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.
-------------+-------------+------------------------+------------+------------
|Erasmus | |Geoffroy St.|Charles
Buffon |Darwin |Lamarck |Hilaire |Darwin
(1761-1778). |(1790-1794). |(1801-1809-1815). |(1795-1831).|(1859).
-------------+-------------+------------------------+------------+------------
| | | |
All animals |All animals |All organisms arose from|Unity of |Universal
possibly |derived from |germs. First germ |organization|tendency to
derived from |a single |originated by |in animal |fortuitous
a single |filament. |spontaneous generation. |kingdom. |variability
type. | |Development from the | |assumed.
| |simple to the complex. |Change of |
Time, its | |Animal series not |"milieu |
great length,| |continuous, but |ambiant," |
stated. | |tree-like; graduated |direct. |
| |from monad to man; | |
Immutability | |constructed the first | |
of species | |phylogenetic tree. | |
stated and | | |Founded the |Struggle
then denied. |Time, great |Time, great length of, |doctrine of |for
|length of, |definitely postulated; |homologies. |existence.
Nature |definitely |its duration practically| |
advances by |demanded. |unlimited. | |
gradations, | | | |
passing from | |Uniformitarianism of | |
one species | |Hutton and of Lyell |Founder of |
to another by| |anticipated. |teratology. |
imperceptible| | | |
degrees. |Effects of |Effects of favorable |His embryo- |
|change of |circumstances, such as |logical |
Changes in |climate, |changes of environment, |studies |
distribution |direct |climate, soil, food, |influenced |
of land and |(briefly |temperature; direct in |his |
water as |stated). |case of plants and |philosophic |
causing | |lowest animals, indirect|views. |
variation. | |in case of the higher | |
| |animals and man. | |
Effects of | | | |
changes of | |Conditions of existence | |
climate, | |remaining constant, | |
direct. | |species do not vary and | |Competition
| |vice-versa. | |strongly
Effects of | | | |advocated.
changes of | |Struggle for existence; | |
food. | |stronger devour the | |Natural
|Domesti- |weaker. Competition | |selection.
Effects of |cation |stated in case of ai or |Species are |
domesti- |briefly |sloth. Balance of |"different |Sexual
cation. |referred to. |nature. |modifi- |selection.
| | |cations of |
Effects of |Effects of |Effects of use and |one and the |Effects of
use. (The |use: |disuse, discussed at |same type." |use and
only examples|characters |length. | |disuse (in
given are the|produced by | | |some
callosities |their own |Vestigial structures the| |cases).
on legs of |exertions in |remains of organs | |
camel, of |consequence |actively used by | |
baboon, and |of their |ancestors of present | |
the |desires, |forms. | |
thickening by|aversions, | | |
use of soles |lust, hunger,|New wants or necessities| |
on man's |and security.|induced by changes of | |
feet.) | |climate, habitat, etc., | |
|Sexual |result in production of | |
|selection, |new propensities, new | |
|law of |habits, and functions. | |
|battle. | | |
| |Change of habits | |
|Protective |originate organs; change| |
|mimicry. |of functions create new | |
| |organs; formation of new| |
|Origin of |habits precede the | |
|organs before|origin of new or | |
|development |modification of organs | |
|of their |already formed. | |
|functions. | | |
| |Geographical isolation | |Isolation
|Inheritance |suggested as a factor in| |"an
|of acquired |case of man. | |important
|characters | | |element."
|(vaguely |Swamping effects of | |
|stated). |crossing. | |
| | | |
|Instincts |Lamarck's definition of | |
|result of |species the most | |
|imitation. |satisfactory yet stated.| |
| | | |
|Opposed |Inheritance of acquired | |Inheritance
|preformation |characters. | |of acquired
|views of | | |characters.
|Haller and |Instinct the result of | |
|Bonnet. |inherited habits. | |
| | | |
| |Opposed preformation | |
| |views; epigenesis | |
| |definitely stated and | |
| |adopted. | |
| | | |
-------------+-------------+------------------------+------------+------------
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.
