Animals, on the whole, know what is necessary for them to know—what the conditions of life have taught their ancestors through countless generations. It is very important, for instance, that amphibians shall have some sense that shall guide them to the water; and they have such a sense. It is said that young turtles and crocodiles put down anywhere will turn instantly toward the nearest water. It is certain that the beasts of the field have such a sense much more fully developed than has man. It is of vital importance that birds should know how to fly, how to build their nests, how to find their proper food, and when and where to migrate, without instruction or example, otherwise the race might become extinct.
Richard Jefferies says that most birds'-nests need a structure around them like a cage to keep the young from falling out or from leaving the nest prematurely. Now, if such a structure were needed, either the race of birds would have failed, or the structure would have been added. Since neither has happened, we are safe in concluding it is not needed.
We are not warranted in attributing to any wild, untrained animal a degree of intelligence that its forbears could not have possessed. The animals for the most part act upon inherited knowledge, that is, knowledge that does not depend upon instruction or experience. For instance, the red squirrels near me seem to know that chestnut-burs will open if cut from the tree and allowed to lie upon the ground. At least, they act upon this theory. I do not suppose this fact or knowledge lies in the squirrel's mind as it would in that of a man—as a deduction from facts of experience or of observation. The squirrel cuts off the chestnuts because he is hungry for them, and because his ancestors for long generations have cut them off in the same way. That the air or sun will cause the burs to open is a bit of knowledge that I do not suppose he possesses in the sense in which we possess it: he is in a hurry for the nuts, and does not by any means always wait for the burs to open; he frequently chips them up and eats the pale nuts.
The same squirrel will bite into the limbs of a maple tree in spring and suck the sap. What does he know about maple trees and the spring flow of sap? Nothing as a mental concept, as a bit of concrete knowledge. He often finds the sap flowing from a crack or other wound in the limbs of a maple, and he sips it and likes it. Then he sinks his teeth into the limb, as his forbears undoubtedly did.
When I was a boy and saw, as I often did on my way to school, where a squirrel had stopped on his course through the woods and dug down through two or three feet of snow, bringing up a beech-nut or an acorn, I used to wonder how he knew the nut was there. I am now convinced that he smelled it.
Why should he not? It stands the squirrel in hand to smell nuts; they are his life. He knows a false nut from a good one without biting into it. Try the experiment upon your tame chipmunk or caged gray squirrel, and see if this is not so. The false or dead nut is lighter, and most persons think this fact guides the squirrel. But this, it seems to me, implies an association of ideas beyond the reach of instinct. A young squirrel will reject a worthless nut as promptly as an old one will. Again the sense of smell is the guide; the sound-meated nut has an odor which the other has not. All animals are keen and wise in relation to their food and to their natural enemies. A red squirrel will chip up green apples and pears for the seeds at the core: can he know, on general principles, that these fruits contain seeds? Does not some clue to them reach his senses?
I have known gray squirrels to go many hundred yards in winter across fields to a barn that contained grain in the sheaf. They could have had no other guide to the grain than the sense of smell. Watch a chipmunk or any squirrel near at hand: as a friend of mine observed, he seems to be smelling with his whole body; his abdomen fairly palpitates with the effort.
The coon knows when the corn is in the milk, gaining that knowledge, no doubt, through his nose. At times he seems to know enough, too, to cut off his foot when caught in a trap, especially if the foot becomes frozen; but if you tell me he will treat his wound by smearing it with pitch or anything else, or in any way except by licking it, I shall discredit you. The practice of the art of healing by the application of external or foreign substances is a conception entirely beyond the capacity of any of the lower animals. If such a practice had been necessary for the continuance of the species, it would probably have been used. The knowledge it implies could not be inherited; it must needs come by experience. When a fowl eats gravel or sand, is it probable that the fowl knows what the practice is for, or has any notion at all about the matter? It has a craving for the gravel, that is all. Nature is wise for it.
The ostrich is described by those who know it intimately as the most stupid and witless of birds, and yet before leaving its eggs exposed to the hot African sun, the parent bird knows enough to put a large pinch of sand on the top of each of them, in order, it is said, to shade and protect the germ, which always rises to the highest point of the egg. This act certainly cannot be the result of knowledge, as we use the term; the young ostrich does it as well as the old. It is the inherited wisdom of the race, or instinct.
A sitting bird or fowl turns its eggs at regular intervals, which has the effect of keeping the yolk from sticking to the shell. Is this act the result of knowledge or of experience? It is again the result of that untaught knowledge called instinct. Some kinds of eggs hatch in two weeks, some in three, others in four. The mother bird has no knowledge of this period. It is not important that she should have. If the eggs are addled or sterile, she will often continue to sit beyond the normal period. If the continuance of the species depended upon her knowing the exact time required to hatch her eggs, as it depends upon her having the incubating fever, of course she would know exactly, and would never sit beyond the required period.
But what shall we say of Mrs. Annie Martin's story, in her "Home Life on an Ostrich Farm," of the white-necked African crow that, in order to feast upon the eggs of the ostrich, carries a stone high in the air above them and breaks them by letting it fall? This looks like reason, a knowledge of the relation of cause and effect. Mrs. Martin says the crows break tortoise-shells in the same way, and have I not heard of our own crows and gulls carrying clams and crabs into the air and dropping them upon the rocks?
If Mrs. Martin's statements are literally true,—if she has not the failing, so common among women observers, of letting her feeling and her fancies color her observations,—then her story shows how the pressure of hunger will develop the wit of a crow.
But the story goes one step beyond my credence. It virtually makes the crow a tool-using animal, and Darwin knew of but two animals, the man-like ape and the elephant, that used anything like a tool or weapon to attain their ends. How could the crow gain the knowledge or the experience which this trick implies? What could induce it to make the first experiment of breaking an egg with a falling stone but an acquaintance with physical laws such as man alone possesses? The first step in this chain of causation it is easy to conceive of any animal taking; namely, the direct application of its own powers or weapons to the breaking of the shell. But the second step,—the making use of a foreign substance or object in the way described,—that is what staggers one.
Our own crow has great cunning, but it is only cunning. He is suspicious of everything that looks like design, that suggests a trap, even a harmless string stretched around a corn-field. As a natural philosopher he makes a poor show, and the egg or the shell that he cannot open with his own beak he leaves behind. Yet even his alleged method of dropping clams upon the rocks to break the shells does not seem incredible. He might easily drop a clam by accident, and then, finding the shell broken, repeat the experiment. He is still only taking the first step in the sequence of causations.
A recent English nature-writer, on the whole, I think, a good observer and truthful reporter, Mr. Richard Kearton, tells of an osprey that did this incredible thing: to prevent its eggs from being harmed by an enforced exposure to the sun, the bird plunged into the lake, then rose, and shook its dripping plumage over the nest. The writer apparently reports this story at second-hand. It is incredible to me, because it implies a knowledge that the hawk could not possibly possess.
Such an emergency could hardly arise once in a lifetime to it or its forbears. Hence the act could not have been the result of inherited habit, or instinct, and as an original act on the part of the osprey it is not credible. The bird probably plunged into the lake for a fish, and then by accident shook itself above the eggs. In any case, the amount of water that would fall upon the eggs under such circumstances would be too slight to temper appreciably the heat.
There is little doubt that among certain of our common birds the male, during periods of excessive heat, has been known to shade the female with his outstretched wings, and the mother bird to shade her young in the same way. But this is a different matter. This emergency must have occurred for ages, and it, again, called only for the first step from cause to effect, and called for the use of no intermediate agent. If the robin were to hold a leaf or a branch above his mate at such times, that would imply reflection.
It is said that elephants in India will besmear themselves with mud as a protection against insects, and that they will break branches from the trees and use them to brush away the flies. If this is true, it shows, I think, something beyond instinct in the elephant; it shows reflection.
All birds are secretive about their nests, and display great cunning in hiding them; but whether they know the value of adaptive material, such as moss, lichens, and dried grass, in helping to conceal them, admits of doubt, because they so often use the results of our own arts, as paper, rags, strings, tinsel, in such a reckless way. In a perfectly wild state they use natural material because it is the handiest and there is really no other. The phoebe uses the moss on or near the rocks where she builds; the sparrows, the bobolinks, and the meadowlarks use the dry grass of the bank or of the meadow bottom where the nest is placed.
