The thud, thud of a horse's hoof does not alarm fish. Basking in the sun under the bank, a jack or pike lying close to the surface of the water will remain unmoved, however heavy the sound may be. The vibrations reach the fish in several ways. There is what we should ourselves call the noise as conveyed by the air, and which in the case of a jack actually at the surface may be supposed to reach him direct. Next there is the vibration passing through the water, which is usually pronounced to be a good medium. Lastly, there is the bodily movement of the substance of the water. When the bank is hard and dry this latter amounts only to a slight shaking, but it frequently happens that the side of a brook or pond is soft, and "gives" under a heavy weight. Sometimes the edge is even pushed into the water, and the brook in a manner squeezed. You can see this when cattle walk by the margin the grassy edge is pushed out, and in a minute way they may be said to contract the stream. It is in too small a degree to have the least apparent effect upon the water, but it is different with the sense of hearing, which is so delicate that the bodily movement thus caused may be reasonably believed to be very audible indeed to the jack. The wire fences which are now so much used round shrubberies and across parks give a very good illustration of the conveyance of sound. Strung tight by a spanner, the strands of twisted wire resemble a stringed instrument. If you place your hand on one of the wires and get a friend to strike it with his stick, say, thirty or forty yards away, you will distinctly feel it vibrate. If the ear is held close enough you will hear it, vibration and sound being practically convertible terms. To the basking jack three such wires extend, and when the cart-horse in the meadow puts down his heavy hoof he strikes them all at once. Yet, though fish are so sensitive to sound, the jack is not in the least alarmed, and there can be little doubt that he knows what it is. A whole herd of cattle feeding and walking about does not disturb him, but if the light step--light in comparison--of a man approach, away he goes. Poachers, therefore, unable to disguise their footsteps, endeavour to conceal them, and by moving slowly to avoid vibrating the earth, and through it the water.
In poaching, the intelligence of the man is backed against the intelligence of the fish or animal, and the poacher tries to get himself into the ways of the creature he means to snare. That is what really takes place as seen by us as lookers-on; to the poacher himself, in nine out of ten cases, it is merely an acquired knack learned from watching others, and improved by practice. But to us, as lookers-on, this is what occurs: the man fits himself to the ways of the creature, and for the time it becomes a struggle between them. It is the same with the Red Indians, and the white trappers and hunters in wild regions, who depend much more on their knowledge of the ways and habits of the fur-bearing animals than upon their skill with the rifle. A man may be an excellent shot with gun or rifle, and yet be quite incapable of coping on comparatively equal terms with wild creatures. He is a sportsman, depending on skill, quick sight, and ready hand--not a hunter. Perhaps the nearest approach to it in legitimate, English sport is in fly-fishing and salmon fishing, when the sportsman relies upon his own unassisted efforts. Deer-stalking, where the sportsman has to reckon on the wind, and its curious twists and turns in valleys and round rocks, would be a very near approach to it did the stalker stalk alone. But all this work is usually done for him by an attendant, a native Highlander; and this man really does pit his intelligence against that of the stag. The Highlander actually is a Red Indian, or hunter, and in this sense struggles with the wild animal. The poacher is the hunter on illegitimate ground, and with arts which it has been mutually agreed shall not be employed.
Considered in this sense it is interesting to observe to what extent the intelligence even of a fish reaches--and I think upon reflection it will be found that the fish is as clever as any creature could be in its position. I deny altogether that the cold-blooded fish--looked on with contempt so far as its intellectual powers are concerned--is stupid, or slow to learn. On the contrary, fish are remarkably quick, not only under natural conditions, but quick at accommodating themselves to altered circumstances which they could not foresee, and the knowledge how to meet which could not have been inherited. The basking jack is not alarmed at the cart-horse's hoofs, but remains quiet, let them come down with ever so heavy a thud. He has observed that these vibrations never cause him any injury. He hears them at all periods of the day and night, often with long intervals of silence and with every possible variation. Never once has the sound been followed by injury or by anything to disturb his peace. So the rooks have observed that passing trains are harmless, and will perch on the telegraph wires or poles over the steam of the roaring locomotive. Observation has given them confidence. Thunder of wheels and immense weight in motion, the open furnace and glaring light, the faces at the long tier of windows--all these terrors do not ruffle a feather. A little boy with a wooden clapper can set a flock in retreat immediately. Now the rooks could not have acquired this confidence in the course of innumerable generations; it is not hereditary; it is purely what we understand by intelligence. Why are the rooks afraid of the little boy with the clapper? Because they have noticed his hostile intent. Why is the basking jack off the instant he hears the light step of a man?
