The Expression of the Emotions in Man and Animals Part 6

Mr. Sutton has often observed the face of the _Macacus rhesus_, when much enraged, growing red. As he was mentioning this to me, another monkey attacked a _rhesus_, and I saw its face redden as plainly as that of a man in a violent pa.s.sion. In the course of a few minutes, after the battle, the face of this monkey recovered its natural tint. At the same time that the face reddened, the naked posterior part of the body, which is always red, seemed to grow still redder; but I cannot positively a.s.sert that this was the case. When the Mandrill is in any way excited, the brilliantly coloured, naked parts of the skin are said to become still more vividly coloured.

With several species of baboons the ridge of the forehead projects much over the eyes, and is studded with a few long hairs, representing our eyebrows. These animals are always looking about them, and in order to look upwards they raise their eyebrows. They have thus, as it would appear, acquired the habit of frequently moving their eyebrows. However this may be, many kinds of monkeys, especially the baboons, when angered or in any way excited, rapidly and incessantly move their eyebrows up and down, as well as the hairy skin of their foreheads.[515] As we a.s.sociate in the case of man the raising and lowering of the eyebrows with definite states of the mind, the almost incessant movement of the eyebrows by monkeys gives them a senseless expression. I once observed a man who had a trick of continually raising his eyebrows without any corresponding emotion, and this gave to him a foolish appearance; so it is with some persons who keep the corners of their mouths a little drawn backwards and upwards, as if by an incipient smile, though at the time they are not amused or pleased.

A young orang, made jealous by her keeper attending to another monkey, slightly uncovered her teeth, and, uttering a peevish noise like _tish-s.h.i.+st_, turned her back on him. Both orangs and chimpanzees, when a little more angered, protrude their lips greatly, and make a harsh barking noise. A young female chimpanzee, in a violent pa.s.sion, presented a curious resemblance to a child in the same state. She screamed loudly with widely open mouth, the lips being retracted so that the teeth were fully exposed. She threw her arms wildly about, sometimes clasping them over her head. She rolled on the ground, sometimes on her back, sometimes on her belly, and bit everything within reach. A young gibbon (_Hylobates syndactylus_) in a pa.s.sion has been described[516] as behaving in almost exactly the same manner.

The lips of young orangs and chimpanzees are protruded, sometimes to a wonderful degree, under various circ.u.mstances. They act thus, not only when slightly angered, sulky, or disappointed, but when alarmed at anything--in one instance, at the sight of a turtle,[517]--and likewise when pleased. But neither the degree of protrusion nor the shape of the mouth is exactly the same, as I believe, in all cases; and the sounds which are then uttered are different. The accompanying drawing represents a chimpanzee made sulky by an orange having been offered him, and then taken away. A similar protrusion or pouting of the lips, though to a much slighter degree, may be seen in sulky children.

[Ill.u.s.tration: Chimpanzee disappointed and sulky. Fig. 18]

Many years ago, in the Zoological Gardens, I placed a looking-gla.s.s on the floor before two young orangs, who, as far as it was known, had never before seen one. At first they gazed at their own images with the most steady surprise, and often changed their point of view. They then approached close and protruded their lips towards the image, as if to kiss it, in exactly the same manner as they had previously done towards each other, when first placed, a few days before, in the same room. They next made all sorts of grimaces, and put themselves in various att.i.tudes before the mirror; they pressed and rubbed the surface; they placed their hands at different distances behind it; looked behind it; and finally seemed almost frightened, started a little, became cross, and refused to look any longer.

When we try to perform some little action which is difficult and requires precision, for instance, to thread a needle, we generally close our lips firmly, for the sake, I presume, of not disturbing our movements by breathing; and I noticed the same action in a young Orang.

The poor little creature was sick, and was amusing itself by trying to kill the flies on the window-panes with its knuckles; this was difficult as the flies buzzed about, and at each attempt the lips were firmly compressed, and at the same time slightly protruded.

Although the countenances, and more especially the gestures, of orangs and chimpanzees are in some respects highly expressive, I doubt whether on the whole they are so expressive as those of some other kinds of monkeys. This may be attributed in part to their ears being immovable, and in part to the nakedness of their eyebrows, of which the movements are thus rendered less conspicuous. When, however, they raise their eyebrows their foreheads become, as with us, transversely wrinkled.

In comparison with man, their faces are inexpressive, chiefly owing to their not frowning under any emotion of the mind--that is, as far as I have been able to observe, and I carefully attended to this point.