CHAPTER XVIII
LAMARCK'S THEORY AS TO THE EVOLUTION OF MAN
Lamarck's views on the origin of man are contained in his _Recherches
sur l'Organisation des Corps vivans_ (1802) and his _Philosophie
zoologique_, published in 1809. We give the following literal
translation in full of the views he presented in 1802, and which were
probably first advanced in lectures to his classes.
"As to man, his origin, his peculiar nature, I have already stated
in this book that I have not kept these subjects in view in making
these observations. His extreme superiority over the other living
creatures indicates that he is a privileged being who has in common
with the animals only that which concerns animal life.
"In truth, we observe a sort of gradation in the intelligence of
animals, like what exists in the gradual improvement of their
organization, and we remark that they have ideas, memory; that they
think, choose, love, hate, that they are susceptible of jealousy,
and that by different inflexions of their voice and by signs they
communicate with and understand each other. It is not less evident
that man alone is endowed with reason, and that on this account he
is clearly distinguished from all the other productions of nature.
"However, were it not for the picture that so many celebrated men
have drawn of the weakness and lack of human reason; were it not
that, independently of all the freaks into which the passions of man
almost constantly allure him, the _ignorance_ which makes him the
opinionated slave of custom and the continual dupe of those who wish
to deceive him; were it not that his reason has led him into the
most revolting errors, since we actually see him so debase himself
as to worship animals, even the meanest, of addressing to them his
prayers, and of imploring their aid; were it not, I say, for these
considerations, should we feel authorized to raise any doubts as to
the excellence of this special light which is the attribute of man?
"An observation which has for a long time struck me is that, having
remarked that the habitual use and exercise of an organ
proportionally develops its size and functions, as the lack of
employment weakens in the same proportion its power, and even more
or less completely atrophies it, I am apprised that of all the
organs of man's body which is the most strongly submitted to this
influence, that is to say, in which the effects of exercise and of
habitual use are the most considerable, is it not the organ of
thought--in a word, is it not the brain of man?
"Compare the extraordinary difference existing in the degree of
intelligence of a man who rarely exercises his powers of thought,
who has always been accustomed to see but a small number of things,
only those related to his ordinary wants and to his limited desires;
who at no time thinks about these same objects, because he is
obliged to occupy himself incessantly with providing for these same
wants; finally, who has few ideas, because his attention,
continually fixed on the same things, makes him notice nothing, that
he makes no comparisons, that he is in the very heart of nature
without knowing it, that he looks upon it almost in the same way as
do the beasts, and that all that surrounds him is nothing to him:
compare, I say, the intelligence of this individual with that of the
man who, prepared at the outset by education, has contracted the
useful practice of exercising the organ of his thought in devoting
himself to the study of the principal branches of knowledge; who
observes and compares everything he sees and which affects him; who
forgets himself in examining everything he can see, who insensibly
accustoms himself to judge of everything for himself, instead of
giving a blind assent to the authority of others; finally, who,
stimulated by reverses and especially by injustice, quietly rises by
reflection to the causes which have produced all that we observe
both in nature and in human society; then you will appreciate how
enormous is the difference between the intelligence of the two men
in question.
"If Newton, Bacon, Montesquieu, Voltaire, and so many other men have
done honor to the human species by the extent of their intelligence
and their genius, how nearly does the mass of brutish, ignorant men
approach the animal, becoming a prey to the most absurd prejudices
and constantly enslaved by their habits, this mass forming the
majority of all nations?
"Search deeply the facts in the comparison I have just made, you
will see how in one part the organ which serves for acts of thought
is perfected and acquires greater size and power, owing to sustained
and varied exercise, especially if this exercise offers no more
interruptions than are necessary to prevent the exhaustion of its
powers; and, on the other hand, you will perceive how the
circumstances which prevent an individual from exercising this
organ, or from exercising it habitually only while considering a
small number of objects which are always of the same nature, impede
the development of his intellectual faculties.