He has observed that after this step there have often followed attempts to injure him; a stone has been flung at him, a long pole thrust into the water; he has been shot at, or felt the pinch of a wire. He remembers this, and does not wait for the attempt to be repeated, but puts himself into safety. If he did not realise that it was a man--and a possible enemy--he would not trouble. The object consequently of the tricks of the poacher is to obliterate himself. If you can contrive to so move, and to so conduct yourself that the fish shall not recognise you as his enemy, you can do much as you please with him, and in varying degrees it is the same with animals. Think a moment by what tokens a fish recognises a man. First, his light, and, compared with other animals, brisk step--a two-step instead of a four-step, remember; two feet, not four hoofs. There is a difference at once in the rhythm of the noise. Four hoofs can by no possibility produce the same sound, or succession of sounds, as is made even by four feet--that is, by two men. The beats are not the same. Secondly, by his motions, and especially the brisk motions of the arms. Thirdly, by this briskness itself; for most animals, except man, move with a slow motion--paradox as it may seem--even when they are going along fast. With them it is usually repose in action. Fourthly, and this is rather curious--experience seems to show that fish, and animals and birds certainly, recognise man by his hat or cap, to which they have a species of superstitious dislike.
Hats are generally of a different hue to the rest of the suit, for one thing; and it was noted, a century ago, that wild creatures have a particular objection to a black hat. A covering to the head at all is so Opposite to their own ideas that it arouses suspicion, for we must remember that animals look on our clothes as our skin. To have a black skin over the hair of the head is somewhat odd. By all these signs a fish knows a man immediately, and as certainly as any creature moving on land would know him. There is no instinctive or hereditary fear of man at all--it is acquired by observation (which a thousand facts demonstrate); so that we are quite justified in believing that a fish really does notice some or all of these attributes of its enemy. What the poacher or wild hunter has to do is to conceal these attributes. To hide the two-step, he walks as slowly as possible, not putting the foot down hard, but feeling the ground first, and gradually pressing it. In this way progress may be made without vibration. The earth is not shaken, and does not communicate the sound to the water. This will bring him to the verge of the place where the fish is basking.
Very probably not only fish, but animals and some birds hear as much by the vibration of the earth as by the sound travelling in the atmosphere, and depend as much upon their immediate perception of the slightest tremor of the earth as upon recognition by the ear in the manner familiar to ourselves. When rabbits, for instance, are out feeding in the grass, it is often possible to get quite close to them by walking in this way, extremely slowly, and carefully placing the foot by slow degrees upon the ground. The earth is then merely pressed, and not stepped upon at all, so that there is no jar. By doing this I have often moved up within gunshot of rabbits without the least aid from cover. Once now and then I have walked across a field straight at them. Something, however, depends on the direction of the wind, for then the question of scent comes in. To some degree it is the same with hares. It is certainly the case with birds, as wood-pigeons, a flock of them, will remain feeding only just the other side of the hedge; but, if you stamp the earth, will rise instantly. So will rooks, though they will not fly far if you are not armed. Partridges certainly secure themselves by their attention to the faint tremor of the ground. Pheasants do so too, and make off, running through the underwood long before any one is in sight. The most sensitive are landrails, and it is difficult to get near them, for this reason. Though the mowing-grass must conceal an approaching person from them as it conceals them from him, these birds change their positions, no matter how quietly he walks. Let him be as cunning as he will, and think to cut off corners and cross the land-rail's retreat, the bird baffles him nine times in ten. That it is advised of the direction the pursuer takes by the vibration of the surface is at least probable. Other birds sit, and hope to escape by remaining still, till they detect the tremor coming direct towards them, when they rise.
