Chapter XVII · THE “PHILOSOPHIE ZOOLOGIQUE” (continued 2)

“In the animals even which enjoy the power of performing certain intelligent acts, it is still more often the inner feeling and the inclinations originating from habits which decide, without choice, the acts which animals perform.

“Moreover, although the executing power of movements and of actions, as also the cause which directs them, should be entirely internal, it is not well, as has been done,[186] to limit to internal impressions the primary cause or provocation of these acts, with the intention to restrict to external impressions that which provokes intelligent acts; for, from what few facts are known bearing on these considerations, we are convinced that, either way, the causes which arouse and provoke acts are sometimes internal and sometimes external, that these same causes give rise in reality to impressions all of which act internally.

“According to the idea generally attached to the word instinct the faculty which this word expresses is considered as a light which illuminates and guides animals in their actions, and which is with them what reason is to us. No one has shown that instinct can be a force which calls into action; that this force acts effectively without any participation of the will, and that it is constantly directed by acquired inclinations.”

There are, the author states, two kinds of causes which can arouse the inner feeling (organic sense)—namely, those which depend on intellectual acts, and those which, without arising from it, immediately excite it and force it to direct its power of acting in the direction of acquired inclinations.

“These are the only causes of this last kind, which constitute all the acts of instinct; and as these acts are not the result of deliberation, of choice, of judgment, the actions which arise from them always satisfy, surely and without error, the wants felt and the propensities arising from habits.

“Hence, instinct in animals is an inclination which necessitates that from sensations provoked while giving rise to wants the animal is impelled to act without the participation of any thought or any act of the will.

“This propensity owes to the organization what the habits have modified in its favor, and it is excited by impressions and wants which arouse the organic sense of the individual and put it in the way of sending the nervous fluid in the direction which the propensity in activity needs to the muscles to be placed in action.

“I have already said that the habit of exercising such an organ, or such a part of the body, to satisfy the needs which often spring up, should give to the subtile fluid which changes its place where is to be operated the power which causes action so great a facility in moving towards this organ, where it has been so often employed, that this habit should in a way become inherent in the nature of the individual, which is unable to change it.

“Moreover, the wants of animals possessing a nervous system being, in each case, dependent on the Structure of these organisms, are:

“1. Of obtaining any kind of food;

“2. Of yielding to sexual fecundation which excites in them certain sensations;

“3. Of avoiding pain;

“4. Of seeking pleasure or happiness.

“To satisfy these wants they contract different kinds of habits, which are transformed into so many propensities, which they can neither resist nor change. From this originate their habitual actions, and their special propensities to which we give the name of instinct.[187]

“This propensity of animals to preserve their habits and to renew the actions resulting from them being once acquired, is then propagated by means of reproduction or generation, which preserves the organization and the disposition of parts in the state thus attained, so that this same propensity already exists in the new individuals even before they have exercised it.

“It is thus that the same habits and the same instinct are perpetuated from generation to generation in the different species or races of animals, without offering any notable variation,[188] so long as it does not suffer change in the circumstances essential to the mode of life.”

“On the Industry of Certain Animals.

“In those animals which have no brain that which we call industry as applied to certain of their actions does not deserve such a name, for it is a mistake to attribute to them a faculty which they do not possess.

“Propensities transmitted and received by heredity (génération); habits of performing complicated actions, and which result from these acquired propensities; finally, different difficulties gradually and habitually overcome by as many emotions of the organic sense (sentiment intérieur), constitute the sum of actions which are always the same in the individuals of the same race, to which we inconsiderately give the name of industry.

“The instinct of animals being formed by the habit of satisfying the four kinds of wants mentioned above, and resulting from the propensities acquired for a long time which urge them on in a way determined for each species, there comes to pass, in the case of some, only a complication in the actions which can satisfy these four kinds of wants, or certain of them, and, indeed, only the different difficulties necessary to be overcome have gradually compelled the animal to extend and make contrivances, and have led it, without choice or any intellectual act, but only by the emotions of the organic sense, to perform such and such acts.

