Popular Science Monthly/Volume 29/June 1886/What May Animals Be Taught?



"THERE exists in animals," says Malebranche, "neither mind nor soul as we commonly understand the terms. They eat without pleasure, they cry out without pain, they grow without knowing it, they desire nothing, they know nothing, and, if they behave in a manner betokening intelligence, it is because God, who made them, has, to preserve them, formed their bodies in such a way that they avoid mechanically and without fear everything that is capable of destroying them." Malebranche was more categorical than Descartes on the subject of soul in beasts. The latter had doubts on the matter. He would not have been far from conceding thought to the higher animals. But then he would have had to concede it to all, even to the oyster and the sponge; and what have the oyster and the sponge that resembles a soul?

We know how this question occupied the seventeenth and eighteenth centuries. In the nineteenth century, Frédéric Cuvier, Flourens, and others took it up, and tried to establish upon facts a distinction between intelligence and instinct. Finally, Darwin came and wiped out every line of demarkation between man and animals. But, whatever may be the favor—rapidly gained—that surrounds the doctrine of transformism, we must not forget, on the one hand, that it is not universally accepted, nor on the other hand, that it does not answer the question of the intelligence of animals.

The great physiologist Schwann, for instance, who died in 1882, maintained that there was an insurmountable barrier between us and those whom Michelet calls our inferior brethren. To him animals were alembics and electric batteries; mechanics, physics, and chemistry could account for all their manifestations. Man alone contained an immaterial principle, the freedom of which constitutes his characteristic appanage. That is what he distinctly declared on that day when the European great men of science came to Liége with an ovation to the illustrious creator of the cellular theory, on the fortieth anniversary of his professorship. "By virtue of the cellular theory," he said, "we now know that a vital force, fundamentally distinct from matter, exists neither in the organism as a whole nor in every cell. All the phenomena of animal and vegetable life can be explained by the properties of atoms, which are the forces of inert nature, or by other forces of the same atoms hitherto unknown. Freedom alone establishes a limit at which the explanation by forces of this kind must necessarily stop. It obliges us to admit only in man a principle that is incompatible with the properties of matter."

To Schwann, as to Malebranche, the animal was an automaton. It is true that he did not regard it as a mechanism moved by an internal or external spring; it was an aggregation of atoms combined in a certain manner. On the other hand and in this he was at variance with Descartes—it was not thought, but liberty which, in his eyes, constituted the distinctive attribute of man. But essentially, to him as to the pure Cartesians, man was an animal inhabited by a spiritual substance a substance distinct from matter. I learned, however, from conversations I had with him on the subject, that he did not deny to animals the faculty of feeling pleasure and pain, memory, intelligence, and a certain amount of reason. In this he wandered essentially from Cartesianism, for in it he accorded thought to matter.

From the exclusively logical point of view, Cartesianism is impregnable. Animals do not feel or reason, but have only the appearance of doing so. From the same point of view Schwann's system is also impregnable. Animals feel and reason, but have not the power of deciding for themselves. From the point of view of feeling or common sense, the latter system is much more acceptable than the other. It may even be said that it satisfies the mind and the heart, and imposes no hindrance to scientific research. This has also been proved by Schwann's own example. But it is not less certainly irreconcilable with transformist theories of the descent of man; by it man should have a place apart in Nature.

The stories that have been recently published and held up to attention, as illustrations of the intelligence of animals, have really no bearing unless they indicate that animal intelligence is comparable to ours, in the sense that a passage may take place from one to the other by insensible degrees. Otherwise there would be no need of the demonstration; and Schwann as well as Darwin, Malebranche as well as Descartes, might subscribe to it; for we might say that, in a certain sense, a mechanism is intelligent.

Now, there are some facts that bear against the assimilation of the two kinds of intelligence. An infant, which in the beginning seems less intelligent than a young puppy, very early manifests its superiority; and one of the first things it learns is that which can not with any amount of attention be taught to a dog. It is the capacity of our race for improvement in contrast with the immobility that seems to attach to animal races. Need we, to illustrate this, speak of machines and tools, writing, and the fine arts? It is true that there are monkeys that can defend themselves with sticks and pebbles; fish that can throw up drops of water to stun the insects they want to swallow; and birds that can embellish their nests and form parterres of flowers which they will keep fresh. But these curious stories are not enough to close the discussion. Moreover, however similar these acts may appear in a material sense, they must not always be regarded as mentally alike. When my dog, at my order, brings my slippers or letters, he does not act with the same mind as a servant.