Rain and dry weather change the susceptibility of the surface to vibrate, and may sometimes in part account for the wildness or apparent tameness of birds and animals. Should any one doubt the existence of such tremors, he has only to lie on the ground with his ear near the surface; but, being unused to the experiment, he will at first only notice the heavier sounds, as of a waggon or a cart-horse. In recent experiments with most delicate instruments devised to show the cosmic vibration of the earth, the movements communicated to it by the tides, or by the "pull" of the sun and moon, it has been found almost impossible as yet to carry out the object, so greatly are these movements obscured by the ceaseless and inexplicable vibrations of the solid earth. There is nothing unreasonable in the supposition that, if an instrument can be constructed to show these, the ears of animals and birds--living organisms, and not iron and steel--should be able to discover the tremors of the surface.
The wild hunter can still further check or altogether prevent observation by moving on hands and knees, when his weight is widely distributed. In the particular instance of a fish he endeavours to come to the margin of the water at the rear of the fish, whose eyes are so placed that it can see best in front. When he has arrived at the margin, and has to rear himself up, if from hands and knees, or, if already upright, when he commences his work, he tries to conceal his arms, or, rather, to minimise their peculiar appearance as much as practicable by keeping them close to his sides. All this time I am supposing that you are looking at the poacher from the fish. To a fish or any wild animal the arms of a man are suspicious. No other creature that they know possesses these singular appurtenances, which move in almost any direction, and yet have nothing to do with locomotion. You may be sure that this great difference in the anatomical construction of a man is recognised by all wild animals once they are compelled for their own safety to observe him. Arms are so entirely opposite to all the varieties of limb possessed by the varieties of living creatures.
Can you put yourselves in the position of either of these creatures--moving on all-fours, on wings, or by the aid of a membraneous tail and fins, and without arms, and imagine how strange the arms of a man must look? Suppose yourself with your arms tucked to your sides under the fur of an animal; something of the idea may be gathered by putting on a cloak without sleeves or armholes. At once it will be apparent how helpless all creatures are in comparison with man. It is true that apes are an exception; yet their arms are also legs, and they are deficient in the power of the thumb. Man may be defined as an animal with arms. While the creatures of the field or the water have no cause to fear him they do not observe him, but the moment they learn that he is bent on their destruction they watch him narrowly, and his arms are, above all, the part which alarms them. To them these limbs are men's weapons--his tusks, and tusks which strike and wound afar. From these proceed an invisible force which can destroy where it would seem the intervening distance alone would afford safety. The sharp shot, the keen hook, the lacerating wire, the spear--everything which kills or wounds, comes in some manner or other from the arms, down to the stone or the primitive knob-kerrie. Consequently animals, birds, and fishes not only in our own, but in the wildest countries, have learned to watch and to dread man's arms. He raises his arms, and in an instant there shoots forth a bright flash of flame, and before the swift wings can beat the air again the partridge is dashed to the ground.
So long as a gun is carried under the arm--that is, with the arms close to the sides--many birds will let the sportsman approach. Rabbits will do the same. Rabbits have one advantage (and perhaps only one): being numerous and feeding out by daylight, all kinds of experiments can be tried on them, while hares are not so easily managed. Suppose a rabbit feeding, and any one with a gun creeping up beside the hedge, while the gun is kept down and the arms down the rabbit remains still; the instant the arms are lifted to point the gun, up he sits, or off he goes. You have only to point your arm at a rook, without any gun, to frighten him. Bird-keepers instinctively raise their arms above their heads, when shouting, to startle birds. Every creature that has ever watched man knows that his arms are dangerous. The poacher or wild hunter has to conceal his arms by reducing their movements to a minimum, and by conducting those movements as slowly as possible.