The English writer to whom I have referred says that the wren builds the outside of its nest of old hay straws when placing it in the side of a rick, of green moss when it is situated in a mossy bank, and of dead leaves when in a hedge-row or a bramble-bush, in each case thus rendering the nest very difficult of detection because it harmonizes so perfectly with its surroundings, and the writer wonders if this harmony is the result of accident or of design. He is inclined to think that it is unpremeditated, as I myself do. The bird uses the material nearest to hand.
Another case, which this same writer gives at second-hand, of a bird recognizing the value of protective coloration, is not credible. A friend of his told him that he had once visited a colony of terns "on an island where the natural breeding accommodation was so limited that many of them had conveyed patches of pebbles on to the grass and laid their eggs thereon."
Here is the same difficulty we have encountered before—one more step of reasoning than the bird is capable of. As a deduction from observed facts, a bird, of course, knows nothing about protective coloring; its wisdom in this respect is the wisdom of Nature, and Nature in animal life never acts with this kind of foresight. A bird may exercise some choice about the background of its nest, but it will not make both nest and background.
Nature learns by endless experiment. Through a long and expensive process of natural selection she seems to have brought the color of certain animals and the color of their environment pretty close together, the better to hide the animals from their enemies and from their prey, as we are told; but the animals themselves do not know this, though they may act as if they did. Young terns and gulls instinctively squat upon the beach, where their colors so harmonize with the sand and pebbles that the birds are virtually invisible. Young partridges do the same in the woods, where the eye cannot tell the reddish tuft of down from the dry leaves. How many gulls and terns and partridges were sacrificed before Nature learned this trick!
I regard the lower animals as incapable of taking the step from the fact to the principle. They have perceptions, but not conceptions. They may recognize a certain fact, but any deduction from that fact to be applied to a different case, or to meet new conditions, is beyond them. Wolves and foxes soon learn to be afraid of poisoned meat: just what gives them the hint it would be hard to say, as the survivors could not know the poison's deadly effect from experience; their fear of it probably comes from seeing their fellows suffer and die after eating it, or maybe through that mysterious means of communication between animals to which I have referred in a previous article. The poison probably changes the odor of the meat, and this strange smell would naturally put them on their guard.
We do not expect rats to succeed in putting a bell on the cat, but if they were capable of conceiving such a thing, that would establish their claim to be regarded as reasonable beings. I should as soon expect a fox or a wolf to make use of a trap to capture its prey as to make use of poison in any way. Why does not the fox take a stick and spring the trap he is so afraid of? Simply because the act would involve a mental process beyond him. He has not yet learned to use even the simplest implement to attain his end. Then he would probably be just as afraid of the trap after it was sprung as before. He in some way associates it with his arch-enemy, man.
Such stories, too, as a chained fox or a coyote getting possession of corn or other grain and baiting the chickens with it—feigning sleep till the chicken gets within reach, and then seizing it—are of the same class, incredible because transcending the inherited knowledge of those animals. I can believe that a fox might walk in a shallow creek to elude the hound, because he may inherit this kind of cunning, and in his own experience he may have come to associate loss of scent with water. Animals stalk their prey, or lie in wait for it, instinctively, not from a process of calculation, as man does. If a fox would bait poultry with corn, why should he not, in his wild state, bait mice and squirrels with nuts and seeds? Has a cat ever been known to bait a rat with a piece of cheese?
Animals seem to have a certain association of ideas; one thing suggests another to them, as with us. This fact is made use of by animal-trainers. I can easily believe the story Charles St. John tells of the fox he saw waylaying some hares, and which, to screen himself the more completely from his quarry, scraped a small hollow in the ground and threw up the sand about it. But if St. John had said that the fox brought weeds or brush to make himself a blind, as the hunter often does, I should have discredited him, just as I discredit the observation of a man quoted by Romanes, who says that jackals, ambushing deer at the latter's watering-place, deliberately wait till the deer have filled themselves with water, knowing that in that state they are more easily run down and captured!
President Roosevelt, in "The Wilderness Hunter,"—a book, by the way, of even deeper interest to the naturalist than to the sportsman,—says that the moose has to the hunter the "very provoking habit of making a half or three-quarters circle before lying down, and then crouching with its head so turned that it can surely perceive any pursuer who may follow its trail." This is the cunning of the moose developed through long generations of its hunted and wolf-pursued ancestors,—a cunning that does not differ from that of a man under the same circumstances, though, of course, it is not the result of the same process of reasoning.
I have known a chipping sparrow to build her nest on a grape-vine just beneath a bunch of small green grapes. Soon the bunch grew and lengthened and filled the nest, crowding out the bird. If the bird could have foreseen the danger, she would have shown something like human reason.
Birds that nest along streams, such as the water-thrush and the water-ouzel, I suppose are rarely ever brought to grief by high water. They have learned through many generations to keep at a safe distance. I have never known a woodpecker to drill its nesting-cavity in a branch or limb that was ready to fall. Not that woodpeckers look the branch or tree over with a view to its stability, but that they will cut into a tree only of a certain hardness; it is a family instinct. Birds sometimes make the mistake of building their nests on slender branches that a summer tempest will turn over, thus causing the eggs or the young to spill upon the ground. Even instinct cannot always get ahead of the weather.
It is almost impossible for us not to interpret the lives of the lower animals in the terms of our own experience and our own psychology. I entirely agree with Lloyd Morgan that we err when we do so, when we attribute to them what we call sentiments or any of the emotions that spring from our moral and aesthetic natures,—the sentiments of justice, truth, beauty, altruism, goodness, duty, and the like,—because these sentiments are the products of concepts and ideas to which the brute natures are strangers. But all the emotions of our animal nature—fear, anger, curiosity, local attachment, jealousy, and rivalry—are undoubtedly the same in the lower orders.
Though almost anything may be affirmed of dogs, for they are nearly half human, yet I doubt if even dogs experience the feeling of shame or guilt or revenge that we so often ascribe to them. These feelings are all complex and have a deep root. When I was a youth, my father had a big churn-dog that appeared one morning with a small bullet-hole in his hip. Day after day the old dog treated his wound with his tongue, after the manner of dogs, until it healed, and the incident was nearly forgotten. One day a man was going by on horseback, when the old dog rushed out, sprang at the man, and came near pulling him from the horse. It turned out that this was the person who had shot the dog, and the dog recognized him.
This looks like revenge, and it would have been such in you or me, but in the dog it was probably simple anger at the sight of the man who had hurt him. The incident shows memory and the association of impressions, but the complex feeling of vengeance, as we know it, is another matter.
If animals do not share our higher intellectual nature, we have no warrant for attributing to them anything like our higher and more complex emotional nature. Musical strains seem to give them pain rather than pleasure, and it is quite evident that perfumes have no attraction for them.
The stories, which seem to be well authenticated, of sheep-killing dogs that have slipped their collars in the night and indulged their passion for live mutton, and then returned and thrust their necks into their collars before their absence was discovered, do not, to my mind, prove that the dogs were trying to deceive their masters and conceal their guilt, but rather show how obedient to the chain and collar the dogs had become. They had long been subject to such control and discipline, and they returned to them again from the mere force of habit.
I do not believe even the dog to be capable of a sense of guilt. Such a sense implies a sense of duty, and this is a complex ethical sense that the animals do not experience. What the dog fears, and what makes him put on his look of guilt and shame, is his master's anger. A harsh word or a severe look will make him assume the air of a culprit whether he is one or not, and, on the other hand, a kind word and a reassuring smile will transform him into a happy beast, no matter if the blood of his victim is fresh upon him.
A dog is to be broken of a bad habit, if at all, not by an appeal to his conscience or to his sense of duty, for he has neither, but by an appeal to his susceptibility to pain.
Both Pliny and Plutarch tell the story of an elephant which, having been beaten by its trainer for its poor dancing, was afterward found all by itself practicing its steps by the light of the moon. This is just as credible as many of the animal stories one hears nowadays.
Many of the actions of the lower animals are as automatic as those of the tin rooster that serves as a weather-vane. See how intelligently the rooster acts, always pointing the direction of the wind without a moment's hesitation. Or behold the vessel anchored in the harbor, how intelligently it adjusts itself to the winds and the tides! I have seen a log, caught in an eddy in a flooded stream, apparently make such struggles to escape that the thing became almost uncanny in its semblance to life. Man himself often obeys just such unseen currents of race or history when he thinks he is acting upon his own initiative.
