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Darwin Correspondence Project

From W. W. Keen   26 September 1873

1729 Chestnut St | Philada.

Sept. 26. 1873.

My dear Sir

In reading carefully of late your Descent of Man, Sexual Selection, & Expression of the Emotions I have been struck with some statements of facts which I regarded as erroneous & also have been reminded of facts corroborating your statements or even going further, which I have jotted down & propose to embody as briefly as possible. No one, so candid and so just as you are, will more rejoice I feel sure if an inadvertent error is eliminated than yourself. Pardon me therefore if I venture to call attention to such.

I quote pages from Appleton’s reprint of the Descent &c. 1872 & the Emotions dated 1873.—1

Descent & Sexual Selection Vol. I.

p. 19 middle— You state that the platysma is an involuntary muscle. On the contrary it is a perfectly voluntary muscle & can be brought into action as perfectly & easily as any muscle. (P.S. You have corrected this in the book on Expression p 298 et seqq.)2

p 20. middle.— The power of voluntarily moving the ears is not unusual as you intimate. Many persons can do so. Most persons in laughing & even smiling move the ears upwards & I think forwards. Possibly the ears are pushed up by the soft parts on the face but I think it is not so.

p. 22 top. I have lately seen a medical friend in whose ears the tubercle instead of being turned inwards remains turned up- & out-wards so that the ear is really a pointed one. If I can do so I hope to obtain for you a Photograph of the auricle.3 Of course you have seen the recent article in Virchow’s Archiv on this Subject4 & are familiar probably with this peculiarity in Hawthorne’s fiction of “Transformation or The Marble Faun” in Donatello who resembles so strikingly the Faun of Praxiteles.*5

p. 24. bottom. The peculiarity noticed by Mr. Paget as hereditary is I think not only (if particularly) hereditary, but, in this country, is very common with advancing age.6 Dr. Wayland late Pres. Brown Univy. & the author of noted text books on Polit. Econ. Moral & Mental Philos. &c. was noted for his bushy shaggy eyebrows & his 2 living sons markedly resemble him in this7

pp. 48–9. With respect to animals learning to avoid traps. With my friend Dr. S. Weir Mitchell I have had much to do with Rattlesnakes. We generally kept them in deep boxes & caught them by means of a long pole with a leather noose at the end. A green (i.e. new) snake could be caught with perfect ease but in a few days after being caught 4 or 5 times he would dodge the noose & in a little time considerable dexterity was required to catch them.8

p. 52 bottom. See Marsh’s Lectures on the Eng. Lang. p. 35 (note) for the Statement that the Massacre of the Sicilian Vespers was all arranged by facial gestures alone no other gestures & no words being used. & some other Statements. The book referred to is not his “Eng. Lang. & its Early Literature”.9

p. 143. If you will observe carefully the hair is best developed not “on the chest & face & junction of the 4 limbs with the trunk” but in the Median line of the body. E.g. On the head it comes to a point in the median line both in front & behind, if whiskers are absent a median10

*An argument to support your view is the growth of the hair up- & for-wards on the top of the auricle with advancing years, more than over the rest of the auricle except the lobule & tragus

[at least 1 folio missing]

assurance that it was so, & that the holes were eaten where the pipes were not obstacles to progress I can scarcely believe that their intelligence has been so cultivated by familiarity with civilized man’s means for getting water as to lead to such an act of reason. I mention it however for what it is worth.11

One point in reference to sexual selection I have to suggest when I am done with my rambling & I fear almost worthless letter. I do not know but that it should rather be classed however as natural selection in relation to sex. I mean the peculiar effect of certain diseases on one sex or the other by reason of the frequency with which it attacks one sex as compared with the other.

My memory may be at fault but I do not recall any allusion to it in any of your books. Yet it must have its influence both as to the number of Survivors of each sex & as to the questions of inheritance in that sex alone or in major part. As an allied subject also I would suggest the fact now believed by many to be true (& my self among the number) that Syphilis (& possibly other diseases) though existing in the Father cannot be & is not transmitted to the child except the mother be first infected ie. if she escapes direct infection the child will also. It is widely & vehemently disputed by many Syphilographers but its supporters I think have the strongest side.12

I hope you will pardon me Sir if I have fruitlessly taken up your time. What is of value if there be any I shall be delighted to have you weigh & use if you think best.