To thoroughly appreciate the importance which animals of all kinds put on the motions of the upper limbs, and to put one's self quite in their position, one has only to recall to mind the well-known trick of the Australian bushrangers. "Bail up!" is their order when they suddenly produce their revolvers; "Bail up!" they shout to the clerks of the bank they are about to sack, to the inmates of a house, or to the travellers they meet on the road. "Hold your arms above your head" is the meaning; and, if it is not immediately obeyed, they fire. They know that every man has a pistol in his pocket or belt; but he cannot use it if compelled to keep his arms high over his head. One or more of the band keep a sharp look-out on the upheld arms while the rest plunder; and, if any are lowered--bang! Like the animals, they know the extreme danger to be apprehended from movements of the human arms. So long as the human arms are "bailed" (though in this case in an opposite direction, i.e. held down), animals are not afraid. Could they make us "bail up," we should be helpless to injure them. Moving his arms as gently as possible, with the elbows close to his sides, the poacher proceeds to slowly push his rod and wire loop towards the basking jack. If he were going to shoot partridges at roost on the ground, he would raise his gun in an equally slow and careful manner. As a partridge is a small bird, and stands at about a shilling in the poacher's catalogue, he does not care to risk a shot at one, but likes to get several at once. This he can do in the spring, when the birds have paired and remain so near together, and again in the latter part of the summer, when the coveys are large, not having yet been much broken up by the sportsmen. These large coveys, having enjoyed an immunity from disturbance all through the summer, wandering at their own will among clover and corn, are not at all difficult to approach, and a shot at them through a gap in a hedge will often bring down four or five. Later on the poacher takes them at roost. They roost on the ground in a circle, heads outwards, much in the same position as the eggs of a lapwing. The spot is marked; and at night, having crept up near enough, the poacher fires at the spot itself rather than at the birds, with a gun loaded with a moderate charge of powder, but a large quantity of shot, that it may spread wide. On moderately light nights he can succeed at this game. It is in raising the arms to point the gun that the risk of alarming the birds has to be met; and so with a hare sitting in a form in daytime. Lift your arms suddenly, and away she goes; keep your arms still, and close to your side, and she will sit till you have crept up actually to her very side, and can pounce on her if you choose.
Sometimes, where fish have not been disturbed by poachers, or loafers throwing stones and otherwise annoying them, they will not heed a passer-by, whose gentle walk or saunter does not affright them with brisk emotion, especially if the saunterer, on espying them, in no degree alters his pace or changes his manner. That wild creatures immediately detect a change of manner, and therefore of mood, any one may demonstrate for himself They are as quick to see it as the dog, who is always with his master, and knows by the very way he puts a book on the table what temper he is in. When a book goes with a bang on the table the dog creeps under it. Wild creatures, too, catch their manners from man. Walk along a lane with your hands in your pockets, and you will see twice as much of the birds and animals, because they will not set themselves to steadfastly watch you. A quick movement sets wings quickly beating. I have noticed that even horses in stables do not like visitors with jerky, brisk, angular ways of moving. A stranger entering in a quiet, easy manner is not very objectionable, but if he comes in in a bustling, citizen-like style, it is quite probable that one or other horse will show a wicked white corner in his eye. It roughs them up the wrong way. Especially all wild creatures dislike the shuffling, mincing step so common in towns. That alone will disturb everything. Indeed, I have often thought that a good and successful wild hunter--like the backwoods. man, or the sportsman in African bush or Indian jungle--is really made as much by his feet as his eyes or hands. Unconsciously he feels with his feet; they come to know the exact time to move, whether a long or short stride be desirable, and where to put down, not to rustle or cause a cracking sound, and accommodate themselves to the slope of the ground, touching it and holding it like hands. A great many people seem to have no feet; they have boots, but no feet. They stamp or clump, or swing their boots along and knock the ground at every step; this matters not in most callings, but if a man wish to become what I have called a wild hunter, he must let his feet learn. He must walk with hands in his boots. Now and then a person walks like this naturally, and he will come in and tell you that he has seen a fish basking, a partridge, a hare, or what not, when another never gets near anything. This is where they have not been much disturbed by loafers, who are worse than poachers.