When I was in Alaska, I saw precipices down which hundreds of horses had dashed themselves in their mad and desperate efforts to escape from the toil and suffering they underwent on the White Pass trail. Shall we say these horses deliberately committed suicide? Suicide it certainly was in effect, but of course not in intention. What does or can a horse know about death, or about self-destruction? These animals were maddened by their hardships, and blindly plunged down the rocks.
The tendency to humanize the animals is more and more marked in all recent nature books that aim at popularity. A recent British book on animal life has a chapter entitled "Animal Materia Medica." The writer, to make out his case, is forced to treat as medicine the salt which the herbivorous animals eat, and the sand and gravel which grain and nut-eating birds take into their gizzards to act as millstones to grind their grist. He might as well treat their food as medicine and be done with it. So far as I know, animals have no remedies whatever for their ailments. Even savages have, for the most part, only "fake" medicines.
A Frenchman has published a book, which has been translated into English, on the "Industries of Animals." Some of these Frenchmen could give points even to our "Modern School of Nature Study." It may be remembered that Michelet said the bird floated, and that it could puff itself up so that it was lighter than the air! Not a little contemporary natural science can beat the bird in this respect.
The serious student of nature can have no interest in belittling or in exaggerating the intelligence of animals. What he wants is the truth about them, and this he will not get from our natural history romancers, nor from the casual, untrained observers, who are sure to interpret the lives of the wood-folk in terms of their own motives and experiences, nor from Indians, trappers, or backwoodsmen, who give such free rein to their fancies and superstitions.
Such a book as Romanes's "Animal Intelligence" is not always a safe guide. It is like a lawyer's plea to the jury for his client. Romanes was so intent upon making out his case that he allowed himself to be imposed upon by the tales of irresponsible observers. Many of his stories of the intelligence of birds and beasts are antecedently improbable. He evidently credits the story of the Bishop of Carlisle, who thinks he saw a jackdaw being tried by a jury of rooks for some misdemeanor. Jack made a speech and the jury cawed back at him, and after a time appeared to acquit Jack! What a child's fancy to be put in a serious work on "Animal Intelligence"! The dead birds we now and then find hanging from the nest, or from the limb of a tree, with a string wound around their necks are no doubt criminals upon whom their fellows have inflicted capital punishment!
Most of the observations upon which Romanes bases his conclusions are like the incident which he quoted from Jesse, who tells of some swallows that in the spirit of revenge tore down a nest from which they had been ejected by the sparrows, in order to destroy the young of their enemies—a feat impossible for swallows to do. Jesse does not say he saw the swallows do it, but he "saw the young sparrows dead upon the ground amid the ruins of the nest," and of course the nest could get down in no other way!
Not to Romanes or Jesse or Michelet must we go for the truth about animals, but to the patient, honest Darwin, to such calm, keen, and philosophical investigators as Lloyd Morgan, and to the books of such sportsmen as Charles St. John, or to our own candid, trained, and many-sided Theodore Roosevelt,—men capable of disinterested observation with no theories about animals to uphold.
DO ANIMALS THINK AND REFLECT?
When we see the animals going about, living their lives in many ways as we live ours, seeking their food, avoiding their enemies, building their nests, digging their holes, laying up stores, migrating, courting, playing, fighting, showing cunning, courage, fear, joy, anger, rivalry, grief, profiting by experience, following their leaders,—when we see all this, I say, what more natural than that we should ascribe to them powers akin to our own, and look upon them as thinking, reasoning, and reflecting. A hasty survey of animal life is sure to lead to this conclusion. An animal is not a clod, nor a block, nor a machine. It is alive and self-directing, it has some sort of psychic life, yet the more I study the subject, the more I am persuaded that with the probable exception of the dog on occasions, and of the apes, animals do not think or reflect in any proper sense of those words. As I have before said, animal life shows in an active and free state that kind of intelligence that pervades and governs the whole organic world,—intelligence that takes no thought of itself. Here, in front of my window, is a black raspberry bush. A few weeks ago its branches curved upward, with their ends swinging fully two feet above the ground; now those ends are thrust down through the weeds and are fast rooted to the soil. Did the raspberry bush think, or choose what it should do? Did it reflect and say, Now is the time for me to bend down and thrust my tip into the ground? To all intents and purposes yes, yet there was no voluntary mental process, as in similar acts of our own. We say its nature prompts it to act thus and thus, and that is all the explanation we can give. Or take the case of the pine or the spruce tree that loses its central and leading shoot. When this happens, does the tree start a new bud and then develop a new shoot to take the place of the lost leader? No, a branch from the first ring of branches below, probably the most vigorous of the whorl, is promoted to the leadership. Slowly it rises up, and in two or three years it reaches the upright position and is leading the tree upward. This, I suspect, is just as much an act of conscious intelligence and of reason as is much to which we are so inclined to apply those words in animal life. I suppose it is all foreordained in the economy of the tree, if we could penetrate that economy. It is in this sense that Nature thinks in the animal, and the vegetable, and the mineral worlds. Her thinking is more flexible and adaptive in the vegetable than in the mineral, and more so in the animal than in the vegetable, and the most so of all in the mind of man.
The way the wild apple trees and the red thorn trees in the pasture, as described by Thoreau, triumph over the cattle that year after year browse them down, suggests something almost like human tactics. The cropped and bruised tree, not being allowed to shoot upward, spreads more and more laterally, thus pushing its enemies farther and farther away, till, after many years, a shoot starts up from the top of the thorny, knotted cone, and in one season, protected by this cheval-de-frise, attains a height beyond the reach of the cattle, and the victory is won. Now the whole push of the large root system goes into the central shoot and the tree is rapidly developed.
This almost looks like a well-laid scheme on the part of the tree to defeat its enemies. But see how inevitable the whole process is. Check the direct flow of a current and it will flow out at the sides; check the side issues and they will push out on their sides, and so on. So it is with the tree or seedling. The more it is cropped, the more it branches and rebranches, pushing out laterally as its vertical growth is checked, till it has surrounded the central stalk on all sides with a dense, thorny hedge. Then as this stalk is no longer cropped, it leads the tree upward. The lateral branches are starved, and in a few years the tree stands with little or no evidence of the ordeal it has passed through. In like manner the nature of the animals prompts them to the deeds they do, and we think of them as the result of a mental process, because similar acts in ourselves are the result of such a process.
See how the mice begin to press into our buildings as the fall comes on. Do they know winter is coming? In the same way the vegetable world knows it is coming when it prepares for winter, or the insect world when it makes ready, but not as you and I know it. The woodchuck "holes up" in late September; the crows flock and select their rookery about the same time, and the small wood newts or salamanders soon begin to migrate to the marshes. They all know winter is coming, just as much as the tree knows, when in August it forms its new buds for the next year, or as the flower knows that its color and perfume will attract the insects, and no more. The general intelligence of nature settles all these and similar things.
When a bird selects a site for its nest, it seems, on first view, as if it must actually think, reflect, compare, as you and I do when we decide where to place our house. I saw a little chipping sparrow trying to decide between two raspberry bushes. She kept going from one to the other, peering, inspecting, and apparently weighing the advantages of each. I saw a robin in the woodbine on the side of the house trying to decide which particular place was the best site for her nest. She hopped to this tangle of shoots and sat down, then to that, she turned around, she readjusted herself, she looked about, she worked her feet beneath her, she was slow in making up her mind. Did she make up her mind? Did she think, compare, weigh? I do not believe it. When she found the right conditions, she no doubt felt pleasure and satisfaction, and that settled the question. An inward, instinctive want was met and satisfied by an outward material condition. In the same way the hermit crab goes from shell to shell upon the beach, seeking one to its liking. Sometimes two crabs fall to fighting over a shell that each wants. Can we believe that the hermit crab thinks and reasons? It selects the suitable shell instinctively, and not by an individual act of judgment. Instinct is not always inerrant, though it makes fewer mistakes than reason does. The red squirrel usually knows how to come at the meat in the butternut with the least gnawing, but now and then he makes a mistake and strikes the edge of the kernel, instead of the flat side. The cliff swallow will stick her mud nest under the eaves of a barn where the boards are planed so smooth that the nest sooner or later is bound to fall. She seems to have no judgment in the matter. Her ancestors built upon the face of high cliffs, where the mud adhered more firmly.
A wood thrush began a nest in one of my maples, as usual making the foundation of dry leaves, bits of paper, and dry grass. After the third day the site on the branch was bare, the wind having swept away every vestige of the nest. As I passed beneath the tree I saw the thrush standing where the nest had been, apparently in deep thought. A few days afterward I looked again, and the nest was completed. The bird had got ahead of the wind at last. The nesting-instinct had triumphed over the weather.