"After what I have just stated as to the results in man of a slight
exercise of the organ by which he thinks, we shall no longer be
astonished to see that in the nations which have come to be the most
distinguished, because there is among them a small number of men who
have been able, by observation and reflection, to create or advance
the higher sciences, the multitude in these same nations have not
been for all that exempted from the most absurd errors, and have not
the less always been the dupe of impostors and victims of their
prejudices.
"Such is, in fact, the fatality attached to the destiny of man that,
with the exception of a small number of individuals who live under
favorable though special circumstances, the multitude, forced to
continually busy itself with providing for its needs, remains
permanently deprived of the knowledge which it should acquire; in
general, exercises to a very slight extent the organ of its
intelligence; preserves and propagates a multitude of prejudices
which enslave it, and cannot be as happy as those who, guiding it,
are themselves guided by reason and justice.
"As to the animals, besides the fact that they in descending order
have the brain less developed, they are otherwise proportionally
more limited in the means of exercising and of varying their
intellectual processes. They each exercise them only on a single or
on some special points, on which they become more or less expert
according to their species. And while their degree of organization
remains the same and the nature of their needs (_besoins_) does not
vary, they can never extend the scope of their intelligence, nor
apply it to other objects than to those which are related to their
ordinary needs.
"Some among them, whose structure is a little more perfect than in
others, have also greater means of varying and extending their
intellectual faculties; but it is always within limits circumscribed
by their necessities and habits.
"The power of habit which is found to be still so great in man,
especially in one who has but slightly exercised the organ of his
thought, is among animals almost insurmountable while their physical
state remains the same. Nothing compels them to vary their powers,
because they suffice for their wants and these require no change.
Hence it is constantly the same objects which exercise their degree
of intelligence, and it results that these actions are always the
same in each species.
"The sole acts of variation, _i.e._, the only acts which rise above
the limits of habits, and which we see performed in animals whose
organization allows them to, are _acts of imitation_. I only speak
of actions which they perform voluntarily or freely (_actions qu'ils
font de leur plein gré_).
"Birds, very limited in this respect in the powers which their
structure furnishes, can only perform acts of imitation with their
vocal organ; this organ, by their habitual efforts to render the
sounds, and to vary them, becomes in them very perfect. Thus we know
that several birds (the parrot, starling, raven, jay, magpie, canary
bird, etc.) imitate the sounds they hear.
"The monkeys, which are, next to man, the animals by their structure
having the best means to this end, are most excellent imitators, and
there is no limit to the things they can mimic.
"In man, infants which are still of the age when simple ideas are
formed on various subjects, and who think but little, forming no
complex ideas, are also very good imitators of everything which they
see or hear.
"But if each order of things in animals is dependent on the state
of organization occurring in each of them, which is not doubted,
there is no occasion for thinking that in these same animals the
order which is superior to all the others in organization is
proportionally so also in extent of means, invariability of actions,
and consequently in intellectual powers.
"For example, in the mammals which are the most highly organized,
the _Quadrumana_, which form a part of them, have, besides the
advantages over other mammals, a conformation in several of their
organs which considerably increases their powers, which allows of a
great variability in their actions, and which extends and even makes
predominant their intelligence, enabling them to deal with a greater
variety of objects with which to exercise their brain. It will
doubtless be said: But although man may be a true mammal in his
general structure, and although among the mammals the _Quadrumana_
are most nearly allied to him, this will not be denied, not only
that man is strongly distinguished from the _Quadrumana_ by a great
superiority of intelligence, but he is also very considerably so in
several structural features which characterize him.
"First, the occipital foramen being situated entirely at the base of
the cranium of man and not carried up behind, as in the other
vertebrates, causes his head to be posed at the extremity of the
vertebral column as on a pivot, not bowed down forward, his face not
looking towards the ground. This position of the head of man, who
can easily turn it to different sides, enables him to see better a
larger number of objects at one time, than the much inclined
position of the head of other mammals allows them to see.
"Secondly, the remarkable mobility of the fingers of the hand of
man, which he employs either all together or several together, or
each separately, according to his pleasure, and besides, the sense
of touch highly developed at the extremity of these same fingers,
enables him to judge the nature of the bodies which surround him, to
recognize them, to make use of them--means which no other animals
possess to such a degree.