Indeed, the assimilation is sometimes justifiable. I had occasion in some articles that appeared in the "Revue Philosophique," on Mr. G. H. Lewes's last book (March and April, 1881), to relate a number of stories in which insects, mollusks, and hydras, as well as dogs, behaved, under particular circumstances, as a man would. Let me repeat one of them: "I was in the habit of giving bones to my poodle Mouston during dinner, and he would go into the yard to gnaw them. When the bone was too large for him, I would get up and go out with him, and split it before his eyes with a hatchet. One day, Mouston, after having gone out with his bone as usual, came back bringing it in his mouth, fixed himself in front of me and wagged his tail. I ordered him back, but he persisted in staying where he was. Finally, I thought of what he wanted and arose, while the animal indulged himself in leaps of satisfaction. The trouble was, that the bone was too large for him. Now, when I call to mind the expression of the dog when he showed me the bone without getting an answer from me, I could not help thinking that he must at that moment have had a very poor opinion of my understanding."

It is evident from this incident that Houston knew explicitly that the bone would be easier to manage if it was split, and that I alone had means of splitting it; and he had a clear and precise idea in anticipation of what he expected from me. Finally, he manifested his desire to me by the only means within his power. How much better could a deaf-mute do than he did?

But it is one thing to think by resemblances, and another thing to think by symbols. A story was recently published by M. Dubuc, of a pointer which had learned after a few years that its master went hunting every Sunday, while on the other days he went to business; and M. Dubuc concluded that the animal had learned to count up to seven.

This conclusion is not legitimate; it may even be said to be wrong. The dog distinguished Sunday by some features that were peculiar to it; by the movements about the house, the behavior and Sunday dress of the servants, the dress of the master, or any one or more of a number of things that make Sunday different from the other days of the week; but we may say without contradiction that it did not count seven. We ourselves, if we were restricted to a life absolutely uniform, would not be able to distinguish the seventh day without mnemotechnic aids, and as a rule we seldom recollect the day or the elate except by the assistance of intrinsic circumstances.

My dog, which was habitually on the watch, perfectly understood whether I was going out to my lectures or for a stroll. For some time, he went with me to the university, when I sent him back. But he very soon took in the signs characteristic of the days and hours when I went to my duty—the regularity, my breakfast habit, my dress, the books under my arm, the direction I took, and my thoughtful air. We all know how observing animals are, and every one who has a dog has remarked how readily they learn that they are to be invited to go with us.

My Mouston was a great vagabond. He would go off in the morning as soon as the door was opened, and would sometimes not return till evening; but if I said to him, "Mouston, we are going to take a walk," he would stay around the house and watch my every motion.

The fondness of dogs for going walking with their masters is worthy of remark. The three dogs I had had the freedom of the street, but it was a great treat to them all to go with me. Probably the pleasure of coming up every once in a while to smell their master's legs goes a great way to compensate them for the restraint of following a fixed road and the often-repeated annoyance of the sudden interruption of interesting conversations that have hardly been begun. We also know how quickly animals acquire the idea of the time of day. Sparrows know when it is time for the bread to be thrown out for them, and collect around the spot at that hour. Lacépède tells of a toad which used to come out of its hole at the time it was accustomed to be fed. I had a lizard that would leave its nest and climb up my sleeve at dinner-time. Persons of my age, in Liege, used to be acquainted with a vagabond dog that regularly at the same hour made the round of the cafés for the bones or the lumps of sugar which he was sure to receive from his friends there; and would as regularly every evening go to his sleeping-place under a particular gateway. This animal evidently perceived the time of day by certain signs that had been taught him by observation; and M. Dubuc's dog knew when it was Sunday, or hunting-day, by the same means. And if, on some Saturday, the house had been arranged and the household had managed to behave in the manner usual to Sunday, the dog too would have been found all prepared for his anticipated hunting excursion, just as if it had not been one day short of his accustomed seven.

This faculty of attentive observation of dogs may be stretched so far as to deceive an experimenter who is a little prepossessed on the subject.

