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Darwin Correspondence Project

From John Wood   11 April 1871

68, Wimpole Street, | Cavendish Square. W.

April 11th. 1871

Dear Sir

I have not observed that the platysma contracts, either in children or adults, under the effects of simple fear, as in the immediate presence of a surgical operator which usually relaxes all the skin muscles*; but since receiving your note I shall observe more closely, and have already set sharp anatomical eyes to watch for this phenomenon1

But I have observed it frequently, both in my own children2 and in adults, to co⁠⟨⁠n⁠⟩⁠tract under the emotions of rage, disgust, & contempt, or when the two former of these are mingled with fear in the shape of horror. The muscle often, if not usually, contracts in nausea & sickness & during the effort of vomiting3

It is particularly excited, like all the muscles of the neck, in hydrophobia,—&, to a less extent, in tetanus.

I believe that it expresses chiefly the passion which indicates resistance, aggression or self defence, and that, through its upward prolongation the “risorius Santorini”, it uncovers the lower canines, as the snarling muscle exposes the upper,—and assists in opening the jaw in readiness to bite. I have observed the platysma to be most developed in persons with a thick, bull neck & broad shoulders; and in families inheriting these peculiarities,—one of which, especially, I have now in mind, it is usually associated with much voluntary power over the “occipito-frontalis”, which is supplied by the same nerve, & which causes the hair to stand on end,—like the “quills upon the fretful porcupine.4 These latter are acted on by the homologous muscle “the panniculus”, in those animals very powerful, as also in the hedgehog & badger.5 In shuddering, all the skin muscles contract in a spasmodic wave (even the “dartos scroti”) in sympathy with the cold sensation experienced by the nerves,6 and in this way, fear may sometimes cause the contraction of the “platysma” also. Duchenne is unquestionably wrong about the action of the “corrugator supercilli   Its inner attachment is lower than the outer. It must, therefore, draw down the brows, as well as inwards. The expression in the photograph is produced, as you say, by the contemporaneous action of the central fibres of the anterior belly of the occipito-frontalis;—but with only slight action of the “orbicularis palpebrarum”.7

I shall be happy at any time to afford you such knowledge as I possess, and remain, | Yours most truly | John Wood

*The expression commonly used of “a fallen countenance”, “his countenance fell” refers to the effect of relaxation of the skin muscles of expression, as in a paralyzed face.

Chas. Darwin Esqre

CD annotations

1.1 I have … badger. 4.10] crossed ink
2.1 But … horror. 2.3] ‘(Horror is not rage)’ pencil
4.4 I have observed] opening square bracket red crayon
4.13 Duchenne] opening square bracket blue crayon
4.13 Duchenne … palpebrarum” 4.18] crossed red crayon
Top of letter: ‘Inheritance’ red crayon


CD’s letter to Wood has not been found, but see the letter from John Wood, 6 April 1871. CD had been making enquiries about the action of the platysma myoides in frightened patients who were about to undergo surgery (see letter to Francis Darwin, 25 March [1871]).
Edith Wood, John Wood (b. 1868), Margaret Wood, Mary Wood, and Sarah Wood.
Wood’s observations of the platysma myoides contracting during vomiting, nausea, and disgust are cited in Expression, p. 302.
CD refers to this observation in Expression, p. 302. The family has not been identified. Wood quotes Shakespeare’s Hamlet, 1.5.
CD refers to Wood’s observations in Expression, p. 182.
Wood describes the contraction of the scrotum in reaction to contact with cold.
Wood refers to Guillaume Benjamin Amand Duchenne and Duchenne 1862, p. 43 and plate 21. Duchenne intended the photograph to express ‘souvenir douloureux’ or ‘appel à la mémoire’ (‘painful memory’ or ‘calling to mind’; see Duchenne 1862, p. 36). CD cites both Duchenne and Wood in Expression, p. 181.


Duchenne, Guillaume Benjamin Amand. 1862. Mécanisme de la physionomie humaine, ou analyse électro-physiologique de l’expression des passions. 1 vol. and ‘Atlas’ of plates. Paris: Ve Jules Renouard, Libraire.

Expression: The expression of the emotions in man and animals. By Charles Darwin. London: John Murray. 1872.


Emotional states leading to contraction of the platysma. Contraction of skin muscles.

Letter details

Letter no.
John Wood
Charles Robert Darwin
Sent from
London, Wimpole St, 68
Source of text
DAR 181: 141
Physical description
ALS 4pp †

Please cite as

Darwin Correspondence Project, “Letter no. 7674,” accessed on 25 September 2023,

Also published in The Correspondence of Charles Darwin, vol. 19