“Hence the origin, in certain animals, of different complicated actions, which has been called industry, and which are so enthusiastically admired, because it has always been supposed, at least tacitly, that these actions were contrived and deliberately planned, which is plainly erroneous. They are evidently the fruit of a necessity which has expanded and directed the habits of the animals performing them, and which renders them such as we observe.

“What I have just said is especially applicable to the invertebrate animals, in which there enters no act of intelligence. None of these can indeed freely vary its actions; none of them has the power of abandoning what we call its industry to adopt any other kind.

“There is, then, nothing wonderful in the supposed industry of the ant-lion (Myrmeleon formica-leo), which, having thrown up a hillock of movable sand, waits until its booty is thrown down to the bottom of its funnel by the showers of sand to become its victim; also there is none in the manœuvre of the oyster, which, to satisfy all its wants, does nothing but open and close its shell. So long as their organization is not changed they will always, both of them, do what we see them do, and they will do it neither voluntarily nor rationally.

“This is not the case with the vertebrate animals, and it is among them, especially in the birds and mammals, that we observe in their actions traces of a true industry; because in difficult cases their intelligence, in spite of their propensity to habits, can aid them in varying their actions. These acts, however, are not common, and are only slightly manifested in certain races which have exercised them more, as we have had frequent occasion to remark.”

Lamarck then (chapter vi.) examines into the nature of the will, which he says is really the principle underlying all the actions of animals. The will, he says, is one of the results of thought, the result of a reflux of a portion of the nervous fluid towards the parts which are to act.

He compares the brain to a register on which are imprinted ideas of all kinds acquired by the individual, so that this individual provokes at will an effusion of the nervous fluid on this register, and directs it to any particular page. The remainder of the second volume (chapter vii.) is devoted to the understanding, its origin and that of ideas. The following additions relative to chapters vii. and viii. of the first part of this work are from vol. ii., pp. 451–466.

In the last of June, 1809, the menagerie of the Museum of Natural History having received a Phoca (Phoca vitulina), Lamarck, as he says, had the opportunity of observing its movements and habits. After describing its habits in swimming and moving on land and observing its relation to the clawed mammals, he says his main object is to remark that the seals do not have the hind legs arranged in the same direction as the axis of their body, because these animals are constrained to habitually use them to form a caudal fin, closing and widening, by spreading their digits, the paddle (palette) which results from their union.

“The morses, on the contrary, which are accustomed to feed on grass near the shore, never use their hind feet as a caudal fin; but their feet are united together with the tail, and cannot separate. Thus in animals of similar origin we see a new proof of the effect of habits on the form and structure of organs.”

He then turns to the flying mammals, such as the flying squirrel (Sciurus volans, ærobates, petaurista, sagitta, and volucella), and then explains the origin of their adaptation for flying leaps.

“These animals, more modern than the seals, having the habit of extending their limbs while leaping to form a sort of parachute, can only make a very prolonged leap when they glide down from a tree or spring only a short distance from one tree to another. Now, by frequent repetitions of such leaps, in the individuals of these races the skin of their sides is expanded on each side into a loose membrane, which connects the hind and fore legs, and which, enclosing a volume of air, prevents their sudden falling. These animals are, moreover, without membranes between the fingers and toes.

“The Galeopithecus (Lemur volans), undoubtedly a more ancient form but with the same habits as the flying squirrel (Pteromys Geoff.), has the skin of the flancs more ample, still more developed, connecting not only the hinder with the fore legs, but in addition the fingers and the tail with the hind feet. Moreover, they leap much farther than the flying squirrels, and even make a sort of flight.[189]

“Finally, the different bats are probably mammals still older than the Galeopithecus, in the habit of extending their membrane and even their fingers to encompass a greater volume of air, so as to sustain their bodies when they fly out into the air.