Frowning, which is one of the most important of all the expressions in man, is due to the contraction of the corrugators by which the eyebrows are lowered and brought together, so that vertical furrows are formed on the forehead. Both the orang and chimpanzee are said[518] to possess this muscle, but it seems rarely brought into action, at least in a conspicuous manner. I made my hands into a sort of cage, and placing some tempting fruit within, allowed both a young orang and chimpanzee to try their utmost to get it out; but although they grew rather cross, they showed not a trace of a frown. Nor was there any frown when they were enraged. Twice I took two chimpanzees from their rather dark room suddenly into bright suns.h.i.+ne, which would certainly have caused us to frown; they blinked and winked their eyes, but only once did I see a very slight frown. On another occasion, I tickled the nose of a chimpanzee with a straw, and as it crumpled up its face, slight vertical furrows appeared between the eyebrows. I have never seen a frown on the forehead of the orang.

The gorilla, when enraged, is described as erecting its crest of hair, throwing down its under lip, dilating its nostrils, and uttering terrific yells. Messrs. Savage and Wyman[519] state that the scalp can be freely moved backwards and forwards, and that when the animal is excited it is strongly contracted; but I presume that they mean by this latter expression that the scalp is lowered; for they likewise speak of the young chimpanzee, when crying out, as having the eyebrows strongly contracted. The great power of movement in the scalp of the gorilla, of many baboons and other monkeys, deserves notice in relation to the power possessed by some few men, either through reversion or persistence, of voluntarily moving their scalps.[520]

_Astonishment, Terror_--A living fresh-water turtle was placed at my request in the same compartment in the Zoological Gardens with many monkeys; and they showed unbounded astonishment, as well as some fear.

This was displayed by their remaining motionless, staring intently with widely opened eyes, their eyebrows being often moved up and down. Their faces seemed somewhat lengthened. They occasionally raised themselves on their hind-legs to get abetter view. They often retreated a few feet, and then turning their heads over one shoulder, again stared intently.

It was curious to observe how much less afraid they were of the turtle than of a living snake which I had formerly placed in their compartment;[521] for in the course of a few minutes some of the monkeys ventured to approach and touch the turtle. On the other hand, some of the larger baboons were greatly terrified, and grinned as if on the point of screaming out. When I showed a little dressed-up doll to the _Cynopithecus niger_, it stood motionless, stared intently with widely opened eyes, and advanced its ears a little forwards. But when the turtle was placed in its compartment, this monkey also moved its lips in an odd, rapid, jabbering manner, which the keeper declared was meant to conciliate or please the turtle.

I was never able clearly to perceive that the eyebrows of astonished monkeys were kept permanently raised, though they were frequently moved up and down. Attention, which precedes astonishment, is expressed by man by a slight raising of the eyebrows; and Dr. d.u.c.h.enne informs me that when he gave to the monkey formerly mentioned some quite new article of food, it elevated its eyebrows a little, thus a.s.suming an appearance of close attention. It then took the food in its fingers, and, with lowered or rectilinear eyebrows, scratched, smelt, and examined it,--an expression of reflection being thus exhibited. Sometimes it would throw back its head a little, and again with suddenly raised eyebrows re-examine and finally taste the food.

In no case did any monkey keep its mouth open when it was astonished.

Mr. Sutton observed for me a young orang and chimpanzee during a considerable length of time; and however much they were astonished, or whilst listening intently to some strange sound, they did not keep their mouths open. This fact is surprising, as with mankind hardly any expression is more general than a widely open mouth under the sense of astonishment. As far as I have been able to observe, monkeys breathe more freely through their nostrils than men do; and this may account for their not opening their mouths when they are astonished; for, as we shall see in a future chapter, man apparently acts in this manner when startled, at first for the sake of quickly drawing a full inspiration, and afterwards for the sake of breathing as quietly as possible.

Terror is expressed by many kinds of monkeys by the utterance of shrill screams; the lips being drawn back, so that the teeth are exposed. The hair becomes erect, especially when some anger is likewise felt. Mr.

Sutton has distinctly seen the face of the _Macacus rhesus_ grow pale from fear. Monkeys also tremble from fear; and sometimes they void their excretions. I have seen one which, when caught, almost fainted from an excess of terror.

