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Darwin Correspondence Project

From Robert Swinhoe   [before 1 October 1865?]1

– – parent stock prove unfruitful— It is rare to induce the Mallard to tread the female Muscovy, and I have never seen the result. But the Chinese assure me that when thus a hybrid is produced, it is in characters scarcely distinguishable from the Muscovy breed.2

I have a curious story of Dog-morality which may be of some use to you— Sodomy is a common crime among Chinese Dogs— I have heard cases of it at Foochow, and its occurrence is well known in Peking. Query whether the Dog apes his lord and master? For the prevalence of this crime in Peking above all places in China is too well known to need comment. The story that I am about to relate has been told to me by Mr. T. Watters a gentleman in this Consulate who has lately joined me from Peking,3 and who was an eye-witness of the facts it contains. Mr. Watters was walking on the Wall of Peking when his attention was attracted to two Chinese Dogs below. One was a rough big brute, and the other a comely smaller animal— The big one commenced to caress the smaller one, but the latter at first objected. At last after many affectionate appeals the smaller dog yielded. Whilst in the act of sodomy several other dogs came up and barked angrily and bit at them. They (the other dogs) then retired for a time as if for consultation, and having evidently watched for the termination of the crime, returned just as the operation was finished. They then rushed upon the big dog. One seized him by the head, two others by the hind legs, and a fourth caught and entirely bit off his penis. The mutilated Dog ran away howling. Mr. Watters saw the Dog several days afterwards, so that the animal did not die from the effect of the laceration. It appears not to be an unusual punishment for Dogs to inflict on one another for this crime. Besides Mr. Watters others in Peking have seen the same inflicted, and one often sees both in Peking and Tientsin Dogs going about with their genital organs mutilated, caused, as the Chinese declare, in nearly every case as an award for this offence against the community of Dogdom.4 As to immoral acts on the part of Dogs I suppose almost every observing man must have had cases fall within his experience. I myself when a lad at home have seen the House-dog committing the sin of Onan5 with his mouth as he lay on the rug at the door—

Some time ago I reported to you that I had noticed incipient spurs on the wings of dried specimens of the Merula albiceps & other thrushes.6 I now think that I must have been mistaken, as in a fresh specimen of an immature M. albiceps lately shot I can find no indication of such spur; and the young bird ought surely to show it if the old bird possessed it in any observable degree.

I find that there is a wild Bos in this island, which appears from Chinese accounts to be the stock of the small cattle that are reared in the farmsteads of Formosa. I do not observe any appreciable difference between the domestic Cattle here and those of south China, and I would therefore infer that the small yellow cow of South China has had its race derived from a stock that formerly existed (and perhaps still exists) in the mountains of the Southern Provinces, instead of being a small derivative of Bos taurus. I will not go so far as to say that the wild Bos of South China (if such there be) is identical with the wild Bos of Formosa, or even to say that differences may not be found on anatomical comparison between the respective domestic breeds. I have not even compared the two latter together, but only speak from what I recollect of the China breed. The Formosan Cow is small extremely graceful, with short usually upright horns, and straight back— The bull is not much larger, but is remarkable for a shoulder hump. The colour of the Bos is usually of a yellowish-brown of lighter or deeper hue, with white belly. A few individuals occur nearly black, but the hair is not much subject to albinistic or melanistic variation, as in thoroughly domesticated animals.7 I intend collecting full particulars on the wild as well as domestic cattle of Formosa, and submitting a Paper on the subject to the Zoological Society.8 I shall further attempt to get live specimens to England.

Believe me, | Dear Sir, | Your’s truly | Robert Swinhoe.

C. Darwin, Esqr.


The date is conjectured on the assumption that the missing portion of the letter contained the information on ducks referred to in the letter to P. L. Sclater, 6 January [1866] (Correspondence vol. 14; see n. 2, below). Based on other Swinhoe correspondence in the 1860s, the approximate length of time for a letter to reach England from Taiwan was three months.
Swinhoe refers to the mallard (Anas platyrhynchos; then A. boschas), and to the Muscovy duck, a species native to tropical America (Cairina moschata; then also Anas moschata). In his letter to P. L. Sclater of 6 January [1866] (Correspondence vol. 14), CD wrote that Swinhoe had informed him ‘of a domestic race of duck in China as perhaps descended from Anas pœcilorhyncha’, the spot-billed duck, a close relative of the mallard. Swinhoe had earlier informed CD of a supposed ‘thorough race’ of duck that had developed from hybrids of the Muscovy duck and Chinese domestic duck (see Correspondence vol. 10, letter from Robert Swinhoe, 12 November 1862). CD had long been interested in crosses with the Muscovy duck (see Correspondence vol. 2, letter to W. D. Fox, [25 January 1841], and Correspondence, vol. 11, letter to W. D. Fox, 9 March [1863] and n. 1). Several notes on the topic are in DAR 205.7: 192 and 201. CD did mention the Muscovy duck, or ‘musk-duck’, in Variation 1: 190 and 2: 40, but did not mention Chinese duck species or breeds. For CD’s interest in determining if domestic breeds of ducks had derived from Anas boschas, see Variation 1: 276–87.
Thomas Watters had been stationed in the Peking consulate as a student interpreter in 1863; in August 1865 he was an interpreter in Taku, south-east of Peking at the mouth of the Pei-ho river. He served as acting consul under Swinhoe in Taiwan from March to October 1866 (Foreign office list), and thus may have visited the consulate in Taiwan prior to this appointment.
Swinhoe’s information does not appear in CD’s discussion of dogs in Variation, Descent, or Expression.
Onan, the second son of Judah, whose ‘sin’ was coitus interruptus (see Gen. 38: 4–10); however the term onanism more commonly refers to masturbation (OED).
In his letter to CD of 4 April 1864 (Correspondence vol. 12), Swinhoe had described a tubercle on the carpal edge of the wing of Turdus albiceps (now T. poliocephalus niveiceps) and noted its appearance on several other species of thrush. Swinhoe had believed the tubercle to be an abortive wing-spur (see also Swinhoe 1864, pp. 363–4). Merula was a synonym of Turdus in the nineteenth century (see Peters et al. 1931–87, 10: 177).
For CD’s interest in varieties of domestic cattle and their descent from wild species, see the letter from Ludwig Rütimeyer, 3 January 1865, nn. 3, 4, and 6. CD did not include Chinese breeds in his discussion of cattle in Variation 1: 79–93.
No paper by Swinhoe on the cattle of Formosa (now Taiwan) has been found.


Reports that dogs caught in the act of sodomy have been attacked by their fellows, who mutilate the offender’s genitals.

Gives a description of the nature and occurrence of the wild Bos of Formosa.

Letter details

Letter no.
Robert Swinhoe
Charles Robert Darwin
Sent from
Source of text
DAR 177: 328
Physical description
6pp inc

Please cite as

Darwin Correspondence Project, “Letter no. 4727,” accessed on 26 April 2017,

Also published in The Correspondence of Charles Darwin, vol. 13