In his paper before the British Association at Aberdeen, Sir John Lubbock related how Mr. Huggins, having arranged cards bearing the ten ciphers, gave his dog a problem, such as to give the square root of nine, or of sixteen, or the sum of two numbers. He would then touch each card in succession, and the dog would make a sound to inform his master when he came to the right one. The dog was always right. The secret of the experiment was that Mr. Huggins unconsciously informed the dog by his attitude when he came to the card that gave the answer. Sir John Lubbock tried to train his dog not to take a piece of bread till he had counted seven; but when he used a metronome the dog showed that he was lost. I made analogous and systematic experiments with my Mouston. They extended to the number four, and I aimed to make the sign of the number more and more indistinct, on each repetition of the experiment. As soon as it was quite effaced, the dog lost his knowledge of it, and his perplexed and inquiring look was amusing.

Sir John Lubbock mentions that Lichtenberg pretended to have a nightingale that could count three. Every day he gave it three meal-maggots, one at a time, and the bird never came back after it had got the third. This observation is very interesting, but we ought to know whether the nightingale did not perceive by some sign that the meal was over. I have no doubt that, if, in the experiments which I have made on siskins and gold-finches, I had had only three grains of hemp-seed in my mouth, they would not have returned after having taken the third seed, or at least would have been likely not to return; but in fact I had many grains, and I frightened them away when they had got three. My experiments were not brought to a conclusion, but, if they had been, it would not have been right to assume too readily that the birds knew how to count. We should have to inquire whether I had not involuntarily made some sign manifesting my intention. The remarkable experiments of Mr. Cumberland have revealed to us a whole category of motions of this kind which had never been taken account of before. Who, previous to him, would have suspected that the hand trembles in a different way when we think of seven and when we think of three?

The solution is not advanced, then, when we tell of the cases, curious and interesting as they may be, in which animals seem to behave like man; or, to speak more exactly, these cases are proof only with respect to persons who are inclined to attribute instincts alone to the animal, and deny it reflection and calculation. As the philosophers are still at this point, it may be well to try to undeceive them. Mutatis mutandis, the spider chooses the place for its web, and the bird for its nest, as the colonist selects the location of his farm-house, or of the pen for his goat or pig. I will agree that we may regard the laying of the eggs, the making and shaping of the nest, and the selection of materials as instinctive acts; but the selection of the place is necessarily of a deliberate and intelligent character.

If there is a difference between animal and human intelligence, it depends upon special causes, and these are what we are trying to disentangle. I have already remarked that man has the faculty of thinking by symbols, while the animal appears not to have it. What is a symbol? It is not easy to define the term. Let us say provisionally that it is a conventional mental sign, representing a clear abstraction. The definition is neither very good nor very clear, but it will do, for want of a better one. Before Thales and Pythagoras, thinkers had distinguished between the common idea and the concept. The common idea is formed within us, we may say, almost physiologically. Take, for example, the idea of horse. When I have seen twenty horses, I have seen for twenty times the qualities which they all have in common, while I have seen for a less number of times, or only once, their respective individual qualities; so that the common image engraves itself in the brain or in the sensorium, if that term is preferred, in deeper and deeper lines and stands out strongly at the base of the particular and fugitive images.

The concept partakes of the common idea, and it might perhaps be maintained that it is formed within us in the same manner. But the degree of abstraction which it necessitates is infinitely more considerable. Let it be, for example, the number four. We agree, it is true, that the idea of, say, any group of four fingers of the hand is a kind of common idea; but it is a good way from this idea, from this kind of group, to that of four distant and different objects, like the four limbs, the four largest cities in the world, the first four Roman emperors, or the four largest fruits. But this is not all. The number four is still easy to transform into images, but that is no longer the case when we come to higher numbers, such as seven, and, with still more reason, 20, 100, 1,000, etc. Yet the large numbers are not more difficult for us to conceive than the small ones. This is because we represent them by conventional signs, or the figures.

We must not, however, forget that some savage peoples can not count beyond four or five. Sir John Lubbock tells in his paper an anecdote of Mr. Galton, who, on one occasion, made a comparison of the arithmetical comprehension of a Damara savage of South Africa and a little dog. According to Mr. Galton, the comparison was not to the advantage of the man.

Let us now examine Sir John Lubbock's experiments. He wrote on his cards such words as go, bone, water, food, etc., in phonetic orthography, so as not to trouble his dog's head with the difficulties of English spelling; also words without significance to the animal, such as simple, nothing, ball, etc.; and he had cards with nothing written on them.