"Thirdly, by the state of his organization man is able to hold
himself up and walk erect. He has, for this attitude which is
natural to him, large muscles at the lower extremities which are
adapted to this end, and it would thus be as difficult to walk
habitually on his four extremities as it would be for the other
mammals, and even for the _Quadrumana_, to walk so habitually erect
on the soles of their feet.
"Moreover, man is not truly quadrumanous; for he has not, like the
monkeys, an almost equal facility in using the fingers of his feet,
and of seizing objects with them. In the feet of man the thumbs are
not in opposition to the other fingers to use in grasping, as in
monkeys, etc.
"I appreciate all these reasons, and I see that man, although near
the _Quadrumana_, is so distinct that he alone represents a separate
order, belonging to a single genus and species, offering, however,
many different varieties. This order may be, if it is desired, that
of the _Bimana_.
"However, if we consider that all the characteristics which have
been cited are only differences in degree of structure, may we not
suppose that this special condition of organization of man _has been
gradually acquired at the close of a long period of time, with the
aid of circumstances which have proved favorable?_[195] What a
subject for reflection for those who have the courage to enter into
it!
"If the _Quadrumana_ have not the occipital opening situated
directly at the base of the cranium as in man, it is assuredly much
less raised posteriorly than in the dog, cat, and all the other
mammals. Thus they all may quite often stand erect, although this
attitude for them is very irksome.
"I have not observed the situation of the occipital opening of the
jacko or orang-outang (_Simia satyrus_ L.); but as I know that this
animal almost habitually walks erect, though it has no strength in
its legs, I suppose that the occipital foramen is not situated so
far from the base of the skull as in the other _Quadrumana_.
"The head of the negro, less flattened in front than that of the
European man, necessarily has the occipital foramen central.
"The more should the jacko contract the habit of walking about, the
less mobility would he have in his toes, so that the thumbs of the
feet, which are already much shorter than the other digits, would
gradually cease to be placed in opposition to the other toes, and to
be useful in grasping. The muscles of its lower extremities would
acquire proportionally greater thickness and strength. Then the
increased or more frequent exercise of the fingers of its hands
would develop nervous masses at their extremities, thus rendering
the sense of touch more delicate. This is what our train of
reasoning indicates from the consideration of a multitude of facts
and observations which support it."[196]
The subject is closed by a quotation from Grandpré on the habits of the
chimpanzee. It is not of sufficient importance to be here reproduced.
Seven years after the publication of these views, Lamarck again returns
to the subject in his _Philosophie zoologique_, which we translate.
"_Some Observations Relative to Man_.
"If man were distinguished from the animals by his structure alone,
it would be easy to show that the structural characters which place
him, with his varieties, in a family by himself, are all the product
of former changes in his actions, and in the habits which he has
adopted and which have become special to the individuals of his
species.
"Indeed, if any race whatever of _Quadrumana_, especially the most
perfect, should lose, by the necessity of circumstances or from any
other cause, the habit of climbing trees, and of seizing the
branches with the feet, as with the hands, to cling to them; and if
the individuals of this race, during a series of generations, should
be obliged to use their feet only in walking, and should cease to
use their hands as feet, there is no doubt, from the observations
made in the preceding chapter, that these _Quadrumana_ would be
finally transformed into _Bimana_, and that the thumbs of their feet
would cease to be shorter than the fingers, their feet only being of
use for walking.
"Moreover, if the individuals of which I speak were impelled by the
necessity of rising up and of looking far and wide, of endeavoring
to stand erect, and of adopting this habit constantly from
generation to generation, there is no doubt that their feet would
gradually and imperceptibly assume a conformation adapted for an
erect posture, that their legs would develop calves, and that these
creatures would not afterwards walk as they do now, painfully on
both hands and feet.