Sufficient facts have now been given with respect to the expressions of various animals. It is impossible to agree with Sir C. Bell when he says[522] that "the faces of animals seem chiefly capable of expressing rage and fear;" and again, when he says that all their expressions "may be referred, more or less plainly, to their acts of volition or necessary instincts." He who will look at a dog preparing to attack another dog or a man, and at the same animal when caressing his master, or will watch the countenance of a monkey when insulted, and when fondled by his keeper, will be forced to admit that the movements of their features and their gestures are almost as expressive as those of man. Although no explanation can be given of some of the expressions in the lower animals, the greater number are explicable in accordance with the three principles given at the commencement of the first chapter.

CHAPTER VI. -- SPECIAL EXPRESSIONS OF MAN: SUFFERING AND WEEPING.

The screaming and weeping Of infants--Forms of features--Age at which weeping commences--The effects of habitual restraint on weeping--Sobbing--Cause of the contraction of the muscles round the eyes during screaming--Cause of the secretion of tears.

IN this and the following chapters the expressions exhibited by Man under various states of the mind will be described and explained, as far as lies in my power. My observations will be arranged according to the order which I have found the most convenient; and this will generally lead to opposite emotions and sensations succeeding each other.

_Suffering of the body and mind: weeping_.--I have already described in sufficient detail, in the third chapter, the signs of extreme pain, as shown by screams or groans, with the writhing of the whole body and the teeth clenched or ground together. These signs are often accompanied or followed by profuse sweating, pallor, trembling, utter prostration, or faintness. No suffering is greater than that from extreme fear or horror, but here a distinct emotion comes into play, and will be elsewhere considered. Prolonged suffering, especially of the mind, pa.s.ses into low spirits, grief, dejection, and despair, and these states will be the subject of the following chapter. Here I shall almost confine myself to weeping or crying, more especially in children.

Infants, when suffering even slight pain, moderate hunger, or discomfort, utter violent and prolonged screams. Whilst thus screaming their eyes are firmly closed, so that the skin round them is wrinkled, and the forehead contracted into a frown. The mouth is widely opened with the lips retracted in a peculiar manner, which causes it to a.s.sume a squarish form; the gums or teeth being more or less exposed. The breath is inhaled almost spasmodically. It is easy to observe infants whilst screaming; but I have found photographs made by the instantaneous process the best means for observation, as allowing more deliberation. I have collected twelve, most of them made purposely for me; and they all exhibit the same general characteristics. I have, therefore, had six of them[601] (Plate I.) reproduced by the heliotype process.

[Ill.u.s.tration: Screaming Infants. Plate I. ]

The firm closing of the eyelids and consequent compression of the eyeball,--and this is a most important element in various expressions,--serves to protect the eyes from becoming too much gorged with blood, as will presently be explained in detail. With respect to the order in which the several muscles contract in firmly compressing the eyes, I am indebted to Dr. Langstaff, of Southampton, for some observations, which I have since repeated. The best plan for observing the order is to make a person first raise his eyebrows, and this produces transverse wrinkles across the forehead; and then very gradually to contract all the muscles round the elves with as much force as possible. The reader who is unacquainted with the anatomy of the face, ought to refer to p. 24, and look at the woodcuts 1 to 3. The corrugators of the brow (_corrugator supercilii_) seem to be the first muscles to contract; and these draw the eyebrows downwards and inwards towards the base of the nose, causing vertical furrows, that is a frown, to appear between the eyebrows; at the same time they cause the disappearance of the transverse wrinkles across the forehead. The orbicular muscles contract almost simultaneously with the corrugators, and produce wrinkles all round the eyes; they appear, however, to be enabled to contract with greater force, as soon as the contraction of the corrugators has given them some support. Lastly, the pyramidal muscles of the nose contract; and these draw the eyebrows and the skin of the forehead still lower down, producing short transverse wrinkles across the base of the nose.[602] For the sake of brevity these muscles will generally be spoken of as the orbiculars, or as those surrounding the eyes.

When these muscles are strongly contracted, those running to the upper lip[603] likewise contract and raise the upper lip. This might have been expected from the manner in which at least one of them, the _malaris_, is connected with the orbiculars. Any one who will gradually contract the muscles round his eyes, will feel, as he increases the force, that his upper lip and the wings of his nose (which are partly acted on by one of the same muscles) are almost always a little drawn up. If he keeps his mouth firmly shut whilst contracting the muscles round the eyes, and then suddenly relaxes his lips, he will feel that the pressure on his eyes immediately increases. So again when a person on a bright, glaring day wishes to look at a distant object, but is compelled partially to close his eyelids, the upper lip may almost always be observed to be somewhat raised. The mouths of some very short-sighted persons, who are forced habitually to reduce the aperture of their eyes, wear from this same reason a grinning expression.

