Lamarck, the Founder of Evolution: His Life and Work

Chapter IV (3)

Text size

"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.

FOOTNOTES:

[179] [Cabanis.] _Rapp. du Phys. et du Moral de l'Homme_, pp. 38 à 39, et 85.

[180] Lamarck's idea of the animal series was that of a branched one, as shown by his genealogical tree on p. 193, and he explains that the series begins at least by two special branches, these ending in branchlets. He thus breaks entirely away from the old idea of a continuous ascending series of his predecessors Bonnet and others. Professor R. Hertwig therefore makes a decided mistake and does Lamarck a great injustice in his "Zoölogy," where he states: "Lamarck, in agreement with the then prevailing conceptions, regarded the animal kingdom as a series grading from the lowest primitive animal up to man" (p. 26); and again, on the next page, he speaks of "the theory of Geoffroy St.-Hilaire and Lamarck" as having in it "as a fundamental error the doctrine of the serial arrangement of the animal world" (English Trans.). Hertwig is in error, and could never have carefully read what Lamarck did say, or have known that he was the first to throw aside the serial arrangement, and to sketch out a genealogical tree.

[181] The foregoing pages (283-286) are reprinted by the author from the _Discours_ of 1803. See pp. 266-270.

[182] Perrier thus comments on this passage: "_Ici nous sommes bien près, semble-t-il, non seulement de la lutte pour la vie telle one la concevra Darwin, mais même de la sélection naturelle. Malheureusement, au lieu de poursuivre l'idée, Lamarck aussitôt s'engage dans une autre voie_," etc. (_La Philosophie zoologique avant Darwin_, p. 81).

[183] The expression "_sentiment intérieur_" may be nearly equivalent to the "organic sense" of modern psychologists, but more probably corresponds to our word consciousness.

[184] Lamarck's division of _Animaux sensibles_ comprises the insects, arachnids, crustacea, annelids, cirrhipedes, and molluscs.

[185] Rather a strange view to take, as the brain of insects is now known to be nearly as complex as that of mammals.

[186] Richerand, _Physiologie_. vol ii. p. 151.

[187] "As all animals do not have the power of performing voluntary acts, so in like manner _instinct_ is not common to all animals: for those lacking the nervous system also want the organic sense, and can perform no instinctive acts.

"These imperfect animals are entirely passive, they do nothing of themselves, they have no wants, and nature as regards them treats them as she does plants. But as they are irritable in their parts, the means which nature employs to maintain their existence enables them to execute movements which we call actions."

It thus appears that Lamarck practically regards the lowest animals as automata, but we must remember that the line he draws between animals with and without a nervous system is an artificial one, as some of the forms which he supposed to be destitute of a nervous system are now known to possess one.

[188] It should be noticed that Lamarck does not absolutely state that there are no variations whatever in instinct. His words are much less positive: "_Sans offrer de variation notable._" This dues not exclude the fact, discovered since his time, that instincts are more or less variable, thus affording grounds for Darwin's theory of the origin of new kinds of instincts from the "accidental variation of instincts." Professor James' otherwise excellent version of Lamarck's view is inexact and misleading when he makes Lamarck say that instincts are "perpetuated _without variation_ from one generation to another, so long as the outward conditions of existence remain the same" (_The Principles of Psychology_, vol. ii., p. 678, 1890). He leaves out the word notable. The italics are ours. Farther on (p. 337), it will be seen that Lamarck acknowledges that in birds and mammals instinct is variable.

[189] It is interesting to compare with this Darwin's theory of the origin of the same animals, the flying squirrels and Galeopithecus (_Origin of Species_, 5th edition, New York, pp. 173-174), and see how he invokes the Lamarckian factors of change of "climate and vegetation" and "changing conditions of life," to originate the variations before natural selection can act. His account is a mixture of Lamarckism with the added Darwinian factors of competition and natural selection. We agree with this view, that the change in environment and competition sets the ball in motion, the work being finished by the selective process. The act of springing and the first attempts at flying also involve strong emotions and mental efforts, and it can hardly be denied that these Lamarckian factors came into continual play during the process of evolution of these flying creatures.

[190] This sagacious, though crude suggestion of the origin of birds and mammals from the reptiles is now, after the lapse of nearly a century, being confirmed by modern morphologists and palæontologists.

[191] Reproduced on page 193.

[192] This is taken from my article, "Lamarck and Neo-lamarckianism," in the _Open Court_, Chicago, February, 1897. Compare also "Darwin Wrong," etc., by R. F. Licorish, M.D., Barbadoes, 1898, reprinted in _Natural Science_, April, 1899.

[193] _Natural Selection_, pp. 41-42.

[194] _American Naturalist_, 1891, p. 17.

Previous Next

Comments

Lamarck, the Founder of Evolution: His Life and WorkChapter IV (3)

0%15 min left in chapter