"Also, if these same individuals should cease using their jaws for
biting in self-defence, tearing or seizing, or using them like
nippers in cutting leaves for food, and should they only be used in
chewing food, there is no doubt that their facial angle would become
higher, that their muzzle would become shorter and shorter, and that
in the end this being entirely effaced, their incisor teeth would
become vertical.
"Now supposing that a race of _Quadrumana_, as for example the most
perfect, had acquired, by habits constant in every individual, the
structure I have just described, and the power of standing erect and
of walking upright, and that as the result of this it had come to
dominate the other races of animals, we should then conceive:
"1. That this race farther advanced in its faculties, having arrived
at the stage when it lords it over the others, will be spread over
the surface of the globe in every suitable place;
"2. That it will hunt the other higher races of animals and will
struggle with them for preëminence (_lui disputer les biens de la
terre_) and that it will force them to take refuge in regions which
it does not occupy;
"3. That being injured by the great multiplication of closely allied
races, and having banished them into forests or other desert places,
it will arrest the progress of improvement in their faculties, while
its own self, the ruler of the region over which it spreads, will
increase in population without hindrance on the part of others, and,
living in numerous tribes, will in succession create new needs which
should stimulate industry and gradually render still more perfect
its means and powers;
"4. That, finally, this preëminent race having acquired an absolute
supremacy over all the others, there arose between it and the
highest animals a difference and indeed a considerable interval.
"Thus the most perfect race of _Quadrumana_ will have been enabled
to become dominant, to change its habits as the result of the
absolute dominion which it will have assumed over the others, and
with its new needs, by progressively acquiring modifications in its
structure and its new and numerous powers, to keep within due limits
the most highly developed of the other races in the state to which
they had advanced, and to create between it and these last very
remarkable distinctions.
"The Angola orang (_Simia troglodytes_ Lin.) is the highest animal;
it is much more perfect than the orang of the Indies (_Simia
satyrus_ Lin.), which is called the orang-outang, and, nevertheless,
as regards their structure they are both very inferior to man in
bodily faculties and intelligence. These animals often stand erect;
but this attitude is not habitual, their organization not having
been sufficiently modified, so that standing still (_station_) is
painful for them.
"It is known, from the accounts of travellers, especially in regard
to the orang of the Indies, that when immediate danger obliges it to
fly, it immediately falls on all fours. This betrays, they tell us,
the true origin of this animal, since it is obliged to abandon the
alien unaccustomed partially erect attitude which is thrust upon it.
"Without doubt this attitude is foreign to it, since in its change
of locality it makes less use of it, which shows that its
organization is less adapted to it; but though it has become easier
for man to stand up straight, is the erect posture wholly natural to
him?
"Although man, who, by his habits, maintained in the individuals of
his species during a great series of generations, can stand erect
only while changing from one place to another, this attitude is not
less in his case a condition of fatigue, during which he is able to
maintain himself in an upright position only during a limited time
and with the aid of the contraction of several of his muscles.
"If the vertebral column of the human body should form the axis of
this body, and sustain the head in equilibrium, as also the other
parts, the man standing would be in a state of rest. But who does
not know that this is not so; that the head is not articulated at
its centre of gravity; that the chest and stomach, as also the
viscera which these cavities contain, weigh heavily almost entirely
on the anterior part of the vertebral column; that the latter rests
on an oblique base, etc.? Also, as M. Richerand observes, there is
needed in standing a force active and watching without ceasing to
prevent the body from falling over, the weight and disposition of
parts tending to make the body fall forward.
"After having developed the considerations regarding the standing
posture of man, the same savant then expresses himself: 'The
relative weight of the head, of the thoracic and abdominal viscera,
tends therefore to throw it in front of the line, according to which
all the parts of the body bear down on the ground sustaining it; a
line which should be exactly perpendicular to this ground in order
that the standing position may be perfect. The following fact
supports this assertion: I have observed that infants with a large
head, the stomach protruding and the viscera loaded with fat,
accustom themselves with difficulty to stand up straight, and it is
not until the end of their second year that they dare to surrender
themselves to their proper forces; they stand subject to frequent
falls and have a natural tendency to revert to the quadrupedal
state.' (_Physiologie_, vol. ii., p. 268.)