The raising of the upper lip draws upwards the flesh of the upper parts of the cheeks, and produces a strongly marked fold on each cheek,--the naso-l.a.b.i.al fold,--which runs from near the wings of the nostrils to the corners of the mouth and below them. This fold or furrow may be seen in all the photographs, and is very characteristic of the expression of a crying child; though a nearly similar fold is produced in the act of laughing or Smiling.[604]

As the upper lip is much drawn up during the act of screaming, in the manner just explained, the depressor muscles of the angles of the mouth (see K in woodcuts 1 and 2) are strongly contracted in order to keep the mouth widely open, so that a full volume of sound may be poured forth.

The action of these opposed muscles, above and below, tends to give to the mouth an oblong, almost squarish outline, as may be seen in the accompanying photographs. An excellent observer,[605] in describing a baby crying whilst being fed, says, "it made its mouth like a square, and let the porridge run out at all four corners." I believe, but we shall return to this point in a future chapter, that the depressor muscles of the angles of the mouth are less under the separate control of the will than the adjoining muscles; so that if a young child is only doubtfully inclined to cry, this muscle is generally the first to contract, and is the last to cease contracting. When older children commence crying, the muscles which run to the upper lip are often the first to contract; and this may perhaps be due to older children not having so strong a tendency to scream loudly, and consequently to keep their mouths widely open; so that the above-named depressor muscles are not brought into such strong action.

With one of my own infants, from his eighth day and for some time afterwards, I often observed that the first sign of a screaming-fit, when it could be observed coming on gradually, was a little frown, owing to the contraction of the corrugators of the brows; the capillaries of the naked head and face becoming at the same time reddened with blood.

As soon as the screaming-fit actually began, all the muscles round the eyes were strongly contracted, and the mouth widely opened in the manlier above described; so that at this early period the features a.s.sumed the same form as at a more advanced age.

Dr. Piderit[606] lays great stress on the contraction of certain muscles which draw down the nose and narrow the nostrils, as eminently characteristic of a crying expression. The _depressores anguli oris_, as we have just seen, are usually contracted at the same time, and they indirectly tend, according to Dr. d.u.c.h.enne, to act in this same manner on the nose. With children having bad colds a similar pinched appearance of the nose may be noticed, which is at least partly due, as remarked to me by Dr. Langstaff, to their constant snuffling, and the consequent pressure of the atmosphere on the two sides. The purpose of this contraction of the nostrils by children having bad colds, or whilst crying, seems to be to cheek the downward flow of the mucus and tears, and to prevent these fluids spreading over the upper lip.

After a prolonged and severe screaming-fit, the scalp, face, and eyes are reddened, owing to the return of the blood from the head having been impeded by the violent expiratory efforts; but the redness of the stimulated eyes is chiefly due to the copious effusion of tears. The various muscles of the face which have been strongly contracted, still twitch a little, and the upper lip is still slightly drawn up or everted,[607] with the corners of the mouth still a little drawn downwards. I have myself felt, and have observed in other grown-up persons, that when tears are restrained with difficulty, as in reading a pathetic story, it is almost impossible to prevent the various muscles.

which with young children are brought into strong action during their screaming-fits, from slightly twitching or trembling.

Infants whilst young do not shed tears or weep, as is well known to nurses and medical men. This circ.u.mstance is not exclusively due to the lacrymal glands being as yet incapable of secreting tears. I first noticed this fact from having accidentally brushed with the cuff of my coat the open eye of one of my infants, when seventy-seven days old, causing this eye to water freely; and though the child screamed violently, the other eye remained dry, or was only slightly suffused with tears. A similar slight effusion occurred ten days previously in both eyes during a screaming-fit. The tears did not run over the eyelids and roll down the cheeks of this child, whilst screaming badly, when 122 days old. This first happened 17 days later, at the age of 139 days.

A few other children have been observed for me, and the period of free weeping appears to be very variable. In one case, the eyes became slightly suffused at the age of only 20 days; in another, at 62 days.

