Chapter 2 The Functions of the Brain

If I begin chopping the foot of a tree, its branches are unmoved by my act, and its leaves murmur¹ as peacefully as ever in the wind. If, on the contrary, I do violence to the foot of a fellow-man, the rest of his body instantly responds to the aggression³ by movements of alarm or defence. The reason of this difference is that the man has a nervous system whilst the tree has none; and the function of the nervous system is to bring each part into harmonious⁴ co-operation with every other. The afferent nerves, when excited by some physical irritant, be this as gross in its mode of operation as a chopping axe⁵ or as subtle as the waves of light, conveys the excitement to the nervous centres. The commotion⁶ set up in the centres does not stop there, but discharges itself, if at all strong, through the efferent nerves into muscles and glands⁷, exciting movements of the limbs and viscera, or acts of secretion⁸, which vary with the animal, and with the irritant applied⁹. These acts of response have usually the common character of being of service. They ward¹¹ off the noxious¹² stimulus¹³ and support the beneficial one; whilst if, in itself indifferent, the stimulus be a sign of some distant circumstance of practical importance, the animal's acts are addressed to this circumstance so as to avoid its perils¹⁴ or secure its benefits, as the case may be. To take a common example, if I hear the conductor calling ' All aboard!' as I enter the depot¹⁵, my heart first stops, then palpitates, and my legs respond to the air-waves falling on my tympanum by quickening their movements. If I stumble as I run, the sensation of falling provokes a movement of the hands towards the direction of the fall, the effect of which is to shield the body from too sudden a shock. If a cinder¹⁷ enter my eye, its lids close forcibly and a copious¹⁸ flow of tears tends to wash it out.

These three responses to a sensational¹⁹ stimulus differ, however, in many respects. The closure of the eye and the lachrymation are quite involuntary, and so is the disturbance²⁰ of the heart. Such involuntary responses we know as 'reflex' acts. The motion of the arms to break the shock of falling may also be called reflex, since it occurs too quickly to be deliberately²¹ intended. Whether it be instinctive²² or whether it result from the pedestrian education of childhood may be doubtful; it is, at any rate, less automatic than the previous acts, for a man might by conscious effort learn to perform it more skilfully²³, or even to suppress it altogether. Actions of this kind, into which instinct and volition²⁴ enter upon equal terms, have been called 'semi-reflex.' The act of running towards the train, on the other hand, has no instinctive element about it. It is purely²⁵ the result of education, and is preceded by a consciousness of the purpose to be attained²⁶ and a distinct mandate²⁷ of the will. It is a 'voluntary act.' Thus the animal's reflex and voluntary performances shade into each other gradually, being connected by acts which may often occur automatically, but may also be modified by conscious intelligence.

An outside observer, unable to perceive the accompanying consciousness, might be wholly at a loss to discriminate²⁸ between the automatic acts and those which volition escorted. But if the criterion of mind's existence be the choice of the proper means for the attainment²⁹ of a supposed end, all the acts seem to be inspired by intelligence, for appropriateness characterizes them all alike. This fact, now, has led to two quite opposite theories about the relation to consciousness of the nervous functions. Some authors, finding that the higher voluntary ones seem to require the guidance of feeling, conclude that over the lowest reflexes some such feeling also presides, though it may be a feeling of which we remain unconscious. Others, finding that reflex and semi-automatic acts may, notwithstanding their appropriateness, take place with an unconsciousness apparently³¹ complete, fly to the opposite extreme and maintain that the appropriateness even of voluntary actions owes nothing to the fact that consciousness attends them. They are, according to these writers, results of physiological³² mechanism³³ pure and simple. In a near chapter we shall return to this controversy³⁴ again. Let us now look a little more closely at the brain and at the ways in which its states may be supposed to condition those of the mind.

The Frog's Nerve-Centres.

Both the minute anatomy³⁵ and the detailed³⁶ physiology³⁷ of the brain are achievements of the present generation, or rather we may say (beginning with Meynert) of the past twenty years. Many points are still obscure and subject to controversy; but a general way of conceiving the organ has been reached on all hands which in its main feature seems not unlikely to stand, and which even gives a most plausible³⁸ scheme of the way in which cerebral³⁹ and mental operations go hand in hand.

The best way to enter the subject will be to take a lower creature, like a frog, and study by the vivisectional method the functions of his different nerve-centres. The frog's nerve-centres are figured in the accompanying diagram, which needs no further explanation. I will first proceed to state what happens when various amounts of the anterior⁴¹ parts are removed, in different frogs, in the way in which an ordinary student removes them; that is, with no extreme precautions as to the purity of the operation. We shall in this way reach a very simple conception of the functions of the various centres, involving the strongest possible contrast between the cerebral hemispheres and the lower lobes⁴². This sharp conception will have didactic advantages, for it is often very instructive to start with too simple a formula and correct it later on. Our first formula, as we shall later see, will have to be softened⁴⁵ down somewhat by the results of more careful experimentation⁴⁶ both on frogs and birds, and by those of the most recent observations on dogs, monkeys, and man. But it will put us, from the outset, in clear possession of some fundamental notions and distinctions which we could otherwise not gain so well, and none of which the later more completed view will overturn.

If, then, we reduce the frog's nervous system to the spinal⁴⁷ cord alone, by making a section behind the base of the skull⁵⁰, between the spinal cord and the medulla oblongata, thereby⁵¹ cutting off the brain from all connection with the rest of the body, the frog will still continue to live, but with a very peculiarly modified activity. It ceases to breathe or swallow; it lies flat on its belly⁵³, and does not, like a normal frog, sit up on its fore⁵⁴ paws, though its hind⁴⁹ legs are kept, as usual, folded against its body and immediately resume this position if drawn⁵⁶ out. If thrown on its back, it lies there quietly, without turning over like a normal frog. Locomotion⁵⁷ and voice seem entirely⁵⁸ abolished. If we suspend it by the nose, and irritate different portions of its skin by acid, it performs a set of remarkable⁵⁹ 'defensive⁶⁰' movements calculated to wipe away the irritant. Thus, if the breast be touched, both fore paws will rub it vigorously; if we touch the outer side of the elbow, the hind foot of the same side will rise directly to the spot and wipe it. The back of the foot will rub the knee if that be attacked, whilst if the foot be cut away, the stump⁶¹ will make ineffectual movements, and then, in many frogs, a pause will come, as if for deliberation, succeeded by a rapid passage of the opposite unmutilated foot to the acidulated spot.

The most striking character of all these movements, after their teleological⁶² appropriateness, is their precision. They vary, in sensitive frogs and with a proper amount of irritation⁶³, so little as almost to resemble in their machine-like regularity⁶⁴ the performances of a jumping-jack, whose legs must twitch⁶⁵ whenever you pull the string. The spinal cord of the frog thus contains arrangements of cells and fibres fitted to convert skin irritations⁶⁶ into movements of defence. We may call it the centre for defensive movements in this animal. We may indeed go farther than this, and by cutting the spinal cord in various places find that its separate segments are independent mechanisms⁶⁷, for appropriate activities of the head and of the arms and legs respec- tively. The segment governing the arms is especially active, in male frogs, in the breeding season; and these members alone with the breast and back appertaining to them, everything else being cut away, will then actively⁷⁰ grasp a finger placed between them and remain hanging to it for a considerable time.

The spinal cord in other animals has analogous⁷¹ powers. Even in man it makes movements of defence. Paraplegics draw up their legs when tickled⁷²; and Robin⁷³, on tickling⁷⁴ the breast of a criminal an hour after decapitation, saw the arm and hand move towards the spot. Of the lower functions of the mammalian cord, studied so ably by Goltz and others, this is not the place to speak.

If, in a second animal, the cut be made just behind the optic lobes so that the cerebellum and medulla oblongata remain attached to the cord, then swallowing, breathing, crawling, and a rather enfeebledjumping and swimming are added to the movements previously⁷⁵ observed.¹ There are other reflexes too. The animal, thrown on his back, immediately turns over to his belly. Placed in a shallow bowl, which is floated on water and made to rotate, he responds to the rotation⁷⁶ by first turning his head and then waltzing around with his entire body, in the opposite direction to the whirling of the bowl. If his support be tilted⁷⁷ so that his head points downwards⁷⁸, he points it up; he points it down if it be pointed⁷⁹ upwards⁸⁰, to the right if it be pointed to the left, etc. But his reactions do not go farther than these movements of the head.; He will not, like frogs whose thalami are preserved, climb up a board if the latter be tilted, but will slide off it to the ground.

If the cut be made on another frog between the thalami and the optic lobes, the locomotion both on land and water becomes quite normal, and, in addition to the reflexes already shown by the lower centres, he croaks⁸¹ regularly whenever he is pinched under the arms. He compensates⁸² rotations⁸³, etc., by movements of the head, and turns over from his back; but still drops off his tilted board. As his optic nerves are destroyed by the usual operation, it is impossible to say whether he will avoid obstacles placed in his path.

When, finally, a frog's cerebral hemispheres alone are cut off by a section between them and the thalami which preserves the latter, an unpractised observer would not at first suspect anything abnormal about the animal. Not only is he capable, on proper instigation, of all the acts already described, but he guides himself by sight, so that if an obstacle be set up between him and the light, and he be forced to move forward, he either jumps over it or swerves⁸⁵ to one side. He manifests sexual passion at the proper season, and, unlike an altogether brainless frog, which embraces anything placed between his arms, postpones⁸⁷ this reflex act until a female of his own species is provided. Thus far, as aforesaid, a person unfamiliar⁸⁸ with frogs might not suspect a mutilation; but even such a person would soon remark the almost entire absence of spontaneous motion-that is, motion unprovoked by any present incitation⁸⁹ of sense. The continued movements of swimming, performed by the creature in the water, seem to be the fatal result of the contact of that fluid with its skin. They cease when a stick, for example, touches his hands. This is a sensible irritant towards which the feet are automatically drawn by reflex action, and on which the animal remains⁹⁰ sitting. He manifests no hunger, and will suffer a fly to crawl over his nose unsnapped at. Fear, too, seems to have deserted⁹¹ him. In a word, he is an extremely complex machine whose actions, so far as they go, tend to self-preservation⁹²; but still a machine, in this sense-that it seems to contain no incalculable element. By applying the right sensory⁹³ stimulus to him we are almost as certain of getting a fixed⁹⁴ response as an organist is of hearing a certain tone when he pulls out a certain stop.

But now if to the lower centres we add the cerebral hemispheres, or if, in other words, we make an intact animal the subject of our observations, all this is changed. In addition to the previous responses to present incitements of sense, our frog now goes through long and complex acts of locomotion spontaneously, or as if moved by what in our- selves we should call an idea. His reactions to outward stimuli⁹⁶ vary their form, too. Instead of making simple defensive movements with his hind legs like a headless frog if touched, or of giving one or two leaps and then sitting still like a hemisphereless one, he makes persistent⁹⁷ and varied⁹⁸ efforts at escape, as if, not the mere⁹⁹ contact of the physiologist¹⁰⁰'s hand, but the notion of danger suggested by it were now his spur. Led by the feeling of hunger, too, he goes in search of insects, fish, or smaller frogs, and varies his procedure with each species of victim. The physiologist cannot by manipulating him elicit¹⁰¹ croaking¹⁰², crawling up a board, swimming or stopping, at will. His conduct has become incalculable. We can no longer foretell¹⁰³ it exactly. Effort to escape is his dominant¹⁰⁴ reaction, but he may do anything else, even swell¹⁰⁵ up and become perfectly¹⁰⁶ passive in our hands.

Such are the phenomena¹⁰⁷ commonly observed, and such the impressions which one naturally receives. Certain general conclusions follow irresistibly¹⁰⁸. First of all the following:

The acts of all the centres involve the use of the same muscles. When a headless frog's hind leg wipes the acid, he calls into play all the leg-muscles which a frog with his full medulla oblongata and cerebellum uses when he turns from his back to his belly. Their contractions¹⁰⁹ are, however, combined differently in the two cases, so that the results vary widely. We must consequently conclude that specific arrangements of cells and fibres exist in the cord for wiping, in the medulla for turning over, etc. Similarly they exist in the thalami for jumping over seen obstacles and for balancing the moved body; in the optic lobes for creeping backwards¹¹², or what not. But in the hemispheres, since the presence of these organs brings no new elementary form of movement with it, but only determines differently the occasions on which the movements shall occur, making the usual stimuli less fatal and machine-like; we need suppose no such machinery¹¹³ directly co-ordinative of muscular contractions to exist. We may rather assume, when the mandate for a wiping-movement is sent forth¹¹⁴ by the hemispheres, that a current goes straight to the wiping-arrangement in the spinal cord, exciting this arrangement as a whole. Similarly, if an intact frog wishes to jump over a stone which he sees, all he need do is to excite from the hemispheres the jumping-centre in the thalami or wherever it may be, and the latter will provide for the details of the execution. It is like a general ordering a colonel to make a certain movement, but not telling him how it shall be done.

The same muscle, then, repeatedly represented at different heights; and at each it enters into a different combination with other muscles to co-operate in some special form of concerted movement. At each height the movement is discharged by some particular form of sensorial stimulus. Thus in the cord, the skin alone occasions movements; in the upper part of the optic lobes, the eyes are added; in the thalami, the semi-circular canals would seem to play a part; whilst the stimuli which discharge the hemispheres would seem not so much to be elementary sorts of sensation, as groups of sensations forming determinate objects or things. Prey¹¹⁵ is not pursued nor are enemies shunned¹¹⁶ by ordinary hemisphereless frogs. Those reactions upon complex circumstances which we call instinctive rather than reflex, are already in this animal dependent on the brain's highest lobes, and still more is this the case with animals higher in the zoological scale.

The results are just the same if, instead of a frog, we take a pigeon, and cut out his hemispheres as they are ordinarily cut out for a lecture-room demonstration¹¹⁷. There is not a movement natural to him which this brainless bird cannot perform if expressly excited thereto; only the inner promptings seem deficient¹¹⁸, and when left to himself he spends most of his time crouched¹¹⁹ on the ground with his head sunk between his shoulders as if asleep.

General Notion of Hemispheres.

All these facts lead us, when we think about them, to some such explanatory conception as this: The lower centres act from present sensational stimuli alone; the hemispheres act from perceptions and considerations, the sensations which they may receive, serving only as suggesters of these. But what are perceptions but sensations grouped together? and what are considerations but expectations, in the fancy, of sensations which will be felt one way or another according as action takes this course or that? If I step aside on seeing a rattlesnake, from considering how dangerous an animal he is, the mental materials which constitute my prudential reflection are images more or less vivid of the movement of his head, of a sudden pain in my leg, of a state of terror, a swelling¹²⁰ of the limb, a chill, delirium¹²¹, unconsciousness, etc., etc., and the ruin of my hopes. But all these images are constructed out of my past experiences. They are reproductions of what I have felt or witnessed. They are, in short, remote sensations; and the difference between the hemisphereless animal and the whole one may be concisely¹²² expressed by saying that the one obeys absent, the other only present, objects.

The hemispheres would then seem to be the seat of memory. Vestiges¹²³ of past experience must in some way be stored up in them, and must, when aroused by present stimuli, first appear as representations of distant goods and evils; and then must discharge into the appropriate motor channels for warding¹²⁴ off the evil and securing the benefits of the good. If we liken the nervous currents to electric currents, we can compare the nervous system, C, below the hemispheres to a direct circuit from sense-organ to muscle along the line S . . . C . . . M of Fig⁴⁰. 2 (p. 21). The hemisphere, H, adds the long circuit or loop-line through which the current may pass when for any reason the direct line is not used.

Thus, a tired wayfarer¹²⁵ on a hot day throws himself on the damp earth beneath a maple-tree. The sensations of delicious rest and coolness pouring themselves through the direct line would naturally discharge into the muscles of complete extension: he would abandon himself to the dangerous repose¹²⁶. But the loop-line being open, part of the current is drafted along it, and awakens¹²⁸ rheumatic or catarral reminiscences, which prevail over the instigations of sense, and make the man arise and pursue his way to where he may enjoy his rest more safely. Presently we shall examine the manner in which the hemispheric loop-line may be supposed to serve as a reservoir for such reminiscences as these. Meanwhile I will ask the reader to notice some corollaries of its being such a reservoir.

First, no animal without it can deliberate, pause, postpone⁸⁶, nicely weigh one motive¹²⁹ against another, or compare. Prudence¹³⁰, in a word, is for such a creature an impossible virtue¹³¹. Accordingly we see that nature removes those functions in the exercise of which prudence is a virtue from the lower centres and hands them over to the cerebrum. Wherever a creature has to deal with complex features of the environment, prudence is a virtue. The higher animals have so to deal; and the more complex the features, the higher we call the animals. The fewer of his acts, then, can such an animal perform without the help of the organs in question. In the frog many acts devolve wholly on the lower centres; in the bird fewer; in the rodent¹³² fewer still; in the dog very few indeed; and in apes and men hardly any at all.

The advantages of this are obvious. Take the prehension of food as an example and suppose it to be a reflex performance of the lower centres. The animal will be condemned¹³³ fatally and irresistibly to snap at it whenever presented, no matter what the circumstances may be; he can no more disobey this prompting than water can refuse to boil when a fire is kindled¹³⁴ under the pot. His life will again and again pay the forfeit¹³⁵ of his gluttony.

Exposure to retaliation¹³⁶, to other enemies, to traps, to poisons, to the dangers of repletion¹³⁷, must be regular parts of his existence. His lack of all thought by which to weigh the danger against the attractiveness of the bait, and of all volition to remain hungry a little while longer, is the direct measure of his lowness in the mental scale. And those fishes which, like our cunners and sculpins, are no sooner thrown back from the hook into the water, than they automatically seize the hook again, would soon expiate¹³⁸ the degradation¹³⁹ of their intelligence by the extinction¹⁴⁰ of their type, did not their exaggerated fecundity¹⁴¹ atone¹⁴² for their imprudence. Appetite and the acts it prompts have consequently become in all higher vertebrates functions of the cerebrum. They disappear when the physiologist's knife has left the subordinate centres alone in place. The brainless pigeon will starve though left on a corn-heap.

Take again the sexual function. In birds this devolves exclusively upon the hemispheres. When these are shorn away the pigeon pays no attention to the billings and cooings of its mate. And Goltz found that a bitch in heat would excite no emotion in male dogs who had suffered large loss of cerebral tissue. Those who have read Darwin's 'Descent of Man' know what immense importance in the amelioration of the breed in birds this author ascribes to the mere fact of sexual selection. The sexual act is not performed until every condition of circumstance and sentiment is fulfilled, until time, place, and partner all are fit. But in frogs and toads¹⁴³ this passion devolves on the lower centres. They show consequently a machine-like obedience¹⁴⁴ to the present incitement⁹⁵ of sense, and an almost total exclusion¹⁴⁵ of the power of choice. Copulation occurs per fas aut nefas, occasionally between males, often with dead females, in puddles¹⁴⁶ exposed on the highway, and the male may be cut in two without letting go his hold. Every spring an immense sacrifice of batrachian life takes place from these causes alone.

No one need be told how dependent all human social elevation¹⁴⁷ is upon the prevalence of chastity. Hardly any factor measures more than this the difference between civili- zation and barbarism. Physiologically¹⁴⁸ interpreted, chastity means nothing more than the fact that present solicitations of sense are overpowered by suggestions of aesthetic¹⁴⁹ and moral fitness which the circumstances awaken¹²⁷ in the cerebrum; and that upon the inhibitory or permissive influence of these alone action directly depends.

Within the psychic¹⁵¹ life due to the cerebrum itself the same general distinction obtains, between considerations of the more immediate⁵⁵ and considerations of the more remote. In all ages the man whose determinations are swayed by reference to the most distant ends has been held to possess the highest intelligence. The tramp who lives from hour to hour; the bohemian whose engagements are from day to day; the bachelor who builds but for a single life; the father who acts for another generation; the patriot¹⁵² who thinks of a whole community and many generations; and finally, the philosopher and saint whose cares are for humanity and for eternity,-these range themselves in an unbroken hierarchy¹⁵³, wherein each successive grade results from an increased manifestation¹⁵⁴ of the special form of action by which the cerebral centres are distinguished¹⁵⁵ from all below them.

In the 'loop-line' along which the memories and ideas of the distant are supposed to lie, the action, so far as it is a physical process, must be interpreted after the type of the action in the lower centres. If regarded here as a reflex process, it must be reflex there as well. The current in both places runs out into the muscles only after it has first run in; but whilst the path by which it runs out is determined¹⁵⁶ in the lower centres by reflections few and fixed amongst the cell-arrangements, in the hemispheres the reflections are many and instable. This, it will be seen, is only a difference of degree and not of kind, and does not change the reflex type. The conception of all action as conforming to this type is the fundamental conception of modern nerve-physiology. So much for our general preliminary conception of the nerve-centres! Let us define it more distinctly before we see how well physiological observation will bear it out in detail.

The Education of the Hemispheres

Nerve-currents run in through sense-organs, and whilst provoking reflex acts in the lower centres, they arouse ideas in the hemispheres, which either permit the reflexes in question, check them, or substitute others for them. All ideas being in the last resort reminiscences, the question to answer is: How can processes become organized in the hemispheres which correspond to reminiscences in the mind?

Nothing is easier than to conceive a possible way in which this might be done, provided four assumptions be granted. These assumptions (which after all are inevitable¹⁵⁷ in any event) are:

1) The same cerebral process which, when aroused from without by a sense-organ, gives the perception of an object, will give an idea of the same object when aroused by other cerebral processes from within.

2) If processes 1, 2, 3, 4 have once been aroused together or in immediate succession, any subsequent arousal of any one of them (whether from without or within) will tend to arouse the others in the original order.[This is the so-called law of association.]

3) Every sensorial excitement propagated to a lower centre tends to spread upwards and arouse an idea.

4) Every idea tends ultimately either to produce a movement or to check one which otherwise would be produced.

Suppose now (these assumptions being granted) that we have a baby before us who sees a candle-flame for the first time, and, by virtue of a reflex tendency common in babies of a certain age, extends his hand to grasp it, so that his fingers get burned. So far we have two reflex currents in play: first, from the eye to the extension movement, along the line 1-1-1-1 of Fig. 3; and second, from the finger to the movement of drawing back the hand, along the line 2-2-2-2.

If this were the baby's whole nervous system, and if the reflexes were once for all organic, we should have no alteration¹⁵⁸ in his behavior, no matter how often the experience recurred¹⁵⁹. The retinal image of the flame would always make the arm shoot forward, the burning of the finger would always send it back. But we know that 'the burnt child dreads¹⁶⁰ the fire,' and that one experience usually protects the fingers forever. The point is to see how the hemispheres may bring this result to pass.

We must complicate¹⁶¹ our diagram (see Fig. 4). Let the current 1-1, from the eye, discharge upward as well as downward when it reaches the lower centre for vision, and arouse the perceptional process s¹ in the hemispheres; let the feeling of the arm's extension also send up a current which leaves a trace of itself, m¹; let the burnt finger leave an analogous trace, s²; and let the movement of retraction¹⁶² leave m². These four processes will now, by virtue of assumption 2), be associated together by the path s¹-m¹-s²-m² running from the first to the last, so that if anything touches off s¹, ideas of the extension, of the burnt finger, and of the retraction will pass in rapid succession through the mind. The effect on the child's conduct when the candle-flame is next presented is easy to imagine. Of course the sight of it arouses the grasping reflex; but it arouses simultaneously¹⁶³ the idea thereof, together with that of the consequent pain, and of the final retraction of the hand; and if these cerebral processes prevail in strength over the immediate sensation in the centres below, the last idea will be the cue by which the final action is discharged. The grasping will be arrested in mid-career, the hand drawn back, and the child's fingers saved.

