The Expression of the Emotions in Man and Animals

Surprise, astonishment—Elevation of the eyebrows—Opening the mouth—Protrusion of the lips—Gestures accompanying surprise—Admiration—Fear—Terror—Erection of the hair—Contraction of the platysma muscle—Dilatation of the pupils—Horror—Conclusion.

Attention, if sudden and close, graduates into surprise; and this into astonishment; and this into stupefied amazement. The latter frame of mind is closely akin to terror. Attention is shown by the eyebrows being slightly raised; and as this state increases into surprise, they are raised to a much greater extent, with the eyes and mouth widely open. The raising of the eyebrows is necessary in order that the eyes should be opened quickly and widely; and this movement produces transverse wrinkles across the forehead. The degree to which the eyes and mouth are opened corresponds with the degree of surprise felt; but these movements must be coordinated; for a widely opened mouth with eyebrows only slightly raised results in a meaningless grimace, as Dr. Duchenne has shown in one of his photographs.[1201] On the other hand, a person may often be seen to pretend surprise by merely raising his eyebrows.

Dr. Duchenne has given a photograph of an old man with his eyebrows well elevated and arched by the galvanization of the frontal muscle; and with his mouth voluntarily opened. This figure expresses surprise with much truth. I showed it to twenty-four persons without a word of explanation, and one alone did not at all understand what was intended. A second person answered terror, which is not far wrong; some of the others, however, added to the words surprise or astonishment, the epithets horrified, woful, painful, or disgusted.

The eyes and mouth being widely open is an expression universally recognized as one of surprise or astonishment. Thus Shakespeare says, “I saw a smith stand with open mouth swallowing a tailor’s news.” (‘King John,’ act iv. scene ii.) And again, “They seemed almost, with staring on one another, to tear the cases of their eyes; there was speech in the dumbness, language in their very gesture; they looked as they had heard of a world destroyed.” (‘Winter’s Tale,’ act v. scene ii.)

My informants answer with remarkable uniformity to the same effect, with respect to the various races of man; the above movements of the features being often accompanied by certain gestures and sounds, presently to be described. Twelve observers in different parts of Australia agree on this head. Mr. Winwood Reade has observed this expression with the negroes on the Guinea coast. The chief Gaika and others answer yes to my query with respect to the Kafirs of South Africa; and so do others emphatically with reference to the Abyssinians, Ceylonese, Chinese, Fuegians, various tribes of North America, and New Zealanders. With the latter, Mr. Stack states that the expression is more plainly shown by certain individuals than by others, though all endeavour as much as possible to conceal their feelings. The Dyaks of Borneo are said by the Rajah Brooke to open their eyes widely, when astonished, often swinging their heads to and fro, and beating their breasts. Mr. Scott informs me that the workmen in the Botanic Gardens at Calcutta are strictly ordered not to smoke; but they often disobey this order, and when suddenly surprised in the act, they first open their eyes and mouths widely. They then often slightly shrug their shoulders, as they perceive that discovery is inevitable, or frown and stamp on the ground from vexation. Soon they recover from their surprise, and abject fear is exhibited by the relaxation of all their muscles; their heads seem to sink between their shoulders; their fallen eyes wander to and fro; and they supplicate forgiveness.

The well-known Australian explorer, Mr. Stuart, has given[1202] a striking account of stupefied amazement together with terror in a native who had never before seen a man on horseback. Mr. Stuart approached unseen and called to him from a little distance. “He turned round and saw me. What he imagined I was I do not know; but a finer picture of fear and astonishment I never saw. He stood incapable of moving a limb, riveted to the spot, mouth open and eyes staring.... He remained motionless until our black got within a few yards of him, when suddenly throwing down his waddies, he jumped into a mulga bush as high as he could get.” He could not speak, and answered not a word to the inquiries made by the black, but, trembling from head to foot, “waved with his hand for us to be off.”

