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Darwin Correspondence Project

From ?   [1873?]1

Expression of the Emotions.

Page 45. 2nd. paragraph.

I had a bulldog who suffered extremely from fleas & when his back was rubbed & scratched he would sometimes turn round & “flea” my hand, that is to say he would nibble at my hand in the same way as he did to his own body when killing fleas.

Page 88. Plaintive or hissing note.

May not this have arisen from seizure by the throat & the utterance of cries in such a situation which would naturally be strained & pitched in a high key?

Page 121Grinning.

The dog I mention above would often when I went out in the morning grin from ear to ear, lifting his fore feet alternatively about half an inch from the ground at the same time, occasionally he would only smile, or simply expose one of his canine teeth. I would suggest that the bull dog from what I have observed exhibits more expressions unacquired from more than any other domesticated dog.

Page 123. Tucking in tail

It is well known that dogs when fighting always keep their tails rigid & stiff until the moment when one gives in & then he immediately drops his tail which I believe takes place without any shrinking in of the hinder parts & even in the hottest part of the scuffle when two dogs have had hold of one another in an exceedingly dangerous manner I have seen the tail held rigidly erect.

Page 116 Necessity of preparation of muscles.

I have always felt that after lying down for a little time that on rising it is necessary to stretch & strain the muscles vigorously, that is to say when lying down in the middle of the day & getting up suddenly.

Page 131. Musk Ox.

I would suggest that the stamping arose from the fact that oxen after they have knocked their enemy down trample him to death. The action of the musk ox is expressive of what he will do if he comes in contact with a foe.2

Page 161 at foot of page

During stooling when necessary to make a continuous effort I have noticed the pressure of the eyelids as mentioned.

Page 207.Laughter.

I would suggest that the origin of laughter has been in the imitation of the reiterated heavy breathing which takes place in sexual connection. I am confirmed in this opinion by the brightening of the eye in both instances, & I have also noticed in one of my friends a young man who indulges in this pleasure to a great extent that the corners of his mouth have gradually become more & more retracted & that if he abstains to some extent that his mouth does not in the same degree present this appearance. The mouth cannot be opened widely as it never is during any strong physical exertion. I am also told that during connection the features of the female present the appearance that is common to what is called “sardonic laughter”. As sexual connection is the highest sensual pleasure, the phenomenas that take place during connection would before language came into use be the easiest way of communicating the idea of pleasure.

Page 216 Kissing

This appears to partake of the nature of suction: When we wish to get the marrow out of bones or the juice from fruit we purse up the mouth much in the same manner as when kissing. A person loved would be associated with the idea of something luxurious hence would arise the idea of partaking from which sucking would be the natural sequence which would gradually develope into kissing.

Page 246 Tendency to break or destroy.

I have frequently felt when out of humour a strong tendency to break or destroy things & suppose this is an inheritance from the time when habit had not controlled the feelings, but when if we felt angry we destroyed the cause of annoyance.

Page 249Protrusion of head.

This appears to me to be connected with the action of fighting with the head whether by butting as amongst the negroes or in more remote times by biting or with the object of commanding an opponent’s attention to what is being said through clearer hearing.

Page 257. Soup in the beard

This appears to me to look disgusting not from any idea connected with the food but that in certain states of imbecility or carelessness there is a tendency to allow mucous from the nose & saliva from the mouth to gather in the beard. Soup or other matter in the beard revives this feeling of disgust originated in the manner mentioned above.

Page 266 Rubbing thumb & two forefingers.

This is the sign in Spain when asking for money. When I first went to that country & before I knew Spanish the servant used always to make that sign when asking for “cuartos”. (Small copper coins, also used colloquially instead of “dinero”.)

Page 277 Moving finger from left to right sign of negation

This action is very commmon in Spain. I might also mention as rather curious that I have observed in Andalucia that the notion of beckoning is the reverse of that in England, whilst we move the hand upwards with the palm towards our face, the Andaluces move the hand downwards with the palm downwards when wishing say a child to come towards them.

Page 283. Breathing with mouth open.

Being of a nervous temperament I am frequently alarmed when in bed & notice that I always breathe with my mouth slightly open, as I can do so more quietly & listen better, although habitually I breathe through the nostrils.

Page 289Hand before mouth.

I would suggest that putting the hand before the mouth has arisen through the necessity of stealing on wild animals or enemies without making any noise & that the elder members of a tribe first acquired this knowledge & subsequently found it necessary to place their hands over the mouths of younger members when in this situation & hence it has been gradually associated with the idea of astonishment.

Page 359. Infantile knowledge of expression.

Some years ago I used to be in the habit when travelling in the train, of making faces when I could do so unobserved, at babies & have frequently made them begin crying.

Page 344Influence of thought on the vaso-motor system.

The most evident proof of this suggesting itself to my mind is the case of medical students who through studying the symptoms of, induce, a disease.


The year is conjectured from the fact that this letter is a response to Expression, which was published in November 1872 (Freeman 1977).
Oxen are domestic cattle (Bos taurus, subfamily Bovinae); musk ox are Ovibos moschatus, subfamily Caprinae.


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

Freeman, Richard Broke. 1977. The works of Charles Darwin: an annotated bibliographical handlist. 2d edition. Folkestone, Kent: William Dawson & Sons. Hamden, Conn.: Archon Books, Shoe String Press.


Notes on CD’s Expression.

Letter details

Letter no.
Charles Robert Darwin
Sent from
Source of text
DAR 159: 138
Physical description
Amem 4pp

Please cite as

Darwin Correspondence Project, “Letter no. 8706,” accessed on 25 September 2021,

Also published in The Correspondence of Charles Darwin, vol. 21