Van the dog soon learned to distinguish the blank cards from the written ones; then he learned to attach an idea to some of the latter; and finally was able to fetch to his master the card that corresponded with his wish. To get a single meal he had to fetch some eighteen or twenty of these cards, and he made no mistakes.

Sir John Lubbock concluded from this success that Van had learned to read. In one sense, this conclusion is absolutely false, but that is not the sense in which Sir John regarded the matter. In another sense it was true, and this is the point on which we need light.

There was never a dog whose master has not said and thought a thousand times that he only lacked speech. In fact, the dog seems to comprehend speech, and speaks in his expression. His eyes behind which, according to Madame de Staël's fine expression, he seems to conceal a human soul—interrogate, supplicate, and answer; his ears are erected, or lop over; his tail wags, and his whole body assumes marked attitudes, not to be misinterpreted, of desire, joy, attention, anger, repentance, fear, shame, and submission. Could he better express all of his feelings if he spoke? Should we understand him any better if he should say to us when he had been guilty of some misdeed, "I deserve to be punished, but don't, I pray you, be too hard on me," or if, after he had been corrected, he should politely thank us for our moderation? We perceive at once the distance between his language and ours. One is natural, the other conventional.

Does he understand our conventional language? He does, and he does not, but in the more exact sense he certainly does not. He understands us when we give him our usual orders: "Down!" "Come here!". "Go back!" "Give me your paw!" "Now, the other one!" "Seek it!" "Bring it here!" "Get out!" But we forget that we accompany our interjections with corresponding gestures, and that the interjection itself is only one gesture more. We forget how we have trained him, how we have worked upon his instinct to make him run for the stick we have thrown, and have taught him to bring it back in his jaws, by leading him, and showing him how, and petting him when he performs the trick aright. You accompany your orders with certain words as if you were speaking to a child, and gave them a precise signification; but the dog does not attach this signification to the word only; to him the word, or the vowel in the word, is only a sign that concurs with all the others in helping to make him understand what we want of him.

If, while sitting at my table, I say to my son, "Charles, will you be so good as to bring me my slippers?" he will understand me. If I say the same thing to my dog, in the same tone and without moving, he will not understand me. I shall have to express myself in a particular manner and a particular tone of voice. He will understand, "Houston, bring the slippers!" or "Houston, slippers!" or "Houston, bring!" But he will not understand the cool, calm request that is sufficient direction to my boy. The word slippers does not call up in him the idea of my slippers, but that of a complex action which he is to perform, consisting of a combination of successive movements winding up with a caress. Provided I make the accustomed gesture, he will obey, though I use the wrong word; and he will not obey, though I use the right word, if I speak in an indifferent tone as if to some one behind the scenes.

It frequently occurs to us to think in this way by sensible images, although we do not remark it. When in the morning I hear the servants go down, make the fire, and arrange the table, hear the rattling of the dishes, I do not think in words that they are getting breakfast, and are preparing the coffee, and putting on the bread, and the butter, and the sugar; but I see these preparations in images; I behold the coffee-pot, the milk-pitcher, the sugar-bowl and sugar, and the slices of bread; and I see in my mind's eye the housemaid in her white apron going back and forth, opening the cupboards, and arranging the table-service. When, after this, she knocks at my door, and calls out, "Breakfast is ready, sir," it is very possible that these words will not awaken in my mind the idea of breakfast, but that of time to get up, to wash, dress, and go to business. I attach to the words, with their strict sense, a more remote sense which is associated with them. This is the way dogs and animals generally think; and this is the meaning our language has to them. They do not analyze, but comprehend in block. This is the way the deaf-mute comprehends our signs.

It surely is not by analysis that the child learns to speak; he understands our phrases as a whole, and it is not till after some time that he comes to see in them separate words; but, finally, he decomposes the phrases. Now, if the child can do this, why can not the animal do it too? Because the animal does not, and the child does speak. The child speaks whenever it gives utterance to its desire or feeling. The dog does not speak, when, knowing that he deserves correction, he comes up, timidly and abjectly, to cringe at the feet of his master. It is voluntarily, that is, after having found out the how and the why, that the child has associated certain movements of the larynx with certain ideas. But you can not teach a dog to come up for correction gamboling and wagging his tail.