That the eyebrows are raised by an innate or instinctive impulse may be inferred from the fact that Laura Bridgman invariably acts thus when astonished, as I have been assured by the lady who has lately had charge of her. As surprise is excited by something unexpected or unknown, we naturally desire, when startled, to perceive the cause as quickly as possible; and we consequently open our eyes fully, so that the field of vision may be increased, and the eyeballs moved easily in any direction. But this hardly accounts for the eyebrows being so greatly raised as is the case, and for the wild staring of the open eyes. The explanation lies, I believe, in the impossibility of opening the eyes with great rapidity by merely raising the upper lids. To effect this the eyebrows must be lifted energetically. Any one who will try to open his eyes as quickly as possible before a mirror will find that he acts thus; and the energetic lifting up of the eyebrows opens the eyes so widely that they stare, the white being exposed all round the iris. Moreover, the elevation of the eyebrows is an advantage in looking upwards; for as long as they are lowered they impede our vision in this direction. Sir C. Bell gives[1203] a curious little proof of the part which the eyebrows play in opening the eyelids. In a stupidly drunken man all the muscles are relaxed, and the eyelids consequently droop, in the same manner as when we are falling asleep.

To counteract this tendency the drunkard raises his eyebrows; and this gives to him a puzzled, foolish look, as is well represented in one of Hogarth’s drawings. The habit of raising the eyebrows having once been gained in order to see as quickly as possible all around us, the movement would follow from the force of association whenever astonishment was felt from any cause, even from a sudden sound or an idea.

With adult persons, when the eyebrows are raised, the whole forehead becomes much wrinkled in transverse lines; but with children this occurs only to a slight degree. The wrinkles run in lines concentric with each eyebrow, and are partially confluent in the middle. They are highly characteristic of the expression of surprise or astonishment. Each eyebrow, when raised, becomes also, as Duchenne remarks,[1204] more arched than it was before.

The cause of the mouth being opened when astonishment is felt, is a much more complex affair; and several causes apparently concur in leading to this movement. It has often been supposed[1205] that the sense of hearing is thus rendered more acute; but I have watched persons listening intently to a slight noise, the nature and source of which they knew perfectly, and they did not open their mouths. Therefore I at one time imagined that the open mouth might aid in distinguishing the direction whence a sound proceeded, by giving another channel for its entrance into the ear through the eustachian tube, But Dr. W. Ogle[1206] has been so kind as to search the best recent authorities on the functions of the eustachian tube, and he informs me that it is almost conclusively proved that it remains closed except during the act of deglutition; and that in persons in whom the tube remains abnormally open, the sense of hearing, as far as external sounds are concerned, is by no means improved; on the contrary, it is impaired by the respiratory sounds being rendered more distinct. If a watch be placed within the mouth, but not allowed to touch the sides, the ticking is heard much less plainly than when held outside. In persons in whom from disease or a cold the eustachian tube is permanently or temporarily closed, the sense of hearing is injured; but this may be accounted for by mucus accumulating within the tube, and the consequent exclusion of air.

Every sudden emotion, including astonishment, quickens the action of the heart, and with it the respiration. Now we can breathe, as Gratiolet remarks[1207] and as appears to me to be the case, much more quietly through the open mouth than through the nostrils. Therefore, when we wish to listen intently to any sound, we either stop breathing, or breathe as quietly as possible, by opening our mouths, at the same time keeping our bodies motionless. One of my sons was awakened in the night by a noise under circumstances which naturally led to great care, and after a few minutes he perceived that his mouth was widely open. He then became conscious that he had opened it for the sake of breathing as quietly as possible. This view receives support from the reversed case which occurs with dogs. A dog when panting after exercise, or on a hot day, breathes loudly; but if his attention be suddenly aroused, he instantly pricks his ears to listen, shuts his mouth, and breathes quietly, as he is enabled to do, through his nostrils.

When the attention is concentrated for a length of time with fixed earnestness on any object or subject, all the organs of the body are forgotten and neglected;[1208] and as the nervous energy of each individual is limited in amount, little is transmitted to any part of the system, excepting that which is at the time brought into energetic action. Therefore many of the muscles tend to become relaxed, and the jaw drops from its own weight. This will account for the dropping of the jaw and open mouth of a man stupefied with amazement, and perhaps when less strongly affected. I have noticed this appearance, as I find recorded in my notes, in very young children when they were only moderately surprised.