Take the case of the little yellow warbler when the cowbird drops her egg into its nest—does anything like a process of thought or reflection pass in the bird's mind then? The warbler is much disturbed when she discovers the strange egg, and her mate appears to share her agitation. Then after a time, and after the two have apparently considered the matter together, the mother bird proceeds to bury the egg by building another nest on top of the old one. If another cowbird's egg is dropped in this one, she will proceed to get rid of this in the same way. This all looks very like reflection. But let us consider the matter a moment. This thing between the cowbird and the warbler has been going on for innumerable generations. The yellow warbler seems to be the favorite host of this parasite, and something like a special instinct may have grown up in the warbler with reference to this strange egg. The bird reacts, as the psychologists say, at sight of it, then she proceeds to dispose of it in the way above described. All yellow warblers act in the same manner, which is the way of instinct. Now if this procedure was the result of an individual thought or calculation on the part of the birds, they would not all do the same thing; different lines of conduct would be hit upon. How much simpler and easier it would be to throw the egg out—how much more like an act of rational intelligence. So far as I know, no bird does eject this parasitical egg, and no other bird besides the yellow warbler gets rid of it in the way I have described. I have found a deserted phoebe's nest with one egg of the phoebe and one of the cowbird in it.
Some of our wild birds have changed their habits of nesting, coming from the woods and the rocks to the protection of our buildings. The phoebe-bird and the cliff swallow are marked examples. We ascribe the change to the birds' intelligence, but to my mind it shows only their natural adaptiveness. Take the cliff swallow, for instance; it has largely left the cliffs for the eaves of our buildings. How naturally and instinctively this change has come about! In an open farming country insect life is much more varied and abundant than in a wild, unsettled country. This greater food supply naturally attracts the swallows. Then the protecting eaves of the buildings would stimulate their nesting-instincts. The abundance of mud along the highways and about the farm would also no doubt have its effect, and the birds would adopt the new sites as a matter of course. Or take the phoebe, which originally built its nest under ledges, and does so still to some extent. It, too, would find a more abundant food supply in the vicinity of farm-buildings and bridges. The protected nesting-sites afforded by sheds and porches would likewise stimulate its nesting-instincts, and attract the bird as we see it attracted each spring.
Nearly everything an animal does is the result of an inborn instinct acted upon by an outward stimulus. The margin wherein intelligent choice plays a part is very small. But it does at times play a part—perceptive intelligence, but not rational intelligence. The insects do many things that look like intelligence, yet how these things differ from human intelligence may be seen in the case of one of our solitary wasps,—the mud-dauber,—which sometimes builds its cell with great labor, then seals it up without laying its egg and storing it with the accustomed spiders. Intelligence never makes that kind of a mistake, but instinct does. Instinct acts more in the invariable way of a machine. Certain of the solitary wasps bring their game—spider, or bug, or grasshopper—and place it just at the entrance of their hole, and then go into their den apparently to see that all is right before they carry it in.
Fabre, the French naturalist, experimented with one of these wasps, as follows: While the wasp was in its den he moved its grasshopper a few inches away. The wasp came out, brought it to the opening as before, and went within a second time; again the game was removed, again the wasp came out and brought it back and entered her nest as before. This little comedy was repeated over and over; each time the wasp felt compelled to enter her hole before dragging in the grasshopper. She was like a machine that would work that way and no other. Step must follow step in just such order. Any interruption of the regular method and she must begin over again. This is instinct, and the incident shows how widely it differs from conscious intelligence.
If you have a tame chipmunk, turn him loose in an empty room and give him some nuts. Finding no place to hide them, he will doubtless carry them into a corner and pretend to cover them up. You will see his paws move quickly about them for an instant as if in the act of pulling leaves or mould over them. His machine, too, must work in that way. After the nuts have been laid down, the next thing in order is to cover them, and he makes the motions all in due form. Intelligence would have omitted this useless act.
A canary-bird in its cage will go through all the motions of taking a bath in front of the cup that holds its drinking-water when it can only dip its bill into the liquid. The sight or touch of the water excites it and sets it going, and with now and then a drop thrown from its beak it will keep up the flirting and fluttering motion of its tail and wings precisely as if taking a real instead of an imaginary bath.
Attempt to thwart the nesting-instinct in a bird and see how persistent it is, and how blind! One spring a pair of English sparrows tried to build a nest on the plate that upholds the roof of my porch. They were apparently attracted by an opening about an inch wide in the top of the plate, that ran the whole length of it. The pair were busy nearly the whole month of April in carrying nesting-material to various points on that plate. That big crack or opening which was not large enough to admit their bodies seemed to have a powerful fascination for them. They carried straws and weed stalks and filled up one portion of it, and then another and another, till the crack was packed with rubbish from one end of the porch to the other, and the indignant broom of the housekeeper grew tired of sweeping up the litter. The birds could not effect an entrance into the interior of the plate, but they could thrust in their nesting-material, and so they persisted week after week, stimulated by the presence of a cavity beyond their reach. The case is a good illustration of the blind working of instinct.
Animals have keen perceptions,—keener in many respects than our own,—but they form no conceptions, have no powers of comparing one thing with another. They live entirely in and through their senses.
It is as if the psychic world were divided into two planes, one above the other,—the plane of sense and the plane of spirit. In the plane of sense live the lower animals, only now and then just breaking for a moment into the higher plane. In the world of sense man is immersed also—this is his start and foundation; but he rises into the plane of spirit, and here lives his proper life. He is emancipated from sense in a way that beasts are not.
Thus, I think, the line between animal and human psychology may be pretty clearly drawn. It is not a dead-level line. Instinct is undoubtedly often modified by intelligence, and intelligence is as often guided or prompted by instinct, but one need not hesitate long as to which side of the line any given act of man or beast belongs. When the fox resorts to various tricks to outwit and delay the hound (if he ever consciously does so), he exercises a kind of intelligence,—the lower form which we call cunning,—and he is prompted to this by an instinct of self-preservation. When the birds set up a hue and cry about a hawk or an owl, or boldly attack him, they show intelligence in its simpler form, the intelligence that recognizes its enemies, prompted again by the instinct of self-preservation. When a hawk does not know a man on horseback from a horse, it shows a want of intelligence. When a crow is kept away from a corn-field by a string stretched around it, the fact shows how masterful is its fear and how shallow its wit. When a cat or a dog, or a horse or a cow, learns to open a gate or a door, it shows a degree of intelligence—power to imitate, to profit by experience. A machine could not learn to do this. If the animal were to close the door or gate behind it, that would be another step in intelligence. But its direct wants have no relation to the closing of the door, only to the opening of it. To close the door involves an after-thought that an animal is not capable of. A horse will hesitate to go upon thin ice or upon a frail bridge, even though it has never had any experience with thin ice or frail bridges. This, no doubt, is an inherited instinct, which has arisen in its ancestors from their fund of general experience with the world. How much with them has depended upon a secure footing! A pair of house wrens had a nest in my well-curb; when the young were partly grown and heard any one come to the curb, they would set up a clamorous calling for food. When I scratched against the sides of the curb beneath them like some animal trying to climb up, their voices instantly hushed; the instinct of fear promptly overcame the instinct of hunger. Instinct is intelligent, but it is not the same as acquired individual intelligence; it is untaught.
When the nuthatch carries a fragment of a hickory-nut to a tree and wedges it into a crevice in the bark, the bird is not showing an individual act of intelligence: all nuthatches do this; it is a race instinct. The act shows intelligence,—that is, it adapts means to an end,—but it is not like human or individual intelligence, which adapts new means to old ends, or old means to new ends, and which springs up on the occasion. Jays and chickadees hold the nut or seed they would peck under the foot, but the nuthatch makes a vise to hold it of the bark of the tree, and one act is just as intelligent as the other; both are the promptings of instinct. But when man makes a vise, or a wedge, or a bootjack, he uses his individual intelligence. When the jay carries away the corn you put out in winter and hides it in old worms' nests and knot-holes and crevices in trees, he is obeying the instinct of all his tribe to pilfer and hide things,—an instinct that plays its part in the economy of nature, as by its means many acorns and chestnuts get planted and large seeds widely disseminated. By this greed of the jay the wingless nuts take flight, oaks are planted amid the pines, and chestnuts amid the hemlocks.