In all this we assume that the hemispheres do not natively couple any particular sense-impression with any special motor discharge. They only register, and preserve traces of, such couplings as are already organized in the reflex centres below. But this brings it inevitably¹⁶⁴ about that, when a chain of experiences has been already registered and the first link is impressed once again from without, the last link will often be awakened¹⁶⁵ in idea long before it can exist in fact. And if this last link were previously coupled with a motion, that motion may now come from the mere ideal suggestion without waiting for the actual impression to arise. Thus an animal with hemispheres acts in anticipation¹⁶⁶ of future things; or, to use our previous formula, he acts from considerations of distant good and ill. If we give the name of partners to the original couplings of impressions with motions in a reflex way, then we may say that the function of the hemispheres is simply to bring about exchanges among the partners. Movement mⁿ, which natively is sensation sⁿ's partner, becomes through the hemispheres the partner of sensation s¹, s² or s³. It is like the great commutating switch-board at a central telephone station. No new elementary process is involved; no impression nor any motion peculiar⁵² to the hemispheres; but any number of combinations impossible to the lower machinery taken alone, and an endless consequent increase in the possibilities of behavior on the creature's part.

All this, as a mere scheme, is so clear and so concordant with the general look of the facts as almost to impose itself on our belief; but it is anything but clear in detail. The brain-physiology of late years has with great effort sought to work out the paths by which these couplings of sensations with movements take place, both in the hemispheres and in the centres below.

So we must next test our scheme by the facts discovered in this direction. We shall conclude, I think, after taking them all into account, that the scheme probably makes the lower centres too machine-like and the hemispheres not quite machine-like enough, and must consequently be softened down a little. So much I may say in advance. Meanwhile, before plunging¹⁶⁷ into the details which await us, it will somewhat clear our ideas if we contrast the modern way of looking at the matter with the phrenological conception which but lately preceded it.

The Phrenological Conception.

In a certain sense Gall¹⁶⁸ was the first to seek to explain in detail how the brain could subserve our mental operations. His way of proceeding¹⁶⁹ was only too simple. He took the faculty¹⁷⁰-psychology¹⁷¹ as his ultimatum¹⁷² on the mental side, and he made no farther psychological analysis. Wherever he found an individual with some strongly-marked trait of character he examined his head; and if he found the latter prominent in a certain region, he said without more ado that that region was the 'organ' of the trait or faculty in question. The traits were of very diverse constitution, some being simple sensibilities like 'weight' or 'color'; some being instinctive tendencies like 'alimentiveness' or 'amativeness;' and others, again, being complex resultants like 'conscientiousness,' 'individuality.' Phrenology fell promptly¹⁷³ into disrepute among scientific men because observation seemed to show that large facul- ties and large 'bumps' might fail to coexist; because the scheme of Gall was so vast as hardly to admit of accurate determination at all-who of us can say even of his own brothers whether their perceptions of weight and of time are well developed or not?-because the followers¹⁷⁵ of Gall and Spurzheim were unable to reform these errors in any appreciable¹⁷⁶ degree; and, finally, because the whole analysis of faculties¹⁷⁷ was vague and erroneous from a psychologic point of view. Popular professors of the lore¹⁷⁸ have nevertheless continued to command the admiration¹⁷⁹ of popular audiences; and there seems no doubt that Phrenology, however little it satisfy our scientific curiosity about the functions of different portions of the brain, may still be, in the hands of intelligent practitioners¹⁸⁰, a useful help in the art of reading character. A hooked nose and a firm jaw¹⁸¹ are usually signs of practical energy; soft, delicate hands are signs of refined sensibility. Even so may a prominent eye be a sign of power over language, and a bull-neck a sign of sensuality. But the brain behind the eye and neck need no more be the organ of the signified faculty than the jaw is the organ of the will or the hand the organ of refinement¹⁸². These correlations¹⁸⁴ between mind and body are, however, so frequent that the 'characters' given by phrenologists are often remarkable for knowingness and insight.

Phrenology hardly does more than restate the problem. To answer the question, "Why do I like children?" by saying, "Because you have a large organ of philoprogenitiveness," but renames the phenomenon to be explained. What is my philoprogenitiveness? Of what mental elements does it consist? And how can a part of the brain be its organ? A science of the mind must reduce such complex manifestations¹⁸⁵ as 'philoprogenitiveness' to their elements. A science of the brain must point out the functions of its elements. A science of the relations of mind and brain must show how the elementary ingredients of the former correspond to the elementary functions of the latter. But phrenology, except by occasional coincidence, takes no account of elements at all. Its 'faculties,' as a rule, are fully² equipped persons in a particular mental attitude. Take, for example, the 'faculty' of language. It involves in reality a host of distinct powers. We must first have images of concrete things and ideas of abstract qualities and relations; we must next have the memory of words and then the capacity so to associate each idea or image with a particular word that, when the word is heard, the idea shall forthwith enter our mind. We must conversely, as soon as the idea arises in our mind, associate with it a mental image of the word, and by means of this image we must innervate our articulatory apparatus¹⁸⁷ so as to reproduce the word as physical sound. To read or to write a language other elements still must be introduced. But it is plain that the faculty of spoken language alone is so complicated as to call into play almost all the elementary powers which the mind possesses, memory, imagination, association, judgment¹⁹⁰, and volition. A portion of the brain competent to be the adequate seat of such a faculty would needs be an entire brain in miniature,-just as the faculty itself is really a specification¹⁹¹ of the entire man, a sort of homunculus. Yet just such homunculi are for the most part the phrenological organs. As Lange says:

"We have a parliament of little men together, each of whom, as happens also in a real parliament, possesses but a single idea which he ceaselessly strives to make prevail"-benevolence, firmness, hope, and the rest. "Instead of one soul, phrenology gives us forty, each alone as enigmatic as the full aggregate¹⁹² psychic life can be. Instead of dividing the latter into effective elements, she divides it into personal beings of peculiar character ..'Herr Pastor¹⁹³, sure there be a horse inside,' called out the peasants to X after their spiritual shepherd had spent hours in explaining to them the construction of the locomotive. With a horse inside truly everything becomes clear, even though it be a queer enough sort of horse-the horse itself calls for no explanation! Phrenology takes a start to get beyond the point of view of the ghost-like soul entity¹⁹⁴, but she ends by populating the whole skull with ghosts of the same order."

Modern Science conceives of the matter in a very different way. Brain and mind alike consist of simple elements, sensory and motor. "All nervous centres," says Dr. Hughlings Jackson, "from the lowest to the very highest (the substrata of consciousness), are made up of nothing else than nervous arrangements, representing impressions and movements . . . I do not see of what other materials the brain can be made." Meynert represents the matter similarly when he calls the cortex of the hemispheres the surface of projection¹⁹⁵ for every muscle and every sensitive point of the body. The muscles and the sensitive points are represented each by a cortical point, and the brain is nothing but the sum of all these cortical points, to which, on the mental side, as many ideas correspond. Ideas of sensation, ideas of motion are, on the other hand, the elementary factors out of which the mind is built up by the associationists in psychology. There is a complete parallelism between the two analyses, the same diagram of little dots, circles, or triangles joined by lines symbolizes¹⁹⁶ equally well the cerebral and mental processes: the dots stand for cells or ideas, the lines for fibres or associations. We shall have later to criticise¹⁹⁷ this analysis so far as it relates to the mind; but there is no doubt that it is a most convenient, and has been a most useful, hypothesis, formulating¹⁹⁸ the facts in an extremely natural way.

If, then, we grant that motor and sensory ideas variously associated are the materials of the mind, all we need do to get a complete diagram of the mind's and the brain's relations should be to ascertain¹⁹⁹ which sensory idea corresponds to which sensational surface of projection, and which motor idea to which muscular surface of projection. The associations would then correspond to the fibrous connections between the various surfaces. This distinct cerebral localization of the various elementary sorts of idea has been treated as a 'postulate²⁰⁰' by many physiologists²⁰¹ (e.g. Munk); and the most stirring controversy in nerve-physiology which the present generation has seen has been the localization-question.

The Localization of Functions in the Hemispheres.

Up to 1870, the opinion which prevailed was that which the experiments of Flourens on pigeons' brains had made plausible, namely, that the different functions of the hemi- spheres were not locally separated, but carried on each by the aid of the whole organ. Hitzig in 1870 showed, however, that in a dog's brain highly specialized²⁰² movements could be produced by electric irritation of determinate regions of the cortex; and Ferrier and Munk, half a dozen years later, seemed to prove, either by irritations or excisions or both, that there were equally determinate regions connected with the senses of sight, touch, hearing, and smell. Munk's special sensorial localizations, however, disagreed with Ferrier's; and Goltz, from his extirpation²⁰⁴-experiments, came to a conclusion adverse²⁰⁵ to strict localization of any kind. The controversy is not yet over. I will not pretend to say anything more of it historically, but give a brief account of the condition in which matters at present stand.

The one thing which is perfectly well established is this, that the 'central' convolutions, on either side of the fissure²⁰⁶ of Rolando, and (at least in the monkey) the calloso-marginal convolution (which is continuous with them on the mesial surface where one hemisphere is applied against the other), form the region by which all the motor incitations which leave the cortex pass out, on their way to those executive centres in the region of the pons, medulla, and spinal cord from which the muscular contractions are discharged in the last resort. The existence of this so-called 'motor zone' is established by the lines of evidence successively given below:

(1) Cortical Irritations. Electrical currents of small intensity²⁰⁷ applied to the surface of the said convolutions in dogs, monkeys, and other animals, produce well-defined movements in face, fore-limb, hind-limb, tail, or trunk, according as one point or another of the surface is irritated. These movements affect almost invariably the side opposite to the brain irritations: If the left hemisphere be excited, the movement is of the right leg, side of face, etc. All the objections at first raised against the validity of these experiments have been overcome. The movements are certainly not due to irritations of the base of the brain by the downward spread of the current, for: a) mechanical irritations will produce them, though less easily than electrical; b) shifting the electrodes to a point close by on the surface changes the movement in ways quite inexplicable²⁰⁸ by changed physical conduction of the current; c) if the cortical 'centre' for a certain movement be cut under with a sharp knife but left in situ, although the electric conductivity is physically²⁰⁹ unaltered by the operation, the physiological conductivity is gone and currents of the same strength no longer produce the movements which they did; d) the time-interval between the application of the electric stimulus to the cortex and the resultant movement is what it would be if the cortex acted physiologically and not merely physically in transmitting the irritation. It is namely a well-known fact that when a nerve-current has to pass through the spinal cord to excite a muscle by reflex action, the time is longer than if it passes directly down the motor nerve: the cells of the cord take a certain time to discharge. Similarly, when a stimulus is applied directly to the cortex the muscle contracts two or three hundredths of a second later than it does when the place on the cortex is cut away and the electrodes are applied to the white fibres below.

(2) Cortical Ablations. When the cortical spot which is found to produce a movement of the fore-leg, in a dog, is excised²¹¹ (see spot 5 in Fig. 5), the leg in question becomes peculiarly affected²¹². At first it seems paralyzed. Soon, however, it is used with the other legs, but badly. The animal does not bear his weight on it, allows it to rest on its dorsal²¹³ surface, stands with it crossing the other leg, does not remove it if it hangs over the edge of a table, can no longer 'give the paw' at word of command if able to do so before the operation, does not use it for scratching the ground, or holding a bone as formerly²¹⁴, lets it slip out when running on a smooth surface or when shaking himself, etc., etc. Sensibility of all kinds seems diminished as well as motility, but of this I shall speak later on. Moreover the dog tends in voluntary movements to swerve⁸⁴ towards the side of the brain-lesion instead of going straight forward. All these symptoms gradually decrease, so that even with a very severe brain-lesion the dog may be outwardly indistinguishable from a well dog after eight or ten weeks. Still, a slight chloroformization will reproduce the disturbances²¹⁵, even then. There is a certain appearance of ataxic in-coördination in the movements -the dog lifts his fore-feet high and brings them down with more strength than usual, and yet the trouble is not ordinary lack of co-ordination.

Neither is there paralysis²¹⁶. The strength of whatever movements are made is as great as ever-dogs with extensive destruction of the motor zone can jump as high and bite as hard as ever they did, but they seem less easily moved to do anything with the affected parts. Dr. Loeb, who has studied the motor disturbances of dogs more carefully than any one, conceives of them en masse as effects of an increased inertia²¹⁷ in all the processes of innervation towards the side opposed to the lesion. All such movements require an unwonted effort for their execution; and when only the normally usual effort is made they fall behind in effectiveness.

Even when the entire motor zone of a dog is removed, there is no permanent paralysis of any part, but only this curious sort of relative inertia when the two sides of the body are compared; and this itself becomes hardly noticeable after a number of weeks have elapsed. Prof Goltz has described a dog whose entire left hemisphere was destroyed, and who retained only a slight motor inertia on the right half of the body. In particular he could use his right paw for holding a bone whilst gnawing²¹⁸ it, or for reaching after a piece of meat.

Had he been taught to give his paw before the operations, it would have been curious to see whether that faculty also came back. His tactile²¹⁹ sensibility was permanently²²⁰ diminished on the right side. In monkeys a genuine paralysis follows upon ablations of the cortex in the motor region. This paralysis affects parts of the body which vary with the brain-parts removed. The monkey's opposite arm or leg hangs flaccid, or at most takes a small part in associated movements. When the entire region is removed there is a genuine and permanent hemiplegia in which the arm is more affected than the leg; and this is followed months later by contracture of the muscles, as in man after inveterate²²¹ hemiplegia. According to Schaefer and Horsley, the trunk-muscles also become paralyzed after destruction of the marginal convolution on both sides (see Fig. 7). These differences between dogs and monkeys show the danger of drawing general conclusions from experiments done on any one sort of animal. I subjoin the figures given by the last-named authors of the motor regions in the monkey's brain.

In man we are necessarily reduced to the observation post-mortem of cortical ablations produced by accident or disease (tumor, hemorrhage, softening²²², etc.). What results during life from such conditions is either localized spasm²²³, or palsy of certain muscles of the opposite side. The cortical regions which invariably produce these results are homologous with those which we have just been studying in the dog, cat, ape, etc. Figs²²⁴. 8 and 9 show the result of 169 cases carefully studied by Exner. The parts shaded are regions where lesions produced no motor disturbance. Those left white were, on the contrary, never injured without motor disturbances of some sort.

Where the injury to the cortical substance is profound in man, the paralysis is permanent and is succeeded by muscular rigidity²²⁵ in the paralyzed parts, just as it may be in the monkey.

(3) Descending²²⁶ degenerations show the intimate connection of the rolandic regions of the cortex with the motor tracts²¹⁰ of the cord. When, either in man or in the lower animals, these regions are destroyed, a peculiar degenerative change known as secondary sclerosis is found to extend downwards through the white fibrous substance of the brain in a perfectly definite manner, affecting certain distinct strands²²⁷ which pass through the inner capsule, crura, and pons, into the anterior pyramids of the medulla oblongata, and from thence (partly crossing to the other side) downwards into the anterior (direct) and lateral²²⁹ (crossed) columns of the spinal cord.

(4) Anatomical proof of the continuity of the rolandic regions with these motor columns of the cord is also clearly given. Flechsig's 'Pyramidenbahn' forms an uninterrupted strand²²⁸ (distinctly traceable in human embryos²³⁰, before its fibres have acquired their white 'medullary sheath') passing upwards from the pyramids of the medulla, and traversing the internal capsule and corona²³¹ radiata to the convolutions in question (Fig. 10). None of the inferior gray matter of the brain seems to have any connection with this important fibrous strand. It passes directly from the cortex to the motor arrangements in the cord, depending for its proper nutrition (as the facts of degeneration show) on the influence of the cortical cells, just as motor nerves depend for their nutrition on that of the cells of the spinal cord. Electrical stimulation²³² of this motor strand in any accessible part of its course has been shown in dogs to produce movements analogous to those which excitement of the cortical surface calls forth.

One of the most instructive proofs of motor localization in the cortex is that furnished by the disease now called aphemia, or motor Aphasia²³³. Motor aphasia is neither loss of voice nor paralysis of the tongue or lips. The patient's voice is as strong as ever, and all the innervations of his hypoglossal and facial nerves, except those necessary for speaking, may go on perfectly well. He can laugh and cry, and even sing; but he either is unable to utter any words at all; or a few meaningless stock phrases form his only speech; or else he speaks incoherently and confusedly, mispronounc- ing, misplacing, and misusing²³⁴ his words in various degrees. Sometimes his speech is a mere broth¹⁷⁴ of unintelligible²³⁵ syllables²³⁶. In cases of pure motor aphasia the patient recognizes his mistakes and suffers acutely from them.

Now whenever a patient dies in such a condition as this, and an examination of his brain is permitted, it is found that the lowest frontal gyrus (see Fig. 11) is the seat of injury. Broca first noticed this fact in 1861, and since then the gyrus has gone by the name of Broca's convolution.

The injury in right-handed people is found on the left hemisphere, and in left-handed people on the right hemisphere. Most people, in fact, are left-brained, that is, all their delicate and specialized movements are handed over to the charge of the left hemisphere. The ordinary right-handedness for such movements is only a consequence of that fact, a consequence which shows outwardly on account of that extensive decussation of the fibres whereby most of those from the left hemisphere pass to the right half of the body only. But the left-brainedness might exist in equal measure and not show outwardly. This would happen wherever organs on both sides of the body could be governed by the left hemisphere; and just such a case seems offered by the vocal²³⁷ organs, in that highly delicate and special motor service which we call speech. Either hemisphere can innervate them bilaterally²³⁹, just as either seems able to innervate bilaterally the muscles of the trunk, ribs²⁴⁰, and diaphragm. Of the special movements of speech, how- ever, it would appear (from the facts of aphasia) that the left hemisphere in most persons habitually²⁴¹ takes exclusive charge. With that hemisphere thrown out of gear, speech is undone²⁴³; even though the opposite hemisphere still be there for the performance of less specialized acts, such as the various movements required in eating.

It will be noticed that Broca's region is homologous with the parts ascertained²⁴⁴ to produce movements of the lips, tongue, and larynx when excited by electric currents in apes (cf. Fig. 6, p. 34). The evidence is therefore as complete as it well can be that the motor incitations to these organs leave the brain by the lower frontal region.

Victims of motor aphasia generally have other disorders²⁴⁶. One which interests us in this connection has been called agraphia: they have lost the power to write. They can read writing and understand it; but either cannot use the pen at all or make egregious²⁴⁷ mistakes with it. The seat of the lesion here is less well determined, owing to an insufficient²⁴⁸ number of good cases to conclude from. There is no doubt, however, that it is (in right-handed people) on the left side, and little doubt that it consists of elements of the hand-and-arm region specialized for that service. The symptom may exist when there is little or no disability in the hand for other uses. If it does not get well, the patient usually educates his right hemisphere, i.e. learns to write with his left hand. In other cases of which we shall say more a few pages later on, the patient can write both spontaneously and at dictation, but cannot read even what he has himself written! All these phenomena are now quite clearly explained by separate brain-centres for the various feelings and movements and tracts for associating these together. But their minute discussion belongs to medicine rather than to general psychology, and I can only use them here to illustrate²⁴⁹ the principles of motor localization. Under the heads of sight and hearing I shall have a little more to say.

The different lines of proof which I have taken up establish conclusively²⁵⁰ the proposition that all the motor impulses which leave the cortex pass out, in healthy animals, from the convolutions about the fissure of Rolando.

When, however, it comes to defining precisely²⁵¹ what is involved in a motor impulse leaving the cortex, things grow more obscure. Does the impulse start independently from the convolutions in question, or does it start elsewhere and merely flow through? And to what particular phase of psychic activity does the activity of these centres correspond? Opinions and authorities here divide; but it will be better, before entering into these deeper aspects of the problem, to cast a glance at the facts which have been made out concerning the relations of the cortex to sight, hearing, and smell.

Sight.

Ferrier was the first in the field here. He found, when the angular convolution (that lying between the 'intra parietal' and 'external occipital' fissures²⁵², and bending round the top of the fissure of Sylvius, in Fig. 6) was excited in the monkey, that movements of the eyes and head as if for vision occurred; and that when it was extirpated²⁵³, what he supposed to be total and permanent blindness of the opposite eye followed. Munk almost immediately declared total and permanent blindness to follow from destruction of the occipital lobe⁴³ in monkeys as well as dogs, and said that the angular gyrus had nothing to do with sight, but was only the centre for tactile sensibility of the eyeball. Munk's absolute tone about his observations and his theoretic arrogance²⁵⁴ have led to his ruin as an authority. But he did two things of permanent value. He was the first to distinguish in these vivisections between sensorial and psychic blindness, and to describe the phenomenon of restitution²⁵⁵ of the visual function after its first impairment by an operation; and the first to notice the hemiopic character of the visual disturbances which result when only one hemisphere is injured. Sensorial blindness is absolute insensibility to light; psychic blindness is inability to recognize the meaning of the optical impressions, as when we see a page of Chinese print but it suggests nothing to us. A hemiopic disturbance of vision is one in which neither retina is affected in its totality, but in which, for example, the left portion of each retina is blind, so that the animal sees nothing situated²⁵⁶ in space towards its right. Later observations have corroborated²⁵⁷ this hemiopic character of all the disturbances of sight from injury to a single hemisphere in the higher animals; and the question whether an animal's apparent blindness is sensorial or only psychic has, since Munk's first publications, been the most urgent one to answer, in all observations relative to the function of sight.

Goltz almost simultaneously with Ferrier and Munk reported experiments which led him to deny that the visual function was essentially²⁵⁸ bound up with any one localized portion of the hemispheres. Other divergent results soon came in from many quarters, so that, without going into the history of the matter any more, I may report the existing state of the case as follows:

In fishes, frogs, and lizards²⁵⁹ vision persists when the hemispheres are entirely removed. This is admitted for frogs and fishes even by Munk, who denies it for birds.

All of Munk's birds seemed totally blind (blind sensorially) after removal of the hemispheres by his operation. The following of a candle by the head and winking²⁶⁰ at a threatened blow, which are ordinarily held to prove the retention²⁶¹ of crude optical sensations by the lower centres in supposed hemisphereless pigeons, are by Munk ascribed to vestiges of the visual sphere of the cortex left behind by the imperfection of the operation. But Schrader, who operated after Munk and with every apparent guarantee of completeness, found that all his pigeons saw after two or three weeks had elapsed, and the inhibitions resulting from the wound had passed away. They invariably avoided even the slightest obstacles, flew very regularly towards certain perches²⁶², etc., differing toto coelo in these respects with certain simply blinded pigeons who were kept with them for comparison. They did not pick up food strewn on the ground, however. Schrader found that they would do this if even a small part of the frontal region of the hemispheres was left, and ascribes their non-self-feeding when deprived of their occipital cerebrum not to a visual, but to a motor, defect, a sort of alimentary²⁶³ aphasia.

In presence of such discord²⁶⁴ as that between Munk and his opponents one must carefully note how differently significant is loss, from preservation, of a function after an operation on the brain. The loss of the function does not necessarily show that it is dependent on the part cut out; but its preservation does show that it is not dependent: and this is true though the loss should be observed ninety-nine times and the preservation only once in a hundred similar excisions. That birds and mammals can be blinded by cortical ablation is undoubted; the only question is, must they be so? Only then can the cortex be certainly called the 'seat of sight.' The blindness may always be due to one of those remote effects of the wound on distant parts, inhibitions, extensions of inflammation,-interferences, in a word,- upon which Brown-Séquard and Goltz have rightly insisted, and the importance of which becomes more manifest every day. Such effects are transient; whereas the symptoms of deprivation²⁶⁵ (Ausfallserscheinungen, as Goltz calls them) which come from the actual loss of the cut-out region must from the nature of the case be permanent. Blindness in the pigeons, so far as it passes away, cannot possibly be charged to their seat of vision being lost, but only to some influence which temporarily depresses the activity of that seat. The same is true mutatis mutandis of all the other effects of operations, and as we pass to mammals we shall see still more the importance of the remark.

In rabbits loss of the entire cortex seems compatible with the preservation of enough sight to guide the poor animals' movements, and enable them to avoid obstacles. Christiani's observations and discussions seem conclusively to have established this, although Munk found that all his animals were made totally blind.