There is still another and highly effective cause, leading to the mouth being opened, when we are astonished, and more especially when we are suddenly startled. We can draw a full and deep inspiration much more easily through the widely open mouth than through the nostrils. Now when we start at any sudden sound or sight, almost all the muscles of the body are involuntarily and momentarily thrown into strong action, for the sake of guarding ourselves against or jumping away from the danger, which we habitually associate with anything unexpected. But we always unconsciously prepare ourselves for any great exertion, as formerly explained, by first taking a deep and full inspiration, and we consequently open our mouths. If no exertion follows, and we still remain astonished, we cease for a time to breathe, or breathe as quietly as possible, in order that every sound may be distinctly heard. Or again, if our attention continues long and earnestly absorbed, all our muscles become relaxed, and the jaw, which was at first suddenly opened, remains dropped. Thus several causes concur towards this same movement, whenever surprise, astonishment, or amazement is felt.

Although when thus affected, our mouths are generally opened, yet the lips are often a little protruded. This fact reminds us of the same movement, though in a much more strongly marked degree, in the chimpanzee and orang when astonished. As a strong expiration naturally follows the deep inspiration which accompanies the first sense of startled surprise, and as the lips are often protruded, the various sounds which are then commonly uttered can apparently be accounted for. But sometimes a strong expiration alone is heard; thus Laura Bridgman, when amazed, rounds and protrudes her lips, opens them, and breathes strongly.[1209] One of the commonest sounds is a deep Oh; and this would naturally follow, as explained by Helmholtz, from the mouth being moderately opened and the lips protruded. On a quiet night some rockets were fired from the ‘Beagle,’ in a little creek at Tahiti, to amuse the natives; and as each rocket, was let off there was absolute silence, but this was invariably followed by a deep groaning Oh, resounding all round the bay. Mr. Washington Matthews says that the North American Indians express astonishment by a groan; and the negroes on the West Coast of Africa, according to Mr. Winwood Reade, protrude their lips, and make a sound like heigh, heigh. If the mouth is not much opened, whilst the lips are considerably protruded, a blowing, hissing, or whistling noise is produced. Mr. R.

Brough Smith informs me that an Australian from the interior was taken to the theatre to see an acrobat rapidly turning head over heels: “he was greatly astonished, and protruded his lips, making a noise with his mouth as if blowing out a match.” According to Mr. Bulmer the Australians, when surprised, utter the exclamation korki, “and to do this the mouth is drawn out as if going to whistle.” We Europeans often whistle as a sign of surprise; thus, in a recent novel[1210] it is said, “here the man expressed his astonishment and disapprobation by a prolonged whistle.” A Kafir girl, as Mr. J. Mansel Weale informs me, “on hearing of the high price of an article, raised her eyebrows and whistled just as a European would.” Mr. Wedgwood remarks that such sounds are written down as whew, and they serve as interjections for surprise.

According to three other observers, the Australians often evince astonishment by a clucking noise. Europeans also sometimes express gentle surprise by a little clicking noise of nearly the same kind. We have seen that when we are startled, the mouth is suddenly opened; and if the tongue happens to be then pressed closely against the palate, its sudden withdrawal will produce a sound of this kind, which might thus come to express surprise.

Turning to gestures of the body. A surprised person often raises his opened hands high above his head, or by bending his arms only to the level of his face. The flat palms are directed towards the person who causes this feeling, and the straightened fingers are separated. This gesture is represented by Mr. Rejlander in Plate VII. fig. 1. In the ‘Last Supper,’ by Leonardo da Vinci, two of the Apostles have their hands half uplifted, clearly expressive of their astonishment. A trustworthy observer told me that he had lately met his wife under most unexpected circumstances: “She started, opened her mouth and eyes very widely, and threw up both her arms above her head.” Several years ago I was surprised by seeing several of my young children earnestly doing something together on the ground; but the distance was too great for me to ask what they were about. Therefore I threw up my open hands with extended fingers above my head; and as soon as I had done this, I became conscious of the action. I then waited, without saying a word, to see if my children had understood this gesture; and as they came running to me they cried out, “We saw that you were astonished at us.” I do not know whether this gesture is common to the various races of man, as I neglected to make inquiries on this head.