While not able to follow you quite as far as you go, yet I accept most of it gladly & as a daily teacher I enjoy the light you have shed on much that has been dark & unmeaning. With the hope that your life may be spared a long while to cement what you have so well built I remain | very respectfully | Your Ob’t Sv’t | W. W. Keen M.D. | Lecturer on Anatomy in the Philadelphia School of Anatomy | Lecturer on Pathol. Anat. in the Jefferson Med. College Phila | Joint Author of Gunshot Wounds & other Injuries of Nerves &13

(I beg leave to name these as an introduction)

I forgot to mention an inherited peculiarity in my children of the use of a single muscle. My wife14 when perplexed or in deep thought often contracts the 2 Corrugator Supercillii muscles just enough to produce a single deep furrow but not a general frown; in fact it is rather almost a pit than a furrow its border is so sharply curved


thus. I have 3 children all girls 5, 4 & 212 years old.15 The eldest & youngest resemble me very markedly & the middle one her mother. The eldest & youngest both will frown when perplexed &c. but it is a more general frown while the 2d. child has the most striking reproduction of this her mothers use of the Corrugator.16

[Dr. Keen, of Philadelphia, calls attention (letter n. d.),17 to his paper in the ‘Med. and Surg. History of the War of the Rebellion (Surgical Part),’ vol. i. pp. 206–7, bearing on this point. A patient lost part of his skull by a gunshot wound, and recovered with a concavity on the surface of his head, into which the scalp dipped to the depth of an inch. Ordinary respiration did not affect the concavity, but on moderate coughing a little cone bulged up, and a severe cough changed the concavity into a convex surface rising above the surface of the head.]18

CD annotations

1.1 In … this 7.5] crossed pencil
1.5 candid … yourself. 1.6] scored blue crayon
4.1 p. … muscle. 4.3] ‘D’ added red crayon
5.1 p 20. … intimate. 5.2] ‘E D’ added red crayon
6.1 p. 22 … one. 6.3] ‘E D’ added red crayon
7.1 p. 24 … age. 7.2] ‘D E’ added red crayon
8.1 pp. 48–9. … them. 8.6] ‘Intellect of Snakes’ added red crayon
9.1 p. 52 … Literature”. 9.4] crossed pencil
10.1 p. 143 … body. 10.2] double scored red crayon; ‘Good’ added pencil
11.1 *An … tragus 11.3] double scored blue crayon
12.1 assurance … side. 13.9] scored blue crayon
18.1 I … Corrugator 18.8] scored blue crayon
Top of letter: ‘Dr W. Keen, Lecturer of anatomy’ pencil; ‘Intellect of Snakes’ blue crayon ‘& Manpencil; ‘Nakedness in Belts view19 | Hair [‘eyebrows &’ del pencil] on body | Intellect of Snakes [underl pencil]’ blue crayon; ‘D.= Descent | E expression’ red crayon, del pencil
End of letter: ‘Mustache & goatee are mostly seen with age it also develops on the nose; it is mainly in the medial line on the neck, chest, belt & back—on the pubes, & the perinæum. The axillæ are morphologically the median line but pushed back (?!)—(N.B— there are often patches on the shoulders—The outer side of [‘for’ del] arms & legs. )’ ink, del pencil, square brackets in ms; ‘Russia〈n〉 Hairy [‘Man’ del] Boy a sort of mane running down neck’20 pencil