Speaking of nuts reminds me of an incident I read of the deer or white-footed mouse—an incident that throws light on the limitation of animal intelligence. The writer gave the mouse hickory-nuts, which it attempted to carry through a crack between the laths in the kitchen wall. The nuts were too large to go through the crack. The mouse would try to push them through; failing in that, he would go through and then try to pull them after him. All night he or his companion seems to have kept up this futile attempt, fumbling and dropping the nut every few minutes. It never occurred to the mouse to gnaw the hole larger, as it would instantly have done had the hole been too small to admit its own body. It could not project its mind thus far; it could not get out of itself sufficiently to regard the nut in its relation to the hole, and it is doubtful if any four-footed animal is capable of that degree of reflection and comparison. Nothing in its own life or in the life of its ancestors had prepared it to meet that kind of a difficulty with nuts. And yet the writer who made the above observation says that when confined in a box, the sides of which are of unequal thickness, the deer mouse, on attempting to gnaw out, almost invariably attacks the thinnest side. How does he know which is the thinnest side? Probably by a delicate and trained sense of feeling or hearing. In gnawing through obstructions from within, or from without, he and his kind have had ample experience.
Now when we come to insects, we find that the above inferences do not hold. It has been observed that when a solitary wasp finds its hole in the ground too small to admit the spider or other insect which it has brought, it falls to and enlarges it. In this and in other respects certain insects seem to take the step of reason that quadrupeds are incapable of.
Lloyd Morgan relates at some length the experiments he tried with his fox terrier, Tony, seeking to teach him how to bring a stick through a fence with vertical palings. The spaces would allow the dog to pass through, but the palings caught the ends of the stick which the dog carried in his mouth. When his master encouraged him, he pushed and struggled vigorously. Not succeeding, he went back, lay down, and began gnawing the stick. Then he tried again, and stuck as before, but by a chance movement of his head to one side finally got the stick through. His master patted him approvingly and sent him for the stick again. Again he seized it by the middle, and of course brought up against the palings. After some struggles he dropped it and came through without it. Then, encouraged by his master, he put his head through, seized the stick, and tried to pull it through, dancing up and down in his endeavors. Time after time and day after day the experiment was repeated with practically the same results. The dog never mastered the problem. He could not see the relation of that stick to the opening in the fence. At one time he worked and tugged three minutes trying to pull the stick through. Of course, if he had had any mental conception of the problem or had thought about it at all, a single trial would have convinced him as well as would a dozen trials. Mr. Morgan tried the experiment with other dogs with like result. When they did get the stick through, it was always by chance.
It has never been necessary that the dog or his ancestors should know how to fetch long sticks through a narrow opening in a fence. Hence he does not know the trick of it. But we have a little bird that knows the trick. The house wren will carry a twig three inches long through a hole of half that diameter. She knows how to manage it because the wren tribe have handled twigs so long in building their nests that this knowledge has become a family instinct.
What we call the intelligence of animals is limited for the most part to sense perception and sense memory. We teach them certain things, train them to do tricks quite beyond the range of their natural intelligence, not because we enlighten their minds or develop their reason, but mainly by the force of habit. Through repetition the act becomes automatic. Who ever saw a trained animal, unless it be the elephant, do anything that betrayed the least spark of conscious intelligence? The trained pig, or the trained dog, or the trained lion does its "stunt" precisely as a machine would do it—without any more appreciation of what it is doing. The trainer and public performer find that things must always be done in the same fixed order; any change, anything unusual, any strange sound, light, color, or movement, and trouble at once ensues.
I read of a beaver that cut down a tree which was held in such a way that it did not fall, but simply dropped down the height of the stump. The beaver cut it off again; again it dropped and refused to fall; he cut it off a third and a fourth time: still the tree stood. Then he gave it up. Now, so far as I can see, the only independent intelligence the animal showed was when it ceased to cut off the tree. Had it been a complete automaton, it would have gone on cutting—would it not?—till it made stove-wood of the whole tree. It was confronted by a new problem, and after a while it took the hint. Of course it did not understand what was the matter, as you and I would have, but it evidently concluded that something was wrong. Was this of itself an act of intelligence? Though it may be that its ceasing to cut off the tree was simply the result of discouragement, and involved no mental conclusion at all. It is a new problem, a new condition, that tests an animal's intelligence. How long it takes a caged bird or beast to learn that it cannot escape! What a man would see at a glance it takes weeks or months to pound into the captive bird, or squirrel, or coon. When the prisoner ceases to struggle, it is probably not because it has at last come to understand the situation, but because it is discouraged. It is checked, but not enlightened.
Even so careful an observer as Gilbert White credits the swallow with an act of judgment to which it is not entitled. He says that in order that the mud nest may not advance too rapidly and so fall of its own weight, the bird works at it only in the morning, and plays and feeds the rest of the day, thus giving the mud a chance to harden. Had not the genial parson observed that this is the practice of all birds during nest-building—that they work in the early morning hours and feed and amuse themselves the rest of the day? In the case of the mud-builders, this interim of course gives the mud a chance to harden, but are we justified in crediting them with this forethought?
Such skill and intelligence as a bird seems to display in the building of its nest, and yet at times such stupidity! I have known a phoebe-bird to start four nests at once, and work more or less upon all of them. She had deserted the ancestral sites under the shelving rocks and come to a new porch, upon the plate of which she started her four nests. She blundered because her race had had little or no experience with porches. There were four or more places upon the plate just alike, and whichever one of these she chanced to strike with her loaded beak she regarded as the right one. Her instinct served her up to a certain point, but it did not enable her to discriminate between those rafters. Where a little original intelligence should have come into play she was deficient. Her progenitors Had built under rocks where there was little chance for mistakes of this sort, and they had learned through ages of experience to blend the nest with its surroundings, by the use of moss, the better to conceal it. My phoebe brought her moss to the new timbers of the porch, where it had precisely the opposite effect to what it had under the gray mossy rocks.
I was amused at the case of a robin that recently came to my knowledge. The bird built its nest in the south end of a rude shed that covered a table at a railroad terminus upon which a locomotive was frequently turned. When her end of the shed was turned to the north she built another nest in the temporary south end, and as the reversal of the shed ends continued from day to day, she soon had two nests with two sets of eggs. When I last heard from her, she was consistently sitting on that particular nest which happened to be for the time being in the end of the shed facing toward the south. The bewildered bird evidently had had no experience with the tricks of turn-tables!
An intelligent man once told me that crabs could reason, and this was his proof: In hunting for crabs in shallow water, he found one that had just cast its shell, but the crab put up just as brave a fight as ever, though of course it was powerless to inflict any pain; as soon as the creature found that its bluff game did not work, it offered no further resistance. Now I should as soon say a wasp reasoned because a stingless drone, or male, when you capture him, will make all the motions with its body, curving and thrusting, that its sting-equipped fellows do. This action is from an inherited instinct, and is purely automatic. The wasp is not putting up a bluff game; it is really trying to sting you, but has not the weapon. The shell-less crab quickly reacts at your approach, as is its nature to do, and then quickly ceases its defense because in its enfeebled condition the impulse of defense is feeble also. Its surrender was on physiological, not upon rational grounds.
Thus do we without thinking impute the higher faculties to even the lowest forms of animal life. Much in our own lives is purely automatic—the quick reaction to appropriate stimuli, as when we ward off a blow, or dodge a missile, or make ourselves agreeable to the opposite sex; and much also is inherited or unconsciously imitative.
Because man, then, is half animal, shall we say that the animal is half man? This seems to be the logic of some people. The animal man, while retaining much of his animality, has evolved from it higher faculties and attributes, while our four-footed kindred have not thus progressed.
Man is undoubtedly of animal origin, but his rise occurred when the principle of variation was much more active, when the forms and forces of nature were much more youthful and plastic, when the seething and fermenting of the vital fluids were at a high pitch in the far past, and it was high tide with the creative impulse. The world is aging, and, no doubt, the power of initiative in Nature is becoming less and less. I think it safe to say that the worm no longer aspires to be man.