With two other children, the tears did NOT run down the face at the ages of 84 and 110 days; but in a third child they did run down at the age of 104 days. In one instance, as I was positively a.s.sured, tears ran down at the unusually early age of 42 days. It would appear as if the lacrymal glands required some practice in the individual before they are easily excited into action, in somewhat the same manner as various inherited consensual movements and tastes require some exercise before they are fixed and perfected. This is all the more likely with a habit like weeping, which must have been acquired since the period when man branched off from the common progenitor of the genus h.o.m.o and of the non-weeping anthropomorphous apes.

The fact of tears not being shed at a very early age from pain or any mental emotion is remarkable, as, later in life, no expression is more general or more strongly marked than weeping. When the habit has once been acquired by an infant, it expresses in the clearest manner suffering of all kinds, both bodily pain and mental distress, even though accompanied by other emotions, such as fear or rage. The character of the crying, however, changes at a very early age, as I noticed in my own infants,--the pa.s.sionate cry differing from that of grief. A lady informs me that her child, nine months old, when in a pa.s.sion screams loudly, but does not weep; tears, however, are shed when she is punished by her chair being turned with its back to the table.

This difference may perhaps be attributed to weeping being restrained, as we shall immediately see, at a more advanced age, under most circ.u.mstances excepting grief; and to the influence of such restraint being transmitted to an earlier period of life, than that at which it was first practised.

With adults, especially of the male s.e.x, weeping soon ceases to be caused by, or to express, bodily pain. This may be accounted for by its being thought weak and unmanly by men, both of civilized and barbarous races, to exhibit bodily pain by any outward sign. With this exception, savages weep copiously from very slight causes, of which fact Sir J.

Lubbock[608] has collected instances. A New Zealand chief "cried like a child because the sailors spoilt his favourite cloak by powdering it with flour." I saw in Tierra del Fuego a native who had lately lost a brother, and who alternately cried with hysterical violence, and laughed heartily at anything which amused him. With the civilized nations of Europe there is also much difference in the frequency of weeping.

Englishmen rarely cry, except under the pressure of the acutest grief; whereas in some parts of the Continent the men shed tears much more readily and freely.

The insane notoriously give way to all their emotions with little or no restraint; and I am informed by Dr. J. Crichton Browne, that nothing is more characteristic of simple melancholia, even in the male s.e.x, than a tendency to weep on the slightest occasions, or from no cause. They also weep disproportionately on the occurrence of any real cause of grief.

The length of time during which some patients weep is astonis.h.i.+ng, as well as the amount of tears which they shed. One melancholic girl wept for a whole day, and afterwards confessed to Dr. Browne, that it was because she remembered that she had once shaved off her eyebrows to promote their growth. Many patients in the asylum sit for a long time rocking themselves backwards and forwards; "and if spoken to, they stop their movements, purse up their eyes, depress the corners of the mouth, and burst out crying." In some of these cases, the being spoken to or kindly greeted appears to suggest some fanciful and sorrowful notion; but in other cases an effort of any kind excites weeping, independently of any sorrowful idea. Patients suffering from acute mania likewise have paroxysms of violent crying or blubbering, in the midst of their incoherent ravings. We must not, however, lay too much stress on the copious shedding of tears by the insane, as being due to the lack of all restraint; for certain brain-diseases, as hemiplegia, brain-wasting, and senile decay, have a special tendency to induce weeping. Weeping is common in the insane, even after a complete state of fatuity has been reached and the power of speech lost. Persons born idiotic likewise weep;[609] but it is said that this is not the case with cretins.

Weeping seems to be the primary and natural expression, as we see in children, of suffering of any kind, whether bodily pain short of extreme agony, or mental distress. But the foregoing facts and common experience show us that a frequently repeated effort to restrain weeping, in a.s.sociation with certain states of the mind, does much in checking the habit. On the other hand, it appears that the power of weeping can be increased through habit; thus the Rev. R. Taylor,[610] who long resided in New Zealand, a.s.serts that the women can voluntarily shed tears in abundance; they meet for this purpose to mourn for the dead, and they take pride in crying "in the most affecting manner."

A single effort of repression brought to bear on the lacrymal glands does little, and indeed seems often to lead to an opposite result. An old and experienced physician told me that he had always found that the only means to check the occasional bitter weeping of ladies who consulted him, and who themselves wished to desist, was earnestly to beg them not to try, and to a.s.sure them that nothing would relieve them so much as prolonged and copious crying.