In dogs also Munk found absolute stone-blindness after ablation of the occipital lobes. He went farther and mapped out determinate portions of the cortex thereupon, which he considered correlated with definite segments of the two retinae, so that destruction of given portions of the cortex produces blindness of the retinal centre, top, bottom, or right or left side, of the same or opposite eye. There seems little doubt that this definite correlation¹⁸³ is mythological²⁶⁶. Other observers, Hitzig, Goltz, Luciani, Loeb, Exner, etc., find, whatever part of the cortex may be ablated on one side, that there usually results a hemiopic disturbance of both eyes, slight and transient when the anterior lobes are the parts attacked, grave when an occipital lobe is the seat of injury, and lasting²⁶⁷ in proportion to the latter's extent. According to Loeb, the defect is a dimness of vision ('hemiamblyopia') in which (however severe) the centres remain the best seeing portions of the retina, just as they are in normal dogs. The lateral or temporal part of each retina seems to be in exclusive connection with the cortex of its own side. The centre and nasal part of each seems, on the contrary, to be connected with the cortex of the opposite hemispheres. Loeb, who takes broader views than any one, conceives the hemiamblyopia as he conceives the motor disturbances, namely, as the expression of an increased inertia in the whole optical machinery, of which the result is to make the animal respond with greater effort to impressions coming from the half of space opposed to the side of the lesion. If a dog has right hemiamblyopia, say, and two pieces of meat are hung before him at once, he invariably turns first to the one on his left. But if the lesion be a slight one, shaking slightly the piece of meat on his right (this makes of it a stronger stimulus) makes him seize upon it first. If only one piece of meat be offered, he takes it, on whichever side it be.

When both occipital lobes are extensively destroyed total blindness may result. Munk maps out his 'Seh- sphäre' definitely, and says that blindness must result when the entire shaded part, marked A, A, in Figs. 12 and 13, is involved in the lesion. Discrepant²⁶⁸ reports of other observations he explains as due to incomplete ablation.

Luciani, Goltz, and Lannegrace, however, contend that they have made complete bilateral²³⁸ extirpations of Munk's Sehsphäre more than once, and found a sort of crude indiscriminating sight of objects to return in a few weeks. The question whether a dog is blind or not is harder to solve than would at first appear; for simply blinded dogs, in places to which they are accustomed, show little of their loss and avoid all obstacles; whilst dogs whose occipital lobes are gone may run against things frequently and yet see notwithstanding. The best proof that they may see is that which Goltz's dogs furnished: they carefully avoided, as it seemed, strips of sunshine or paper on the floor, as if they were solid obstacles. This no really blind dog would do. Luciani tested his dogs when hungry (a condition which sharpens their attention) by strewing²⁶⁹ pieces of meat and pieces of cork²⁷⁰ before them. If they went straight at them, they saw; and if they chose the meat and left the cork, they saw discriminatingly. The quarrel is very acrimonious²⁷¹; indeed the subject of localization of functions in the brain seems to have a peculiar effect on the temper of those who cultivate it experimentally. The amount of preserved vision which Goltz and Luciani report seems hardly to be worth considering, on the one hand; and on the other, Munk admits in his penultimate paper that out of 85 dogs he only 'succeeded' 4 times in his operation of producing complete blindness by complete extirpation of his 'Sehsphäre'. The safe conclusion for us is that Luciani's diagram, Fig. 14, represents something like the truth.

The occipital lobes are far more important for vision than any other part of the cortex, so that their complete destruction makes the animal almost blind. As for the crude sensibility to light which may then remain, nothing exact is known either about its nature or its seat.

In the monkey, doctors also disagree. The truth seems, however, to be that the occipital lobes in this animal also are the part connected most intimately with the visual function. The function would seem to go on when very small portions of them are left, for Ferrier found no 'appreciable impairment' of it after almost complete destruction of them on both sides. On the other hand, he found complete and permanent blindness to ensue when they and the angular gyri in addition were destroyed on both sides. Munk, as well as Brown and Schaefer, found no disturbance of sight from destroying the angular gyri alone, although Ferrier found blindness to ensue. This blindness was probably due to inhibitions exerted in distans, or to cutting of the white optical fibres passing under the angular gyri on their way to the occipital lobes. Brown and Schaefer got complete and permanent blindness in one monkey from total destruction of both occipital lobes. Luciani and Seppili, performing this operation on two monkeys, found that the animals were only mentally, not sensorially, blind. After some weeks they saw their food, but could not distinguish by sight between figs and pieces of cork. Luciani and Seppili seem, however, not to have extirpated the entire lobes. When one lobe only is injured the affection of sight is hemiopic in monkeys: in this all observers agree. On the whole, then, Munk's original location of vision in the occipital lobes is confirmed by the later evidence.

In man we have more exact results, since we are not driven to interpret the vision from the outward conduct. On the other hand, however, we cannot vivisect, but must wait for pathological lesions to turn up. The pathologists who have discussed these (the literature is tedious ad libitum) conclude that the occipital lobes are the indispensable part for vision in man. Hemiopic disturbance in both eyes comes from lesion of either one of them, and total blindness, sensorial as well as psychic, from destruction of both.

Hemiopia may also result from lesion in other parts, especially the neighboring angular and supra-marginal gyri, and it may accompany extensive injury in the motor region of the cortex. In these cases it seems probable that it is due to an actio in distans, probably to the interruption of fibres proceeding from the occipital lobe. There seem to be a few cases on record where there was injury to the occipital lobes without visual defect. Ferrier has collected as many as possible to prove his localization in the angular gyrus. A strict application of logical principles would make one of these cases outweigh²⁷² one hundred contrary ones. And yet, remembering how imperfect observations may be, and how individual brains may vary, it would certainly be rash for their sake to throw away the enormous amount of positive evidence for the occipital lobes. Individual variability is always a possible explanation of an anomalous²⁷³ case. There is no more prominent anatomical fact than that of the 'decussation of the pyramids,' nor any more usual pathological fact than its consequence, that left-handed hemorrhages into the motor region produce right-handed paralyses. And yet the decussation is variable in amount, and seems sometimes to be absent altogether. If, in such a case as this last, the left brain were to become the seat of apoplexy, the left and not the right half of the body would be the one to suffer paralysis.

The schema on the opposite page, copied from Dr.Seguin, expresses, on the whole, the probable truth about the regions concerned in vision. Not the entire occipital lobes, but the so-called cunei, and the first convolutions, are the cortical parts most intimately concerned. Nothnagel agrees with Seguin in this limitation of the essential tracts.

A most interesting effect of cortical disorder²⁴⁵ is mental blindness. This consists not so much in insensibility to optical impressions, as in inability to understand them. Psychologically it is interpretable as loss of associations between optical sensations and what they signify; and any interruption of the paths between the optic centres and the centres for other ideas ought to bring it about. Thus, printed letters of the alphabet, or words, signify certain sounds and certain articulatory movements. If the connection between the articulating or auditory centres, on the one hand, and the visual centres on the other, be ruptured²⁷⁴, we ought a priori to expect that the sight of words would fail to awaken the idea of their sound, or the movement for pronouncing them.

We ought, in short, to have alexia, or inability to read: and this is just what we do have in many cases of extensive injury about the fronto-temporal regions, as a complication of aphasic²⁷⁵ disease. Nothnagel suggests that whilst the cuneus is the seat of optical sensations, the other parts of the occipital lobe may be the field of optical memories and ideas, from the loss of which mental blindness should ensue. In fact, all the medical authors speak of mental blindness as if it must consist in the loss of visual images from the memory. It seems to me, however, that this is a psychological misapprehension. A man whose power of visual imagination has decayed (no unusual phenomenon in its lighter²⁷⁶ grades) is not mentally blind in the least, for he recognizes perfectly all that he sees. On the other hand, he may be mentally blind, with his optical imagination well preserved; as in the interesting case publislied by Wilbrand in 1887. In the still more interesting case of mental blindness recently published by Lissauer, though the patient made the most ludicrous mistakes, calling for instance a clothes-brush a pair of spectacles, an umbrella a plant with flowers, an apple a portrait of a lady, etc. etc., he seemed, according to the reporter, to have his mental images fairly well preserved. It is in fact the momentary²⁷⁷ loss of our non-optical images which makes us mentally blind, just as it is that of our non-auditory images which makes us mentally deaf. I am mentally deaf if, hearing a bell, I can't recall how it looks; and mentally blind if, seeing it, I can't recall its sound or its name. As a matter of fact, I should have to be not merely mentally blind, but stone-blind, if all my visual images were lost. For although I am blind to the right half of the field of view if my left occipital region is injured, and to the left half if my right region is injured, such hemianopsia does not deprive me of visual images, experience seeming to show that the unaffected hemisphere is always sufficient for production of these. To abolish them entirely I should have to be deprived of both occipital lobes, and that would deprive me not only of my inward images of sight, but of my sight altogether. Recent pathological annals seem to offer a few such cases. Meanwhile there are a number of cases of mental blindness, especially for written language, coupled with hemianopsia, usually of the rightward field of view. These are all explicable by the breaking down, through disease, of the connecting tracts between the occipital lobes and other parts of the brain, especially those which go to the centres for speech in the frontal and temporal regions of the left hemisphere. They are to be classed among disturbances of conduction or of association; and nowhere can I find any fact which should force us to believe that optical images need be lost in mental blindness, or that the cerebral centres for such images are locally distinct from those for direct sensations from the eyes.

Where an object fails to be recognized by sight, it often happens that the patient will recognize and name it as soon as he touches it with his hand. This shows in an interes- ting way how numerous the associative paths are which all end by running out of the brain through the channel of speech. The hand-path is open, though the eye-path be closed. When mental blindness is most complete, neither sight, touch, nor sound avails to steer²⁷⁸ the patient, and a sort of dementia which has been called asymbolia or apraxia is the result. The commonest articles are not understood. The patient will put his breeches on one shoulder and his hat upon the other, will bite into the soap and lay his shoes on the table, or take his food into his hand and throw it down again, not knowing what to do with it, etc. Such disorder can only come from extensive brain-injury.

The method of degeneration corroborates²⁷⁹ the other evidence localizing the tracts of vision. In young animals one gets secondary degeneration of the occipital regions from destroying an eyeball, and, vice¹⁰ versa, degeneration of the optic nerves from destroying the occipital regions. The corpora geniculata, thalami, and subcortical fibres leading to the occipital lobes are also found atrophied²⁸⁰ in these cases. The phenomena are not uniform, but are indisputable; so that, taking all lines of evidence together, the special connection of vision with the occipital lobes is perfectly made out. It should be added that the occipital lobes have frequently been found shrunken in cases of inveterate blindness in man.

Hearing.

Hearing is hardly as definitely localized as sight. In the dog, Luciani's diagram will show the regions which directly or indirectly²⁸¹ affect it for the worse when injured. As with sight, one-sided lesions produce symptoms on both sides. The mixture of black dots and gray dots in the diagram is meant to represent this mixture of 'crossed' and 'uncrossed' connections, though of course no topographical exactitude is aimed at. Of all the region, the temporal lobe is the most important part; yet permanent absolute deafness did not result in a dog of Luciani's, even from bilateral destruction of both temporal lobes in their entirety.

In the monkey, Ferrier and Yeo once found permanent deafness to follow destruction of the upper temporal convolution (the one just below the fissure of Sylvius in Fig.6) on both sides. Brown and Schaefer found, on the contrary, that in several monkeys this operation failed to noticeably affect the hearing. In one animal, indeed, both entire temporal lobes were destroyed. After a week or two of depression of the mental faculties this beast recovered and became one of the brightest monkeys possible, domineering over all his mates, and admitted by all who saw him to have all his senses, including hearing, 'perfectly acute.' Terrible recriminations have, as usual, ensued between the investigators²⁸³, Ferrier denying that Brown and Schaefer's ablations were complete, Schaefer that Ferrier's monkey was really deaf. In this unsatisfactory condition the subject must be left, although there seems no reason to doubt that Brown and Schaefer's observation is the more important of the two.

In man the temporal lobe is unquestionably, the seat of the hearing function, and the superior convolution adjacent to the sylvian fissure is its most important part. The phenomena of aphasia show this. We studied motor aphasia a few pages back; we must now consider sensory aphasia.

Our knowledge of this disease has had three stages: we may talk of the period of Broca, the period of Wernicke, and the period of Charcot. What Broca's discovery was we have seen. Wernicke was the first to discriminate those cases in which the patient can not even understand speech from those in which he can understand, only not talk; and to ascribe the former condition to lesion of the temporal lobe. The condition in question is word-deafness, and the disease is auditory aphasia. The latest statistical²⁸⁴ survey of the subject is that by Dr. Allen Starr. In the seven cases of pure word-deafness which he has collected, cases in which the patient could read, talk, and write, but not understand what was said to him, the lesion was limited to the first and second temporal convolutions in their posterior two thirds. The lesion (in right-handed, i.e. left-brained, persons) is always on the left side, like the lesion in motor aphasia. Crude hearing would not be abolished, even were the left centre for it utterly²⁸⁵ destroyed; the right centre would still provide for that. But the linguistic²⁸⁶ use of hearing appears bound up with the integrity of the left centre more or less exclusively. Here it must be that words heard enter into association with the things which they represent, on the one hand, and with the movements necessary for pronouncing them, on the other. In a large majority of Dr. Starr's fifty cases, the power either to name objects or to talk coherently was impaired²⁸⁷. This shows that in most of us (as Wernicke said) speech must go on from auditory cues; that is, it must be that our ideas do not innervate our motor centres directly, but only after first arousing the mental sound of the words. This is the immediate stimulus to articulation²⁸⁸; and where the possibility of this is abolished by the destruction of its usual channel in the left temporal lobe, the articulation must suffer. In the few cases in which the channel is abolished with no bad effect on speech we must suppose an idiosyncrasy. The patient must innervate his speech-organs either from the corresponding portion of the other hemisphere or directly from the centres of ideation, those, namely, of vision, touch, etc., without leaning on the auditory region. It is the minuter analysis of the facts in the light of such individual differences as these which constitutes Charcot's contribution towards clearing up the subject.

Every namable thing, act, or relation has numerous properties, qualities, or aspects. In our minds the properties of each thing, together with its name, form an associated group. If different parts of the brain are severally concerned with the several properties, and a farther part with the hearing, and still another with the uttering, of the name, there must inevitably be brought about (through the law of association which we shall later study) such a dynamic connection amongst all these brain-parts that the activity of anyone of them will be likely to awaken the activity of all the rest. When we are talking as we think, the ultimate process is that of utterance²⁸⁹. If the brain-part for that be injured, speech is impossible or disorderly, even though all the other brain-parts be intact: and this is just the condition of things which, on page 37, we found to be brought about by limited lesion of the left inferior frontal convolution. But back of that last act various orders of succession are possible in the associations of a talking man's ideas. The more usual order seems to be from the tactile, visual, or other properties of the things thought-about to the sound of their names, and then to the latter's utterance. But if in a certain individual the thought of the look of an object or of the look of its printed name be the process which habitually precedes articulation, then the loss of the hearing centre will pro¹⁶ tanto not affect that individual's speech. He will be mentally deaf, i.e. his understanding of speech will suffer, but he will not be aphasic. In this way it is possible to explain the seven cases of pure word-deafness which figure in Dr. Starr's table.

If this order of association be ingrained and habitual²⁴² in that individual, injury to his visual centres will make him not only word-blind, but aphasic as well. His speech will become confused in consequence of an occipital lesion. Naunyn, consequently, plotting out on a diagram of the hemisphere the 71 irreproachably²⁹⁰ reported cases of aphasia which he was able to collect, finds that the lesions concentrate themselves in three places: first, on Broca's, centre; second, on Wernicke's; third, on the supra-marginal and angular gyri under which those fibres pass which connect the visual centres with the rest of the brain (see Fig. 17). With this result Dr. Starr's analysis of purely sensory cases agrees.

In a later chapter we shall again return to these differences in the effectiveness of the sensory spheres in different individuals. Meanwhile few things show more beautifully than the history of our knowledge of aphasia how the sagacity and patience of many banded workers are in time certain to analyze²⁹¹ the darkest confusion into an orderly display. There is no 'centre of Speech' in the brain any more than there is a faculty of Speech in the mind. The entire brain, more or less, is at work in a man who uses language. The subjoined diagram, from Ross, shows the four parts most critically concerned, and, in the light of our text, needs no farther explanation (see Fig. 18).

Smell.

Everything conspires²⁹² to point to the median descending part of the temporal lobes as being the organs of smell. Even Ferrier and Munk agree on the hippocampal gyrus, though Ferrier restricts olfaction, as Munk does not to the lobule or uncinate process of the convolution, reserving the rest of it for touch.

Anatomy and pathology also point to the hippocampal gyrus; but as the matter is less interesting from the point of view of human psychology than were sight and hearing, I will say no more, but simply add Luciani and Seppili's diagram of the dog's smell-centre.

Taste

Of we know little that is definite.[sic] What little there is points to the lower temporal regions again. Consult Ferrier as below.

Touch.

Interesting problems arise with regard to the seat of tactile and muscular sensibility. Hitzig, whose experiments on dogs' brains fifteen years ago opened the entire subject which we are discussing, ascribed the disorders of motility observed after ablations of the motor region to a loss of what he called muscular consciousness.

The animals do not notice eccentric positions of their limbs, will stand with their legs crossed, with the affected paw resting on its back or hanging over a table's edge, etc.; and do not resist our bending and stretching of it as they resist with the unaffected paw. Goltz, Munk, Schiff, Herzen, and others promptly ascertained an equal defect of cutaneous sensibility to pain, touch, and cold. The paw is not withdrawn²⁹³ when pinched, remains standing³⁰ in cold water, etc. Ferrier meanwhile denied that there was any true anaesthesia produced by ablations in the motor zone, and explains the appearance of it as an effect of the sluggish²⁹⁴ motor responses of the affected side. Munk and Schiff , on the contrary, conceive of the 'motor zone' as essentially sensory, and in different ways explain the motor disorders as secondary results of the anaesthesia which is always there. Munk calls the motor zone the Fühlsphäre of the animal's limbs, etc., and makes it coördinate with the Sehsphäre, the Hörsphäre, etc., the entire cortex being, according to him, nothing but a projection-surface for sensations, with no exclusively or essentially motor part. Such a view would be important if true, through its bearings on the psychology of volition. What is the truth? As regards the fact of cutaneous anaesthesia from motor-zone ablations, all other observers are against Ferrier, so that he is probably wrong in denying it. On the other hand, Munk and Schiff are wrong in making the motor symptoms depend on the anaesthesia, for in certain rare cases they have been observed to exist not only without insensibility, but with actual hyperaesthesia of the parts. The motor and sensory symptoms seem, therefore, to be independent variables.

In monkeys the latest experiments are those of Horsley and Schaefer, whose results Ferrier accepts. They find that excision²⁰³ of the hippocampal convolution produces transient insensibility of the opposite side of the body, and that permanent insensibility is produced by destruction of its continuation upwards above the corpus callosum, the so-called gyrus fornicatus (the part just below the 'calloso-marginal fissure' in Fig.7). The insensibility is at its maximum when the entire tract¹¹¹ comprising both convolutions is destroyed. Ferrier says that the sensibility of monkeys is 'entirely unaffected' by ablations of the motor zone, and Horsley and Schaefer consider it by no means necessarily abolished. Luciani found it diminished in his three experiments on apes. In man we have the fact that one-sided paralysis from disease of the opposite motor zone may or may not be accompanied with anaesthesia of the parts.

Luciani, who believes that the motor zone is also sensory, tries to minimize the value of this evidence by pointing to the insufficiency with which patients are examined. He himself believes that in dogs the tactile sphere extends backwards and forwards of the directly excitable region, into the frontal and parietal lobes (see Fig. 20). Nothnagel considers that pathological evidence points in the same direction; and Dr. Mills, carefully reviewing the evidence, adds the gyri fornicatus and hippocampi to the cutaneo-muscular region in man. If one compare Luciani's diagrams together (Figs. 14,16, 19, 20) one will see that the entire parietal region of the dog's skull is common to the four senses of sight, hearing, smell, and touch, including muscular feeling. The corresponding region in the human brain (upper parietal and supra-marginal gyri-see Fig. 17, p.56) seems to be a somewhat similar place of conflux. Optical aphasias and motor and tactile disturbances all result from its injury, especially when that is on the left side. The lower we go in the animal scale the less differentiated²⁹⁵ the functions of the several brain-parts seem to be. It may be that the region in question still represents in ourselves something like this primitive²⁹⁶ condition, and that the surrounding parts, in adapting themselves more and more to specialized and narrow functions, have left it as a sort of carrefour through which they send currents and converse¹⁸⁶. That it should be connected with musculo-cutaneous feeling is, however, no reason why the motor zone proper should not be so connected too. And the cases of paralysis from the motor zone with no accompanying anaesthesia may be explicable without denying all sensory function to that region. For, as my colleague Dr.James Putnam informs me, sensibility is always harder to kill than motility, even where we know for a certainty that the lesion affects tracts that are both sensory and motor. Persons whose hand is paralyzed in its movements from compression of arm-nerves during sleep, still feel with their fingers; and they may still feel in their feet when their legs are paralyzed by bruising²⁹⁷ of the spinal cord. In a similar way, the motor cortex might be sensitive as well as motor, and yet by this greater subtlety²⁹⁸ (or whatever the peculiarity²⁹⁹ may be) in the sensory currents, the sensibility might survive an amount of injury there by which the motility was destroyed. Nothnagel considers that there are grounds for supposing the muscular sense to be exclusively connected with the parietal lobe and not with the motor zone. "Disease of this lobe gives pure ataxy without palsy, and of the motor zone pure palsy without loss of muscular sense." He fails, however, to convince more competent critics than the present writer, so I conclude with them that as yet we have no decisive grounds for locating muscular and cutaneous feeling apart. Much still remains to be learned about the relations between musculo-cutaneous sensibility and the cortex, but one thing is certain: that neither the occipital, the forward frontal, nor the temporal lobes seem to have anything essential to do with it in man. It is knit up with the performances of the motor zone and of the convolutions backwards and midwards of them. The reader must remember this conclusion when we come to the chapter on the Will.

I must add a word about the connection of aphasia with the tactile sense. On p.40 I spoke¹⁸⁸ of those cases in which the patient can write but not read his own writing. He cannot read by his eyes; but he can read by the feeling in his fingers, if he retrace³⁰⁰ the letters in the air. It is convenient for such a patient to have a pen in hand whilst reading in this way, in order to make the usual feeling of writing more complete. In such a case we must suppose that the path between the optical and the graphic²⁸² centres remains open, whilst that between the optical and the auditory and articulatory centres is closed. Only thus can we understand how the look of the writing should fail to suggest the sound of the words to the patient's mind, whilst it still suggests the proper movements of graphic imitation. These movements in their turn must of course be felt, and the feeling of them must be associated with the centres for hearing and pronouncing the words. The injury in cases like this where very special combinations fail, whilst others go on as usual, must always be supposed to be of the nature of increased resistance to the passage of certain currents of association. If any of the elements of mental function were destroyed the incapacity would necessarily be much more formidable. A patient who can both read and write with his fingers most likely uses an identical 'graphic' centre, at once sensory and motor, for both operations.

I have now given, as far as the nature of this book will allow, a complete account of the present state of the localization-question. In its main outlines it stands firm, though much has still to be discovered. The anterior frontal lobes, for example, so far as is yet known, have no definite functions. Goltz finds that dogs bereft³⁰¹ of them both are incessantly³⁰² in motion, and excitable by every small stimulus. They are irascible and amative in an extraordinary degree, and their sides grow bare with perpetual reflex scratching; but they show no local troubles of either motion or sensibility. In monkeys not even this lack of inhibitory ability is shown, and neither stimulation nor excision of the prefrontal lobes produces any symptoms whatever. One monkey of Horsley and Schaefer's was as tame, and did certain tricks as well, after as before the operation. It is probable that we have about reached the limits of what can be learned about brain-functions from vivisecting inferior animals, and that we must hereafter look more exclusively to human pathology for light. The existence of separate speech and writing centres in the left hemisphere in man; the fact that palsy from cortical injury is so much more complete and enduring in man and the monkey than in dogs; and the farther fact that it seems more difficult to get complete sensorial blindness from cortical ablations in the lower animals than in man, all show that functions get more specially⁶⁸ localized as evolution goes on. In birds localization seems hardly to exist, and in rodents³⁰³ it is much less conspicuous³⁰⁴ than in carnivora. Even for man, however, Munk's way of mapping out the cortex into absolute areas within which only one movement or sensation is represented is surely false. The truth seems to be rather that, although there is a correspondence of certain regions of the brain to certain regions of the body, yet the several parts within each bodily region are represented throughout the whole of the corresponding brain-region like pepper and salt sprinkled from the same caster. This, however, does not prevent each 'part' from having its focus at one spot within the brain-region. The various brain-regions merge³⁰⁵ into each other in the same mixed way. As Mr.Horsley says: "There are border centres, and the area of representation of the face merges³⁰⁶ into that for the representation of the upper limb. If there was a focal lesion at that point, you would have the movements of these two parts starting together." The accompanying figure from Paneth shows just how the matter stands in the dog.