“By these habits, for so long a period contracted and preserved, the bats have obtained not only lateral membranes, but also an extraordinary elongation of the fingers of their fore feet (with the exception of the thumb), between which are these very ample membranes uniting them; so that these membranes of the hands become continuous with those of the flanks, and with those which connect the tail with the two hind feet, forming in these animals great membranous wings with which they fly perfectly, as everybody knows.

“Such is then the power of habits, which have a singular influence on the conformation of parts, and which give to the animals which have for a long time contracted certain of them, faculties not found in other animals.

“As regards the amphibious animals of which I have often spoken, it gives me pleasure to communicate to my readers the following reflections which have arisen from an examination of all the objects which I have taken into consideration in my studies, and seen more and more to be confirmed.

“I do not doubt but that the mammals have in reality originated from them, and that they are the veritable cradle (berceau) of the entire animal kingdom.

“Indeed, we see that the least perfect animals (and they are the most numerous) live only in the water; hence it is probable, as I have said (vol. ii., p. 85), that it is only in the water or in very humid places that nature causes and still forms, under favorable conditions, direct or spontaneous generations which have produced the simplest animalcules and those from which have successively been derived all the other animals.

“We know that the Infusoria, the polyps, and the Radiata only live in the water; that the worms even only live some in the water and others in very damp places.

“Moreover, regarding the worms, which seem to form an initial branch of the animal scale, since it is evident that the Infusoria form another branch, we may suppose that among those of them which are wholly aquatic—namely, which do not live in the bodies of other animals, such as the Gordius and many others still unknown—there are doubtless a great many different aquatic forms; and that among these aquatic worms, those which afterwards habitually expose themselves to the air have probably produced amphibious insects, such as the mosquitoes, the ephemeras, etc., etc., which have successively given origin to all the insects which live solely in the air. But several races of these having changed their habits by the force of circumstances, and having formed habits of a life solitary, retired, or hidden, have given rise to the arachnides, almost all of which also live in the air.

“Finally, those of the arachnides which have frequented the water, which have consequently become progressively habituated to live in it, and which finally cease to expose themselves to the air—this indicates the relations which, connecting the Scolopendræ to Julus, this to the Oniscus, and the last to Asellus, shrimps, etc., have caused the existence of all the Crustacea.

“The other aquatic worms which are never exposed to the air, multiplying and diversifying their races with time, and gradually making progress in the complication of their structure, have caused the formation of the Annelida, Cirripedia, and molluscs, which together form an uninterrupted portion of the animal scale.

“In spite of the considerable hiatus which we observe between the known molluscs and the fishes, the molluscs, whose origin I have just indicated, have, by the intermediation of those yet remaining unknown, given origin to the fishes, as it is evident that the latter have given rise to the reptiles.

“In continuing to consult the probabilities on the origin of different animals, we cannot doubt but that the reptiles, by two distinct branches which circumstances have brought about, have given rise on one side to the formation of birds, and on the other to that of amphibious mammals, which have given in their turn origin to all the other mammals.[190]

“Indeed, the fishes having caused the formation of Batrachia, and these of the Ophidian reptiles, both having only one auricle in the heart, nature has easily come to give a heart with a double auricle to other reptiles which constitute two special branches; finally, she has easily arrived at the end of forming, in the animals which had originated from each of these branches, a heart with two ventricles.

“Thus, among the reptiles whose heart has a double auricle, on the one side, the Chelonians seem to have given origin to the birds; if, independently of several relations which we cannot disregard, I should place the head of a tortoise on the neck of certain birds, I should perceive almost no disparity in the general physiognomy of the factitious animal; and on the other side, the saurians, especially the ‘planicaudes,’ such as the crocodiles, seem to have given origin to the amphibious mammals.

“If the branch of the Chelonians has given rise to birds, we can yet presume that the palmipede aquatic birds, especially the brevipennes, such as the penguins and the manchots, have given origin to the monotremes.

“Finally, if the branch of saurians has given rise to the amphibious mammals, it will be most probable that this branch is the source whence all the mammals have taken their origin.