The screaming of infants consists of prolonged expirations, with short and rapid, almost spasmodic inspirations, followed at a somewhat more advanced age by sobbing. According to Gratiolet,[611] the glottis is chiefly affected during the act of sobbing. This sound is heard "at the moment when the inspiration conquers the resistance of the glottis, and the air rushes into the chest." But the whole act of respiration is likewise spasmodic and violent. The shoulders are at the same time generally raised, as by this movement respiration is rendered easier.

With one of my infants, when seventy-seven days old, the inspirations were so rapid and strong that they approached in character to sobbing; when 138 days old I first noticed distinct sobbing, which subsequently followed every bad crying-fit. The respiratory movements are partly voluntary and partly involuntary, and I apprehend that sobbing is at least in part due to children having some power to command after early infancy their vocal organs and to stop their screams, but from having less power over their respiratory muscles, these continue for a time to act in an involuntary or spasmodic manner, after having been brought into violent action. Sobbing seems to be peculiar to the human species; for the keepers in the Zoological Gardens a.s.sure me that they have never heard a sob from any kind of monkey; though monkeys often scream loudly whilst being chased and caught, and then pant for a long time. We thus see that there is a close a.n.a.logy between sobbing and the free shedding of tears; for with children, sobbing does not commence during early infancy, but afterwards comes on rather suddenly and then follows every bad crying-fit, until the habit is checked with advancing years.

_On the cause of the contraction of the muscles round the eyes during screaming_.--We have seen that infants and young children, whilst screaming, invariably close their eyes firmly, by the contraction of the surrounding muscles, so that the skin becomes wrinkled all around. With older children, and even with adults, whenever there is violent and unrestrained crying, a tendency to the contraction of these same muscles may be observed; though this is often checked in order not to interfere with vision.

Sir C. Bell explains[612] this action in the following manner:--"During every violent act of expiration, whether in hearty laughter, weeping, coughing, or sneezing, the eyeball is firmly compressed by the fibres of the orbicularis; and this is a provision for supporting and defending the vascular system of the interior of the eye from a retrograde impulse communicated to the blood in the veins at that time. When we contract the chest and expel the air, there is a r.e.t.a.r.dation of the blood in the veins of the neck and head; and in the more powerful acts of expulsion, the blood not only distends the vessels, but is even regurgitated into the minute branches. Were the eye not properly compressed at that time, and a resistance given to the shock, irreparable injury might be inflicted on the delicate textures of the interior of the eye." He further adds, "If we separate the eyelids of a child to examine the eye, while it cries and struggles with pa.s.sion, by taking off the natural support to the vascular system of the eye, and means of guarding it against the rush of blood then occurring, the conjunctiva becomes suddenly filled with blood, and the eyelids everted."

Not only are the muscles round the eyes strongly contracted, as Sir C. Bell states and as I have often observed, during screaming, loud laughter, coughing, and sneezing, but during several other a.n.a.logous actions. A man contracts these muscles when he violently blows his nose.

I asked one of my boys to shout as loudly as he possibly could, and as soon as he began, he firmly contracted his...o...b..cular muscles; I observed this repeatedly, and on asking him why he had every time so firmly closed his eyes, I found that he was quite unaware of the fact: he had acted instinctively or unconsciously.

It is not necessary, in order to lead to the contraction of these muscles, that air should actually be expelled from the chest; it suffices that the muscles of the chest and abdomen should contract with great force, whilst by the closure of the glottis no air escapes. In violent vomiting or retching the diaphragm is made to descend by the chest being filled with air; it is then held in this position by the closure of the glottis, "as well as by the contraction of its own fibres."[613] The abdominal muscles now contract strongly upon the stomach, its proper muscles likewise contracting, and the contents are thus ejected. During each effort of vomiting "the head becomes greatly congested, so that the features are red and swollen, and the large veins of the face and temples visibly dilated." At the same time, as I know from observation, the muscles round the eyes are strongly contracted.

This is likewise the case when the abdominal muscles act downwards with unusual force in expelling the contents of the intestinal ca.n.a.l.

The greatest exertion of the muscles of the body, if those of the chest are not brought into strong action in expelling or compressing the air within the lungs, does not lead to the contraction of the muscles round the eyes. I have observed my sons using great force in gymnastic exercises, as in repeatedly raising their suspended bodies by their arms alone, and in lifting heavy weights from the ground, but there was hardly any trace of contraction in the muscles round the eyes.