I am speaking now of localizations breadthwise over the brain-surface. It is conceivable that there might be also localizations depthwise through the cortex. The more superficial cells are smaller, the deepest layer of them is large; and it has been suggested that the superficial cells are sensorial, the deeper ones motor; or that the superficial ones in the motor region are correlated with the extremities³⁰⁷ of the organs to be moved(fingers, etc.), the deeper ones with the more central segments (wrist, elbow, etc.). It need hardly be said that all such theories are as yet but guesses.

We thus see that the postulate of Meynert and Jackson which we started with on p.30 is on the whole most satisfactorily corroborated by subsequent objective research. The highest centres do probably contain nothing but arrangements for representing impressions and movements, and other arrangements for coupling the activity of these arrangements together. Currents pouring in from the sense-organs first excite some arrangements, which in turn excite others, until at last a motor discharge downwards of some sort occurs.

When this is once clearly grasped there remains little ground for keeping up that old controversy about the motor zone, as to whether it is in reality motor or sensitive. The whole cortex, inasmuch as currents run through it, is both. All the currents probably have feelings going with them, and sooner or later bring movements about. In one aspect, then, every centre is afferent, in another efferent, even the motor cells of the spinal cord having these two aspects inseparably conjoined. Marique, and Exner and Paneth have shown that by cutting round a 'motor' centre and so separating it from the influence of the rest of the cortex, the same disorders are produced as by cutting it out, so that really it is only the mouth of the funnel³⁰⁸, as it were, through which the stream of innervation, starting from elsewhere, pours; consciousness accompanying the stream, and being mainly of things seen if the stream is strongest occipitally, of things heard if it is strongest temporally, of things felt, etc., if the stream occupies most intensely the 'motor zone.' It seems to me that some broad and vague formulation like this is as much as we can safely venture on in the present state of science; and in subsequent chapters I expect to give confirmatory reasons for my view.

Man's Consciousness Limited to the Hemispheres

But is the consciousness which accompanies the activity of the cortex the only consciousness that man has? or are his lower centres conscious as well?

This is a difficult question to decide, how difficult one only learns when one discovers that the cortex-consciousness itself of certain objects can be seemingly annihilated³⁰⁹ in any good hypnotic subject by a bare wave of his opera- tor's hand, and yet be proved by circumstantial evidence to exist all the while in a split-off condition, quite as 'ejective' to the rest of the subject's mind as that mind is to the mind of the bystanders. The lower centres themselves may conceivably all the while have a split-off consciousness of their own, similarly ejective to the cortex-consciousness; but whether they have it or not can never be known from merely introspective evidence. Meanwhile the fact that occipital destruction in man may cause a blindness which is apparently absolute (no feeling remaining either of light or dark over one half of the field of view), would lead us to suppose that if our lower optical centres, the corpora quadrigemina, and thalami, do have any consciousness, it is at all events a consciousness which does not mix with that which accompanies the cortical activities, and which has nothing to do with our personal Self. In lower animals this may not be so much the case. The traces of sight found (supra, p. 46) in dogs and monkeys whose occipital lobes were entirely destroyed, may possibly have been due to the fact that the lower centres of these animals saw, and that what they saw was not ejective but objective to the remaining cortex, i.e. it formed part of one and the same inner world with the things which that cortex perceived. It may be, however, that the phenomena were due to the fact that in these animals the cortical 'centres' for vision reach outside of the occipital zone, and that destruction of the latter fails to remove them as completely as in man. This, as we know, is the opinion of the experimenters themselves. For practical purposes, nevertheless, and limiting the meaning of the word consciousness to the personal self of the individual, we can pretty confidently answer the question prefixed to this paragraph by saying that the cortex is the sole organ of consciousness in man. If there be any consciousness pertaining⁶⁹ to the lower centres, it is a consciousness of which the self knows nothing.

The Restitution of Function.

Another problem, not so metaphysical, remains. The most general and striking fact connected with cortical injury is that of the restoration of function. Functions lost at first are after a few days or weeks restored. How are we to understand this restitution?

Two theories are in the field:

1) Restitution is due to the vicarious action either of the rest of the cortex or of centres lower down, acquiring functions which until then they had not performed;

2) It is due to the remaining centres (whether cortical or 'lower') resuming functions which they had always had, but of which the wound had temporarily inhibited³¹⁰ the exercise. This is the view of which Goltz and Brown-Séquard are the most distinguished defenders³¹¹.

Inhibition is a vera causa, of that there can be no doubt. The pneumogastric nerve inhibits³¹² the heart, the splanchnic inhibits the intestinal³¹³ movements, and the superior laryngeal those of inspiration. The nerve-irritations which may inhibit¹⁵⁰ the contraction¹¹⁰ of arterioles are innumerable, and reflex actions are often repressed by the simultaneous excitement of other sensory nerves. For all such facts the reader must consult the treatises³¹⁴ on physiology. What concerns us here is the inhibition exerted by different parts of the nerve-centres, when irritated, on the activity of distant parts. The flaccidity of a frog from 'shock,' for a minute or so after his medulla oblongata is cut, is an inhibition from the seat of injury which quickly passes away.

What is known as 'surgical³¹⁵ shock' (unconsciousness, pallor, dilatation of splanchnic blood-vessels, and general syncope and collapse) in the human subject is an inhibition which lasts a longer time. Goltz, Freusberg, and others, cutting the spinal cord in dogs, proved that there were functions inhibited still longer by the wound, but which reestablished themselves ultimately if the animal was kept alive. The lumbar region of the cord was thus found to contain independent vaso-motor centres, centres for erec- tion, for control of the sphincters, etc., which could be excited to activity by tactile stimuli and as readily reinhibited by others simultaneously applied. We may therefore plausibly³¹⁶ suppose that the rapid reappearance of motility, vision, etc., after their first disappearance³¹⁷ in consequence of a cortical mutilation, is due to the passing off of inhibitions exerted by the irritated surface of the wound. The only question is whether all restorations of function must be explained in this one simple way, or whether some part of them may not be owing to the formation of entirely new paths in the remaining centres, by which they become 'educated' to duties which they did not originally possess. In favor of an indefinite extension of the inhibition theory facts may be cited such as the following: In dogs whose disturbances due to cortical lesion have disappeared, they may in consequence of some inner or outer accident reappear in all their intensity for 24 hours or so and then disappear again. In a dog made half blind by an operation, and then shut up in the dark, vision comes back just as quickly as in other similar dogs whose sight is exercised systematically³¹⁸ every day. A dog which has learned to beg before the operation recommences this practice quite spontaneously a week after a double-sided ablation of the motor zone. Occasionally, in a pigeon (or even, it is said, in a dog) we see the disturbances less marked immediately after the operation than they are half an hour later. This would be impossible were they due to the subtraction³¹⁹ of the organs which normally carried them on. Moreover the entire drift of recent physiological and pathological speculation³²⁰ is towards enthroning inhibition as an ever-present and indispensable condition of orderly activity. We shall see how great is its importance, in the chapter on the Will. Mr. Charles Mercier considers that no muscular contraction, once begun, would ever stop without it, short of exhaustion³²¹ of the system; and Brown-Séquard has for years been accumulating examples to show how far its influence extends. Under these circumstances it seems as if error might more probably lie in cutailing its sphere too much than in stretching it too far as an explanation of the phenomena following cortical lesion.

On the other hand, if we admit no re-education of centres, we not only fly in the face of an a priori probability, but we find ourselves compelled by facts to suppose an almost incredible number of functions natively lodged³²² in the centres below the thalami or even in those below the corpora quadrigemina. I will consider the a priori objection after first taking a look at the facts which I have in mind. They confront us the moment we ask ourselves just which are the parts which perform the functions abolished by an operation after sufficient time has elapsed for restoration to occur?.

The first observers thought that they must be the corresponding parts of the opposite or intact hemisphere. But as long ago as 1875 Carville and Duret tested this by cutting out the fore-leg-centre on one side, in a dog, and then, after waiting till restitution had occurred, cutting it out on the opposite side as well. Goltz and others have done the same thing. If the opposite side were really the seat of the restored function, the original palsy should have appeared again and been permanent. But it did not appear at all; there appeared only a palsy of the hitherto unaffected side. The next supposition is that the parts surrounding the cut-out region learn vicariously to perform its duties. But here, again, experiment seems to upset the hypothesis, so far as the motor zone goes at least; for we may wait till motility has returned in the affected limb, and then both irritate the cortex surrounding the wound without exciting the limb to movement, and ablate it, without bringing back the vanished palsy. It would accordingly seem that the cerebral centres below the cortex must be the seat of the regained³²³ activities. But Goltz destroyed a dog's entire left hemisphere, together with the corpus striatum and the thalamus on that side, and kept him alive until a surprisingly small amount of motor and tactile disturbance remained. These centres cannot here have accounted for the restitution. He has even, as it would appear, ablated both the hemispheres of a dog, and kept him alive 51 days, able to walk and stand. The corpora striata and thalami in this dog were also practically gone. In view of such results we seem driven, with M.Francois-Franck, to fall back on the ganglia lower still, or even on the spinal cord as the 'vicarious' organ of which we are in quest. If the abeyance³²⁴ of function between the operation and the restoration was due exclusively to inhiibition, then we must suppose these lowest centres to be in reality extremely accomplished³²⁵ organs. They must always have done what we now find them doing after function is restored, even when the hemispheres were intact. Of course this is conceivably the case; yet it does not seem very plausible. And the a priori considerations which a moment since I said I should urge, make it less plausible still.

For, in the first place, the brain is essentially a place of currents, which run in organized paths. Loss of function can only mean one of two things, either that a current can no longer run in, or that if it runs in, it can no longer run out, by its old path. Either of these inabilities may come from a local ablation; and 'restitution' can then only mean that, in spite of a temporary block, an inrunning current has at last become enabled to flow out by its old path again-e.g., the sound of 'give your paw' discharges after some weeks into the same canine³²⁶ muscles into which it used to discharge before the operation. As far as the cortex itself goes, since one of the purposes for which it actually exists is the production of new paths, the only question before us is: Is the formation of these particular 'vicarious' paths too much to expect of its plastic powers? It would certainly be too much to expect that a hemisphere should receive currents from optic fibres whose arriving-place within it is destroyed, or that it should discharge into fibres of the pyramidal strand if their place of exit is broken down. Such lesions as these must be irreparable within that hemisphere. Yet even then, through the other hemisphere, the corpus callosum, and the bilateral connections in the spinal cord, one can imagine some road by which the old muscles might eventually be innervated by the same incoming currents which innervated them before the block. And for all minor³²⁷ interruptions, not involving the arriving-place of the 'cortico-petal' or the place of exit of the 'cortico-fugal' fibres, roundabout paths of some sort through the affected hemisphere itself must exist, for every point of it is, remotely at least, in potential communication with every other point. The normal paths are only paths of least resistance. If they get blocked or cut, paths formerly more resistant³²⁸ become the least resistant paths under the changed conditions. It must never be forgotten that a current that runs in has got to run out somewhere; and if it only once succeeds by accident in striking into its old place of exit again, the thrill of satisfaction which the consciousness connected with the whole residual³²⁹ brain then receives will reinforce and fix the paths of that moment and make them more likely to be struck into again. The resultant feeling that the old habitual act is at last successfully back again, becomes itself a new stimulus which stamps all the existing currents in. It is matter of experience that such feelings of successful achievement do tend to fix in our memory whatever processes have led to them; and we shall have a good deal more to say upon the subject when we come to the Chapter on the Will.

My conclusion then is this: that some of the restitution of function (especially where the cortical lesion is not too great) is probably due to genuinely vicarious function on the part of the centres that remain; whilst some of it is due to the passing off of inhibitions. In other words, both the vicarious theory and the inhibition theory are true in their measure. But as for determining that measure, or saying which centres are vicarious, and to what extent they can learn new tricks, that is impossible at present.

Final Correction of the Meynert Scheme.

And now, after learning all these facts, what are we to think of the child and the candle-flame, and of that scheme which provisionally imposed itself on our acceptance after surveying the actions of the frog? (Cf. pp. 25-6, supra.) It will be remembered that we then considered the lower centres en masse as machines for responding to present sense-impressions exclusively, and the hemispheres as equally exclusive organs of action from inward considerations or ideas; and that, following Meynert, we supposed the hemispheres to have no native tendencies to determinate activity, but to be merely superadded organs for breaking up the various reflexes performed by the lower centres, and combining their motor and sensory elements in novel ways. It will also be remembered that I prophesied³³⁰ that we should be obliged to soften⁴⁴ down the sharpness of this distinction after we had completed our survey of the farther facts. The time has now come for that correction to be made.

Wider and completer observations show us both that the lower centres are more spontaneous, and that the hemispheres are more automatic, than the Meynert scheme allows. Schrader's observations in Goltz's Laboratory on hemisphereless frogs and pigeons give an idea quite different from the picture of these creatures which is classically current. Steiner's observations on frogs already went a good way in the same direction, showing, for example, that locomotion is a well-developed function of the medulla oblongata. But Schrader, by great care in the operation, and by keeping the frogs a long time alive, found that at least in some of them the spinal cord would produce movements of locomotion when the frog was smartly roused by a poke¹⁸⁹, and that swimming and croaking could sometimes be performed when nothing above the medulla oblongata remained. Schrader's hemisphereless frogs moved spontaneously, ate flies, buried themselves in the ground, and in short did many things which before his observations were supposed to be impossible unless the hemispheres remained. Steinert and Vulpian have remarked an even greater vivacity³³¹ in fishes deprived of their hemispheres. Vulpian says of his brainless carps that three days after the operation one of them darted³³² at food and at a knot tied on the end of a string, holding the latter so tight between his jaws³³³ that his head was drawn out of water. Later, "they see morsels³³⁴ of white of egg; the moment these sink through the water in front of them, they follow and seize them, sometimes after they are on the bottom, sometimes before they have reached it. In capturing and swallowing this food they execute just the same movements as the intact carps which are in the same aquarium³³⁵. The only difference is that they seem to see them at less distance, seek them with less impetuosity and less perseverance³³⁶ in all the points of the bottom of the aquarium, but they struggle (so to speak) sometimes with the sound carps to grasp the morsels. It is certain that they do not confound these bits of white of egg with other white bodies, small pebbles³³⁷ for example, which are at the bottom of the water. The same carp which, three days after operation, seized the knot on a piece of string, no longer snaps at it now, but if one brings it near her, she draws away from it by swimming backwards before it comes into contact with her mouth." Already on pp.9-10,as the reader may remember, we instanced those adaptations of conduct to new conditions, on the part of the frog's spinal cord and thalami, which led Pfüger and Lewes on the one hand and Goltz on the other to locate in these organs an intelligence akin⁴⁸ to that of which the hemispheres are the seat.

When it comes to birds deprived of their hemispheres, the evidence that some of their acts have conscious purpose behind them is quite as persuasive³³⁸. In pigeons Schrader found that the state of somnolence³³⁹ lasted only three or four days, after which time the birds began indefatigably³⁴⁰ to walk about the room. They climbed out of boxes in which they were put, jumped over or flew up upon obstacles, and their sight was so perfect that neither in walking nor flying did they ever strike any object in the room. They had also definite ends or purposes, flying straight for more convenient perching places when made uncomfortable by movements imparted to those on which they stood; and of several possible perches they always chose the most convenient. "If we give the dove the choice of a horizontal bar (Reck) or an equally distant table to fly to, she always gives decided³⁴¹ preference to the table. Indeed she chooses the table even if it is several meters farther off than the bar or the chair." Placed on the back of a chair, she flies first to the seat and then to the floor, and in general,"will forsake³⁴² a high position, although it give her sufficiently³⁴³ firm support, and in order to reach the ground will make use of the environing objects as intermediate goals of flight, showing a perfectly correct judgment of their distance. Although able to fly directly to the ground, she prefers to make the journey in successive stages. . . . Once on the ground, she hardly ever rises spontaneously into the air."

Young rabbits deprived of their hemispheres will stand, run, start at noises, avoid obstacles in their path, and give responsive cries of suffering when hurt. Rats will do the same, and throw themselves moreover into an attitude of defence. Dogs never survive such an operation if performed at once. But Goltz's latest dog, mentioned on p. 70, which is said to have been kept alive for fifty-one days after both hemispheres had been removed by a series of ablations and the corpora striata and thalami had softened away, shows how much the mid-brain centres and the cord can do even in the canine species. Taken together, the number of reactions shown to exist in the lower centres by these observations make out a pretty good case for the Meynert scheme, as applied to these lower animals. That scheme demands hemispheres which shall be mere supplements or organs of repetition, and in the light of these observations they obviously are so to a great extent. But the Meynert scheme also demands that the reactions of the lower centres shall all be native, and we are not absolutely sure that some of those which we have been considering may not have been acquired after the injury; and it furthermore demands that they should be machine-like, whereas the expression of some of them makes us doubt whether they may not be guided by an intelligence of low degree.

Even in the lower animals, then, there is reason to soften down that opposition³⁴⁴ between the hemispheres and the lower centres which the scheme demands. The hemispheres may, it is true, only supplement the lower centres, but the latter resemble the former in nature and have some small amount at least of 'spontaneity' and choice.

But when we come to monkeys and man the scheme well-nigh breaks down altogether; for we find that the hemispheres do not simply repeat voluntarily actions which the lower centres perform as machines. There are many functions which the lower centres cannot by themselves perform at all. When the motor cortex is injured in a man or a monkey genuine paralysis ensues, which in man is incurable³⁴⁵, and almost or quite equally so in the ape. Dr. Seguin knew a man with hemi-blindness, from cortical injury, which had persisted unaltered for twenty-three years. 'Traumatic inhibition' cannot possibly account for this. The blindness must have been an 'Ausfallserscheinung,' due to the loss of vision's essential organ. It would seem, then, that in these higher creatures the lower centres must be less adequate than they are farther down in the zoological scale; and that even for certain elementary combinations of movement and impression the co-operation of the hemispheres is necessary from the start. Even in birds and dogs the power of eating properly is lost when the frontal lobes are cut off.

The plain truth is that neither in man nor beast are the hemispheres the virgin³⁴⁶ organs which our scheme called them. So far from being unorganized at birth, they must have native tendencies to reaction of a determinate sort. These are the tendencies which we know as emotions and instincts, and which we must study with some detail in later chapters of this book. Both instincts and emotions are reactions upon special sorts of objects of perception; they depend on the hemispheres; and they are in the first instance reflex, that is, they take place the first time the exciting object is met, are accompanied by no forethought or deliberation, and are irresistible³⁴⁷. But they are modifiable to a certain extent by experience, and on later occasions of meeting the exciting object, the instincts expecially have less of the blind impulsive³⁴⁸ character which they had at first. All this will be explained at some length in Chapter XXIV. Meanwhile we can say that the multiplicity of emotional and instincitive reactions in man, together with his extensive associative power, permit of extensive recouplings of the original sensory and motor partners. The consequences of one instinctive reaction often prove to be the inciters of an opposite reaction, and being suggested on later occasions by the original object, may then suppress the first reaction altogether, just as in the case of the child and the flame. For this education the hemispheres do not need to be tabuloe rasoe at first, as the Meynert scheme would have them; and so far from their being educated by the lower centres exclusively, they educate themselves.

We have already noticed the absence of reactions from fear and hunger in the ordinary brainless frog. Schrader gives a striking account of the instinctless condition of his brainless pigeons, active as they were in the way of locomotion and voice. "The hemisphereless animal moves in a world of bodies which . . . are all of equal value for him. . . . He is, to use Goltz's apt expression, impersonal³⁴⁹. . . . Every object is for him only a space-occupying mass, he turns out of his path for an ordinary pigeon no otherwise than for a stone. He may try to climb over both. All authors agree that they never found any difference, whether it was an inanimate body, a cat, a dog, or a bird of prey which came in their pigeon's way. The creature knows neither friends nor enemies, in the thickest company it lives like a hermit³⁵⁰. The languishing³⁵¹ cooing of the male awakens no more impression than the rattling³⁵² of the peas, or the call-whistle which in the days before the injury used to make the birds hasten to be fed. Quite as little as the earlier observers have I seen hemisphereless she-birds answer the courting of the male. A hemisphereless male will coo all day long and show distinct signs of sexual excitement, but his activity is without any object, it is entirely indifferent to him whether the she-bird be there or not. If one is placed near him, he leaves her unnoticed. . . . As the male pays no attention to the female, so she pays none to her young. The brood may follow the mother ceaselessly calling for food, but they might as well ask it from a stone. . . . The hemi sphereless pigeon is in the highest degree tame, and fears man as little as cat or bird of prey."

Putting together now all the facts and reflections which we have been through, it seems to me that we can no longer hold strictly³⁵³ to the Meynert scheme. If anywhere, it will apply to the lowest animals; but in them especially the lower centres seem to have a degree of spontaneity and choice. On the whole, I think that we are driven to substitute for it some such general conception as the following, which allows for zoological differences as we know them, and is vague and elastic³⁵⁴ enough to receive any number of future discoveries of detail.

Conclusion.

All the centres, in all animals, whilst they are in one aspect mechanisms, probably are, or at least once were, organs of consciousness in another, although the consciousness is doubtless much more developed in the hemispheres than it is anywhere else. The consciousness must everywhere prefer some of the sensations which it gets to others; and if it can remember these in their absence, however dimly, they must be its ends of desire. If, moreover, it can identify in memory any motor discharges which may have led to such ends, and associate the latter with them, then these motor discharges themselves may in turn become desired as means. This is the development of will; and its realization³⁵⁵ must of course be proportional to the possible complication of the consciousness. Even the spinal cord may possibly have some little power of will in this sense, and of effort towards modified behavior in consequence of new experiences of sensibility.

All nervous centres have then in the first instance one essential function, that of 'intelligent' action. They feel, prefer one thing to another, and have 'ends.' Like all other organs, however, they evolve from ancestor to descendant, and their evolution takes two directions the lower centres passing downwards into more unhesitating automatism, and the higher ones upwards into larger intellectuality. Thus it may happen that those functions which can safely grow uniform and fatal become least accompanied by mind, and that their organ, the spinal cord, becomes a more and more soulless machine; whilst on the contrary those functions which it benefits the animal to have adapted to delicate environing variations pass more and more to the hemispheres, whose anatomical structure and attendant consciousness grow more and more elaborate as zoological evolution proceeds. In this way it might come about that in man and the monkeys the basal ganglia should do fewer things by themselves than they can do in dogs, fewer in dogs than in rabbits, fewer in rabbits than in hawks³⁵⁶, fewer in hawks than in pigeons, fewer in pigeons than in frogs, fewer in frogs than in fishes, and that the hemispheres should correspondingly do more. This passage of functions forward to the ever-enlarging hemispheres would be itself one of the evolutive changes, to be explained like the development of the hemispheres themselves, either by fortunate variation or by inherited effects of use. The reflexes, on this view, upon which the education of our human hemispheres depends, would not be due to the basal ganglia alone. They would be tendencies in the hemispheres themselves, modifiable by education, unlike the reflexes of the medulla oblongata, pons, optic lobes and spinal cord. Such cerebral reflexes, if they exist, form a basis quite as good as that which the Meynert scheme offers, for the acquisition of memories and associations which may later result in all sorts of 'changes of partners' in the psychic world. The diagram of the baby and the candle (see page 25) can be re-edited, if need be, as an entirely cortical transaction. The original tendency to touch will be a cortical instinct; the burn will leave an image in another part of the cortex, which, being recalled by association, will inhibit the touching³⁵⁷ tendency the next time the candle is perceived, and excite the tendency to withdraw-so that the retinal picture will, upon that next time, be coupled with the original motor partner of the pain. We thus get whatever psychological truth the Meynert scheme possesses without entangling³⁵⁸ ourselves on a dubious³⁵⁹ anatomy and physiology.