“I therefore believe myself authorized to think that the terrestrial mammals originally descended from those aquatic mammals that we call Amphibia. Because the latter being divided into three branches by the diversity of the habits which, with the lapse of time, they have adopted, some have caused the formation of the Cetacea, others that of the ungulated mammals, and still others that of the unguiculate mammals.

“For example, those of the Amphibia which have preserved the habit of frequenting the shores differ in the manner of taking their food. Some among them accustoming themselves to browse on herbage, such as the morses and lamatines, gradually gave origin to the ungulate mammals, such as the pachyderms, ruminants, etc.; the others, such as the Phocidæ, contracting the habit of feeding on fishes and marine animals, caused the existence of the unguiculate mammals, by means of races which, while becoming differentiated, became entirely terrestrial.

“But those aquatic mammals which would form the habit of never leaving the water, and only rising to breathe at the surface, would probably give origin to the different known cetaceans. Moreover, the ancient and complete habitation of the Cetacea in the ocean has so modified their structure that it is now very difficult to recognize the source whence they have derived their origin.

“Indeed, since the enormous length of time during which these animals have lived in the depths of the sea, never using their hind feet in seizing objects, their disused feet have wholly disappeared, as also their skeleton, and even the pelvis serving as their attachment.

“The alteration which the cetaceans have undergone in their limbs, owing to the influence of the medium in which they live and the habits which they have there contracted, manifests itself also in their fore limbs, which, entirely enveloped by the skin, no longer show externally the fingers in which they end; so that they only offer on each side a fin which contains concealed within it the skeleton of a hand.

“Assuredly, the cetaceans being mammals, it entered into the plan of their structure to have four limbs like the others, and consequently a pelvis to sustain their hind legs. But here, as elsewhere, that which is lacking in them is the result of atrophy brought about, at the end of a long time, by the want of use of the parts which were useless.

“If we consider that in the Phocæ, where the pelvis still exists, this pelvis is impoverished, narrowed, and with no projections on the hips, we see that the lessened (médiocre) use of the hind feet of these animals must be the cause, and that if this use should entirely cease, the hind limbs and even the pelvis would in the end disappear.

“The considerations which I have just presented may doubtless appear as simple conjectures, because it is possible to establish them only on direct and positive proofs. But if we pay any attention to the observations which I have stated in this work, and if then we examine carefully the animals which I have mentioned, as also the result of their habits and their surroundings, we shall find that these conjectures will acquire, after this examination, an eminent probability.

“The following tableau[191] will facilitate the comprehension of what I have just stated. It will be seen that, in my opinion, the animal scale begins at least by two special branches, and that in the course of its extent some branchlets (rameaux) would seem to terminate in certain places.

“This series of animals beginning with two branches where are situated the most imperfect, the first of these branches received their existence only by direct or spontaneous generation.

“A strong reason prevents our knowing the changes successively brought about which have produced the condition in which we observe them; it is because we are never witnesses of these changes. Thus we see the work when done, but never watching them during the process, we are naturally led to believe that things have always been as we see them, and not as they have progressively been brought about.

“Among the changes which nature everywhere incessantly produces in her ensemble, and her laws remain always the same, such of these changes as, to bring about, do not need much more time than the duration of human life, are easily understood by the man who observes them; but he cannot perceive those which are accomplished at the end of a considerable time.

“If the duration of human life only extended to the length of a second, and if there existed one of our actual clocks mounted and in movement, each individual of our species who should look at the hour-hand of this clock would never see it change its place in the course of his life, although this hand would really not be stationary. The observations of thirty generations would never learn anything very evident as to the displacement of this hand, because its movement, only being that made during half a minute, would be too slight to make an impression; and if observations much more ancient should show that this same hand had really moved, those who should see the statement would not believe it, and would suppose there was some error, each one having always seen the hand on the same point of the dial-plate.

“I leave to my readers all the applications to be made regarding this supposition.