A PINCH OF SALT
Probably I have become unusually cautious of late about accepting offhand all I read in print on subjects of natural history. I take much of it with a liberal pinch of salt. Newspaper reading tends to make one cautious—and who does not read newspapers in these days? One of my critics says, apropos of certain recent strictures of mine upon some current nature writers, that I discredit whatever I have not myself seen; that I belong to that class of observers "whose view-point is narrowed to the limit of their own personal experience." This were a grievous fault if it were true, so much we have to take upon trust in natural history as well as in other history, and in life in general. "Mr. Burroughs might have remembered," says another critic discussing the same subject, "that nobody has seen quite so many things as everybody." How true! If I have ever been guilty of denying the truth of what everybody has seen, my critic has just ground for complaint. I was conscious, in the paper referred to, of denying only the truth of certain things that one man alone had reported having seen,—things so at variance not only with my own observations, but with those of all other observers and with the fundamental principles of animal psychology, that my "will to believe," always easy to move, balked and refused to take a step.
 Atlantic Monthly, March, 1903.
In matters of belief in any field, it is certain that the scientific method, the method of proof, is not of equal favor with all minds. Some persons believe what they can or must, others what they would. One person accepts what agrees with his reason and experience, another what is agreeable to his or her fancy. The grounds of probability count much with me; the tone and quality of the witness count for much. Does he ring true? Is his eye single? Does he see out of the back of his head?—that is, does he see on more than one side of a thing? Is he in love with the truth, or with the strange, the bizarre? Last of all, my own experience comes in to correct or to modify the observations of others. If what you report is antecedently improbable, I shall want concrete proof before accepting it, and I shall cross-question your witness sharply. If you tell me you have seen apples and acorns, or pears and plums, growing upon the same tree, I shall discredit you. The thing has never been known and is contrary to nature. But if you tell me you have seen a peach tree bearing nectarines, or have known a nectarine-stone to produce a peach tree, I shall still want to cross-question you sharply, but I may believe you. Such things have happened. Or if you tell me that you have seen an old doe with horns, or a hen with spurs, or a male bird incubating and singing on the nest, unusual as the last occurrence is, I shall not dispute you. I will concede that you may have seen a white crow or a white blackbird or a white robin, or a black chipmunk or a black red squirrel, and many other departures from the usual in animal life; but I cannot share the conviction of the man who told me he had seen a red squirrel curing rye before storing it up in its den, or of the writer who believes the fox will ride upon the back of a sheep to escape the hound, or of another writer that he has seen the blue heron chumming for fish. Even if you aver that you have seen a woodpecker running down the trunk of a tree as well as up, I shall be sure you have not seen correctly. It is the nuthatch and not the woodpecker that hops up and down and around the trees. It is easy to transcend any man's experience; not so easy to transcend his reason. "Nobody has seen so many things as everybody," yet a dozen men cannot see any farther than one, and the truth is not often a matter of majorities. If you tell me any incident in the life of bird or beast that implies the possession of what we mean by reason, I shall be very skeptical.
Am I guilty, then, as has been charged, of preferring the deductive method of reasoning to the more modern and more scientific inductive method? But I doubt if the inductive method would avail one in trying to prove that the old cow really jumped over the moon. We do deny certain things upon general principles, and affirm others. I do not believe that a rooster ever laid an egg, or that a male tiger ever gave milk. If your alleged fact contradicts fundamental principles, I shall beware of it; if it contradicts universal experience, I shall probe it thoroughly. A college professor wrote me that he had seen a crow blackbird catch a small fish and fly away with it in its beak. Now I have never seen anything of the kind, but I know of no principle upon which I should feel disposed to question the truth of such an assertion. I have myself seen a crow blackbird kill an English sparrow. Both proceedings I think are very unusual, but neither is antecedently improbable. If the professor had said that he saw the blackbird dive head first into the water for the fish, after the manner of the kingfisher, I should have been very skeptical. He only saw the bird rise up from the edge of the water with the wriggling fish in its mouth. It had doubtless seized it in shallow water near the shore. But I should discredit upon general principles the statement of the woman who related with much detail how she and her whole family had seen a pair "of small brown birds" carry their half-fledged young from their nest in a low bush, where there was danger from cats, to a new nest which they had just finished in the top of a near-by tree! Could any person who knows the birds credit such a tale? The bank-teller throws out the counterfeit coin or bill because his practiced eye and touch detect the fraud at once. On similar grounds the experienced observer rejects all such stories as the above. Darwin quotes an authority for the statement that our ruffed grouse makes its drumming sound by striking its wings together over its back. A recent writer says the sound is not made with the wings at all, but is made with the voice, just as a rooster crows. Every woodsman knows that neither statement is true, and he knows it, not on general principles, but from experience—he has seen the grouse drum.
Birds that are not flycatchers sometimes take insects in the air; they do it clumsily, but they get the bug. On the other hand, flycatchers sometimes eat fruit. I have seen the kingbird carry off raspberries. All such facts are matters of observation. In the search for truth we employ both the deductive and the inductive methods; we deduce principles from facts, and we test alleged facts by principles.
The other day an intelligent woman told me this about a canary-bird: The bird had a nest with young in the corner of her cage; near by were some other birds in a cage—I forget what they were; they had a full view of all the domestic affairs of the canary. This publicity she evidently did not like, for she tore out of the paper that covered the bottom of her cage a piece as large as one's hand and wove it into the wires so as to make a screen against her inquisitive neighbors. My informant evidently believed this story. It was agreeable to her fancies and feelings. But see the difficulties in the way. How could the bird with its beak tear out a broad piece of paper? then, how could it weave it into the wires of its cage? Furthermore, the family of birds to which the canary belongs are not weavers; they build cup-shaped nests, and they have had no use for screens or covers, and they never have made them. Just what was the truth about the matter I cannot say, but if we know anything about animal psychology, we know that was not the truth. It is always risky to attribute to an animal any act its ancestors could not have performed.
Again, things are reported as facts that are not so much contrary to reason as contrary to all experience, and with these, too, I have my difficulties. A recent writer upon our wild life says he has discovered that the cowbird watches over its young and assists the foster-parents in providing food for them—an observation so contrary to all that we know of parasitical birds, both at home and abroad, that no real observer can credit the statement. Our cowbird has been under observation for a hundred years or more; every dweller in the country must see one or more young cowbirds being fed by their foster-parents every season, yet no competent observer has ever reported any care of the young bird by its real parent. If this were true, it would make the cowbird only half parasitical—an unheard-of phenomenon.
The same writer tells this incident about a grouse that had a nest near his cabin. One morning he heard a strange cry in the direction of the nest, and taking the path that led to it, he met the grouse running toward him with one wing pressed close to her side, and fighting off two robber crows with the other. Under the closed wing the grouse was carrying an egg, which she had managed to save from the ruin of her nest. The bird was coming to the hermit for succor. Now, am I skeptical about such a story, put down in apparent good faith in a book of natural history as a real occurrence, because I have never seen the like? No; I am skeptical because the incident is so contrary to all that we know about grouse and all other wild birds. Our belief in nearly all matters takes the line of least resistance, and it is easier for me to believe that the writer deceived himself, than that such a thing ever happened. In the first place, a grouse could not pick up an egg with her wing when crows were trying to rob her, and, in the second place, she would not think far enough to do it if she had the power. What was she going to do with the egg? Bring it to the hermit for his breakfast? This last supposition is just as reasonable as any part of the story. A grouse will not readily leave her unfledged young, but she will leave her eggs when disturbed by man or beast with apparent unconcern.
It is the rarest thing in the world that real observers see any of these startling and exceptional things in nature. Thoreau saw none. White saw none. Charles St. John saw none. John Muir reports none, Audubon none. It is always your untrained observer that has his poser, his shower of frogs or lizards, or his hoop snakes, and the like. The impossible things that country people see or hear of would make a book of wonders. In some places fishermen believe that the loon carries its egg under its wing till it hatches, and one would say that they are in a position to know. So they are. But opportunity is only half the problem; the verifying mind is the other half. One of our writers of popular nature books relates this curious incident of "animal surgery" among wild ducks. He discovered two eider ducks swimming about a fresh-water pond and acting queerly, "dipping their heads under water and keeping them there for a minute or more at a time." He later discovered that the ducks had large mussels attached to their tongues, and that they were trying to get rid of them by drowning them. The birds had discovered that the salt-water mussel cannot live in fresh water. Now am I to accept this story without question because I find it printed in a book? In the first place, is it not most remarkable that if the ducks had discovered that the bivalves could not live in fresh water, they should not also have discovered that they could not live in the air? In fact, that they would die as soon in the air as in the fresh water? See how much trouble the ducks could have saved themselves by going and sitting quietly upon the beach, or putting their heads under their wings and going to sleep on the wave. Oysters are often laid down in fresh water to "fatten" before being sent to market, and probably mussels would thrive for a short time in fresh water equally well. In the second place, a duck's tongue is a very short and stiff affair, and is fixed in the lower mandible as in a trough. Ducks do not protrude the tongue when they feed; they cannot protrude it; and if a duck can crush a mussel-shell with its beak, what better position could it have the bivalve in than fast to the tongue between the upper and the lower mandible? The story is certainly a very "fishy" one. In all such cases the mind follows the line of least resistance. If the ducks were deliberately holding their bills under water, it is easier to believe that they did it because they thereby found some relief from pain, than that they knew the bivalves would let go their hold sooner in fresh water than in salt or than in the air. A duck's mouth held open and the tongue pinched by a shell-fish would doubtless soon be in a feverish and abnormal condition, which cool water would tend to alleviate. One is unable to see how the ducks could have acquired the kind of human experimental knowledge attributed to them. A person might learn such a secret, but surely not a duck. In discovering and in eluding its enemies, and in many other ways, the duck's wits are very sharp, but to attribute to them a knowledge of the virtues of fresh water over salt in a certain unusual emergency—an emergency that could not have occurred to the race of ducks, much less to individuals often enough for a special instinct to have been developed to meet it—is to make them entirely human.
