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Darwin Correspondence Project

From John Edward Gray   4 February 1868


4 Feb 1868

My Dear Darwin

My Bookseller sent me your Dom Anim last night1   I naturally turned to the part I was last at work on the Pig.

Can you tell me where I can see Nathusius Especially the Figure of the skull2

In my late monograph the result of the Examination of nearly 100 skull mostly of Wild Pigs & different breed of domestic ones I had come to the conclusion that there are two sorts of Domestic Pig. The true Domestic & the semidomestic animal of the Wild Species3

Indeed I divide Pig

1 Wild—head long tapers. Young streaked, ears prick

2 Domestic head short nose keeled forehead flat. Young coloured like parent ears often large & flapping

I am amused at Narthusius saying that the Masked Pig has the skull of the Domest4   it almost makes one lose one confidence in his observation

This to the Potamochœrus or Painted Pig as Domestic Pig which I call Scroffa has to Sus but it cannot be a domestic breed of that genus—.5

Potamochœrus was said to be Naturalized in Brazil, it is so no longer but it may be the Red Pig you speak of in the West Indies6

I suspect the great defect of Narthusius Essay will be his want of Skull of Exotic Pig   There is a Sus Indicus that is the name of the Wild Boar of India7

We have not Narthusius here   is it in Roy Soc8

With kindest Regards | Ever Yours sincerely | J E Gray

Wattled Pig are not uncommon in English farm yard or were not.9


Gray refers to Variation.
CD referred frequently to the work of Hermann von Nathusius in his discussion of domestic pigs (Variation 1: 65–79). He particularly recommended Nathusius 1864, ‘with its excellent figures’ (ibid. p. 71), and also cited Nathusius 1860.
Gray refers to his ‘Synopsis of the species of pigs (Suidæ) in the British Museum’, in which he divided domestic pigs into two genera, Scrofa and Centuriosus (J. E. Gray 1868, pp. 38–41).
CD reported that, according to Nathusius, the skull of the Japan or masked pig closely resembled that of a domestic pig, ‘the short-eared Chinese breed of the S[us] Indicus type’ (Variation 1: 70). Using comparisons between the skulls of wild and domestic pigs of Europe and Asia, Gray described the pig as a distinct species (Sus pliciceps) that as yet had only been observed in its domesticated state, and that might be descended from a species found wild in the valleys of Japan (J. E. Gray 1862). In his most recent work, Gray had placed the pig in a different genus, Centuriosus pliciceps (J. E. Gray 1868, pp. 40–1).
In Gray’s taxonomy, Potamochoerus porcus (the red river hog) was placed in synonymy with the ‘painted pig’ (J. E. Gray 1868, p. 36). Gray used ‘Scrofa’ both as a specific epithet (Sus scrofa, the wild boar), and as a genus name for domestic pigs (Scrofa domestica, ibid. pp. 22–32).
Gray refers to CD’s remark that red feral pigs had been observed in Jamaica (Variation 1: 78). In his description of the red river hog (Potamochoerus porcus), Gray noted that despite repeated efforts, he had found no confirmation that the animal had been naturalised in Brazil (J. E. Gray 1868, pp. 36–7).
Gray had described the Indian wild boar as Sus indicus (J. E. Gray 1843, p. 185). For more on the differences between Gray’s and Nathusius’s taxonomy, see the letter from J. E. Gray, 15 February 1868 and n. 3.
Gray refers to the libraries of the British Museum and Royal Society of London.
Gray classed the ‘wattled pig’ as a variety of Scrofa domestica (J. E. Gray 1868, p. 39).


Discussion of the pig in light of CD’s Variation.

Work of Hermann von Nathusius [Die Racen des Schweines (1860)].

Letter details

Letter no.
John Edward Gray
Charles Robert Darwin
Sent from
British Museum
Source of text
DAR 165: 213
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 5839,” accessed on 16 June 2019,

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