That it is innate or natural may be inferred from the fact that Laura Bridgman, when amazed, “spreads her arms and turns her hands with extended fingers upwards;”[1211] nor is it likely, considering that the feeling of surprise is generally a brief one, that she should have learnt this gesture through her keen sense of touch.

Huschke describes[1212] a somewhat different yet allied gesture, which he says is exhibited by persons when astonished. They hold themselves erect, with the features as before described, but with the straightened arms extended backwards—the stretched fingers being separated from each other. I have never myself seen this gesture; but Huschke is probably correct; for a friend asked another man how he would express great astonishment, and he at once threw himself into this attitude.

These gestures are, I believe, explicable on the principle of antithesis. We have seen that an indignant man holds his head erect, squares his shoulders, turns out his elbows, often clenches his fist, frowns, and closes his mouth; whilst the attitude of a helpless man is in every one of these details the reverse. Now, a man in an ordinary frame of mind, doing nothing and thinking of nothing in particular, usually keeps his two arms suspended laxly by his sides, with his hands somewhat flexed, and the fingers near together. Therefore, to raise the arms suddenly, either the whole arms or the fore-arms, to open the palms flat, and to separate the fingers,—or, again, to straighten the arms, extending them backwards with separated fingers,—are movements in complete antithesis to those preserved under an indifferent frame of mind, and they are, in consequence, unconsciously assumed by an astonished man. There is, also, often a desire to display surprise in a conspicuous manner, and the above attitudes are well fitted for this purpose. It may be asked why should surprise, and only a few other states of the mind, be exhibited by movements in antithesis to others. But this principle will not be brought into play in the case of those emotions, such as terror, great joy, suffering, or rage, which naturally lead to certain lines of action and produce certain effects on the body, for the whole system is thus preoccupied; and these emotions are already thus expressed with the greatest plainness.

There is another little gesture, expressive of astonishment of which I can offer no explanation; namely, the hand being placed over the mouth or on some part of the head. This has been observed with so many races of man, that it must have some natural origin. A wild Australian was taken into a large room full of official papers, which surprised him greatly, and he cried out, cluck, cluck, cluck, putting the back of his hand towards his lips. Mrs. Barber says that the Kafirs and Fingoes express astonishment by a serious look and by placing the right hand upon the mouth, uttering the word mawo, which means ‘wonderful.’ The Bushmen are said[1213] to put their right hands to their necks, bending their heads backwards. Mr. Winwood Reade has observed that the negroes on the West Coast of Africa, when surprised, clap their hands to their mouths, saying at the same time, “My mouth cleaves to me,” i. e. to my hands; and he has heard that this is their usual gesture on such occasions. Captain Speedy informs me that the Abyssinians place their right hand to the forehead, with the palm outside. Lastly, Mr. Washington Matthews states that the conventional sign of astonishment with the wild tribes of the western parts of the United States “is made by placing the half-closed hand over the mouth; in doing this, the head is often bent forwards, and words or low groans are sometimes uttered.” Catlin[1214] makes the same remark about the hand being pressed over the mouth by the Mandans and other Indian tribes.

Admiration.—Little need be said on this head. Admiration apparently consists of surprise associated with some pleasure and a sense of approval. When vividly felt, the eyes are opened and the eyebrows raised; the eyes become bright, instead of remaining blank, as under simple astonishment; and the mouth, instead of gaping open, expands into a smile.

Fear, Terror.—The word ‘fear’ seems to be derived from what is sudden and dangerous;[1215] and that of terror from the trembling of the vocal organs and body. I use the word ‘terror’ for extreme fear; but some writers think it ought to be confined to cases in which the imagination is more particularly concerned. Fear is often preceded by astonishment, and is so far akin to it, that both lead to the senses of sight and hearing being instantly aroused. In both cases the eyes and mouth are widely opened, and the eyebrows raised. The frightened man at first stands like a statue motionless and breathless, or crouches down as if instinctively to escape observation.