“Nature, that immense totality of different beings and bodies, in every part of which exists an eternal circle of movements and changes regulated by law; totality alone unchangeable, so long as it pleases its Sublime Author to make it exist, should be regarded as a whole constituted by its parts, for a purpose which its Author alone knows, and not exclusively for any one of them.

“Each part necessarily is obliged to change, and to cease to be one in order to constitute another, with interests opposed to those of all; and if it has the power of reasoning it finds this whole imperfect. In reality, however, this whole is perfect, and completely fulfils the end for which it was designed.”

The last work in which Lamarck discussed the theory of descent was in his introduction to the Animaux sans Vertèbres. But here the only changes of importance are his four laws, which we translate, and a somewhat different phylogeny of the animal kingdom.

The four laws differ from the two given in the Philosophie zoologique in his theory (the second law) accounting for the origin of a new organ, the result of a new need.

“First law: Life, by its proper forces, continually tends to increase the volume of every body which possesses it, and to increase the size of its parts, up to a limit which it brings about.

“Second law: The production of a new organ in an animal body results from the supervention of a new want (besoin) which continues to make itself felt, and of a new movement which this want gives rise to and maintains.

“Third law: The development of organs and their power of action are constantly in ratio to the employment of these organs.

“Fourth law: Everything which has been acquired, impressed upon, or changed in the organization of individuals, during the course of their life is preserved by generation and transmitted to the new individuals which have descended from those which have undergone those changes.”

In explaining the second law he says:

“The foundation of this law derives its proof from the third, in which the facts known allow of no doubt; for, if the forces of action of an organ, by their increase, further develop this organ—namely, increase its size and power, as is constantly proved by facts—we may be assured that the forces by which it acts, just originated by a new want felt, would necessarily give birth to the organ adapted to satisfy this new want, if this organ had not before existed.

“In truth, in animals so low as not to be able to feel, it cannot be that we should attribute to a felt want the formation of a new organ, this formation being in such a case the product of a mechanical cause, as that of a new movement produced in a part of the fluids of the animal.

“It is not the same in animals with a more complicated structure, and which are able to feel. They feel wants, and each want felt, exciting their inner feeling, forthwith sets the fluids in motion and forces them towards the point of the body where an action may satisfy the want experienced. Now, if there exists at this point an organ suitable for this action, it is immediately cited to act; and if the organ does not exist, and only the felt want be for instance pressing and continuous, gradually the organ originates, and is developed on account of the continuity and energy of its employment.

“If I had not been convinced: 1, that the thought alone of an action which strongly interests it suffices to arouse the inner feeling of an individual; 2, that a felt want can itself arouse the feeling in question; 3, that every emotion of inner feeling, resulting from a want which is aroused, directs at the same instant a mass of nervous fluid to the points to be set in activity, that it also creates a flow thither of the fluids of the body, and especially nutrient ones; that, finally, it then places in activity the organs already existing, or makes efforts for the formation of those which would not have existed there, and which a continual want would therefore render necessary—I should have had doubts as to the reality of the law which I have just indicated.

“But, although it may be very difficult to verify this law by observation, I have no doubt as to the grounds on which I base it, the necessity of its existence being involved in that of the third law, which is now well established.

“I conceive, for example, that a gasteropod mollusc, which, as it crawls along, finds the need of feeling the bodies in front of it, makes efforts to touch those bodies with some of the foremost parts of its head, and sends to these every time supplies of nervous fluids, as well as other fluids—I conceive, I say, that it must result from this reiterated afflux towards the points in question that the nerves which abut at these points will, by slow degrees, be extended. Now, as in the same circumstances other fluids of the animal flow also to the same places, and especially nourishing fluids, it must follow that two or more tentacles will appear and develop insensibly under those circumstances on the points referred to.

“This is doubtless what has happened to all the races of Gasteropods, whose wants have compelled them to adopt the habit of feeling bodies with some part of their head.