As a rule, poachers are intermittent in their action, and they do not want to disturb the game, as it makes it wild and interferes with their profits. Loafers are not intermittent--they are always about, often in gangs, and destroy others' sports without having any themselves. Near large towns there are places where the fish have to be protected with hurdles thrown across the stream on poles, that the stones and brickbats hurled by every rascal passing may not make their very life a burden. A rural poacher is infinitely preferable. The difference in the ways of fish when they have been much disturbed and when they have been let alone is at at once discerned. No sooner do you approach a fish who has been much annoyed and driven than he strikes, and a quick-rotating curl on the surface shows with what vehemence his tail was forced against it. In other places, if a fish perceives you, he gives himself so slight a propulsion that the curl hardly rises, and you can see him gliding slowly into the deeper or overshadowed water. If in terror he would go so quickly as to be almost invisible. In places where the fish have been much disturbed the poacher, or any one who desires to watch their habits, has to move as slowly as the hands of a clock, and even then they will scarcely bear the very sight of a man, sometimes not at all. The least briskness of movement would send them into the depths out of sight. Cattle, to whom they are accustomed, walk slowly, and so do horses left to themselves in the meads by water. The slowest man walking past has quicker, perhaps because shorter, movements than those of cattle and horses, so that, even when bushes intervene and conceal his form, his very ways often proclaim him.
Most people will only grant a moderate degree of intelligence to fish, linking coldness of blood to narrowness of intellect, and convinced that there can be but little brain in so small a compass as its head. That the jack can compete with the dog, of course, is out of the question: but I am by no means prepared to admit that fish are so devoid of sense as supposed. Not long since an experiment was tried with a jack, an account of which appeared in the papers. The jack was in a tank, and after awhile the tank was partly divided by inserting a plate of glass. He was then hunted round, and notes taken of the number of times he bumped his head against the plate of glass, and how long it took him to learn that there was something to obstruct his path. Further statistics were kept as to the length of his memory when he had learnt the existence of the glass--that is, to see if he would recollect it several days afterwards. The fish was some time learning the position of the glass; and then, if much alarmed, he would forget its position and dash against it. But he did learn it, and retained his memory some while. It seems to me that this was a very hard and unfair test. The jack had to acquire the idea of something transparent, and yet hard as wood. A moment's thought will show how exactly opposite the qualities of glass are to anything either this particular fish or his ancestors could have met with--no hereditary intelligence to aid him, no experience bearing, however slightly, upon the subject.
Accustomed all his life to transparent water, he had also been accustomed to find it liquid, and easily parted. Put suddenly face to face with the transparent material which repelled him, what was he to think? Much the same effect would be produced if you or I, having been accustomed, of course, all our lives, to the fluidity of air, which opens for our passage, were opposed by a solid block of transparent atmosphere. Imagine any one running for a train, and striking his head with all his might against such a block. He would rise, shake himself together, and endeavour to pursue his journey, and be again repelled. More than likely he would try three times before he became convinced that it really was something in the air itself which stopped him. Then he would thrust with his stick and feel, more and more astounded every moment, and scarcely able to believe his own senses. During the day, otherwise engaged, he would argue himself into the view that he had made a mistake, and determine to try again, though more cautiously. But so strong is habit that if a cause for alarm arose, and he started running, he might quite probably go with tremendous force up to the solid block of transparent air, to be hurled back as the jack was.
These are no mere suppositions, for quite recently I heard of a case which nearly parallels the conduct of the jack. A messenger was despatched by rail to a shop for certain articles, and was desired to return by a certain time. The parcel was made up, the man took it, heard an engine whistle, turned to run, and in his haste dashed himself right through a plate-glass window into the street. He narrowly escaped decapitation, as the great pieces of glass fell like the knife of a guillotine. Cases of people injuring themselves by walking against plate-glass are by no means uncommon; when the mind is preoccupied it takes much the same place as the plate of glass in the water and the jack. Authorities on mythology state that some Oriental nations had not arrived at the conception of a fluid heaven--of free space; they thought the sky was solid, like a roof. The fish was very much in the same position. The reason why fish swim round and round in tanks, and do not beat themselves against the glass walls, is evidently because they can see where the water ends. A distinction is apparent between it and the air outside; but when the plate of glass was put inside the tank the jack saw water beyond it, or through it. I never see a fish in a tank without remembering this experiment and the long train of reflections it gives rise to. To take a fish from his native brook, and to place him suddenly in the midst of such, to him, inconceivable conditions, is almost like watching the actual creation of mind. His mind has to be created anew to meet it, and that it did ultimately meet the conditions shows that even the fish--the cold-blooded, the narrow-brained--is not confined to the grooves of hereditary knowledge alone, but is capable of wider and novel efforts. I thought the jack came out very well indeed from the trial, and I have mentioned the matter lest some should think I have attributed too much intelligence to fish.