The deaf-mute comprehends and speaks to himself in reading writing. He speaks to you when he writes to you, because the voluntary and trained movement of his eyes or fingers has put on for him a precise signification. The parrot would be speaking if he said, "Let us have breakfast" whenever he wanted to eat; but he does not speak when he amuses himself by hailing every visitor with these words.

To return to Sir John Lubbock's dog, he speaks when he goes deliberately to look for the card which corresponds with his desire; we might perhaps say that he reads, for he distinguishes it among the others. Only, the sign might be a triangle or a square, a round figure or a dart; the result would be the same, and would have no bearing. Sir John's idea of phonetic writing has an air of whimsicality; and I am inclined to believe it must have been sportive, and that the secret of the matter lay in the simplification of the figure of which the dog had to grasp the meaning.

The question now arises whether we can hope to go much further with the animal. It is one of the most important questions in the discussion. After all, if the transformist doctrine is true, and there was an ancestor of man that did not know how to speak, and man has had to learn to speak, why may not the dog do the same? Professor P. J. Van Beneden, of the University of Louvain, had, and may still have, a dog which could accompany with his voice a tolerably complicated air played on the piano. My dog Marquis could sing in unison an air of "La Favorita" when a contralto friend gave him the keynote. Could we not get him to give some signification to his vowels? Possibly, but it would be a very hard task, for these reasons:

We speak and we write and read with the eyes. The blind man reads with his fingers and writes; the deaf-mute reads with his eyes, and he writes and even speaks without hearing. Language, under whatever form it is manifested, consists essentially of a series of voluntary and conscious movements, at least in the beginning (I mean reading with the eyes), to which we attach a certain meaning. These movements are of the most various and complicated character. The organs which produce them are either the vocal apparatus, exceedingly mobile and susceptible of assuming a great variety of figures, which includes the larynx, glottis, palate, cheeks, tongue, teeth, lips, and nose, or the fingers placed at the end of the arms, capable of various movements, or the eyes. The dog has neither our larynx nor hands; there remain to him only the eyes. He can not, then, learn to speak or to write. Could we teach him to read; and to what extent? The question comes back in a manner to this: Could we teach an armless mute, not deaf, to read? I think it would be a more formidable task than was that of teaching Laura Bridgman.

Under the old way it was very hard to teach children to read, even with the help of hearing, the sight, and the voice. We showed them the letter A, pronounced it, and made them repeat it; then we passed to the letter E, and so on. At the end of a year the most intelligent, at the end of two years less bright, ones were able to attach a determined sound to certain shapes, that is, when we bring it down to the final analysis, to certain conscious motions of the eyes. After that we taught them writing.

Not a great while ago a pedagogue was struck with an inspiration of genius. It occurred to him to teach reading and writing together. At first sight it seemed absurd to think of simplifying reading by adding writing to it. But what was the outcome of his plan? Why, that now, children, in the course of three months, and with much less difficulty and without help from the application of the ruler to their fingers, learn to read and write with much greater facility and correctness than they formerly could in three years.

This comes from the fact that the motions of the hand are associated with those of the eyes, and the form of the letters is thus engraved upon the memory by means of two different instruments, and therefore much more quickly, one assisting the other; and because the other associations of prolonged sound and articulate sound with that form have become surer and more rapid.

Would it be possible, by showing him the letter A, to make a mute, not deaf but armless, understand that the sign corresponds with a sound? Evidently the experiment would not succeed. We might with patience teach him to kneel, to get up, to walk, or to make certain gestures as we show him certain figures. We could do this with the mute more easily than with the dog, because we could exemplify the movement to him, and because also, imperfect as he is, he is a man and not a brute. He would also attach the same meaning to the pronounced sound, and would thus learn that the written sign A answers exactly to the sound A, as he would obey orders given by the voice, and we would be able to say that he understood language. He might also, if we put the alphabet at his command, manifest his wishes by indicating the sign corresponding with them, and we might be able to say that he had a language. Possibly we might be able to go further still, and train him to the point of interpreting the design; but I do not hazard much in saying that his education would still leave an enormous amount to be desired. It is very hard to make a great scholar even out of a deaf-mute who has arms and has learned to speak, and Sandersons are exceedingly rare.