 I have tried the experiment on two ordinary clams, and they both died on the third day.
The whole idea of animal surgery which the incident implies—such as mending broken legs with clay, salving wounds with pitch, or resorting to bandages or amputations—is preposterous. Sick or wounded animals will often seek relief from pain by taking to the water or to the mud, or maybe to the snow, just as cows will seek the pond or the bushes to escape the heat and the flies, and that is about the extent of their surgery. The dog licks his wound; it no doubt soothes and relieves it. The cow licks her calf; she licks him into shape; it is her instinct to do so. That tongue of hers is a currycomb, plus warmth and moisture and flexibility. The cat always carries her kittens by the back of the neck; it is her best way to carry them, though I do not suppose this act is the result of experiment on her part.
A chimney swift has taken up her abode in my study chimney. At intervals, day or night, when she hears me in the room, she makes a sudden flapping and drumming sound with her wings to scare me away. It is a very pretty little trick and quite amusing. If you appear above the opening of the top of a chimney where a swift is sitting on her nest, she will try to drum you away in the same manner. I do not suppose there is any thought or calculation in her behavior, any more than there is in her nest-building, or any other of her instinctive doings. It is probably as much a reflex act as that of a bird when she turns her eggs, or feigns lameness or paralysis, to lure you away from her nest, or as the "playing possum" of a rose-bug or potato-bug when it is disturbed.
One of the writers referred to above relates with much detail this astonishing thing of the Canada lynx: He saw a pack of them trailing their game—a hare—through the winter woods, not only hunting in concert, but tracking their quarry. Now any candid and informed reader will balk at this story, for two reasons: (1) the cat tribe do not hunt by scent, but by sight,—they stalk or waylay their game; (2) they hunt singly, they are all solitary in their habits, they are probably the most unsocial of the carnivora,—they prowl, they listen, they bide their time. Wolves often hunt in packs. I have no evidence that foxes do, and if the cats ever do, it is a most extraordinary departure. A statement of such an exceptional occurrence should always put one on his guard. In the same story the lynx is represented as making curious antics in the air to excite the curiosity of a band of caribou, and thus lure one of them to its death at the teeth and claws of the waiting hidden pack. This also is so uncatlike a proceeding that no woodsman could ever credit it. Hunters on the plains sometimes "flag" deer and antelope, and I have seen even a loon drawn very near to a bather in the water who was waving a small red flag. But none of our wild creatures use lures, or decoys, or disguises. This would involve a process of reasoning quite beyond them.
Many instances have been recorded of animals seeking the protection of man when pursued by their deadly enemies. I heard of a rat which, when hunted by a weasel, rushed into a room where a man was sleeping, and took refuge in the bed at his feet. I heard Mr. Thompson Seton tell of a young pronghorn buck that was vanquished by a rival, and so hotly pursued by its antagonist that it sought shelter amid his horses and wagons. On another occasion Mr. Seton said a jack rabbit pursued by a weasel upon the snow sought safety under his sled. In all such cases, if the frightened animal really rushed to man for protection, that act would show a degree of reason. The animal must think, and weigh the pros and cons. But I am convinced that the truth about such cases is this: The greater fear drives out the lesser fear; the animal loses its head, and becomes oblivious to everything but the enemy that is pursuing it. The rat was so terrified at the demon of a weasel that it had but one impulse, and that was to hide somewhere. Doubtless had the bed been empty, it would have taken refuge there just the same. How could an animal know that a man will protect it on special occasions, when ordinarily it has exactly the opposite feeling? A deer hotly pursued by a hound might rush into the barn-yard or into the open door of the barn in sheer desperation of uncontrollable terror. Then we should say the creature knew the farmer would protect it, and every woman who read the incident, and half the men, would believe that that thought was in the deer's mind. When the hunted deer rushes into the lake or pond, it does so, of course, with a view to escape its pursuers, and wherever it seeks refuge this is its sole purpose. I can easily fancy a bird pursued by a hawk darting into an open door or window, not with the thought that the inmates of the house will protect it, but in a panic of absolute terror. Its fear is then centred upon something behind it, not in front of it.
When an animal does something necessary to its self-preservation, or to the continuance of its species, it probably does not think about it as a person would, any more than the plant or tree thinks about the light when it bends toward it, or about the moisture when it sends down its tap-root. Touch the tail of a porcupine ever so lightly, and it springs up like a trap and your hand is stuck with quills. I do not suppose there is any more thinking about the act, or any more conscious exercise of will-power, than there is in a trap. An outward stimulus is applied and the reaction is quick. Does not man wink, and dodge, and sneeze, and laugh, and cry, and blush, and fall in love, and do many other things without thought or will? I do not suppose the birds think about migrating, as man does when he migrates; they simply obey an inborn impulse to move south or north, as the case may be. They do not think about the great lights upon the coast that blaze out with a fatal fascination in their midnight paths. If they had independent powers of thought, they would avoid them. But the lighthouse is comparatively a new thing in the life of birds, and instinct has not yet taught them to avoid it. To adapt means to an end is an act of intelligence, but that intelligence may be inborn and instinctive as in the animals, or it may be acquired and therefore rational as in man.
"Surely," said a woman to me, "when a cat sits watching at a mouse-hole, she has some image in her mind of the mouse in its hole?" Not in any such sense as we have when we think of the same subject. The cat has either seen the mouse go into the hole, or else she smells him; she knows he is there through her senses, and she reacts to that impression. Her instinct prompts her to hunt and to catch mice; she doesn't need to think about them as we do about the game we hunt; Nature has done that for her in the shape of an inborn impulse that is awakened by the sight or smell of mice. We have no ready way to describe her act as she sits intently by the hole but to say, "The cat thinks there is a mouse there," while she is not thinking at all, but simply watching, prompted to it by her inborn instinct for mice.
The cow's mouth will water at the sight of her food when she is hungry. Is she thinking about it? No more than you are when your mouth waters as your full dinner-plate is set down before you. Certain desires and appetites are aroused through sight and smell without any mental cognition. The sexual relations of the animals also illustrate this fact.
We know that the animals do not think in any proper sense as we do, or have concepts and ideas, because they have no language. To be sure, a deaf mute thinks without language because a human being has the intelligence which language implies, or which was begotten in his ancestors by its use through long ages. Not so with the lower animals. They are like very young children in this respect; they have impressions, perceptions, emotions, but not ideas. The child perceives things, discriminates things, knows its mother from a stranger, is angry, or glad, or afraid, long before it has any language or any proper concepts. Animals know only through their senses, and this "knowledge is restricted to things present in time and space." Reflection, or a return upon themselves in thought, of this they are not capable. Their only language consists of various cries and calls, expressions of pain, alarm, joy, love, anger. They communicate with one another, and come to share one another's mental or emotional states, through these cries and calls. A dog barks in various tones and keys, each of which expresses a different feeling in the dog. I can always tell when my dog is barking at a snake; there is something peculiar in the tone. The hunter knows when his hound has driven the fox to hole by a change in his baying. The lowing and bellowing of horned cattle are expressions of several different things. The crow has many caws, that no doubt convey various meanings. The cries of alarm and distress of the birds are understood by all the wild creatures that hear them; a feeling of alarm is conveyed to them—an emotion, not an idea.