The heart beats quickly and violently, so that it palpitates or knocks against the ribs; but it is very doubtful whether it then works more efficiently than usual, so as to send a greater supply of blood to all parts of the body; for the skin instantly becomes pale, as during incipient faintness. This paleness of the surface, however, is probably in large part, or exclusively, due to the vasomotor centre being affected in such a manner as to cause the contraction of the small arteries of the skin. That the skin is much affected under the sense of great fear, we see in the marvellous and inexplicable manner in which perspiration immediately exudes from it. This exudation is all the more remarkable, as the surface is then cold, and hence the term a cold sweat; whereas, the sudorific glands are properly excited into action when the surface is heated. The hairs also on the skin stand erect; and the superficial muscles shiver. In connection with the disturbed action of the heart, the breathing is hurried. The salivary glands act imperfectly; the mouth becomes dry,[1216] and is often opened and shut. I have also noticed that under slight fear there is a strong tendency to yawn. One of the best-marked symptoms is the trembling of all the muscles of the body; and this is often first seen in the lips. From this cause, and from the dryness of the mouth, the voice becomes husky or indistinct, or may altogether fail. “Obstupui, steteruntque comae, et vox faucibus haesit.”

Of vague fear there is a well-known and grand description in Job:—“In thoughts from the visions of the night, when deep sleep falleth on men, fear came upon me, and trembling, which made all my bones to shake. Then a spirit passed before my face; the hair of my flesh stood up. It stood still, but I could not discern the form thereof: an image was before my eyes, there was silence, and I heard a voice, saying, Shall mortal man be more just than God? Shall a man be more pure than his Maker?” (Job iv. 13)

As fear increases into an agony of terror, we behold, as under all violent emotions, diversified results. The heart beats wildly, or may fail to act and faintness ensue; there is a death-like pallor; the breathing is laboured; the wings of the nostrils are wildly dilated; “there is a gasping and convulsive motion of the lips, a tremor on the hollow cheek, a gulping and catching of the throat;”[1217] the uncovered and protruding eyeballs are fixed on the object of terror; or they may roll restlessly from side to side, huc illuc volvens oculos totumque pererrat.[1218] The pupils are said to be enormously dilated. All the muscles of the body may become rigid, or may be thrown into convulsive movements. The hands are alternately clenched and opened, often with a twitching movement. The arms may be protruded, as if to avert some dreadful danger, or may be thrown wildly over the head. The Rev. Mr. Hagenauer has seen this latter action in a terrified Australian. In other cases there is a sudden and uncontrollable tendency to headlong flight; and so strong is this, that the boldest soldiers may be seized with a sudden panic.

As fear rises to an extreme pitch, the dreadful scream of terror is heard. Great beads of sweat stand on the skin. All the muscles of the body are relaxed. Utter prostration soon follows, and the mental powers fail. The intestines are affected. The sphincter muscles cease to act, and no longer retain the contents of the body.

Dr. J. Crichton Browne has given me so striking an account of intense fear in an insane woman, aged thirty-five, that the description though painful ought not to be omitted. When a paroxysm seizes her, she screams out, “This is hell!” “There is a black woman!” “I can’t get out!”—and other such exclamations. When thus screaming, her movements are those of alternate tension and tremor. For one instant she clenches her hands, holds her arms out before her in a stiff semi-flexed position; then suddenly bends her body forwards, sways rapidly to and fro, draws her fingers through her hair, clutches at her neck, and tries to tear off her clothes. The sterno-cleido-mastoid muscles (which serve to bend the head on the chest) stand out prominently, as if swollen, and the skin in front of them is much wrinkled. Her hair, which is cut short at the back of her head, and is smooth when she is calm, now stands on end; that in front being dishevelled by the movements of her hands. The countenance expresses great mental agony. The skin is flushed over the face and neck, down to the clavicles, and the veins of the forehead and neck stand out like thick cords. The lower lip drops, and is somewhat everted. The mouth is kept half open, with the lower jaw projecting. The cheeks are hollow and deeply furrowed in curved lines running from the wings of the nostrils to the corners of the mouth. The nostrils themselves are raised and extended. The eyes are widely opened, and beneath them the skin appears swollen; the pupils are large.