Some such shadowy view of the evolution of the centres, of the relation of consciousness to them, and of the hemispheres to the, other lobes, is, it seems to me, that in which it is safest to indulge. If it has no other advantage, it at any rate makes us realize how enormous are the gaps in our knowledge, the moment we try to cover the facts by any one formula of a general kind.

1 murmur   

n.低语，低声的怨言；v.低语，低声而言

参考例句：

• They paid the extra taxes without a murmur.他们毫无怨言地交了附加税。
• There was a low murmur of conversation in the hall.大厅里有窃窃私语声。

2 fully   

adv.完全地，全部地，彻底地；充分地

参考例句：

• The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气，然后全部呼出。
• They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。

3 aggression   

n.进攻，侵略，侵犯，侵害

参考例句：

• So long as we are firmly united, we need fear no aggression.只要我们紧密地团结，就不必惧怕外来侵略。
• Her view is that aggression is part of human nature.她认为攻击性是人类本性的一部份。

4 harmonious   

adj.和睦的，调和的，和谐的，协调的

参考例句：

• Their harmonious relationship resulted in part from their similar goals.他们关系融洽的部分原因是他们有着相似的目标。
• The room was painted in harmonious colors.房间油漆得色彩调和。

5 axe   

n.斧子；v.用斧头砍，削减

参考例句：

• Be careful with that sharp axe.那把斧子很锋利，你要当心。
• The edge of this axe has turned.这把斧子卷了刃了。

6 commotion   

n.骚动，动乱

参考例句：

• They made a commotion by yelling at each other in the theatre.他们在剧院里相互争吵，引起了一阵骚乱。
• Suddenly the whole street was in commotion.突然间，整条街道变得一片混乱。

7 glands   

n.腺( gland的名词复数 )

参考例句：

• a snake's poison glands 蛇的毒腺
• the sebaceous glands in the skin 皮脂腺

8 secretion   

n.分泌

参考例句：

• Is there much secretion from your eyes?你眼里的分泌物多吗？
• In addition,excessive secretion of oil,water scarcity are also major factors.除此之外，油脂分泌过盛、缺水也都是主要因素。

9 applied   

adj.应用的；v.应用，适用

参考例句：

• She plans to take a course in applied linguistics.她打算学习应用语言学课程。
• This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。

10 vice   

n.坏事；恶习；[pl.]台钳，老虎钳；adj.副的

参考例句：

• He guarded himself against vice.他避免染上坏习惯。
• They are sunk in the depth of vice.他们堕入了罪恶的深渊。

11 ward   

n.守卫，监护，病房，行政区，由监护人或法院保护的人（尤指儿童）；vt.守护，躲开

参考例句：

• The hospital has a medical ward and a surgical ward.这家医院有内科病房和外科病房。
• During the evening picnic,I'll carry a torch to ward off the bugs.傍晚野餐时，我要点根火把，抵挡蚊虫。

12 noxious   

adj.有害的，有毒的；使道德败坏的，讨厌的

参考例句：

• Heavy industry pollutes our rivers with noxious chemicals.重工业产生的有毒化学品会污染我们的河流。
• Many household products give off noxious fumes.很多家用产品散发有害气体。

13 stimulus   

n.刺激，刺激物，促进因素，引起兴奋的事物

参考例句：

• Regard each failure as a stimulus to further efforts.把每次失利看成对进一步努力的激励。
• Light is a stimulus to growth in plants.光是促进植物生长的一个因素。

14 perils   

极大危险( peril的名词复数 )； 危险的事（或环境）

参考例句：

• The commander bade his men be undaunted in the face of perils. 指挥员命令他的战士要临危不惧。
• With how many more perils and disasters would he load himself? 他还要再冒多少风险和遭受多少灾难？

15 depot   

n.仓库，储藏处；公共汽车站；火车站

参考例句：

• The depot is only a few blocks from here.公共汽车站离这儿只有几个街区。
• They leased the building as a depot.他们租用这栋大楼作仓库。

16 pro   

n.赞成，赞成的意见，赞成者

参考例句：

• The two debating teams argued the question pro and con.辩论的两组从赞成与反对两方面辩这一问题。
• Are you pro or con nuclear disarmament?你是赞成还是反对核裁军？

17 cinder   

n.余烬，矿渣

参考例句：

• The new technology for the preparation of superfine ferric oxide from pyrite cinder is studied.研究了用硫铁矿烧渣为原料，制取超细氧化铁红的新工艺。
• The cinder contains useful iron,down from producing sulphuric acid by contact process.接触法制硫酸的矿渣中含有铁矿。

18 copious   

adj.丰富的，大量的

参考例句：

• She supports her theory with copious evidences.她以大量的例证来充实自己的理论。
• Every star is a copious source of neutrinos.每颗恒星都是丰富的中微子源。

19 sensational   

adj.使人感动的，非常好的，轰动的，耸人听闻的

参考例句：

• Papers of this kind are full of sensational news reports.这类报纸满是耸人听闻的新闻报道。
• Their performance was sensational.他们的演出妙极了。

20 disturbance   

n.动乱，骚动；打扰，干扰；(身心)失调

参考例句：

• He is suffering an emotional disturbance.他的情绪受到了困扰。
• You can work in here without any disturbance.在这儿你可不受任何干扰地工作。

21 deliberately   

adv.审慎地；蓄意地；故意地

参考例句：

• The girl gave the show away deliberately.女孩故意泄露秘密。
• They deliberately shifted off the argument.他们故意回避这个论点。

22 instinctive   

adj.(出于)本能的；直觉的；(出于)天性的

参考例句：

• He tried to conceal his instinctive revulsion at the idea.他试图饰盖自己对这一想法本能的厌恶。
• Animals have an instinctive fear of fire.动物本能地怕火。

23 skilfully   

adv. (美skillfully)熟练地

参考例句：

• Hall skilfully weaves the historical research into a gripping narrative. 霍尔巧妙地把历史研究揉进了扣人心弦的故事叙述。
• Enthusiasm alone won't do. You've got to work skilfully. 不能光靠傻劲儿，得找窍门。

24 volition   

n.意志；决意

参考例句：

• We like to think that everything we do and everything we think is a product of our volition.我们常常认为我们所做和所想的一切都出自自己的意愿。
• Makin said Mr Coombes had gone to the police of his own volition.梅金说库姆斯先生是主动去投案的。

25 purely   

adv.纯粹地，完全地

参考例句：

• I helped him purely and simply out of friendship.我帮他纯粹是出于友情。
• This disproves the theory that children are purely imitative.这证明认为儿童只会单纯地模仿的理论是站不住脚的。

26 attained   

（通常经过努力）实现( attain的过去式和过去分词 )； 达到； 获得； 达到（某年龄、水平、状况）

参考例句：

• She has attained the degree of Master of Arts. 她已获得文学硕士学位。
• Lu Hsun attained a high position in the republic of letters. 鲁迅在文坛上获得崇高的地位。

27 mandate   

n.托管地；命令，指示

参考例句：

• The President had a clear mandate to end the war.总统得到明确的授权结束那场战争。
• The General Election gave him no such mandate.大选并未授予他这种权力。

28 discriminate   

v.区别，辨别，区分；有区别地对待

参考例句：

• You must learn to discriminate between facts and opinions.你必须学会把事实和看法区分出来。
• They can discriminate hundreds of colours.他们能分辨上百种颜色。

29 attainment   

n.达到，到达；［常pl.］成就，造诣

参考例句：

• We congratulated her upon her attainment to so great an age.我们祝贺她高寿。
• The attainment of the success is not easy.成功的取得并不容易。

30 standing   

n.持续，地位；adj.永久的，不动的，直立的，不流动的

参考例句：

• After the earthquake only a few houses were left standing.地震过后只有几幢房屋还立着。
• They're standing out against any change in the law.他们坚决反对对法律做任何修改。

31 apparently   

adv.显然地；表面上，似乎

参考例句：

• An apparently blind alley leads suddenly into an open space.山穷水尽，豁然开朗。
• He was apparently much surprised at the news.他对那个消息显然感到十分惊异。

32 physiological   

adj.生理学的，生理学上的

参考例句：

• He bought a physiological book.他买了一本生理学方面的书。
• Every individual has a physiological requirement for each nutrient.每个人对每种营养成分都有一种生理上的需要。

33 mechanism   

n.机械装置；机构，结构

参考例句：

• The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。
• The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。

34 controversy   

n.争论，辩论，争吵

参考例句：

• That is a fact beyond controversy.那是一个无可争论的事实。
• We ran the risk of becoming the butt of every controversy.我们要冒使自己在所有的纷争中都成为众矢之的的风险。

35 anatomy   

n.解剖学，解剖；功能，结构，组织

参考例句：

• He found out a great deal about the anatomy of animals.在动物解剖学方面，他有过许多发现。
• The hurricane's anatomy was powerful and complex.对飓风的剖析是一项庞大而复杂的工作。

36 detailed   

adj.详细的，详尽的，极注意细节的，完全的

参考例句：

• He had made a detailed study of the terrain.他对地形作了缜密的研究。
• A detailed list of our publications is available on request.我们的出版物有一份详细的目录备索。

37 physiology   

n.生理学，生理机能

参考例句：

• He bought a book about physiology.他买了一本生理学方面的书。
• He was awarded the Nobel Prize for achievements in physiology.他因生理学方面的建树而被授予诺贝尔奖。

38 plausible   

adj.似真实的，似乎有理的，似乎可信的

参考例句：

• His story sounded plausible.他说的那番话似乎是真实的。
• Her story sounded perfectly plausible.她的说辞听起来言之有理。

39 cerebral   

adj.脑的，大脑的；有智力的，理智型的

参考例句：

• Your left cerebral hemisphere controls the right-hand side of your body.你的左半脑控制身体的右半身。
• He is a precise,methodical,cerebral man who carefully chooses his words.他是一个一丝不苟、有条理和理智的人，措辞谨慎。

40 fig   

n.无花果(树)

参考例句：

• The doctor finished the fig he had been eating and selected another.这位医生吃完了嘴里的无花果，又挑了一个。
• You can't find a person who doesn't know fig in the United States.你找不到任何一个在美国的人不知道无花果的。

41 anterior   

adj.较早的；在前的

参考例句：

• We've already finished the work anterior to the schedule.我们已经提前完成了工作。
• The anterior part of a fish contains the head and gills.鱼的前部包括头和鳃。

42 lobes   

n.耳垂( lobe的名词复数 )；（器官的）叶；肺叶；脑叶

参考例句：

• The rotor has recesses in its three faces between the lobes. 转子在其凸角之间的三个面上有凹槽。 来自辞典例句
• The chalazal parts of the endosperm containing free nuclei forms several lobes. 包含游离核的合点端胚乳部分形成几个裂片。 来自辞典例句

43 lobe   

n.耳垂，（肺，肝等的）叶

参考例句：

• Tiny electrical sensors are placed on your scalp and on each ear lobe.小电器传感器放置在您的头皮和对每个耳垂。
• The frontal lobe of the brain is responsible for controlling movement.大脑前叶的功能是控制行动。

44 soften   

v.(使)变柔软；(使)变柔和

参考例句：

• Plastics will soften when exposed to heat.塑料适当加热就可以软化。
• This special cream will help to soften up our skin.这种特殊的护肤霜有助于使皮肤变得柔软。

45 softened   

（使）变软( soften的过去式和过去分词 )； 缓解打击； 缓和； 安慰

参考例句：

• His smile softened slightly. 他的微笑稍柔和了些。
• The ice cream softened and began to melt. 冰淇淋开始变软并开始融化。

46 experimentation   

n.实验，试验，实验法

参考例句：

• Many people object to experimentation on animals.许多人反对用动物做实验。
• Study and analysis are likely to be far cheaper than experimentation.研究和分析的费用可能要比实验少得多。

47 spinal   

adj.针的，尖刺的，尖刺状突起的；adj.脊骨的，脊髓的

参考例句：

• After three days in Japan,the spinal column becomes extraordinarily flexible.在日本三天，就已经使脊椎骨变得富有弹性了。
• Your spinal column is made up of 24 movable vertebrae.你的脊柱由24个活动的脊椎骨构成。

48 akin   

adj.同族的，类似的

参考例句：

• She painted flowers and birds pictures akin to those of earlier feminine painters.她画一些同早期女画家类似的花鸟画。
• Listening to his life story is akin to reading a good adventure novel.听他的人生故事犹如阅读一本精彩的冒险小说。

49 hind   

adj.后面的，后部的

参考例句：

• The animal is able to stand up on its hind limbs.这种动物能够用后肢站立。
• Don't hind her in her studies.不要在学业上扯她后腿。

50 skull   

n.头骨；颅骨

参考例句：

• The skull bones fuse between the ages of fifteen and twenty-five.头骨在15至25岁之间长合。
• He fell out of the window and cracked his skull.他从窗子摔了出去，跌裂了颅骨。

51 thereby   

adv.因此，从而

参考例句：

• I have never been to that city,,ereby I don't know much about it.我从未去过那座城市，因此对它不怎么熟悉。
• He became a British citizen,thereby gaining the right to vote.他成了英国公民，因而得到了投票权。

52 peculiar   

adj.古怪的，异常的；特殊的，特有的

参考例句：

• He walks in a peculiar fashion.他走路的样子很奇特。
• He looked at me with a very peculiar expression.他用一种很奇怪的表情看着我。

53 belly   

n.肚子，腹部；(像肚子一样)鼓起的部分，膛

参考例句：

• The boss has a large belly.老板大腹便便。
• His eyes are bigger than his belly.他眼馋肚饱。

54 fore   

adv.在前面；adj.先前的；在前部的；n.前部

参考例句：

• Your seat is in the fore part of the aircraft.你的座位在飞机的前部。
• I have the gift of fore knowledge.我能够未卜先知。

55 immediate   

adj.立即的；直接的，最接近的；紧靠的

参考例句：

• His immediate neighbours felt it their duty to call.他的近邻认为他们有责任去拜访。
• We declared ourselves for the immediate convocation of the meeting.我们主张立即召开这个会议。

56 drawn   

v.拖，拉，拔出；adj.憔悴的，紧张的

参考例句：

• All the characters in the story are drawn from life.故事中的所有人物都取材于生活。
• Her gaze was drawn irresistibly to the scene outside.她的目光禁不住被外面的风景所吸引。

57 locomotion   

n.运动，移动

参考例句：

• By land,air or sea,birds are masters of locomotion.无论是通过陆地，飞越空中还是穿过海洋，鸟应算是运动能手了。
• Food sources also elicit oriented locomotion and recognition behavior patterns in most insects.食物源也引诱大多数昆虫定向迁移和识别行为。

58 entirely   

ad.全部地，完整地；完全地，彻底地

参考例句：

• The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
• His life was entirely given up to the educational work. 他的一生统统献给了教育工作。

59 remarkable   

adj.显著的，异常的，非凡的，值得注意的

参考例句：

• She has made remarkable headway in her writing skills.她在写作技巧方面有了长足进步。
• These cars are remarkable for the quietness of their engines.这些汽车因发动机没有噪音而不同凡响。

60 defensive   

adj.防御的；防卫的；防守的

参考例句：

• Their questions about the money put her on the defensive.他们问到钱的问题，使她警觉起来。
• The Government hastily organized defensive measures against the raids.政府急忙布置了防卫措施抵御空袭。

61 stump   

n.残株，烟蒂，讲演台；v.砍断，蹒跚而走

参考例句：

• He went on the stump in his home state.他到故乡所在的州去发表演说。
• He used the stump as a table.他把树桩用作桌子。

62 teleological   

adj.目的论的

参考例句：

• Teleological method of interpretation is a very important legal science method. 而作为法学方法的目的解释亦是一种十分重要的法学方法。 来自互联网
• Can evolution evolve its own teleological purpose? 进化能进化自己的目的吗？ 来自互联网

63 irritation   

n.激怒，恼怒，生气

参考例句：

• He could not hide his irritation that he had not been invited.他无法掩饰因未被邀请而生的气恼。
• Barbicane said nothing,but his silence covered serious irritation.巴比康什么也不说，但是他的沉默里潜伏着阴郁的怒火。

64 regularity   

n.规律性，规则性；匀称，整齐

参考例句：

• The idea is to maintain the regularity of the heartbeat.问题就是要维持心跳的规律性。
• He exercised with a regularity that amazed us.他锻炼的规律程度令我们非常惊讶。

65 twitch   

v.急拉，抽动，痉挛，抽搐；n.扯，阵痛，痉挛

参考例句：

• The smell made my dog's nose twitch.那股气味使我的狗的鼻子抽动着。
• I felt a twitch at my sleeve.我觉得有人扯了一下我的袖子。

66 irritations   

n.激怒( irritation的名词复数 )；恼怒；生气；令人恼火的事

参考例句：

• For a time I have forgotten the worries and irritations I was nurturing before. 我暂时忘掉了过去积聚的忧愁和烦躁。 来自辞典例句
• Understanding God's big picture can turn irritations into inspirations. 明了神的蓝图，将使你的烦躁转为灵感。 来自互联网

67 mechanisms   

n.机械( mechanism的名词复数 )；机械装置；[生物学] 机制；机械作用

参考例句：

• The research will provide direct insight into molecular mechanisms. 这项研究将使人能够直接地了解分子的机理。 来自《简明英汉词典》
• He explained how the two mechanisms worked. 他解释这两台机械装置是如何工作的。 来自《简明英汉词典》

68 specially   

adv.特定地；特殊地；明确地

参考例句：

• They are specially packaged so that they stack easily.它们经过特别包装以便于堆放。
• The machine was designed specially for demolishing old buildings.这种机器是专为拆毁旧楼房而设计的。

69 pertaining   

与…有关系的，附属…的，为…固有的(to)

参考例句：

• Living conditions are vastly different from those pertaining in their country of origin. 生活条件与他们祖国大不相同。
• The inspector was interested in everything pertaining to the school. 视察员对有关学校的一切都感兴趣。

70 actively   

adv.积极地，勤奋地

参考例句：

• During this period all the students were actively participating.在这节课中所有的学生都积极参加。
• We are actively intervening to settle a quarrel.我们正在积极调解争执。

71 analogous   

adj.相似的；类似的

参考例句：

• The two situations are roughly analogous.两种情況大致相似。
• The company is in a position closely analogous to that of its main rival.该公司与主要竞争对手的处境极为相似。

72 tickled   

（使）发痒( tickle的过去式和过去分词 )； （使）愉快，逗乐

参考例句：

• We were tickled pink to see our friends on television. 在电视中看到我们的一些朋友，我们高兴极了。
• I tickled the baby's feet and made her laugh. 我胳肢孩子的脚，使她发笑。

73 robin   

n.知更鸟，红襟鸟

参考例句：

• The robin is the messenger of spring.知更鸟是报春的使者。
• We knew spring was coming as we had seen a robin.我们看见了一只知更鸟，知道春天要到了。

74 tickling   

反馈，回授，自旋挠痒法

参考例句：

• Was It'spring tickling her senses? 是不是春意撩人呢？
• Its origin is in tickling and rough-and-tumble play, he says. 他说，笑的起源来自于挠痒痒以及杂乱无章的游戏。

75 previously   

adv.以前，先前（地）

参考例句：

• The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
• Let me digress for a moment and explain what had happened previously.让我岔开一会儿，解释原先发生了什么。

76 rotation   

n.旋转；循环，轮流

参考例句：

• Crop rotation helps prevent soil erosion.农作物轮作有助于防止水土流失。
• The workers in this workshop do day and night shifts in weekly rotation.这个车间的工人上白班和上夜班每周轮换一次。

77 tilted   

v. 倾斜的

参考例句：

• Suddenly the boat tilted to one side. 小船突然倾向一侧。
• She tilted her chin at him defiantly. 她向他翘起下巴表示挑衅。

78 downwards   

adj./adv.向下的（地），下行的（地）

参考例句：

• He lay face downwards on his bed.他脸向下伏在床上。
• As the river flows downwards,it widens.这条河愈到下游愈宽。

79 pointed   

adj.尖的，直截了当的

参考例句：

• He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
• She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。

80 upwards   

adv.向上，在更高处...以上

参考例句：

• The trend of prices is still upwards.物价的趋向是仍在上涨。
• The smoke rose straight upwards.烟一直向上升。

81 croaks   

v.呱呱地叫( croak的第三人称单数 )；用粗的声音说

参考例句：

• A burst of noisy croaks came from the pond. 从池塘里传来了一阵喧噪的蛙鸣。 来自互联网
• The noise in the zoo turned out to be the croaks of bullfrogs. 动物园里喧噪得很，原来是一群牛蛙在叫。 来自互联网

82 compensates   

补偿，报酬( compensate的第三人称单数 )； 给（某人）赔偿（或赔款）

参考例句：

• The company compensates her for extra work. 公司因她的额外工作而给她报酬。
• A vertical spring compensates for the weight of the sensing element. 用一根垂直弹簧补偿敏感元件的负荷。

83 rotations   

旋转( rotation的名词复数 )； 转动； 轮流； 轮换

参考例句：

• Farmers traditionally used long-term rotations of hay, pasture, and corn. 农民以往长期实行干草、牧草和玉米轮作。
• The crankshaft makes three rotations for each rotation of the rotor. 转子每转一周，曲轴转3周。

84 swerve   

v.突然转向，背离；n．转向，弯曲，背离

参考例句：

• Nothing will swerve him from his aims.什么也不能使他改变目标。
• Her car swerved off the road into a 6ft high brick wall.她的车突然转向冲出了马路，撞向6英尺高的一面砖墙。

85 swerves   

n.（使）改变方向，改变目的( swerve的名词复数 )v.（使）改变方向，改变目的( swerve的第三人称单数 )

参考例句：

• The road swerves to the right. 道路向右转弯。 来自《现代汉英综合大词典》
• At the last moment, Nina swerves and slams into a parked car. 在最后关头，尼娜突然转弯，将车猛烈撞入一辆停着的车中。 来自互联网

86 postpone   

v.延期，推迟

参考例句：

• I shall postpone making a decision till I learn full particulars.在未获悉详情之前我得从缓作出决定。
• She decided to postpone the converastion for that evening.她决定当天晚上把谈话搁一搁。

87 postpones   

v.延期，推迟( postpone的第三人称单数 )

参考例句：

• So it at least postpones the amount of taxes on due. 因此它至少推延了税金的交纳。 来自互联网
• Even if it does, this just postpones the day of reckoning. 但即便如此，也只是推迟了不得不解决根本问题的日子而已。 来自互联网

88 unfamiliar   

adj.陌生的，不熟悉的

参考例句：

• I am unfamiliar with the place and the people here.我在这儿人地生疏。
• The man seemed unfamiliar to me.这人很面生。

89 incitation   

刺激，激励

参考例句：

90 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

91 deserted   

adj.荒芜的，荒废的，无人的，被遗弃的

参考例句：

• The deserted village was filled with a deathly silence.这个荒废的村庄死一般的寂静。
• The enemy chieftain was opposed and deserted by his followers.敌人头目众叛亲离。

92 preservation   

n.保护，维护，保存，保留，保持

参考例句：

• The police are responsible for the preservation of law and order.警察负责维持法律与秩序。
• The picture is in an excellent state of preservation.这幅画保存得极为完好。

93 sensory   

adj.知觉的，感觉的，知觉器官的

参考例句：

• Human powers of sensory discrimination are limited.人类感官分辨能力有限。
• The sensory system may undergo long-term adaptation in alien environments.感觉系统对陌生的环境可能经过长时期才能适应。

94 fixed   

adj.固定的，不变的，准备好的；(计算机)固定的

参考例句：

• Have you two fixed on a date for the wedding yet?你们俩选定婚期了吗？
• Once the aim is fixed,we should not change it arbitrarily.目标一旦确定，我们就不应该随意改变。

95 incitement   

激励； 刺激； 煽动； 激励物

参考例句：

• incitement to racial hatred 种族仇恨的挑起
• Interest is an incitement to study. 兴趣刺激学习。