“But if there occur, among the Gasteropods, any races which, by the circumstances which concern their mode of existence or life, do not experience such wants, then their head remains without tentacles; it has even no projection, no traces of tentacles, and this is what has happened in the case of Bullæa, Bulla, and Chiton.”

In the Supplément à la Distribution générale des Animaux (Introduction, p. 342), concerning the real order of origin of the invertebrate classes, Lamarck proposes a new genealogical tree. He states that the order of the animal series “is far from simple, that it is branching, and seems even to be composed of several distinct series;” though farther on (p. 456) he adds:

“Je regarde l’ordre de la production des animaux comme formé de deux séries distinctes.

“Ainsi, je soumets à la méditation des zoologistes l’ordre présumé de la formation des animaux, tel que l’exprime le tableau suivant:”

In the matter of the origin of instinct, as in evolution in general, Lamarck appears to have laid the foundation on which Darwin’s views, though he throws aside Lamarck’s factors, must rest. The “inherited habit” theory is thus stated by Lamarck.

Instinct, he claims, is not common to all animals, since the lowest forms, like plants, are entirely passive under the influences of the surrounding medium; they have no wants, are automata.

“But animals with a nervous system have wants, i.e., they feel hunger, sexual desires, they desire to avoid pain or to seek pleasure, etc. To satisfy these wants they contract habits, which are gradually transformed into so many propensities which they can neither resist nor change. Hence arise habitual actions and special propensities, to which we give the name of instinct.

“These propensities are inherited and become innate in the young, so that they act instinctively from the moment of birth. Thus the same habits and instincts are perpetuated from one generation to another, with no notable variations, so long as the species does not suffer change in the circumstances essential to its mode of life.”

The same views are repeated in the introduction to the Animaux sans Vertèbres (1815), and again in 1820, in his last work, and do not need to be translated, as they are repetitions of his previously published views in the Philosophie zoologique.

Unfortunately, to illustrate his thoughts on instinct Lamarck does not give us any examples, nor did he apparently observe to any great extent the habits of animals. In these days one cannot follow him in drawing a line—as regards the possession of instincts—between the lowest organisms, or Protozoa, and the groups provided with a nervous system.

Lamarck’s meaning of the word “besoins,” or wants or needs.—Lamarck’s use of the word wants or needs (besoins) has, we think, been greatly misunderstood and at times caricatured or pronounced as “absurd.” The distinguished French naturalist, Quatrefages, although he was not himself an evolutionist, has protested against the way Lamarck’s views have been caricatured. By nearly all authors he is represented as claiming that by simply “willing” or “desiring” the individual bird or other animal radically and with more or less rapidity changed its shape or that of some particular organ or part of the body. This is, as we have seen, by no means what he states. In no instance does he speak of an animal as simply “desiring” to modify an organ in any way. The doctrine of appetency attributed to Lamarck is without foundation. In all the examples given he intimates that owing to changes in environment, leading to isolation in a new area separating a large number of individuals from their accustomed habitat, they are driven by necessity (besoin) or new needs to adopt a new or different mode of life—new habits. These efforts, whatever they may be—such as attempts to fly, swim, wade, climb, burrow, etc., continued for a long time “in all the individuals of its species,” or the great number forced by competition to migrate and become segregated from the others of the original species—finally, owing to the changed surroundings, affect the mass of individuals thus isolated, and their organs thus exercised in a special direction undergo a slow modification.

Even so careful a writer as Dr. Alfred R. Wallace does not quite fairly, or with exactness, state what Lamarck says, when in his classical essay of 1858 he represents Lamarck as stating that the giraffe acquired its long neck by desiring to reach the foliage of the more lofty shrubs, and constantly stretching its neck for the purpose. On the contrary, he does not use the word “desiring” at all. What Lamarck does say is that—

“The giraffe lives in dry, desert places, without herbage, so that it is obliged to browse on the leaves of trees, and is continually forced to reach up to them. It results from this habit, continued for a long time in all the individuals of its species, that its fore limbs have become so elongated that the giraffe, without raising itself erect on its hind legs, raises its head and reaches six meters high (almost twenty feet).”[192]