Other creatures besides fish are puzzled by glass. One day I observed a robin trying to get in at the fanlight of a hall door. Repeatedly he struck himself against it, beat it with his wings, and struggled to get through the pane. Possibly there was a spider inside which tempted him; but allowing that temptation, it was remarkable that the robin should so strive in vain. Always about houses, he must have had experience of the properties of glass, and yet forgot it so soon. His ancestors for many generations must have had experience of glass, still it did not prevent him making many trials. The slowness of the jack to learn the impenetrable nature of the glass plate and its position is not the least indication of lack of intelligence. In daily life we constantly see people do things they have observed injure them, and yet, in spite of experience, go and do the same again.
The glass experiment proves to me that the jack, like all other creatures, really has a latent power of intelligence beyond that brought into play by the usual circumstances of existence. Consider the conditions under which the jack exists--the jack we have been approaching so carefully. His limits are the brook, the ponds it feeds, and the ditches that enter it. He can only move a short distance up the stream because there is a high hatch, nor can he go far down because of a mill; if he could, the conditions would be much the same; but, as a matter of fact, the space he has at his command is not much. The running water, the green flags, the lesser fishes, the water-rats, the horses and cattle on the bank--these are about all the things that he is likely to be interested in. Of these only the water, the lesser fishes, the flags, and the bottom or sides of the brook, are actually in his touch and complete understanding. As he is unable to live out of water, the horse on the bank, in whose very shadow he sometimes lies, might be a mile away for aught it concerns him. By no possible means can he discover anything about it. The horse may be itself nothing more than a shadow, unless in a shallow place he steps in and splashes. Night and day he knows, the cool night, and the sunbeams in which he basks; but he has no way of ascertaining the nature of anything outside the water. Centuries spent in such conditions could add but little to his experience.
Does he hear the stream running past him? Do the particles of water, as they brush his sides and fins, cause a sound, as the wind by us? While he lurks beneath a weed in the still pool, suddenly a shoal of roach rush by with a sound like a flock of birds whose wings beat the air. The smooth surface of the still water appears to cover an utter silence, but probably to the fish there are ceaseless sounds. Water-fowl feeding in the weedy corners, whose legs depend down into the water and disturb it; water-rats diving and running along the bottom; water-beetles moving about; eels in the mud; the lower parts of flags and aquatic grasses swinging as the breeze ruffles their tips; the thud, thud of a horse's hoofs, and now and then the more distant roll of a hay-laden waggon. And thunder--how does thunder sound under the surface? It seems reasonable to suppose that fish possess a wide gamut of hearing since their other senses are necessarily somewhat curtailed, and that they are peculiarly sensitive to vibratory movements is certain from the destruction a charge of dynamite causes if exploded under water. Even in the deep sea the discharge of a torpedo will kill thousands of herrings. They are as it were killed by noise. So that there are grounds for thinking that my quiet jack in the pool, under the bank of the brook, is most keenly alive by his sense of hearing to things that are proceeding both out and in the water. More especially, no doubt, of things in the water itself. With all this specialised power of hearing he is still circumscribed and limited to the groove of the brook. The birds fly from field to field, from valley to mountain, and across the sea. Their experience extends to whole countries, and their opportunities are constant. How much more fortunate in this respect than the jack! A small display of intelligence by the fish is equivalent to a large display by the bird.
When the jack has been much disturbed no one can do more than obtain a view of him, however skilfully he may conceal himself. The least sign of further proceedings will send the jack away; sometimes the mere appearance of the human form is sufficient. If less suspicious, the rod with the wire attached--or if you wish to make experiments, the rod without the wire--can be placed in the water, and moved how you choose.
[The end]
Richard Jefferies's essay: Mind Under Water