Mr. Bell has also described[1219] an agony of terror and of despair, which he witnessed in a murderer, whilst carried to the place of execution in Turin. “On each side of the car the officiating priests were seated; and in the centre sat the criminal himself. It was impossible to witness the condition of this unhappy wretch without terror; and yet, as if impelled by some strange infatuation, it was equally impossible not to gaze upon an object so wild, so full of horror. He seemed about thirty-five years of age; of large and muscular form; his countenance marked by strong and savage features; half naked, pale as death, agonized with terror, every limb strained in anguish, his hands clenched convulsively, the sweat breaking out on his bent and contracted brow, he kissed incessantly the figure of our Saviour, painted on the flag which was suspended before him; but with an agony of wildness and despair, of which nothing ever exhibited on the stage can give the slightest conception.”

I will add only one other case, illustrative of a man utterly prostrated by terror. An atrocious murderer of two persons was brought into a hospital, under the mistaken impression that he had poisoned himself; and Dr. W. Ogle carefully watched him the next morning, while he was being handcuffed and taken away by the police. His pallor was extreme, and his prostration so great that he was hardly able to dress himself. His skin perspired; and his eyelids and head drooped so much that it was impossible to catch even a glimpse of his eyes. His lower jaw hung down. There was no contraction of any facial muscle, and Dr. Ogle is almost certain that the hair did not stand on end, for he observed it narrowly, as it had been dyed for the sake of concealment.

With respect to fear, as exhibited by the various races of man, my informants agree that the signs are the same as with Europeans. They are displayed in an exaggerated degree with the Hindoos and natives of Ceylon. Mr. Geach has seen Malays when terrified turn pale and shake; and Mr. Brough Smyth states that a native Australian “being on one occasion much frightened, showed a complexion as nearly approaching to what we call paleness, as can well be conceived in the case of a very black man.” Mr. Dyson Lacy has seen extreme fear shown in an Australian, by a nervous twitching of the hands, feet, and lips; and by the perspiration standing on the skin. Many savages do not repress the signs of fear so much as Europeans; and they often tremble greatly. With the Kafir, Gaika says, in his rather quaint English, the shaking “of the body is much experienced, and the eyes are widely open.” With savages, the sphincter muscles are often relaxed, just as may be observed in much frightened dogs, and as I have seen with monkeys when terrified by being caught.

The erection of the hair.—Some of the signs of fear deserve a little further consideration. Poets continually speak of the hair standing on end; Brutus says to the ghost of Caesar, “that mak’st my blood cold, and my hair to stare.” And Cardinal Beaufort, after the murder of Gloucester exclaims, “Comb down his hair; look, look, it stands upright.” As I did not feel sure whether writers of fiction might not have applied to man what they had often observed in animals, I begged for information from Dr. Crichton Browne with respect to the insane. He states in answer that he has repeatedly seen their hair erected under the influence of sudden and extreme terror. For instance, it is occasionally necessary to inject morphia, under the skin of an insane woman, who dreads the operation extremely, though it causes very little pain; for she believes that poison is being introduced into her system, and that her bones will be softened, and her flesh turned into dust. She becomes deadly pale; her limbs are stiffened by a sort of tetanic spasm, and her hair is partially erected on the front of the head.