But would the dog ever accomplish much more than to attach a kind of concrete significance to the figures of the letters; than to associate his necessities or his natural or artificial wants with them? It is very doubtful, and that is what is indicated by Sir John Lubbock's experiments:

Sir John painted six cards, two blue, two red, and two yellow. Three of these were put before the dog, who was to bring his master the card of the color that was shown him. Although he was rewarded every time he succeeded, he never fairly understood what was wanted of him. This was because the action of bringing the card of the right color did not appeal directly enough to his senses. Sir John obtained no better result with six cards marked I, II, III, etc. Van never exactly grasped the conformity of the figures.

What was it prevented my dog, upon whom I tried experiments in numbers, grasping the difference between three and four pieces of meat? He failed because he had to abstract the ideas of the numbers 3 and 4 from the variety of the figures which were presented to him. I have no doubt he might in time have learned to distinguish the triangles from the squares which I formed on the plate with the three and the four pieces of meat. The thing that baffled the beast—we must not forget that the dog carries the faculty of observation to a considerable length—was the incessantly variable diversity of the figures. Under these circumstances, the problem was made too complicated for his head, those means only being given which I had prepared for entering into communication with his intelligence.

If any of the readers of these pages is tempted to teach a dog arithmetic, he would do well, I think, to begin by making him distinguish one from two, permitting him to touch only a single piece at the word one, and two pieces at the word two. Then he could pass on to three, and, if he went so far, to four. After that, he might essay addition: one and two, one and three, and two and three. The experiment would be very interesting and instructive, whatever the result might be. For, as Sir John Lubbock says, we ought not to aim for any one result rather than another, but for the truth.

Is the dog, after all, a suitable subject to experiment upon, in regard to the distance that separates man from animals? Would it not be better to select the monkey, intractable as he is, but formed like us, and not only able to imitate our gestures but fond of doing so? We might by this means attempt a verification of M. Noiré's seductive hypothesis respecting the origin of language: that it is the product of a social state already considerably advanced, and that the sounds, being at first simply utterances accompanying the movements of the whole, finally become the signs of those movements. But suppose, for a moment, that the dog acquires some notion of number, what are we to conclude from it? Is the advance of such a kind that it can be communicated to the whole species or to a particular breed? That would be at least doubtful. There have been very serious and learned controversies respecting the possibility of the transmission by generation of acquired advantages. Weissmann decides the question in the negative. Only aptitudes are transmitted by descent. The discussion appears to be, to some extent, an affair of words. Some say pointer-dogs have been formed by hunters, who taught particular individuals not to chase after game, but only to signalize its presence, and that the knowledge of the fathers passed to their posterity. Others reply that this is not the case; even in the times of the corporations or trade-guilds the sons of shoemakers were not born shoemakers. Special aptitudes, manifested by particular individuals, have been turned to the best advantage; they have been cultivated, and thus breeds have been created by selection. I say that this is a question of words, because in any case the re-enforcement of the aptitude is something acquired, and this acquisition, it is admitted, passes to descendants.

Let us suppose, then, that we have created a race of calculating dogs. We might, by a bold but legitimate generalization, infer from that that all animals would be susceptible of acquiring abstract notions or of thinking by symbols. But the dog would have had an educator. Must man, then, also have had his educator? We see, thus, how this question would take shape, and it certainly would be no less grave or less perplexing than the alternative.

Again, let us suppose that the attempts utterly fail. We might, indeed, contend that the check was only a temporary one. But let us waive the evasion, and reason as though the dog were radically incapable of representing his thoughts by symbols. Would not absolute transformism, that is, the applicability of transformism to man, receive a mortal blow? I do not believe it. The only really legitimate conclusion would be, that not all species are indefinitely perfectible, but that only a few species, perhaps only one, have really entered upon the road to infinite progress, while the others have gone into a kind of blind alley. It is in the same way that the main stem of a tree may theoretically grow up indefinitely toward the sky, while the development of the lateral branches is necessarily limited by the power of the wood to resist rupture.

We thus see that this problem is one of an exceedingly interesting and tempting character. Although Malebranche has no partisans now, those who agree to some extent with Schwann form legions, and in their eyes transformism has only the value of a general doctrine. It is the question of the origin of man and his place in the world, which is raised by Sir John Lubbock's cards, and on which, with the co-operation of his dog Van, he has contributed to throw a little light. Anthropology also can only follow his experiments, the abortive ones as well as the successful ones, with legitimate curiosity, and return its most earnest thanks for them.—Translated for the Popular Science Monthly from the Revue Scientifique'.