We submit that this mode of evolution of the giraffe is quite as reasonable as the very hypothetical one advanced by Mr. Wallace;[193] i.e., that a variety occurred with a longer neck than usual, and these “at once secured a fresh range of pasture over the same ground as their shorter-necked companions, and on the first scarcity of food were thereby enabled to outlive them.” Mr. Wallace’s account also of Lamarck’s general theory appears to us to be one-sided, inadequate, and misleading. He states it thus: “The hypothesis of Lamarck—that progressive changes in species have been produced by the attempts of animals to increase the development of their own organs, and thus modify their structure and habits.” This is a caricature of what Lamarck really taught. Wants, needs (besoins), volitions, desires, are not mentioned by Lamarck in his two fundamental laws (see p. 303), and when the word besoins is introduced it refers as much to the physiological needs as to the emotions of the animal resulting from some new environment which forces it to adopt new habits such as means of locomotion or of acquiring food.

It will be evident to one who has read the original or the foregoing translations of Lamarck’s writings that he does not refer so much to mental desires or volitions as to those physiological wants or needs thrust upon the animal by change of circumstances or by competition; and his besoins may include lust, hunger, as well as the necessity of making muscular exertions such as walking, running, leaping, climbing, swimming, or flying.

As we understand Lamarck, when he speaks of the incipient giraffe or long-necked bird as making efforts to reach up or outwards, the efforts may have been as much physiological, reflex, or instinctive as mental. A recent writer, Dr. R. T. Jackson, curiously and yet naturally enough uses the same phraseology as Lamarck when he says that the long siphon of the common clam (Mya) “was brought about by the effort to reach the surface, induced by the habit of deep burial” in its hole.[194]

On the other hand, can we in the higher vertebrates entirely dissociate the emotional and mental activities from their physiological or instinctive acts? Mr. Darwin, in his Expressions of the Emotions in Man and Animals, discusses in an interesting and detailed way the effects of the feelings and passions on some of the higher animals.

It is curious, also, that Dr. Erasmus Darwin went at least as far as Lamarck in claiming that the transformations of animals “are in part produced by their own exertions in consequence of their desires and aversions, of their pleasures and their pains, or of irritations or of associations.”

Cope, in the final chapter of his Primary Factors of Organic Evolution, entitled “The Functions of Consciousness,” goes to much farther extremes than the French philosopher has been accused of doing, and unhesitatingly attributes consciousness to all animals. “Whatever be its nature,” he says, “the preliminary to any animal movement which is not automatic is an effort.” Hence he regards effort as the immediate source of all movement, and considers that the control of muscular movements by consciousness is distinctly observable; in fact, he even goes to the length of affirming that reflex acts are the product of conscious acts, whereas it is plain enough that reflex acts are always the result of some stimulus.

Another case mentioned by Lamarck in his Animaux sans Vertèbres, which has been pronounced as absurd and ridiculous, and has aided in throwing his whole theory into disfavor, is his way of accounting for the development of the tentacles of the snail, which is quoted on p. 348.

This account is a very probable and, in fact, the only rational explanation. The initial cause of such structures is the intermittent stimulus of occasional contact with surrounding objects, the irritation thus set up causing a flow of the blood to the exposed parts receiving the stimuli. The general cause is the same as that concerned in the production of horns and other hard defensive projections on the heads of various animals.