96 stimuli   

n.刺激（物）

参考例句：

• It is necessary to curtail or alter normally coexisting stimuli.必需消除或改变正常时并存的刺激。
• My sweat glands also respond to emotional stimuli.我的汗腺对情绪刺激也能产生反应。

97 persistent   

adj.坚持不懈的，执意的；持续的

参考例句：

• Albert had a persistent headache that lasted for three days.艾伯特连续头痛了三天。
• She felt embarrassed by his persistent attentions.他不时地向她大献殷勤，使她很难为情。

98 varied   

adj.多样的，多变化的

参考例句：

• The forms of art are many and varied.艺术的形式是多种多样的。
• The hotel has a varied programme of nightly entertainment.宾馆有各种晚间娱乐活动。

99 mere   

adj.纯粹的；仅仅，只不过

参考例句：

• That is a mere repetition of what you said before.那不过是重复了你以前讲的话。
• It's a mere waste of time waiting any longer.再等下去纯粹是浪费时间。

100 physiologist   

n.生理学家

参考例句：

• Russian physiologist who observed conditioned salivary responses in dogs (1849-1936). （1849-1936）苏联生理学家，在狗身上观察到唾液条件反射，曾获1904年诺贝尔生理学-医学奖。
• The physiologist recently studied indicated that evening exercises beneficially. 生理学家新近研究表明，傍晚锻炼最为有益。

101 elicit   

v.引出,抽出,引起

参考例句：

• It was designed to elicit the best thinking within the government. 机构的设置是为了在政府内部集思广益。
• Don't try to elicit business secrets from me. I won't tell you anything. 你休想从我这里套问出我们的商业机密, 我什么都不会告诉你的。

102 croaking   

v.呱呱地叫( croak的现在分词 )；用粗的声音说

参考例句：

• the croaking of frogs 蛙鸣
• I could hear croaking of the frogs. 我能听到青蛙呱呱的叫声。 来自《简明英汉词典》

103 foretell   

v.预言，预告，预示

参考例句：

• Willow trees breaking out into buds foretell the coming of spring.柳枝绽青报春来。
• The outcome of the war is hard to foretell.战争胜负难以预卜。

104 dominant   

adj.支配的，统治的；占优势的；显性的；n.主因，要素，主要的人(或物)；显性基因

参考例句：

• The British were formerly dominant in India.英国人从前统治印度。
• She was a dominant figure in the French film industry.她在法国电影界是个举足轻重的人物。

105 swell   

vi.膨胀，肿胀；增长，增强

参考例句：

• The waves had taken on a deep swell.海浪汹涌。
• His injured wrist began to swell.他那受伤的手腕开始肿了。

106 perfectly   

adv.完美地，无可非议地，彻底地

参考例句：

• The witnesses were each perfectly certain of what they said.证人们个个对自己所说的话十分肯定。
• Everything that we're doing is all perfectly above board.我们做的每件事情都是光明正大的。

107 phenomena   

n.现象

参考例句：

• Ade couldn't relate the phenomena with any theory he knew.艾德无法用他所知道的任何理论来解释这种现象。
• The object of these experiments was to find the connection,if any,between the two phenomena.这些实验的目的就是探索这两种现象之间的联系，如果存在着任何联系的话。

108 irresistibly   

adv.无法抵抗地，不能自持地；极为诱惑人地

参考例句：

• Her gaze was drawn irresistibly to the scene outside. 她的目光禁不住被外面的风景所吸引。 来自《简明英汉词典》
• He was irresistibly attracted by her charm. 他不能自已地被她的魅力所吸引。 来自《简明英汉词典》

109 contractions   

n.收缩( contraction的名词复数 )；缩减；缩略词；（分娩时）子宫收缩

参考例句：

• Contractions are much more common in speech than in writing. 缩略词在口语里比在书写中常见得多。 来自《简明英汉词典》
• Muscle contractions are powered by the chemical adenosine triphosphate(ATP ). 肌肉收缩是由化学物质三磷酸腺苷(ATP)提供动力的。 来自辞典例句

110 contraction   

n.缩略词，缩写式，害病

参考例句：

• The contraction of this muscle raises the lower arm.肌肉的收缩使前臂抬起。
• The forces of expansion are balanced by forces of contraction.扩张力和收缩力相互平衡。

111 tract   

n.传单，小册子，大片(土地或森林)

参考例句：

• He owns a large tract of forest.他拥有一大片森林。
• He wrote a tract on this subject.他曾对此写了一篇短文。

112 backwards   

adv.往回地，向原处，倒，相反，前后倒置地

参考例句：

• He turned on the light and began to pace backwards and forwards.他打开电灯并开始走来走去。
• All the girls fell over backwards to get the party ready.姑娘们迫不及待地为聚会做准备。

113 machinery   

n.(总称)机械，机器；机构

参考例句：

• Has the machinery been put up ready for the broadcast?广播器材安装完毕了吗？
• Machinery ought to be well maintained all the time.机器应该随时注意维护。

114 forth   

adv.向前；向外，往外

参考例句：

• The wind moved the trees gently back and forth.风吹得树轻轻地来回摇晃。
• He gave forth a series of works in rapid succession.他很快连续发表了一系列的作品。

115 prey   

n.被掠食者，牺牲者，掠食；v.捕食，掠夺，折磨

参考例句：

• Stronger animals prey on weaker ones.弱肉强食。
• The lion was hunting for its prey.狮子在寻找猎物。

116 shunned   

v.避开，回避，避免( shun的过去式和过去分词 )

参考例句：

• She was shunned by her family when she remarried. 她再婚后家里人都躲着她。
• He was a shy man who shunned all publicity. 他是个怕羞的人，总是避开一切引人注目的活动。 来自《简明英汉词典》

117 demonstration   

n.表明，示范，论证，示威

参考例句：

• His new book is a demonstration of his patriotism.他写的新书是他的爱国精神的证明。
• He gave a demonstration of the new technique then and there.他当场表演了这种新的操作方法。

118 deficient   

adj.不足的，不充份的，有缺陷的

参考例句：

• The crops are suffering from deficient rain.庄稼因雨量不足而遭受损害。
• I always have been deficient in selfconfidence and decision.我向来缺乏自信和果断。

119 crouched   

v.屈膝，蹲伏( crouch的过去式和过去分词 )

参考例句：

• He crouched down beside her. 他在她的旁边蹲了下来。
• The lion crouched ready to pounce. 狮子蹲下身，准备猛扑。

120 swelling   

n.肿胀

参考例句：

• Use ice to reduce the swelling. 用冰敷消肿。
• There is a marked swelling of the lymph nodes. 淋巴结处有明显的肿块。

121 delirium   

n. 神智昏迷,说胡话;极度兴奋

参考例句：

• In her delirium, she had fallen to the floor several times. 她在神志不清的状态下几次摔倒在地上。
• For the next nine months, Job was in constant delirium.接下来的九个月，约伯处于持续精神错乱的状态。

122 concisely   

adv.简明地

参考例句：

• These equations are written more concisely as a single columnmatrix equation. 这些方程以单列矩阵方程表示会更简单。 来自辞典例句
• The fiber morphology can be concisely summarized. 可以对棉纤维的形态结构进行扼要地归纳。 来自辞典例句

123 vestiges   

残余部分( vestige的名词复数 )； 遗迹； 痕迹； 毫不

参考例句：

• the last vestiges of the old colonial regime 旧殖民制度最后的残余
• These upright stones are the vestiges of some ancient religion. 这些竖立的石头是某种古代宗教的遗迹。

124 warding   

监护，守护（ward的现在分词形式）

参考例句：

• Magina channels a powerful warding magic damping the negative effects of spells. 敌法师用守护魔法来抵御负面法术的攻击。
• Indeed, warding off disruption is the principal property of complex systems. 的确，避免破损解体是复杂系统主要的属性。

125 wayfarer   

n.旅人

参考例句：

• You are the solitary wayfarer in this deserted street.在这冷寂的街上，你是孤独的行人。
• The thirsty wayfarer was glad to find a fresh spring near the road.口渴的徒步旅行者很高兴在路边找到新鲜的泉水。

126 repose   

v.(使)休息；n.安息

参考例句：

• Don't disturb her repose.不要打扰她休息。
• Her mouth seemed always to be smiling,even in repose.她的嘴角似乎总是挂着微笑，即使在睡眠时也是这样。

127 awaken   

vi.醒，觉醒；vt.唤醒，使觉醒，唤起，激起

参考例句：

• Old people awaken early in the morning.老年人早晨醒得早。
• Please awaken me at six.请于六点叫醒我。

128 awakens   

v.（使）醒( awaken的第三人称单数 )；（使）觉醒；弄醒；（使）意识到

参考例句：

• The scene awakens reminiscences of my youth. 这景象唤起我年轻时的往事。 来自《现代英汉综合大词典》
• The child awakens early in the morning. 这个小孩早晨醒得早。 来自辞典例句

129 motive   

n.动机，目的；adv.发动的，运动的

参考例句：

• The police could not find a motive for the murder.警察不能找到谋杀的动机。
• He had some motive in telling this fable.他讲这寓言故事是有用意的。

130 prudence   

n.谨慎，精明，节俭

参考例句：

• A lack of prudence may lead to financial problems.不够谨慎可能会导致财政上出现问题。
• The happy impute all their success to prudence or merit.幸运者都把他们的成功归因于谨慎或功德。

131 virtue   

n.德行，美德；贞操；优点；功效，效力

参考例句：

• He was considered to be a paragon of virtue.他被认为是品德尽善尽美的典范。
• You need to decorate your mind with virtue.你应该用德行美化心灵。

132 rodent   

n.啮齿动物；adj.啮齿目的

参考例句：

• When there is a full moon,this nocturnal rodent is careful to stay in its burrow.月圆之夜，这种夜间活动的啮齿类动物会小心地呆在地洞里不出来。
• This small rodent can scoop out a long,narrow tunnel in a very short time.这种小啮齿动物能在很短的时间里挖出一条又长又窄的地道来。

133 condemned   

adj. 被责难的, 被宣告有罪的 动词condemn的过去式和过去分词

参考例句：

• He condemned the hypocrisy of those politicians who do one thing and say another. 他谴责了那些说一套做一套的政客的虚伪。
• The policy has been condemned as a regressive step. 这项政策被认为是一种倒退而受到谴责。

134 kindled   

（使某物）燃烧，着火( kindle的过去式和过去分词 )； 激起（感情等）； 发亮，放光

参考例句：

• We watched as the fire slowly kindled. 我们看着火慢慢地燃烧起来。
• The teacher's praise kindled a spark of hope inside her. 老师的赞扬激起了她内心的希望。

135 forfeit   

vt.丧失；n.罚金，罚款，没收物

参考例句：

• If you continue to tell lies,you will forfeit the good opinion of everyone.你如果继续撒谎，就会失掉大家对你的好感。
• Please pay for the forfeit before you borrow book.在你借书之前请先付清罚款。

136 retaliation   

n.报复，反击

参考例句：

• retaliation against UN workers 对联合国工作人员的报复
• He never said a single word in retaliation. 他从未说过一句反击的话。 来自《简明英汉词典》

137 repletion   

n.充满，吃饱

参考例句：

• It is better to die of repletion than to endure hunger.饱死胜过挨饿。
• A baby vomits milk from repletion.婴儿吃饱会吐奶。

138 expiate   

v.抵补，赎罪

参考例句：

• He tried to expiate his crimes by giving money to the church.他以捐款给教会来赎罪。
• It seemed that Alice was expiating her father's sins with her charity work.似乎艾丽斯正在通过自己的慈善工作来弥补父亲的罪过。

139 degradation   

n.降级；低落；退化；陵削；降解；衰变

参考例句：

• There are serious problems of land degradation in some arid zones.在一些干旱地带存在严重的土地退化问题。
• Gambling is always coupled with degradation.赌博总是与堕落相联系。

140 extinction   

n.熄灭，消亡，消灭，灭绝，绝种

参考例句：

• The plant is now in danger of extinction.这种植物现在有绝种的危险。
• The island's way of life is doomed to extinction.这个岛上的生活方式注定要消失。

141 fecundity   

n.生产力；丰富

参考例句：

• The probability of survival is the reciprocal of fecundity.生存的概率是生殖力的倒数。
• The boy's fecundity of imagination amazed his teacher.男孩想像力的丰富使教师感到惊异。

142 atone   

v.赎罪，补偿

参考例句：

• He promised to atone for his crime.他承诺要赎自己的罪。
• Blood must atone for blood.血债要用血来还。

143 toads   

n.蟾蜍，癞蛤蟆( toad的名词复数 )

参考例句：

• All toads blink when they swallow. 所有的癞蛤蟆吞食东西时都会眨眼皮。 来自《简明英汉词典》
• Toads have shorter legs and are generally more clumsy than frogs. 蟾蜍比青蛙脚短，一般说来没有青蛙灵活。 来自辞典例句

144 obedience   

n.服从，顺从

参考例句：

• Society has a right to expect obedience of the law.社会有权要求人人遵守法律。
• Soldiers act in obedience to the orders of their superior officers.士兵们遵照上级军官的命令行动。

145 exclusion   

n.拒绝，排除，排斥，远足，远途旅行

参考例句：

• Don't revise a few topics to the exclusion of all others.不要修改少数论题以致排除所有其他的。
• He plays golf to the exclusion of all other sports.他专打高尔夫球，其他运动一概不参加。

146 puddles   

n.水坑， （尤指道路上的）雨水坑( puddle的名词复数 )

参考例句：

• The puddles had coalesced into a small stream. 地面上水洼子里的水汇流成了一条小溪。
• The road was filled with puddles from the rain. 雨后路面到处是一坑坑的积水。 来自《简明英汉词典》

147 elevation   

n.高度；海拔；高地；上升；提高

参考例句：

• The house is at an elevation of 2,000 metres.那幢房子位于海拔两千米的高处。
• His elevation to the position of General Manager was announced yesterday.昨天宣布他晋升总经理职位。

148 physiologically   

ad.生理上，在生理学上

参考例句：

• Therefore, the liver and gallbladder cannot be completely separated physiologically and pathologically. 因此，肝胆在生理和病理上不能完全分离。
• Therefore, the liver and gallbladder are closely related physiologically and pathologically. 因此，肝胆在生理和病理上紧密联系。

149 aesthetic   

adj.美学的，审美的，有美感

参考例句：

• My aesthetic standards are quite different from his.我的审美标准与他的大不相同。
• The professor advanced a new aesthetic theory.那位教授提出了新的美学理论。

150 inhibit   

vt.阻止，妨碍，抑制

参考例句：

• Don't let ego and greed inhibit clear thinking and hard work.不要让自我和贪婪妨碍清晰的思维和刻苦的工作。
• They passed a law to inhibit people from parking in the street.他们通过一项法令以阻止人们在街上停车。

151 psychic   

n.对超自然力敏感的人；adj.有超自然力的

参考例句：

• Some people are said to have psychic powers.据说有些人有通灵的能力。
• She claims to be psychic and to be able to foretell the future.她自称有特异功能，能预知未来。

152 patriot   

n.爱国者，爱国主义者

参考例句：

• He avowed himself a patriot.他自称自己是爱国者。
• He is a patriot who has won the admiration of the French already.他是一个已经赢得法国人敬仰的爱国者。

153 hierarchy   

n.等级制度；统治集团，领导层

参考例句：

• There is a rigid hierarchy of power in that country.那个国家有一套严密的权力等级制度。
• She's high up in the management hierarchy.她在管理阶层中地位很高。

154 manifestation   

n.表现形式；表明；现象

参考例句：

• Her smile is a manifestation of joy.她的微笑是她快乐的表现。
• What we call mass is only another manifestation of energy.我们称之为质量的东西只是能量的另一种表现形态。

155 distinguished   

adj.卓越的，杰出的，著名的

参考例句：

• Elephants are distinguished from other animals by their long noses.大象以其长长的鼻子显示出与其他动物的不同。
• A banquet was given in honor of the distinguished guests.宴会是为了向贵宾们致敬而举行的。

156 determined   

adj.坚定的；有决心的

参考例句：

• I have determined on going to Tibet after graduation.我已决定毕业后去西藏。
• He determined to view the rooms behind the office.他决定查看一下办公室后面的房间。

157 inevitable   

adj.不可避免的，必然发生的

参考例句：

• Mary was wearing her inevitable large hat.玛丽戴着她总是戴的那顶大帽子。
• The defeat had inevitable consequences for British policy.战败对英国政策不可避免地产生了影响。

158 alteration   

n.变更，改变；蚀变

参考例句：

• The shirt needs alteration.这件衬衣需要改一改。
• He easily perceived there was an alteration in my countenance.他立刻看出我的脸色和往常有些不同。

159 recurred   

再发生，复发( recur的过去式和过去分词 )； 治愈

参考例句：

• Old memories constantly recurred to him. 往事经常浮现在他的脑海里。
• She always winced when he recurred to the subject of his poems. 每逢他一提到他的诗作的时候，她总是有点畏缩。

160 dreads   

n.恐惧，畏惧( dread的名词复数 )；令人恐惧的事物v.害怕，恐惧，担心( dread的第三人称单数 )

参考例句：

• The little boy dreads going to bed in the dark. 这孩子不敢在黑暗中睡觉。 来自《简明英汉词典》
• A burnt child dreads the fire. [谚]烧伤过的孩子怕火（惊弓之鸟，格外胆小）。 来自《现代英汉综合大词典》

161 complicate   

vt.使复杂化，使混乱，使难懂

参考例句：

• There is no need to complicate matters.没有必要使问题复杂化。
• These events will greatly complicate the situation.这些事件将使局势变得极其复杂。

162 retraction   

n.撤消；收回

参考例句：

• He demanded a full retraction of the allegations against him.他要求完全收回针对他的言论。
• The newspaper published a retraction of the erroneous report.那家报纸声明撤回那篇错误的报道。

163 simultaneously   

adv.同时发生地，同时进行地

参考例句：

• The radar beam can track a number of targets almost simultaneously.雷达波几乎可以同时追着多个目标。
• The Windows allow a computer user to execute multiple programs simultaneously.Windows允许计算机用户同时运行多个程序。

164 inevitably   

adv.不可避免地；必然发生地

参考例句：

• In the way you go on,you are inevitably coming apart.照你们这样下去，毫无疑问是会散伙的。
• Technological changes will inevitably lead to unemployment.技术变革必然会导致失业。

165 awakened   

v.（使）醒( awaken的过去式和过去分词 )；（使）觉醒；弄醒；（使）意识到

参考例句：

• She awakened to the sound of birds singing. 她醒来听到鸟的叫声。
• The public has been awakened to the full horror of the situation. 公众完全意识到了这一状况的可怕程度。 来自《简明英汉词典》

166 anticipation   

n.预期，预料，期望

参考例句：

• We waited at the station in anticipation of her arrival.我们在车站等着，期待她的到来。
• The animals grew restless as if in anticipation of an earthquake.各种动物都变得焦躁不安，像是感到了地震即将发生。

167 plunging   

adj.跳进的，突进的v.颠簸( plunge的现在分词 )；暴跌；骤降；突降

参考例句：

• War broke out again, plunging the people into misery and suffering. 战祸复发，生灵涂炭。 来自《现代汉英综合大词典》
• He is plunging into an abyss of despair. 他陷入了绝望的深渊。 来自《简明英汉词典》

168 gall   

v.使烦恼，使焦躁，难堪；n.磨难

参考例句：

• It galled him to have to ask for a loan.必须向人借钱使他感到难堪。
• No gall,no glory.没有磨难，何来荣耀。

169 proceeding   

n.行动，进行，(pl.)会议录，学报

参考例句：

• This train is now proceeding from Paris to London.这次列车从巴黎开往伦敦。
• The work is proceeding briskly.工作很有生气地进展着。

170 faculty   

n.才能；学院，系；(学院或系的)全体教学人员

参考例句：

• He has a great faculty for learning foreign languages.他有学习外语的天赋。
• He has the faculty of saying the right thing at the right time.他有在恰当的时候说恰当的话的才智。

171 psychology   

n.心理，心理学，心理状态

参考例句：

• She has a background in child psychology.她受过儿童心理学的教育。
• He studied philosophy and psychology at Cambridge.他在剑桥大学学习哲学和心理学。

172 ultimatum   

n.最后通牒

参考例句：

• This time the proposal was couched as an ultimatum.这一次该提议是以最后通牒的形式提出来的。
• The cabinet met today to discuss how to respond to the ultimatum.内阁今天开会商量如何应对这道最后通牒。

173 promptly   

adv.及时地，敏捷地

参考例句：

• He paid the money back promptly.他立即还了钱。
• She promptly seized the opportunity his absence gave her.她立即抓住了因他不在场给她创造的机会。

174 broth   

n.原(汁)汤(鱼汤、肉汤、菜汤等)

参考例句：

• Every cook praises his own broth.厨子总是称赞自己做的汤。
• Just a bit of a mouse's dropping will spoil a whole saucepan of broth.一粒老鼠屎败坏一锅汤。

175 followers   

追随者( follower的名词复数 )； 用户； 契据的附面； 从动件

参考例句：

• the followers of Mahatma Gandhi 圣雄甘地的拥护者
• The reformer soon gathered a band of followers round him. 改革者很快就获得一群追随者支持他。

176 appreciable   

adj.明显的，可见的，可估量的，可觉察的

参考例句：

• There is no appreciable distinction between the twins.在这对孪生子之间看不出有什么明显的差别。
• We bought an appreciable piece of property.我们买下的资产有增值的潜力。

177 faculties   

n.能力( faculty的名词复数 )；全体教职员；技巧；院

参考例句：

• Although he's ninety, his mental faculties remain unimpaired. 他虽年届九旬，但头脑仍然清晰。
• All your faculties have come into play in your work. 在你的工作中，你的全部才能已起到了作用。 来自《简明英汉词典》

178 lore   

n.传说；学问，经验，知识

参考例句：

• I will seek and question him of his lore.我倒要找上他，向他讨教他的渊博的学问。
• Early peoples passed on plant and animal lore through legend.早期人类通过传说传递有关植物和动物的知识。

179 admiration   

n.钦佩，赞美，羡慕

参考例句：

• He was lost in admiration of the beauty of the scene.他对风景之美赞不绝口。
• We have a great admiration for the gold medalists.我们对金牌获得者极为敬佩。

180 practitioners   

n.习艺者，实习者( practitioner的名词复数 )；从业者（尤指医师）

参考例句：

• one of the greatest practitioners of science fiction 最了不起的科幻小说家之一
• The technique is experimental, but the list of its practitioners is growing. 这种技术是试验性的，但是采用它的人正在增加。 来自辞典例句

181 jaw   

n.颚，颌，说教，流言蜚语；v.喋喋不休，教训

参考例句：

• He delivered a right hook to his opponent's jaw.他给了对方下巴一记右钩拳。
• A strong square jaw is a sign of firm character.强健的方下巴是刚毅性格的标志。

182 refinement   

n.文雅；高尚；精美；精制；精炼

参考例句：

• Sally is a woman of great refinement and beauty. 莎莉是个温文尔雅又很漂亮的女士。
• Good manners and correct speech are marks of refinement.彬彬有礼和谈吐得体是文雅的标志。

183 correlation   

n.相互关系，相关，关连

参考例句：

• The second group of measurements had a high correlation with the first.第二组测量数据与第一组高度相关。
• A high correlation exists in America between education and economic position.教育和经济地位在美国有极密切的关系。

184 correlations   

相互的关系( correlation的名词复数 )

参考例句：

• One would expect strong and positive correlations between both complexes. 人们往往以为这两个综合体之间有紧密的正相关。
• The correlations are of unequal value. 这些对应联系的价值并不相同。

185 manifestations   

n.表示，显示（manifestation的复数形式）

参考例句：

• These were manifestations of the darker side of his character. 这些是他性格阴暗面的表现。 来自《简明英汉词典》
• To be wordly-wise and play safe is one of the manifestations of liberalism. 明哲保身是自由主义的表现之一。 来自《现代汉英综合大词典》

186 converse   

vi.谈话，谈天，闲聊；adv.相反的，相反

参考例句：

• He can converse in three languages.他可以用3种语言谈话。
• I wanted to appear friendly and approachable but I think I gave the converse impression.我想显得友好、平易近人些,却发觉给人的印象恰恰相反。

