaffinch a male Linnet and two hen Canaries— they paired but unfortunately disagreed—both laying eggs in the same nest— to obviate the difficulty, as there was fierce contention, I took away the weaker hen—when the other refused to sit— the Eggs were beautiful; six partaking of the Linnet character, and four of the Chaffinch— I am now preparing to repeat the experiment more carefully not allowing more than one pair of birds to each cage   I hope by crossing to realize the facts of the case   I have now—


2 Chaffinches. 2 Linnets

2 Greenfinches 2 Canaries

2 Linnets 1 Siskin

2 Goldfinches 3 Greenfinches—

Besides which I have two very fine (Song) thrushes reared by hand & thought of pairing them with Blackbirds— I should feel much obliged for any hint as to the advisability of the attempt—3 enclosed is an extract from Bewick4 which may be already familiar to you— if so I trust it will be excused—

I am Sir | Your’s Obediently | R G Mumbray

To | Doctor Darwin


“There are many varieties of Pheasants—some as white as snow which will intermix with the common ones”

“During the breeding season the cock Pheasant will sometimes mix with our common Hen and produce a Hybrid breed of which we have known several instances” (Bewick’s Brit: Birds V. i p 333.)5

I have often noticed what are called Pheasant Fowls, but understand it was a foreign breed—and not the result of crossing with our (now native) Pheasant6

R. G. M.


The reference is to Origin and the chapter on hybridism (pp. 245–78).
Johann Matthäus Bechstein’s discussion of the breeding of caged birds was published in the fourth volume of Bechstein 1789–95 and in Bechstein 1840; all five volumes are in the Darwin Library–CUL and are heavily annotated (see Marginalia 1: 38–47). Bechstein discussed the breeding of canaries with other finches in Bechstein 1789–95, 4: 468–9, and in Bechstein 1840, pp. 247–8; these pages are annotated in CD’s copies. CD’s reading notebooks record that he read Bechstein 1789–95 in 1842 and re-read one volume of it in 1856 (see Correspondence vol. 4, Appendix IV). In Origin, p. 252, CD mentioned crosses of the canary with nine other finches, noting that since none of the nine were known to breed freely in confinement, one could not expect perfect fertility. In Variation 2: 154, CD cited Bechstein as the ‘highest authority on cage-birds’.
No further correspondence with Mumbray has been found. Although CD cited Bechstein and other authors on the breeding of caged birds in Variation and in Descent, he did not cite Mumbray’s experiments.
Thomas Bewick.
Mumbray evidently refers to the rare fifth edition of the first volume of Bewick’s History of British birds (Bewick 1804 [c. 1814–16]), which was issued circa 1814–16 to complement surplus stocks of an earlier edition (see Roscoe 1953, pp. 89–94). The first quotation reads: ‘There are many varieties of Pheasants, of extraordinary beauty and brilliancy of colours: in many gentlemen’s woods there is a kind as white as snow, which will intermix with the common ones’ (Bewick 1804 [c. 1814–16], p. 336). The second quotation reads: ‘During the breeding season the cocks will sometimes intermix with the Common Hen, and produce a hybrid breed, of which we have known several instances’ (Bewick 1804 [c. 1814–16], p. 337). CD had mentioned pheasants reared by a domestic hen in Origin, pp. 215–16, and discussed pheasants in Variation 2: 45, 68, and Descent 2: 122, 228; he did not cite Bewick’s work on birds.
In Variation 1: 244, CD mentioned that the fowl breeds called ‘“pheasant”-fowls’ were called this because they had spangled feathers like the common pheasant. He said that this was not due to crossing distinct breeds but was true for many gallinaceous birds and was a case of analogous variation.


Bechstein, Johann Matthäus. 1789–95. Gemeinnützige Naturgeschichte Deutschlands nach allen drey Reichen. Ein Handbuch zur deutlichern und vollständigern Selbstbelehrung besonders für Forstmänner, Jugendlehrer und Oekonomen. 4 vols. Leipzig: Siegfried Lebrecht Crusius.

Bechstein, Johann Matthäus. 1840. Naturgeschichte der Stubenvögel, oder Anleitung zur Kenntniss, Wartung, Zähmung, Fortpflanzung und zum Fang derjenigen in- und ausländischen Vögel, welche man in der Stube halten kann. 4th edition. Halle: E. Heynemann.

Bewick, Thomas. 1804 [c. 1814–16]. History of British birds. 2 vols. Newcastle: T. Bewick. [Vol. 1, though dated 1804, was published c. 1814–16. See Roscoe 1953, pp. 89–95.]

Correspondence: The correspondence of Charles Darwin. Edited by Frederick Burkhardt et al. 27 vols to date. Cambridge: Cambridge University Press. 1985–.

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

Marginalia: Charles Darwin’s marginalia. Edited by Mario A. Di Gregorio with the assistance of Nicholas W. Gill. Vol. 1. New York and London: Garland Publishing. 1990.

Origin: On the origin of species by means of natural selection, or the preservation of favoured races in the struggle for life. By Charles Darwin. London: John Murray. 1859.

Roscoe, Sydney. 1953. Thomas Bewick. A bibliography raisonné of editions of the General history of quadrupeds, the History of British birds, and the Fables of Aesopissued in his lifetime. London: Oxford University Press.

Variation: The variation of animals and plants under domestication. By Charles Darwin. 2 vols. London: John Murray. 1868.


Has verified J. M. Bechstein’s contention that species of finches hybridise.

Quotes Thomas Bewick’s observations on hybrids between pheasants and common fowl. RGM had often noticed so-called "pheasant fowl", but thought it was a foreign bird.

Letter details

Letter no.
Robert Goodwin Mumbray
Charles Robert Darwin
Sent from
Richmond Hill
Source of text
DAR 171: 318–318/1
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 4392,” accessed on 21 September 2021,

Also published in The Correspondence of Charles Darwin, vol. 12