D. Appleton & Co. published American editions of CD’s works; Descent US ed. was published in 1871 and reprinted in 1872, and Expression US ed. was published in 1873. Parts of this letter were previously published in Correspondence vol. 21; since then, the end of the letter, from paragraph 12, ‘assurance that it was so’, to paragraph 21, ending ‘use of the Corrugator’, has been identified in DAR 169: 2. A middle section of the letter is still missing, but is partially accounted for by the note from Expression 2d ed. reproduced at the foot of the letter.
In Expression US ed., pp. 298–303, CD described the movements (such as shuddering) that caused an involuntary contraction of the platysma myoides muscle, and noted how simulating these movements sometimes produced the same contraction. In Descent 2d ed., p. 13, CD omitted the reference to the platysma’s movement being involuntary.
The tubercle, or blunt point, projecting inwards from the folded margin of the ear in some humans (see Descent 1: 22, fig. 2) was first drawn to CD’s attention by Thomas Woolner (see Correspondence vol. 18, letter to Thomas Woolner, 10 March [1870]). CD viewed this point as a vestige of formerly pointed ears in humans or their ancestors. There is no evidence that Keen sent a photograph of his friend’s ears to CD.
Keen probably refers to Ludwig Meyer’s article in Archiv für pathologische Anatomie und Physiologie und für klinische Medicin (Meyer 1871), which maintained that the ‘Woolnerian tip’ visible on some ears was merely a random variation, not evidence for a former pointed ear-shape in humans. Rudolf Carl Virchow was the editor of Archiv für pathologische Anatomie und Physiologie und für klinische Medicin.
Nathaniel Hawthorne’s novel The marble faun (Hawthorne 1860), also known as Transformation, featured Donatello, count of Monte Beni, whose character combined human and animal qualities. His appearance was modelled on Praxiteles’s statue, the Faun, which was on display in the Uffizi Gallery, Florence.
James Paget had informed CD that the occurrence of eyebrows with some hairs longer than the others often ran in families (Descent 1: 25).
Francis Wayland had been president of Brown University, Providence. His sons were Francis Wayland Jr and Heman Lincoln Wayland.
CD added this observation to Descent 2d ed., p. 352. Silas Weir Mitchell had investigated the effects of snake venom on the nervous system as part of his research on the physiology of the cerebellum (ANB).
In Descent 1: 54, CD had stated that humans’ unique use of articulate speech did not preclude the use of gestures and facial movements. The massacre of thousands of French inhabitants of Sicily had begun on Easter Monday 1282 with the killing of some French soldiers at vespers in Palermo (see Runciman 2012, pp. 214–27). George Perkins Marsh’s statement that facial signs alone were used to start the massacre was in his Lectures on the English language (G. P. Marsh 1861, p. 35 n.), which Keen distinguished from Marsh’s The origin and history of the English language, and of the early literature it embodies (G. P. Marsh 1862).
See Descent 1: 149. CD did not add the point about hair being best developed along the median line of the body to Descent 2d ed.
The missing discussion probably had to do with rats’ gnawing holes in lead pipes to get water (see Correspondence vol. 23, letter from Arthur Nicols, [before 10 November 1875], and this volume, letter from J. A. Ransome-Marriott, 1 September 1876).
CD did not mention syphilis in the first edition of Descent. In Descent 2d ed., p. 7, he used syphilis as an example of a disease that could be transmitted between humans and animals, showing that their tissues and blood were similar; however, he did not discuss the inheritance of the disease. Syphilographer: an expert in the study and treatment of syphilis (OED).
Keen et al. 1864.
Emma Corinna Borden Keen.
Corrine, Florence, and Dora Keen.
CD discussed the use of the corrugator muscles in frowning and deep thought in Expression, pp. 181 and 222–3.
This comment, published in Expression 2d ed., p. 169 n. 19, was probably drawn from the missing part of Keen’s letter.
In Expression, p. 161 (and Expression 2d ed., pp. 168–9), CD discussed how violent expiration (such as coughing) led to the dilation of blood vessels in the head, indicated by the rise and fall of the brain and the advance of the eyes in their sockets with each expiration. The medical and surgical history of the war of the rebellion (1861–65), Surgical volume part 1, vol. 2, pp. 206–7, recorded the accounts of various surgeons who had treated a soldier with the gunshot wound to the head; Keen had examined the patient mentioned in his letter in 1870 and believed that this case might throw light on the anatomy of the optic nerve. A longer account of the case was published in Keen and Thomson 1871. There is an independently paginated offprint of Keen and Thomson 1871 in the Darwin Pamphlet Collection–CUL. CD scored the passages relating to coughing on pages 2 and 4, and wrote at the top of the pamphlet, ‘for Expression p. 2, 4’.
In Descent 2d ed., p. 57, CD added, with some reservations, Thomas Belt’s suggestion that hairlessness in the tropics was advantageous because it made getting rid of parasitical insects easier (see Belt 1874, p. 209). CD himself accounted for hairlessness as a secondary sexual characteristic acquired through sexual selection (Descent 2d ed., pp. 58, 600–1).
CD had obtained the information about the Russian hairy boy from Alexander von Brandt (see Correspondence vol. 22, letter to C. S. Tomes, 16 February [1874]).


Sends corrections of Descent and Expression.

Letter details

Letter no.
William Williams Keen
Charles Robert Darwin
Sent from
Source of text
DAR 89: 24–5, DAR 169: 2, and Expression 2d ed., p. 169 n. 19
Physical description
8pp inc †, CD note ††

Please cite as

Darwin Correspondence Project, “Letter no. 9072,” accessed on 24 April 2019,

Also published in The Correspondence of Charles Darwin, vol. 24 (Supplement) and 21