187 apparatus   

n.装置，器械；器具，设备

参考例句：

• The school's audio apparatus includes films and records.学校的视听设备包括放映机和录音机。
• They had a very refined apparatus.他们有一套非常精良的设备。

188 spoke   

n.（车轮的）辐条；轮辐；破坏某人的计划；阻挠某人的行动 v.讲，谈（speak的过去式）；说；演说；从某种观点来说

参考例句：

• They sourced the spoke nuts from our company.他们的轮辐螺帽是从我们公司获得的。
• The spokes of a wheel are the bars that connect the outer ring to the centre.辐条是轮子上连接外圈与中心的条棒。

189 poke   

n.刺，戳，袋；vt.拨开，刺，戳；vi.戳，刺，捅，搜索，伸出，行动散慢

参考例句：

• We never thought she would poke her nose into this.想不到她会插上一手。
• Don't poke fun at me.别拿我凑趣儿。

190 judgment   

n.审判；判断力，识别力，看法，意见

参考例句：

• The chairman flatters himself on his judgment of people.主席自认为他审视人比别人高明。
• He's a man of excellent judgment.他眼力过人。

191 specification   

n.详述；[常pl.]规格，说明书，规范

参考例句：

• I want to know his specification of details.我想知道他对细节的详述。
• Examination confirmed that the quality of the products was up to specification.经检查，产品质量合格。

192 aggregate   

adj.总计的，集合的；n.总数；v.合计；集合

参考例句：

• The football team had a low goal aggregate last season.这支足球队上个赛季的进球总数很少。
• The money collected will aggregate a thousand dollars.进帐总额将达一千美元。

193 pastor   

n.牧师，牧人

参考例句：

• He was the son of a poor pastor.他是一个穷牧师的儿子。
• We have no pastor at present:the church is run by five deacons.我们目前没有牧师：教会的事是由五位执事管理的。

194 entity   

n.实体，独立存在体，实际存在物

参考例句：

• The country is no longer one political entity.这个国家不再是一个统一的政治实体了。
• As a separate legal entity,the corporation must pay taxes.作为一个独立的法律实体，公司必须纳税。

195 projection   

n.发射，计划，突出部分

参考例句：

• Projection takes place with a minimum of awareness or conscious control.投射在最少的知觉或意识控制下发生。
• The projection of increases in number of house-holds is correct.对户数增加的推算是正确的。

196 symbolizes   

v.象征，作为…的象征( symbolize的第三人称单数 )

参考例句：

• The use of light and dark symbolizes good and evil. 用光明与黑暗来象征善与恶。
• She likes olive because It'symbolizes peace. 她喜欢橄榄色因为它象征着和平。 来自《简明英汉词典》

197 criticise   

v.批评，评论；非难

参考例句：

• Right and left have much cause to criticise government.左翼和右翼有很多理由批评政府。
• It is not your place to criticise or suggest improvements!提出批评或给予改进建议并不是你的责任！

198 formulating   

v.构想出( formulate的现在分词 )；规划；确切地阐述；用公式表示

参考例句：

• At present, the Chinese government is formulating nationwide regulations on the control of such chemicals. 目前，中国政府正在制定全国性的易制毒化学品管理条例。 来自汉英非文学 - 白皮书
• Because of this, the U.S. has taken further steps in formulating the \"Magellan\" programme. 为此，美国又进一步制定了“麦哲伦”计划。 来自百科语句

199 ascertain   

vt.发现，确定，查明，弄清

参考例句：

• It's difficult to ascertain the coal deposits.煤储量很难探明。
• We must ascertain the responsibility in light of different situtations.我们必须根据不同情况判定责任。

200 postulate   

n.假定，基本条件；vt.要求，假定

参考例句：

• Let's postulate that she is a cook.我们假定她是一位厨师。
• Freud postulated that we all have a death instinct as well as a life instinct.弗洛伊德曾假定我们所有人都有生存本能和死亡本能。

201 physiologists   

n.生理学者( physiologist的名词复数 )；生理学( physiology的名词复数 )；生理机能

参考例句：

• Quite unexpectedly, vertebrate physiologists and microbial biochemists had found a common ground. 出乎意外，脊椎动物生理学家和微生物生化学家找到了共同阵地。 来自辞典例句
• Physiologists are interested in the workings of the human body. 生理学家对人体的功能感兴趣。 来自辞典例句

202 specialized   

adj.专门的，专业化的

参考例句：

• There are many specialized agencies in the United Nations.联合国有许多专门机构。
• These tools are very specialized.这些是专用工具。

203 excision   

n.删掉；除去

参考例句：

• The excision of the clause has been decided.已经决定删除这个条款。
• Complete excision is a curative treatment.完全切除是唯一有效的治疗方式。

204 extirpation   

n.消灭，根除，毁灭；摘除

参考例句：

• Gamma Knife surgery has recently been tried as an alternative to surgical extirpation. 伽玛刀治疗最近被尝试作为手术根治之外的另一种选择。 来自辞典例句
• Gamma Knife surgery (GKS) has recently been tried as an alternative to surgical extirpation. 伽玛刀治疗(GKS)最近被尝试作为手术根治之外的另一种选择。 来自互联网

205 adverse   

adj.不利的；有害的；敌对的，不友好的

参考例句：

• He is adverse to going abroad.他反对出国。
• The improper use of medicine could lead to severe adverse reactions.用药不当会产生严重的不良反应。

206 fissure   

n.裂缝；裂伤

参考例句：

• Though we all got out to examine the fissure,he remained in the car.我们纷纷下车察看那个大裂缝，他却呆在车上。
• Ground fissure is the main geological disaster in Xi'an city construction.地裂缝是西安市主要的工程地质灾害问题。

207 intensity   

n.强烈，剧烈；强度；烈度

参考例句：

• I didn't realize the intensity of people's feelings on this issue.我没有意识到这一问题能引起群情激奋。
• The strike is growing in intensity.罢工日益加剧。

208 inexplicable   

adj.无法解释的，难理解的

参考例句：

• It is now inexplicable how that development was misinterpreted.当时对这一事态发展的错误理解究竟是怎么产生的，现在已经无法说清楚了。
• There are many things which are inexplicable by science.有很多事科学还无法解释。

209 physically   

adj.物质上，体格上，身体上，按自然规律

参考例句：

• He was out of sorts physically,as well as disordered mentally.他浑身不舒服，心绪也很乱。
• Every time I think about it I feel physically sick.一想起那件事我就感到极恶心。

210 tracts   

大片土地( tract的名词复数 )； 地带； （体内的）道； （尤指宣扬宗教、伦理或政治的）短文

参考例句：

• vast tracts of forest 大片大片的森林
• There are tracts of desert in Australia. 澳大利亚有大片沙漠。

211 excised   

v.切除，删去( excise的过去式和过去分词 )

参考例句：

• Certain passages were excised from the book. 书中某些段落已删去。
• Similarly, any pigment nevus that is chronically irritated should be excised. 同样，凡是经常受慢性刺激的各种色素痣切勿予以切除。 来自辞典例句

212 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

213 dorsal   

adj.背部的，背脊的

参考例句：

• His dorsal fin was down and his huge pectorals were spread wide.它的脊鳍朝下耷拉着，巨大的胸鳍大张着。
• The shark's dorsal fin was cut off by the fisherman.鲨鱼的背鳍被渔夫割了下来。

214 formerly   

adv.从前，以前

参考例句：

• We now enjoy these comforts of which formerly we had only heard.我们现在享受到了过去只是听说过的那些舒适条件。
• This boat was formerly used on the rivers of China.这船从前航行在中国内河里。

215 disturbances   

n.骚乱( disturbance的名词复数 )；打扰；困扰；障碍

参考例句：

• The government has set up a commission of inquiry into the disturbances at the prison. 政府成立了一个委员会来调查监狱骚乱事件。
• Extra police were called in to quell the disturbances. 已调集了增援警力来平定骚乱。

216 paralysis   

n.麻痹(症)；瘫痪(症)

参考例句：

• The paralysis affects his right leg and he can only walk with difficulty.他右腿瘫痪步履维艰。
• The paralysis affects his right leg and he can only walk with difficulty.他右腿瘫痪步履维艰。

217 inertia   

adj.惰性，惯性，懒惰，迟钝

参考例句：

• We had a feeling of inertia in the afternoon.下午我们感觉很懒。
• Inertia carried the plane onto the ground.飞机靠惯性着陆。

218 gnawing   

a.痛苦的，折磨人的

参考例句：

• The dog was gnawing a bone. 那狗在啃骨头。
• These doubts had been gnawing at him for some time. 这些疑虑已经折磨他一段时间了。

219 tactile   

adj.触觉的，有触觉的，能触知的

参考例句：

• Norris is an expert in the tactile and the tangible.诺里斯创作最精到之处便是，他描绘的人物使人看得见摸得着。
• Tactile communication uses touch rather than sight or hearing.触觉交流，是用触摸感觉，而不是用看或听来感觉。

220 permanently   

adv.永恒地，永久地，固定不变地

参考例句：

• The accident left him permanently scarred.那次事故给他留下了永久的伤疤。
• The ship is now permanently moored on the Thames in London.该船现在永久地停泊在伦敦泰晤士河边。

221 inveterate   

adj.积习已深的，根深蒂固的

参考例句：

• Hitler was not only an avid reader but also an inveterate underliner.希特勒不仅酷爱读书，还有写写划划的习惯。
• It is hard for an inveterate smoker to give up tobacco.要一位有多年烟瘾的烟民戒烟是困难的。

222 softening   

变软，软化

参考例句：

• Her eyes, softening, caressed his face. 她的眼光变得很温柔了。它们不住地爱抚他的脸。 来自汉英文学 - 家（1-26） - 家（1-26）
• He might think my brain was softening or something of the kind. 他也许会觉得我婆婆妈妈的，已经成了个软心肠的人了。

223 spasm   

n.痉挛，抽搐；一阵发作

参考例句：

• When the spasm passed,it left him weak and sweating.一阵痉挛之后，他虚弱无力，一直冒汗。
• He kicked the chair in a spasm of impatience.他突然变得不耐烦，一脚踢向椅子。

224 figs   

figures 数字，图形，外形

参考例句：

• The effect of ring dyeing is shown in Figs 10 and 11. 环形染色的影响如图10和图11所示。
• The results in Figs. 4 and 5 show the excellent agreement between simulation and experiment. 图4和图5的结果都表明模拟和实验是相当吻合的。

225 rigidity   

adj.钢性，坚硬

参考例句：

• The rigidity of the metal caused it to crack.这金属因刚度强而产生裂纹。
• He deplored the rigidity of her views.他痛感她的观点僵化。

226 descending   

n. 下行 adj. 下降的

参考例句：

• The results are expressed in descending numerical order . 结果按数字降序列出。
• The climbers stopped to orient themselves before descending the mountain. 登山者先停下来确定所在的位置，然后再下山。

227 strands   

n.（线、绳、金属线、毛发等的）股( strand的名词复数 )；缕；海洋、湖或河的)岸；（观点、计划、故事等的）部份v.使滞留，使搁浅( strand的第三人称单数 )

参考例句：

• Twist a length of rope from strands of hemp. 用几股麻搓成了一段绳子。 来自《简明英汉词典》
• She laced strands into a braid. 她把几股线编织成一根穗带。 来自《简明英汉词典》

228 strand   

vt.使（船）搁浅，使（某人）困于（某地）

参考例句：

• She tucked a loose strand of hair behind her ears.她把一缕散发夹到了耳后。
• The climbers had been stranded by a storm.登山者被暴风雨困住了。

229 lateral   

adj.侧面的，旁边的

参考例句：

• An airfoil that controls lateral motion.能够控制横向飞行的机翼。
• Mr.Dawson walked into the court from a lateral door.道森先生从一个侧面的门走进法庭。

230 embryos   

n.晶胚；胚，胚胎( embryo的名词复数 )

参考例句：

• Somatic cells of angiosperms enter a regenerative phase and behave like embryos. 被子植物体细胞进入一个生殖阶段，而且其行为象胚。 来自辞典例句
• Evolution can explain why human embryos look like gilled fishes. 进化论能够解释为什么人类的胚胎看起来象除去了内脏的鱼一样。 来自辞典例句

231 corona   

n.日冕

参考例句：

• The corona gains and loses energy continuously.日冕总是不断地获得能量和损失能量。
• The corona is a brilliant,pearly white,filmy light,about as bright as the full moon.光环带是一种灿烂的珠白色朦胧光，几乎像满月一样明亮。

232 stimulation   

n.刺激，激励，鼓舞

参考例句：

• The playgroup provides plenty of stimulation for the children.幼儿游戏组给孩子很多启发。
• You don't get any intellectual stimulation in this job.你不能从这份工作中获得任何智力启发。

233 aphasia   

n.失语症

参考例句：

• Unfortunately,he suffered from sudden onset of aphasia one week later.不幸的是，他术后一星期突然出现失语症。
• My wife is in B-four,stroke and aphasia.我的妻子住在B-4房间，患的是中风和失语症。

234 misusing   

v.使用…不当( misuse的现在分词 )；把…派作不正当的用途；虐待；滥用

参考例句：

• This means we must stop misusing them. 也就是说，我们已必须停止滥用抗菌素不可了。 来自英汉非文学 - 生命科学 - 预防生物武器
• Misusing organic fertilizer may cause a decrease in the soil's quality. 滥用有机肥料可能会导致土地的土质下降。 来自互联网

235 unintelligible   

adj.无法了解的，难解的，莫明其妙的

参考例句：

• If a computer is given unintelligible data, it returns unintelligible results.如果计算机得到的是难以理解的数据，它给出的也将是难以理解的结果。
• The terms were unintelligible to ordinary folk.这些术语一般人是不懂的。

236 syllables   

n.音节( syllable的名词复数 )

参考例句：

• a word with two syllables 双音节单词
• 'No. But I'll swear it was a name of two syllables.' “想不起。不过我可以发誓，它有两个音节。” 来自英汉文学 - 双城记

237 vocal   

adj.直言不讳的；嗓音的；n.[pl.]声乐节目

参考例句：

• The tongue is a vocal organ.舌头是一个发音器官。
• Public opinion at last became vocal.终于舆论哗然。

238 bilateral   

adj.双方的，两边的，两侧的

参考例句：

• They have been negotiating a bilateral trade deal.他们一直在商谈一项双边贸易协定。
• There was a wide gap between the views of the two statesmen on the bilateral cooperation.对双方合作的问题，两位政治家各自所持的看法差距甚大。

239 bilaterally   

[医]adv.两侧，双向地

参考例句：

• The data in the Performance Test shall be Bilaterally recorded and confirmed. 在生产线考核期间的数据应由双方共同记录并确认。
• Anatomic constraints may preclude the insertion a transarticular screw unilaterally or bilaterally. 解剖制约可能妨碍单边或双边插入关节螺钉。

240 ribs   

n.肋骨( rib的名词复数 )；（船或屋顶等的）肋拱；肋骨状的东西；（织物的）凸条花纹

参考例句：

• He suffered cracked ribs and bruising. 他断了肋骨还有挫伤。
• Make a small incision below the ribs. 在肋骨下方切开一个小口。

241 habitually   

ad.习惯地，通常地

参考例句：

• The pain of the disease caused him habitually to furrow his brow. 病痛使他习惯性地紧皱眉头。
• Habitually obedient to John, I came up to his chair. 我已经习惯于服从约翰，我来到他的椅子跟前。

242 habitual   

adj.习惯性的；通常的，惯常的

参考例句：

• He is a habitual criminal.他是一个惯犯。
• They are habitual visitors to our house.他们是我家的常客。

243 undone   

a.未做完的，未完成的

参考例句：

• He left nothing undone that needed attention.所有需要注意的事他都注意到了。

244 ascertained   

v.弄清，确定，查明( ascertain的过去式和过去分词 )

参考例句：

• The previously unidentified objects have now been definitely ascertained as being satellites. 原来所说的不明飞行物现在已证实是卫星。 来自《简明英汉词典》
• I ascertained that she was dead. 我断定她已经死了。 来自《简明英汉词典》

245 disorder   

n.紊乱，混乱；骚动，骚乱；疾病，失调

参考例句：

• When returning back,he discovered the room to be in disorder.回家后，他发现屋子里乱七八糟。
• It contained a vast number of letters in great disorder.里面七零八落地装着许多信件。

246 disorders   

n.混乱( disorder的名词复数 )；凌乱；骚乱；（身心、机能）失调

参考例句：

• Reports of anorexia and other eating disorders are on the increase. 据报告，厌食症和其他饮食方面的功能紊乱发生率正在不断增长。 来自《简明英汉词典》
• The announcement led to violent civil disorders. 这项宣布引起剧烈的骚乱。 来自《简明英汉词典》

247 egregious   

adj.非常的，过分的

参考例句：

• When it comes to blatant lies,there are none more egregious than budget figures.谈到公众谎言，没有比预算数字更令人震惊的。
• What an egregious example was here!现摆着一个多么触目惊心的例子啊。

248 insufficient   

adj.(for，of)不足的，不够的

参考例句：

• There was insufficient evidence to convict him.没有足够证据给他定罪。
• In their day scientific knowledge was insufficient to settle the matter.在他们的时代，科学知识还不能足以解决这些问题。

249 illustrate   

v.举例说明，阐明；图解，加插图

参考例句：

• The company's bank statements illustrate its success.这家公司的银行报表说明了它的成功。
• This diagram will illustrate what I mean.这个图表可说明我的意思。

250 conclusively   

adv.令人信服地，确凿地

参考例句：

• All this proves conclusively that she couldn't have known the truth. 这一切无可置疑地证明她不可能知道真相。 来自《简明英汉词典》
• From the facts,he was able to determine conclusively that the death was not a suicide. 根据这些事实他断定这起死亡事件并非自杀。 来自《简明英汉词典》

251 precisely   

adv.恰好，正好，精确地，细致地

参考例句：

• It's precisely that sort of slick sales-talk that I mistrust.我不相信的正是那种油腔滑调的推销宣传。
• The man adjusted very precisely.那个人调得很准。

252 fissures   

n.狭长裂缝或裂隙( fissure的名词复数 )；裂伤；分歧；分裂v.裂开( fissure的第三人称单数 )

参考例句：

• Rising molten rock flows out on the ocean floor and caps the fissures, trapping the water. 上升熔岩流到海底并堵住了裂隙，结果把海水封在里面。 来自辞典例句
• The French have held two colloquia and an international symposium on rock fissures. 法国已经开了两次岩石裂缝方面的报告会和一个国际会议。 来自辞典例句

253 extirpated   

v.消灭，灭绝( extirpate的过去式和过去分词 )；根除

参考例句：

• Many species have been extirpated from large areas. 许多种动物已在大片区域内灭绝。 来自辞典例句
• The brigands have never been really extirpated from the neighborhood of Rome. 罗马附近的土匪实际上从来没有真正被消灭干净过。 来自互联网

254 arrogance   

n.傲慢，自大

参考例句：

• His arrogance comes out in every speech he makes.他每次讲话都表现得骄傲自大。
• Arrogance arrested his progress.骄傲阻碍了他的进步。

255 restitution   

n.赔偿；恢复原状

参考例句：

• It's only fair that those who do the damage should make restitution.损坏东西的人应负责赔偿，这是再公平不过的了。
• The victims are demanding full restitution.受害人要求全额赔偿。

256 situated   

adj.坐落在...的，处于某种境地的

参考例句：

• The village is situated at the margin of a forest.村子位于森林的边缘。
• She is awkwardly situated.她的处境困难。

257 corroborated   

v.证实，支持（某种说法、信仰、理论等）( corroborate的过去式 )

参考例句：

• The evidence was corroborated by two independent witnesses. 此证据由两名独立证人提供。
• Experiments have corroborated her predictions. 实验证实了她的预言。 来自《简明英汉词典》

258 essentially   

adv.本质上，实质上，基本上

参考例句：

• Really great men are essentially modest.真正的伟人大都很谦虚。
• She is an essentially selfish person.她本质上是个自私自利的人。

259 lizards   

n.蜥蜴( lizard的名词复数 )

参考例句：

• Nothing lives in Pompeii except crickets and beetles and lizards. 在庞培城里除了蟋蟀、甲壳虫和蜥蜴外，没有别的生物。 来自辞典例句
• Can lizards reproduce their tails? 蜥蜴的尾巴断了以后能再生吗？ 来自辞典例句

260 winking   

n.瞬眼，目语v.使眼色( wink的现在分词 )；递眼色（表示友好或高兴等）；（指光）闪烁；闪亮

参考例句：

• Anyone can do it; it's as easy as winking. 这谁都办得到，简直易如反掌。 来自《现代汉英综合大词典》
• The stars were winking in the clear sky. 星星在明亮的天空中闪烁。 来自《简明英汉词典》

261 retention   

n.保留，保持，保持力，记忆力

参考例句：

• They advocate the retention of our nuclear power plants.他们主张保留我们的核电厂。
• His retention of energy at this hour is really surprising.人们惊叹他在这个时候还能保持如此旺盛的精力。

262 perches   

栖息处( perch的名词复数 )； 栖枝； 高处； 鲈鱼

参考例句：

• Other protection can be obtained by providing wooden perches througout the orchards. 其它保护措施是可在种子园中到处设置木制的栖木。
• The birds were hopping about on their perches and twittering. 鸟儿在栖木上跳来跳去，吱吱地叫着。

263 alimentary   

adj.饮食的，营养的

参考例句：

• He had the disease of alimentary canal.他患了消化道疾病。
• This system is mainly a long tube,called the alimentary canal.这一系统主要是一根长管，称作消化道。

264 discord   

n.不和，意见不合，争论，（音乐）不和谐

参考例句：

• These two answers are in discord.这两个答案不一样。
• The discord of his music was hard on the ear.他演奏的不和谐音很刺耳。

265 deprivation   

n.匮乏；丧失；夺去，贫困

参考例句：

• Many studies make it clear that sleep deprivation is dangerous.多实验都证实了睡眠被剥夺是危险的。
• Missing the holiday was a great deprivation.错过假日是极大的损失。

266 mythological   

adj.神话的

参考例句：

• He is remembered for his historical and mythological works. 他以其带有历史感和神话色彩的作品而著称。
• But even so, the cumulative process had for most Americans a deep, almost mythological significance. 不过即使如此，移民渐增的过程，对于大部分美国人，还是意味深长的，几乎有不可思议的影响。

267 lasting   

adj.永久的，永恒的；vbl.持续，维持

参考例句：

• The lasting war debased the value of the dollar.持久的战争使美元贬值。
• We hope for a lasting settlement of all these troubles.我们希望这些纠纷能获得永久的解决。

268 discrepant   

差异的

参考例句：

• A HANDING FEE OF USD80. 00 TO BE DEDUCTED FOR ALL DISCREPANT. 有不符点的单据将收取80美元的费用。
• As the process, modern standard ought to be discrepant, grading. 作为过程，现代化的标准应当是有差异的、分阶段的。

269 strewing   

v.撒在…上( strew的现在分词 )；散落于；点缀；撒满

参考例句：

• What a mess! Look at the pajamas strewing on the bed. 真是乱七八糟！看看睡衣乱放在床上。 来自英汉 - 翻译样例 - 口语

270 cork   

n.软木，软木塞

参考例句：

• We heard the pop of a cork.我们听见瓶塞砰的一声打开。
• Cork is a very buoyant material.软木是极易浮起的材料。

271 acrimonious   

adj.严厉的，辛辣的，刻毒的

参考例句：

• He had an acrimonious quarrel with his girlfriend yesterday.昨天他跟他的女朋友激烈争吵了一番。
• His parents went through an acrimonious divorce.他的父母在激烈吵吵闹闹中离了婚。

272 outweigh   

vt.比...更重，...更重要

参考例句：

• The merits of your plan outweigh the defects.你制定的计划其优点胜过缺点。
• One's merits outweigh one's short-comings.功大于过。

273 anomalous   

adj.反常的；不规则的

参考例句：

• For years this anomalous behaviour has baffled scientists.几年来这种反常行为让科学家们很困惑。
• The mechanism of this anomalous vascular response is unknown.此种不规则的血管反应的机制尚不清楚。

