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Darwin Correspondence Project

From John Edward Gray   28 January 1862

B M.

28 Jan 62.

My Dear Darwin

I am going to read a curious paper at the Society this eveng.1

The discovery of a New Species of Domestic Animal

This species is curious as being only known in the domestic state! no wild prototype of it having as yet been sent to our Collection

The Animal is the Japan Pig   It is very different in its osteology from any of the Wild or Domestic Swine of Europe or Asia

The skull being much more like a Potamochœrus of Africa than a sus in general outline with the Characters of a Sus. yet there a[re] characters enough to make it form a peculiar section of the related genus sus characterized by the symetrical Plicature of the face the flatness & margins of the nose of the skull and the width of the Palate

Ever Yours Sincerely | J. E Gray

You will find a figure of the head in the July issue Proceedings for 1861.2 & of the Entire Animal in the Illustrated News of this Month.3 I think the 11th   I call it Sus pliciceps


Gray read his paper on the skull of the Japanese pig, Sus pliciceps (J. E. Gray 1862a), before the Zoological Society of London on 28 January 1862. CD referred to Gray’s paper in his discussion of variation in domestic pigs in Variation 1: 69–70.
The Proceedings of the Scientific Meetings of the Zoological Society of London for each year were published in three parts, in the months of May, August, and February (the part published in February completing the volume for the preceding year). The woodcut to which Gray refers appeared in the issue for August 1861, p. 263. A copy appears in Variation 1: 69.
An illustration of ‘Japanese pigs’ appeared in the Illustrated London News, 11 January 1862, p. 49.


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


The Japan pig, an unusual domestic species with no wild prototype.

Letter details

Letter no.
John Edward Gray
Charles Robert Darwin
Sent from
British Museum
Source of text
DAR 165: 204
Physical description

Please cite as

Darwin Correspondence Project, “Letter no. 3416,” accessed on 7 August 2020,

Also published in The Correspondence of Charles Darwin, vol. 10