How could a crow tell his fellows of some future event, or of some experience of the day? How could he tell him this thing is dangerous, this is harmless, save by his actions in the presence of those things? Or how tell of a newly found food supply save by flying eagerly to it? A fox or a wolf could warn its fellow of the danger of poisoned meat by showing alarm in the presence of the meat. Such meat would no doubt have a peculiar odor to the keen scent of the fox or the wolf. Animals that live in communities, such as bees and beavers, cooperate with each other without language, because they form a sort of organic unity, and what one feels all the others feel. One spirit, one purpose, fills the community.
It is said on good authority that prairie-dogs will not permit weeds or tall grass to grow about their burrows, as these afford cover for coyotes and other enemies to stalk them. If they cannot remove these screens, they will leave the place. And yet they will sometimes allow a weed such as the Norse nettle or the Mexican poppy to grow on the mound at the mouth of the den where it will afford shade and not obstruct the view. At first thought this conduct may look like a matter of calculation and forethought, but it is doubtless the result of an instinct that has been developed in the tribe by the struggle for existence, and with any given rodent is quite independent of experience. It is an inherited fear of every weed or tuft of grass that might conceal an enemy.
I am told that prairie wolves will dig up and eat meat that has been poisoned and then buried, when they will not touch it if left on the surface. In such a case the ranchmen think the wolf has been outwitted; but the truth probably is that there was no calculation in the matter; the soil drew out or dulled the smell of the poison and of the man's hand, and so allayed the wolf's suspicions.
I suppose that when an animal practices deception, as when a bird feigns lameness or a broken wing to decoy you away from her nest or her young, it is quite unconscious of the act. It takes no thought about the matter. In trying to call a hen to his side, a rooster will often make believe he has food in his beak, when the pretended grain or insect may be only a pebble or a bit of stick. He picks it up and then drops it in sight of the hen, and calls her in his most persuasive manner. I do not suppose that in such cases the rooster is conscious of the fraud he is practicing. His instinct, under such circumstances, is to pick up food and call the attention of the hen to it, and when no food is present, he instinctively picks up a pebble or a stick. His main purpose is to get the hen near him, and not to feed her. When he is intent only on feeding her, he never offers her a stone instead of bread.
We have only to think of the animals as habitually in a condition analogous to, or identical with, the unthinking and involuntary character of much of our own lives. They are creatures of routine. They are wholly immersed in the unconscious, involuntary nature out of which we rise, and above which our higher lives go on.
THE LITERARY TREATMENT OF NATURE
The literary treatment of natural history themes is, of course, quite different from the scientific treatment, and should be so. The former, compared with the latter, is like free-hand drawing compared with mechanical drawing. Literature aims to give us the truth in a way to touch our emotions, and in some degree to satisfy the enjoyment we have in the living reality. The literary artist is just as much in love with the fact as is his scientific brother, only he makes a different use of the fact, and his interest in it is often of a non-scientific character. His method is synthetic rather than analytic. He deals in general, and not in technical truths,—truths that he arrives at in the fields and woods, and not in the laboratory.
The essay-naturalist observes and admires; the scientific naturalist collects. One brings home a bouquet from the woods; the other, specimens for his herbarium. The former would enlist your sympathies and arouse your enthusiasm; the latter would add to your store of exact knowledge. The one is just as shy of over-coloring or falsifying his facts as the other, only he gives more than facts,—he gives impressions and analogies, and, as far as possible, shows you the live bird on the bough.
The literary and the scientific treatment of the dog, for instance, will differ widely, not to say radically, but they will not differ in one being true and the other false. Each will be true in its own way. One will be suggestive and the other exact; one will be strictly objective, but literature is always more or less subjective. Literature aims to invest its subject with a human interest, and to this end stirs our sympathies and emotions. Pure science aims to convince the reason and the understanding alone. Note Maeterlinck's treatment of the dog in a late magazine article, probably the best thing on our four-footed comrade that English literature has to show. It gives one pleasure, not because it is all true as science is true, but because it is so tender, human, and sympathetic, without being false to the essential dog nature; it does not make the dog do impossible things. It is not natural history, it is literature; it is not a record of observations upon the manners and habits of the dog, but reflections upon him and his relations to man, and upon the many problems, from the human point of view, that the dog must master in a brief time: the distinctions he must figure out, the mistakes he must avoid, the riddles of life he must read in his dumb dog way. Of course, as a matter of fact, the dog is not compelled "in less than five or six weeks to get into his mind, taking shape within it, an image and a satisfactory conception of the universe." No, nor in five or six years. Strictly speaking, he is not capable of conceptions at all, but only of sense impressions; his sure guide is instinct—not blundering reason. The dog starts with a fund of knowledge, which man acquires slowly and painfully. But all this does not trouble one in reading of Maeterlinck's dog. Our interest is awakened, and our sympathies are moved, by seeing the world presented to the dog as it presents itself to us, or by putting ourselves in the dog's place. It is not false natural history, it is a fund of true human sentiment awakened by the contemplation of the dog's life and character.
Maeterlinck does not ascribe human powers and capacities to his dumb friend, the dog; he has no incredible tales of its sagacity and wit to relate; it is only an ordinary bull pup that he describes, but he makes us love it, and, through it, all other dogs, by his loving analysis of its trials and tribulations, and its devotion to its god, man. In like manner, in John Muir's story of his dog Stickeen,—a story to go with "Rab and his Friends,"—our credulity is not once challenged. Our sympathies are deeply moved because our reason is not in the least outraged. It is true that Muir makes his dog act like a human being under the press of great danger; but the action is not the kind that involves reason; it only implies sense perception, and the instinct of self-preservation. Stickeen does as his master bids him, and he is human only in the human emotions of fear, despair, joy, that he shows.
In Mr. Egerton Young's book, called "My Dogs of the Northland," I find much that is interesting and several vivid dog portraits, but Mr. Young humanizes his dogs to a greater extent than does either Muir or Maeterlinck. For instance, he makes his dog Jack take special delight in teasing the Indian servant girl by walking or lying upon her kitchen floor when she had just cleaned it, all in revenge for the slights the girl had put upon him; and he gives several instances of the conduct of the dog which he thus interprets. Now one can believe almost anything of dogs in the way of wit about their food, their safety, and the like, but one cannot make them so entirely human as deliberately to plan and execute the kind of revenge here imputed to Jack. No animal could appreciate a woman's pride in a clean kitchen floor, or see any relation between the tracks which he makes upon the floor and her state of feeling toward himself. Mr. Young's facts are doubtless all right; it is his interpretation of them that is wrong.
It is perfectly legitimate for the animal story writer to put himself inside the animal he wishes to portray, and tell how life and the world look from that point of view; but he must always be true to the facts of the case, and to the limited intelligence for which he speaks.
In the humanization of the animals, and of the facts of natural history which is supposed to be the province of literature in this field, we must recognize certain limits. Your facts are sufficiently humanized the moment they become interesting, and they become interesting the moment you relate them in any way to our lives, or make them suggestive of what we know to be true in other fields and in our own experience. Thoreau made his battle of the ants interesting because he made it illustrate all the human traits of courage, fortitude, heroism, self-sacrifice. Burns's mouse at once strikes a sympathetic chord in us without ceasing to be a mouse; we see ourselves in it. To attribute human motives and faculties to the animals is to caricature them; but to put us in such relation with them that we feel their kinship, that we see their lives embosomed in the same iron necessity as our own, that we see in their minds a humbler manifestation of the same psychic power and intelligence that culminates and is conscious of itself in man,—that, I take it, is the true humanization.
We like to see ourselves in the nature around us. We want in some way to translate these facts and laws of outward nature into our own experiences; to relate our observations of bird or beast to our own lives. Unless they beget some human emotion in me,—the emotion of the beautiful, the sublime,—or appeal to my sense of the fit, the permanent,—unless what you learn in the fields and the woods corresponds in some way with what I know of my fellows, I shall not long be deeply interested in it. I do not want the animals humanized in any other sense. They all have human traits and ways; let those be brought out—their mirth, their joy, their curiosity, their cunning, their thrift, their relations, their wars, their loves—and all the springs of their actions laid bare as far as possible; but I do not expect my natural history to back up the Ten Commandments, or to be an illustration of the value of training-schools and kindergartens, or to afford a commentary upon the vanity of human wishes. Humanize your facts to the extent of making them interesting, if you have the art to do it, but leave the dog a dog, and the straddle-bug a straddle-bug.