Dr. Browne further remarks that the bristling of the hair which is so common in the insane, is not always associated with terror. It is perhaps most frequently seen in chronic maniacs, who rave incoherently and have destructive impulses; but it is during their paroxysms of violence that the bristling is most observable. The fact of the hair becoming erect under the influence both of rage and fear agrees perfectly with what we have seen in the lower animals. Dr. Browne adduces several cases in evidence. Thus with a man now in the Asylum, before the recurrence of each maniacal paroxysm, “the hair rises up from his forehead like the mane of a Shetland pony.” He has sent me photographs of two women, taken in the intervals between their paroxysms, and he adds with respect to one of these women, “that the state of her hair is a sure and convenient criterion of her mental condition.” I have had one of these photographs copied, and the engraving gives, if viewed from a little distance, a faithful representation of the original, with the exception that the hair appears rather too coarse and too much curled. The extraordinary condition of the hair in the insane is due, not only to its erection, but to its dryness and harshness, consequent on the subcutaneous glands failing to act. Dr. Bucknill has said[1220] that a lunatic “is a lunatic to his finger’s ends;” he might have added, and often to the extremity of each particular hair.

Dr. Browne mentions as an empirical confirmation of the relation which exists in the insane between the state of their hair and minds, that the wife of a medical man, who has charge of a lady suffering from acute melancholia, with a strong fear of death, for herself, her husband and children, reported verbally to him the day before receiving my letter as follows, “I think Mrs. —— will soon improve, for her hair is getting smooth; and I always notice that our patients get better whenever their hair ceases to be rough and unmanageable.”

Dr. Browne attributes the persistently rough condition of the hair in many insane patients, in part to their minds being always somewhat disturbed, and in part to the effects of habit,—that is, to the hair being frequently and strongly erected during their many recurrent paroxysms. In patients in whom the bristling of the hair is extreme, the disease is generally permanent and mortal; but in others, in whom the bristling is moderate, as soon as they recover their health of mind the hair recovers its smoothness.

In a previous chapter we have seen that with animals the hairs are erected by the contraction of minute, unstriped, and involuntary muscles, which run to each separate follicle. In addition to this action, Mr. J. Wood has clearly ascertained by experiment, as he informs me, that with man the hairs on the front of the head which slope forwards, and those on the back which slope backwards, are raised in opposite directions by the contraction of the occipito-frontalis or scalp muscle. So that this muscle seems to aid in the erection of the hairs on the head of man in the same manner as the homologous panniculus carnosus aids, or takes the greater part, in the erection of the spines on the backs of some of the lower animals.

Contraction of the platysma myoides muscle.—This muscle is spread over the sides of the neck, extending downwards to a little beneath the collar-bones, and upwards to the lower part of the cheeks. A portion, called the risorius, is represented in the woodcut (M) fig. 2. The contraction of this muscle draws the corners of the mouth and the lower parts of the checks downwards and backwards. It produces at the same time divergent, longitudinal, prominent ridges on the sides of the neck in the young; and, in old thin persons, fine transverse wrinkles. This muscle is sometimes said not to be under the control of the will; but almost every one, if told to draw the corners of his mouth backwards and downwards with great force, brings it into action. I have, however, heard of a man who can voluntarily act on it only on one side of his neck.

Sir C. Bell[1221] and others have stated that this muscle is strongly contracted under the influence of fear; and Duchenne insists so strongly on its importance in the expression of this emotion, that he calls it the muscle of fright.[1222] He admits, however, that its contraction is quite inexpressive unless associated with widely open eyes and mouth. He has given a photograph (copied and reduced in the accompanying woodcut) of the same old man as on former occasions, with his eyebrows strongly raised, his mouth opened, and the platysma contracted, all by means of galvanism. The original photograph was shown to twenty-four persons, and they were separately asked, without any explanation being given, what expression was intended: twenty instantly answered, “intense fright” or “horror”; three said pain, and one extreme discomfort. Dr. Duchenne has given another photograph of the same old man, with the platysma contracted, the eyes and mouth opened, and the eyebrows rendered oblique, by means of galvanism. The expression thus induced is very striking (see Plate VII. fig. 2); the obliquity of the eyebrows adding the appearance of great mental distress. The original was shown to fifteen persons; twelve answered terror or horror, and three agony or great suffering. From these cases, and from an examination of the other photographs given by Dr. Duchenne, together with his remarks thereon, I think there can be little doubt that the contraction of the platysma does add greatly to the expression of fear.