274 ruptured   

v.（使）破裂( rupture的过去式和过去分词 )；（使体内组织等）断裂；使（友好关系）破裂；使绝交

参考例句：

• They reported that the pipeline had ruptured. 他们报告说管道已经破裂了。 来自《简明英汉词典》
• The wall through Berlin was finally ruptured, prefiguring the reunification of Germany. 柏林墙终于倒塌了，预示着德国的重新统一。 来自辞典例句

275 aphasic   

n. adj.患失语症者失语症的

参考例句：

• Aphasic examination revealed aphasia in 17 cases with dominant thalamic stroke. 17例优势侧丘脑卒中有不同程度的失语，而非优势侧丘脑卒中无失语表现。 来自互联网
• He was aphasic, they explained to the girl. 他们对女孩说他患了失语症。 来自互联网

276 lighter   

n.打火机，点火器；驳船；v.用驳船运送；light的比较级

参考例句：

• The portrait was touched up so as to make it lighter.这张画经过润色，色调明朗了一些。
• The lighter works off the car battery.引燃器利用汽车蓄电池打火。

277 momentary   

adj.片刻的，瞬息的；短暂的

参考例句：

• We are in momentary expectation of the arrival of you.我们无时无刻不在盼望你的到来。
• I caught a momentary glimpse of them.我瞥了他们一眼。

278 steer   

vt.驾驶，为…操舵；引导；vi.驾驶

参考例句：

• If you push the car, I'll steer it.如果你来推车，我就来驾车。
• It's no use trying to steer the boy into a course of action that suits you.想说服这孩子按你的方式行事是徒劳的。

279 corroborates   

v.证实，支持（某种说法、信仰、理论等）( corroborate的第三人称单数 )

参考例句：

• This article narrates a innovated dynamic penetration test method that mainly corroborates soil bearing capacity. 探讨了一种改进的动力触探方法，主要用于确定土的承载力。 来自互联网
• David, soon to be king of Israel, had an experience that corroborates this idea. 大卫即将成为以色列的国王之际，曾有过一次这样的经历。 来自互联网

280 atrophied   

adj.萎缩的，衰退的v.（使）萎缩，（使）虚脱，（使）衰退( atrophy的过去式和过去分词 )

参考例句：

• Patients exercised their atrophied limbs in the swimming pool. 病人们在泳池里锻炼萎缩的四肢。 来自辞典例句
• Method: Using microwave tissue thermocoaqulation to make chronic tonsillitis coagulated and atrophied. 方法：采用微波热凝方法使慢性扁桃体炎组织凝固、萎缩。 来自互联网

281 indirectly   

adv.间接地，不直接了当地

参考例句：

• I heard the news indirectly.这消息我是间接听来的。
• They were approached indirectly through an intermediary.通过一位中间人，他们进行了间接接触。

282 graphic   

adj.生动的，形象的，绘画的，文字的，图表的

参考例句：

• The book gave a graphic description of the war.这本书生动地描述了战争的情况。
• Distinguish important text items in lists with graphic icons.用图标来区分重要的文本项。

283 investigators   

n.调查者，审查者( investigator的名词复数 )

参考例句：

• This memo could be the smoking gun that investigators have been looking for. 这份备忘录可能是调查人员一直在寻找的证据。
• The team consisted of six investigators and two secretaries. 这个团队由六个调查人员和两个秘书组成。 来自《简明英汉词典》

284 statistical   

adj.统计的，统计学的

参考例句：

• He showed the price fluctuations in a statistical table.他用统计表显示价格的波动。
• They're making detailed statistical analysis.他们正在做具体的统计分析。

285 utterly   

adv.完全地，绝对地

参考例句：

• Utterly devoted to the people,he gave his life in saving his patients.他忠于人民，把毕生精力用于挽救患者的生命。
• I was utterly ravished by the way she smiled.她的微笑使我完全陶醉了。

286 linguistic   

adj.语言的，语言学的

参考例句：

• She is pursuing her linguistic researches.她在从事语言学的研究。
• The ability to write is a supreme test of linguistic competence.写作能力是对语言能力的最高形式的测试。

287 impaired   

adj.受损的；出毛病的；有（身体或智力）缺陷的v.损害，削弱( impair的过去式和过去分词 )

参考例句：

• Much reading has impaired his vision. 大量读书损害了他的视力。 来自《现代汉英综合大词典》
• His hearing is somewhat impaired. 他的听觉已受到一定程度的损害。 来自《现代汉英综合大词典》

288 articulation   

n.（清楚的）发音；清晰度，咬合

参考例句：

• His articulation is poor.他发音不清楚。
• She spoke with a lazy articulation.她说话慢吞吞的。

289 utterance   

n.用言语表达，话语，言语

参考例句：

• This utterance of his was greeted with bursts of uproarious laughter.他的讲话引起阵阵哄然大笑。
• My voice cleaves to my throat,and sob chokes my utterance.我的噪子哽咽，泣不成声。

290 irreproachably   

adv.不可非难地，无过失地

参考例句：

291 analyze   

vt.分析，解析 (=analyse)

参考例句：

• We should analyze the cause and effect of this event.我们应该分析这场事变的因果。
• The teacher tried to analyze the cause of our failure.老师设法分析我们失败的原因。

292 conspires   

密谋( conspire的第三人称单数 )； 搞阴谋； （事件等）巧合； 共同导致

参考例句：

• You speak as if all Sparta conspires against you. 你说得好像整个斯巴达在共谋对抗你。
• The mystical organization syndicate, conspires to harass the social order. 神秘组织辛迪加，密谋扰乱社会治安。

293 withdrawn   

vt.收回；使退出；vi.撤退，退出

参考例句：

• Our force has been withdrawn from the danger area.我们的军队已从危险地区撤出。
• All foreign troops should be withdrawn to their own countries.一切外国军队都应撤回本国去。

294 sluggish   

adj.懒惰的，迟钝的，无精打采的

参考例句：

• This humid heat makes you feel rather sluggish.这种湿热的天气使人感到懒洋洋的。
• Circulation is much more sluggish in the feet than in the hands.脚部的循环比手部的循环缓慢得多。

295 differentiated   

区分，区别，辨别( differentiate的过去式和过去分词 )； 区别对待； 表明…间的差别，构成…间差别的特征

参考例句：

• The development of mouse kidney tubules requires two kinds of differentiated cells. 小鼠肾小管的发育需要有两种分化的细胞。
• In this enlargement, barley, alfalfa, and sugar beets can be differentiated. 在这张放大的照片上，大麦，苜蓿和甜菜都能被区分开。

296 primitive   

adj.原始的；简单的；n.原(始)人，原始事物

参考例句：

• It is a primitive instinct to flee a place of danger.逃离危险的地方是一种原始本能。
• His book describes the march of the civilization of a primitive society.他的著作描述了一个原始社会的开化过程。

297 bruising   

adj.殊死的；十分激烈的v.擦伤(bruise的现在分词形式)

参考例句：

• He suffered cracked ribs and bruising. 他断了肋骨还有挫伤。
• He slipped and fell, badly bruising an elbow. 他滑倒了，一只胳膊肘严重擦伤。 来自辞典例句

298 subtlety   

n.微妙，敏锐，精巧；微妙之处，细微的区别

参考例句：

• He has shown enormous strength,great intelligence and great subtlety.他表现出充沛的精力、极大的智慧和高度的灵活性。
• The subtlety of his remarks was unnoticed by most of his audience.大多数听众都没有觉察到他讲话的微妙之处。

299 peculiarity   

n.独特性，特色；特殊的东西；怪癖

参考例句：

• Each country has its own peculiarity.每个国家都有自己的独特之处。
• The peculiarity of this shop is its day and nigth service.这家商店的特点是昼夜服务。

300 retrace   

v.折回；追溯，探源

参考例句：

• He retraced his steps to the spot where he'd left the case.他折回到他丢下箱子的地方。
• You must retrace your steps.你必须折回原来走过的路。

301 bereft   

adj.被剥夺的

参考例句：

• The place seemed to be utterly bereft of human life.这个地方似乎根本没有人烟。
• She was bereft of happiness.她失去了幸福。

302 incessantly   

ad.不停地

参考例句：

• The machines roar incessantly during the hours of daylight. 机器在白天隆隆地响个不停。
• It rained incessantly for the whole two weeks. 雨不间断地下了整整两个星期。

303 rodents   

n.啮齿目动物( rodent的名词复数 )

参考例句：

• Rodents carry diseases and are generally regarded as pests. 啮齿目动物传播疾病，常被当作害虫对待。 来自《简明英汉词典》
• Some wild rodents in Africa also harbor the virus. 在非洲，有些野生啮齿动物也是储毒者。 来自辞典例句

304 conspicuous   

adj.明眼的，惹人注目的；炫耀的，摆阔气的

参考例句：

• It is conspicuous that smoking is harmful to health.很明显，抽烟对健康有害。
• Its colouring makes it highly conspicuous.它的色彩使它非常惹人注目。

305 merge   

v.(使)结合，(使)合并，(使)合为一体

参考例句：

• I can merge my two small businesses into a large one.我可以将我的两家小商店合并为一家大商行。
• The directors have decided to merge the two small firms together.董事们已决定把这两家小商号归并起来。

306 merges   

（使）混合( merge的第三人称单数 )； 相融； 融入； 渐渐消失在某物中

参考例句：

• The 2012 Nobel Prize in Literature was awarded to Mo Yan"who with hallucinatory realism merges folk tales, history and the contemporary". 2012年诺贝尔文学奖得主为莫言，他“很好地将魔幻现实与民间故事、历史与当代结合在一起”。
• A device that collates, merges, or matches sets of punched cards or other documents. 一种整理、合并或比较一组穿孔卡片或其它文档的设备。

307 extremities   

n.端点( extremity的名词复数 )；尽头；手和足；极窘迫的境地

参考例句：

• She was most noticeable, I thought, in respect of her extremities. 我觉得她那副穷极可怜的样子实在太惹人注目。 来自辞典例句
• Winters may be quite cool at the northwestern extremities. 西北边区的冬天也可能会相当凉。 来自辞典例句

308 funnel   

n.漏斗；烟囱；v.汇集

参考例句：

• He poured the petrol into the car through a funnel.他用一个漏斗把汽油灌入汽车。
• I like the ship with a yellow funnel.我喜欢那条有黄烟囱的船。

309 annihilated   

v.（彻底）消灭( annihilate的过去式和过去分词 )；使无效；废止；彻底击溃

参考例句：

• Our soldiers annihilated a force of three hundred enemy troops. 我军战士消灭了300名敌军。 来自《现代汉英综合大词典》
• We annihilated the enemy. 我们歼灭了敌人。 来自《简明英汉词典》

310 inhibited   

a.拘谨的，拘束的

参考例句：

• Boys are often more inhibited than girls about discussing their problems. 男孩子往往不如女孩子敢于谈论自己的问题。
• Having been laughed at for his lameness,the boy became shy and inhibited. 那男孩因跛脚被人讥笑，变得羞怯而压抑。

311 defenders   

n.防御者( defender的名词复数 )；守卫者；保护者；辩护者

参考例句：

• The defenders were outnumbered and had to give in. 抵抗者寡不敌众，只能投降。 来自《简明英汉词典》
• After hard fighting,the defenders were still masters of the city. 守军经过奋战仍然控制着城市。 来自《简明英汉词典》

312 inhibits   

阻止，抑制( inhibit的第三人称单数 )； 使拘束，使尴尬

参考例句：

• A small manufacturing sector inhibits growth in the economy. 制造业规模太小有碍经济增长。
• His bad English inhibits him from speaking freely. 他英语学得不好，这使他不能表达自如。

313 intestinal   

adj.肠的；肠壁；肠道细菌

参考例句：

• A few other conditions are in high intestinal obstruction. 其它少数情况是高位肠梗阻。 来自辞典例句
• This complication has occasionally occurred following the use of intestinal antiseptics. 这种并发症偶而发生在使用肠道抗菌剂上。 来自辞典例句

314 treatises   

n.专题著作，专题论文，专著( treatise的名词复数 )

参考例句：

• Many treatises in different languages have been published on pigeons. 关于鸽类的著作，用各种文字写的很多。 来自辞典例句
• Many other treatises incorporated the new rigor. 许多其它的专题论文体现了新的严密性。 来自辞典例句

315 surgical   

adj.外科的，外科医生的，手术上的

参考例句：

• He performs the surgical operations at the Red Cross Hospital.他在红十字会医院做外科手术。
• All surgical instruments must be sterilised before use.所有的外科手术器械在使用之前，必须消毒。

316 plausibly   

似真地

参考例句：

• The case was presented very plausibly. 案情的申述似很可信。
• He argued very plausibly for its acceptance. 他为使之认可辩解得头头是道。

317 disappearance   

n.消失，消散，失踪

参考例句：

• He was hard put to it to explain her disappearance.他难以说明她为什么不见了。
• Her disappearance gave rise to the wildest rumours.她失踪一事引起了各种流言蜚语。

318 systematically   

adv.有系统地

参考例句：

• This government has systematically run down public services since it took office.这一屆政府自上台以来系统地削减了公共服务。
• The rainforest is being systematically destroyed.雨林正被系统地毀灭。

319 subtraction   

n.减法，减去

参考例句：

• We do addition and subtraction in arithmetic.在算术里,我们作加减运算。
• They made a subtraction of 50 dollars from my salary.他们从我的薪水里扣除了五十美元。

320 speculation   

n.思索，沉思；猜测；投机

参考例句：

• Her mind is occupied with speculation.她的头脑忙于思考。
• There is widespread speculation that he is going to resign.人们普遍推测他要辞职。

321 exhaustion   

n.耗尽枯竭，疲惫，筋疲力尽，竭尽，详尽无遗的论述

参考例句：

• She slept the sleep of exhaustion.她因疲劳而酣睡。
• His exhaustion was obvious when he fell asleep standing.他站着睡着了，显然是太累了。

322 lodged   

v.存放( lodge的过去式和过去分词 )；暂住；埋入；（权利、权威等）归属

参考例句：

• The certificate will have to be lodged at the registry. 证书必须存放在登记处。 来自《简明英汉词典》
• Our neighbours lodged a complaint against us with the police. 我们的邻居向警方控告我们。 来自《简明英汉词典》

323 regained   

复得( regain的过去式和过去分词 )； 赢回； 重回； 复至某地

参考例句：

• The majority of the people in the world have regained their liberty. 世界上大多数人已重获自由。
• She hesitated briefly but quickly regained her poise. 她犹豫片刻，但很快恢复了镇静。

324 abeyance   

n.搁置，缓办，中止，产权未定

参考例句：

• The question is in abeyance until we know more about it.问题暂时搁置，直到我们了解更多有关情况再行研究。
• The law was held in abeyance for well over twenty years.这项法律被搁置了二十多年。

325 accomplished   

adj.有才艺的；有造诣的；达到了的

参考例句：

• Thanks to your help,we accomplished the task ahead of schedule.亏得你们帮忙,我们才提前完成了任务。
• Removal of excess heat is accomplished by means of a radiator.通过散热器完成多余热量的排出。

326 canine   

adj.犬的，犬科的

参考例句：

• The fox is a canine animal.狐狸是犬科动物。
• Herbivorous animals have very small canine teeth,or none.食草动物的犬牙很小或者没有。

327 minor   

adj.较小(少)的，较次要的；n.辅修学科；vi.辅修

参考例句：

• The young actor was given a minor part in the new play.年轻的男演员在这出新戏里被分派担任一个小角色。
• I gave him a minor share of my wealth.我把小部分财产给了他。

328 resistant   

adj.(to)抵抗的，有抵抗力的

参考例句：

• Many pests are resistant to the insecticide.许多害虫对这种杀虫剂有抵抗力。
• They imposed their government by force on the resistant population.他们以武力把自己的统治强加在持反抗态度的人民头上。

329 residual   

adj.复播复映追加时间；存留下来的，剩余的

参考例句：

• There are still a few residual problems with the computer program.电脑程序还有一些残留问题。
• The resulting residual chromatism is known as secondary spectrum.所得到的剩余色差叫做二次光谱。

330 prophesied   

v.预告，预言( prophesy的过去式和过去分词 )

参考例句：

• She prophesied that she would win a gold medal. 她预言自己将赢得金牌。
• She prophesied the tragic outcome. 她预言有悲惨的结果。 来自《简明英汉词典》

331 vivacity   

n.快活，活泼，精神充沛

参考例句：

• Her charm resides in her vivacity.她的魅力存在于她的活泼。
• He was charmed by her vivacity and high spirits.她的活泼与兴高采烈的情绪把他迷住了。

332 darted   

v.投掷，投射( dart的过去式和过去分词 )；向前冲，飞奔

参考例句：

• The lizard darted out its tongue at the insect. 蜥蜴伸出舌头去吃小昆虫。 来自《简明英汉词典》
• The old man was displeased and darted an angry look at me. 老人不高兴了，瞪了我一眼。 来自《简明英汉词典》

333 jaws   

n.口部；嘴

参考例句：

• The antelope could not escape the crocodile's gaping jaws. 那只羚羊无法从鱷鱼张开的大口中逃脱。
• The scored jaws of a vise help it bite the work. 台钳上有刻痕的虎钳牙帮助它紧咬住工件。

334 morsels   

n.一口( morsel的名词复数 )；（尤指食物）小块，碎屑

参考例句：

• They are the most delicate morsels. 这些确是最好吃的部分。 来自辞典例句
• Foxes will scratch up grass to find tasty bug and beetle morsels. 狐狸会挖草地，寻找美味的虫子和甲壳虫。 来自互联网

335 aquarium   

n.水族馆，养鱼池，玻璃缸

参考例句：

• The first time I saw seals was in an aquarium.我第一次看见海豹是在水族馆里。
• I'm going to the aquarium with my parents this Sunday.这个星期天，我要和父母一起到水族馆去。

336 perseverance   

n.坚持不懈，不屈不挠

参考例句：

• It may take some perseverance to find the right people.要找到合适的人也许需要有点锲而不舍的精神。
• Perseverance leads to success.有恒心就能胜利。

337 pebbles   

[复数]鹅卵石； 沙砾； 卵石，小圆石( pebble的名词复数 )

参考例句：

• The pebbles of the drive crunched under his feet. 汽车道上的小石子在他脚底下喀嚓作响。
• Line the pots with pebbles to ensure good drainage. 在罐子里铺一层鹅卵石，以确保排水良好。

338 persuasive   

adj.有说服力的，能说得使人相信的

参考例句：

• His arguments in favour of a new school are very persuasive.他赞成办一座新学校的理由很有说服力。
• The evidence was not really persuasive enough.证据并不是太有说服力。

339 somnolence   

n.想睡，梦幻；欲寐；嗜睡；嗜眠

参考例句：

• At length he managed to get him into a condition of somnolence. 他终于促使他进入昏昏欲睡的状态。 来自辞典例句
• A lazy somnolence descended on the crowd. 一阵沉沉欲睡的懒意降落在人群里面。 来自辞典例句

340 indefatigably   

adv.不厌倦地，不屈不挠地

参考例句：

• AOBO-willing to create a beautiful future by working indefatigably with you! 奥博(AOBO)愿以不懈的努力，与你共同演绎美好的未来！ 来自互联网
• Pursue your object, be it what it will, steadily and indefatigably. 不管追求什么目标，都应坚持不懈。 来自互联网

341 decided   

adj.决定了的，坚决的；明显的，明确的

参考例句：

• This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
• There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。

342 forsake   

vt.遗弃，抛弃；舍弃，放弃

参考例句：

• She pleaded with her husband not to forsake her.她恳求丈夫不要抛弃她。
• You must forsake your bad habits.你必须革除你的坏习惯。

343 sufficiently   

adv.足够地，充分地

参考例句：

• It turned out he had not insured the house sufficiently.原来他没有给房屋投足保险。
• The new policy was sufficiently elastic to accommodate both views.新政策充分灵活地适用两种观点。

344 opposition   

n.反对，敌对

参考例句：

• The party leader is facing opposition in his own backyard.该党领袖在自己的党內遇到了反对。
• The police tried to break down the prisoner's opposition.警察设法制住了那个囚犯的反抗。

345 incurable   

adj.不能医治的，不能矫正的，无救的；n.不治的病人，无救的人

参考例句：

• All three babies were born with an incurable heart condition.三个婴儿都有不可治瘉的先天性心脏病。
• He has an incurable and widespread nepotism.他们有不可救药的，到处蔓延的裙带主义。

346 virgin   

n.处女，未婚女子；adj.未经使用的；未经开发的

参考例句：

• Have you ever been to a virgin forest?你去过原始森林吗？
• There are vast expanses of virgin land in the remote regions.在边远地区有大片大片未开垦的土地。

347 irresistible   

adj.非常诱人的，无法拒绝的，无法抗拒的

参考例句：

• The wheel of history rolls forward with an irresistible force.历史车轮滚滚向前，势不可挡。
• She saw an irresistible skirt in the store window.她看见商店的橱窗里有一条叫人着迷的裙子。

348 impulsive   

adj.冲动的，刺激的；有推动力的

参考例句：

• She is impulsive in her actions.她的行为常出于冲动。
• He was neither an impulsive nor an emotional man,but a very honest and sincere one.他不是个一冲动就鲁莽行事的人，也不多愁善感.他为人十分正直、诚恳。

349 impersonal   

adj.无个人感情的，与个人无关的，非人称的

参考例句：

• Even his children found him strangely distant and impersonal.他的孩子们也认为他跟其他人很疏远，没有人情味。
• His manner seemed rather stiff and impersonal.他的态度似乎很生硬冷淡。

350 hermit   

n.隐士，修道者；隐居

参考例句：

• He became a hermit after he was dismissed from office.他被解职后成了隐士。
• Chinese ancient landscape poetry was in natural connections with hermit culture.中国古代山水诗与隐士文化有着天然联系。

351 languishing   

a. 衰弱下去的

参考例句：

• He is languishing for home. 他苦思家乡。
• How long will she go on languishing for her red-haired boy? 为想见到她的红头发的儿子，她还将为此烦恼多久呢？

352 rattling   

adj. 格格作响的, 活泼的, 很好的 adv. 极其, 很, 非常 动词rattle的现在分词

参考例句：

• This book is a rattling good read. 这是一本非常好的读物。
• At that same instant,a deafening explosion set the windows rattling. 正在这时，一声震耳欲聋的爆炸突然袭来，把窗玻璃震得当当地响。

353 strictly   

adv.严厉地，严格地；严密地

参考例句：

• His doctor is dieting him strictly.他的医生严格规定他的饮食。
• The guests were seated strictly in order of precedence.客人严格按照地位高低就座。

354 elastic   

n.橡皮圈，松紧带；adj.有弹性的；灵活的

参考例句：

• Rubber is an elastic material.橡胶是一种弹性材料。
• These regulations are elastic.这些规定是有弹性的。

355 realization   

n.实现；认识到，深刻了解

参考例句：

• We shall gladly lend every effort in our power toward its realization.我们将乐意为它的实现而竭尽全力。
• He came to the realization that he would never make a good teacher.他逐渐认识到自己永远不会成为好老师。

356 hawks   

鹰( hawk的名词复数 )； 鹰派人物，主战派人物

参考例句：

• Two hawks were hover ing overhead. 两只鹰在头顶盘旋。
• Both hawks and doves have expanded their conditions for ending the war. 鹰派和鸽派都充分阐明了各自的停战条件。

357 touching   

adj.动人的，使人感伤的

参考例句：

• It was a touching sight.这是一幅动人的景象。
• His letter was touching.他的信很感人。

358 entangling   

v.使某人（某物/自己）缠绕，纠缠于（某物中），使某人（自己）陷入（困难或复杂的环境中）( entangle的现在分词 )

参考例句：

• We increasingly want an end to entangling alliances. 我们越来越想终止那些纠缠不清的盟约。 来自辞典例句
• What a thing it was to have her love him, even if it be entangling! 得到她的爱是件多么美妙的事，即使为此陷入纠葛中去也值得！ 来自英汉文学 - 嘉莉妹妹

359 dubious   

adj.怀疑的，无把握的；有问题的，靠不住的

参考例句：

• What he said yesterday was dubious.他昨天说的话很含糊。
• He uses some dubious shifts to get money.他用一些可疑的手段去赚钱。