In commenting on this case of the snail, Professor Cleland, in his just and discriminating article on Lamarck, says:

“However absurd this may seem, it must be admitted that, unlimited time having been once granted for organs to be developed in series of generations, the objections to their being formed in the way here imagined are only such as equally apply to the theory of their origin by natural selection.... In judging the reasonableness of the second law of Lamarck [referring to new wants, see p. 346] as compared with more modern and now widely received theories, it must be observed that it is only an extension of his third law; and that third law is a fact. The strengthening of the blacksmith’s arm by use is proverbially notorious. It is, therefore, only the sufficiency of the Lamarckian hypothesis to explain the first commencement of new organs which is in question, if evolution by the mere operation of forces acting in the organic world be granted; and surely the Darwinian theory is equally helpless to account for the beginning of a new organ, while it demands as imperatively that every stage in the assumed hereditary development of an organ must have been useful.... Lamarck gave great importance to the influence of new wants acting indirectly by stimulating growth and use. Darwin has given like importance to the effects of accidental variations acting indirectly by giving advantage in the struggle for existence. The speculative writings of Darwin have, however, been interwoven with a vast number of beautiful experiments and observations bearing on his speculations, though by no means proving his theory of evolution; while the speculations of Lamarck lie apart from his wonderful descriptive labors, unrelieved by intermixture with other matters capable of attracting the numerous class who, provided they have new facts set before them, are not careful to limit themselves to the conclusions strictly deducible therefrom. But those who read the Philosophie Zoologique will find how many truths often supposed to be far more modern are stated with abundant clearness in its pages.” (Encyc. Brit., art. “Lamarck.”)

COMPARATIVE SUMMARY OF THE VIEWS OF THE FOUNDERS OF THE THEORY OF EVOLUTION, WITH DATES OF PUBLICATION.

Buffon (1761–1778). Erasmus Darwin (1790–1794). Lamarck (1801–1809–1815). Geoffroy St. Hilaire (1795–1831). Charles Darwin (1859).

All animals possibly derived from a single type. All animals derived from a single filament. All organisms arose from germs. First germ originated by spontaneous generation. Development from the simple to the complex. Animal series not continuous, but tree-like; graduated from monad to man; constructed the first phylogenetic tree. Unity of organization in animal kingdom.

Time, its great length, stated. Time, great length of, definitely demanded. Time, great length of, definitely postulated; its duration practically unlimited. Change of “milieu ambiant,” direct.

Immutability of species stated and then denied. Uniformitarianism of Hutton and of Lyell anticipated. Founded the doctrine of homologies.

Nature advances by gradations, passing from one species to another by imperceptible degrees. Founder of teratology. Universal tendency to fortuitous variability assumed.

Changes in distribution of land and water as causing variation. His embryological studies influenced his philosophic views.

Effects of changes of climate, direct. Effects of change of climate, direct (briefly stated). Effects of favorable circumstances, such as changes of environment, climate, soil, food, temperature; direct in case of plants and lowest animals, indirect in case of the higher animals and man.

Effects of changes of food. Conditions of existence remaining constant, species do not vary and vice-versa. Struggle for existence.

Effects of domestication. Domestication briefly referred to. Struggle for existence; stronger devour the weaker. Competition stated in case of ai or sloth. Balance of nature. Competition strongly advocated.

Effects of use. (The only examples given are the callosities on legs of camel, of baboon, and the thickening by use of soles on man’s feet.) Effects of use: characters produced by their own exertions in consequence of their desires, aversions, lust, hunger, and security. Effects of use and disuse, discussed at length. Natural selection.

Sexual selection, law of battle. Vestigial structures the remains of organs actively used by ancestors of present forms. Sexual selection.

Protective mimicry. New wants or necessities induced by changes of climate, habitat, etc., result in production of new propensities, new habits, and functions. Effects of use and disuse (in some cases).

Origin of organs before development of their functions. Change of habits originate organs; change of functions create new organs; formation of new habits precede the origin of new or modification of organs already formed. Effects of use and disuse (in some cases).

Geographical isolation suggested as a factor in case of man. Isolation “an important element.”

Swamping effects of crossing. Lamarck’s definition of species the most satisfactory yet stated. Species are “different modifications of one and the same type.”

Inheritance of acquired characters (vaguely stated). Inheritance of acquired characters. Inheritance of acquired characters.

Instincts result of imitation. Instinct the result of inherited habits.

Opposed preformation views of Haller and Bonnet. Opposed preformation views; epigenesis definitely stated and adopted.

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