"This disposition of the parts which cause the erect position of
man, being a state of activity, and consequently fatiguing, instead
of being a state of rest, would then betray in him an origin
analogous to that of the mammals, if his organization alone should
be taken into consideration.
"Now in order to follow, in all its particulars, the hypothesis
presented in the beginning of these observations, it is fitting to
add the following considerations:
"The individuals of the dominant race previously mentioned, having
taken possession of all the inhabitable places which were suitable
for them, and having to a very considerable extent multiplied their
necessities in proportion as the societies which they formed became
more numerous, were able equally to increase their ideas, and
consequently to feel the need of communicating them to their
fellows. We conceive that there would arise the necessity of
increasing and of varying in the same proportion the _signs_ adopted
for the communication of these ideas. It is then evident that the
members of this race would have to make continual efforts, and to
employ every possible means in these efforts, to create, multiply,
and render sufficiently varied the _signs_ which their ideas and
their numerous wants would render necessary.
"It is not so with any other animals; because, although the most
perfect among them, such as the _Quadrumana_, live mostly in troops,
since the eminent supremacy of the race mentioned they have remained
stationary as regards the improvement of their faculties, having
been driven out from everywhere and banished to wild, desert,
usually restricted regions, whither, miserable and restless, they
are incessantly constrained to fly and hide themselves. In this
situation these animals no longer contract new needs, they acquire
no new ideas; they have but a small number of them, and it is always
the same ones which occupy their attention, and among these ideas
there are very few which they have need of communicating to the
other individuals of their species. There are, then, only very few
different _signs_ which they employ among their fellows, so that
some movements of the body or of certain of its parts, certain
hisses and cries raised by the simple inflexions of the voice,
suffice them.
"On the contrary, the individuals of the dominant race already
mentioned, having had need of multiplying the _signs_ for the rapid
communication of their ideas, now become more and more numerous,
and, no longer contented either with pantomimic signs or possible
inflexions of their voice to represent this multitude of signs now
become necessary, would succeed by different efforts in forming
_articulated sounds_: at first they would use only a small number,
conjointly with the inflexions of their voice; as the result they
would multiply, vary, and perfect them, according to their
increasing necessities, and according as they would be more
accustomed to produce them. Indeed, the habitual exercise of their
throat, their tongue, and their lips to make articulate sounds, will
have eminently developed in them this faculty.
"Hence for this particular race the origin of the wonderful power of
_speech_; and as the distance between the regions where the
individuals composing it would be spread would favor the corruption
of the signs fitted to express each idea, from this arose the origin
of languages, which must be everywhere diversified.
"Then in this respect necessities alone would have accomplished
everything; they would give origin to efforts; and the organs fitted
for the articulation of sounds would be developed by their habitual
use.
"Such would be the reflections which might be made if man,
considered here as the preëminent race in question, were
distinguished from the animals only by his physical characters, and
if his origin were not different from theirs."
This is certainly, for the time it was written, an original,
comprehensive, and bold attempt at explaining in a tentative way, or at
least suggesting, the probable origin of man from some arboreal creature
allied to the apes. It is as regards the actual evolutional steps
supposed to have been taken by the simian ancestors of man, a more
detailed and comprehensive hypothesis than that offered by Darwin in his
_Descent of Man_,[197] which Lamarck has anticipated. Darwin does not
refer to this theory of Lamarck, and seems to have entirely overlooked
it, as have others since his time. The theory of the change from an
arboreal life and climbing posture to an erect one, and the
transformation of the hinder pair of hands into the feet of the erect
human animal, remind us of the very probable hypothesis of Mr. Herbert
Spencer, as to the modification of the quadrumanous posterior pair of
hands to form the plantigrade feet of man.
FOOTNOTES:
[195] Author's italics.
[196] "How much this unclean beast resembles man!"--_Ennius_.
"Indeed, besides other resemblances the monkey has mammæ, a clitoris,
nymphs, uterus, uvula, eye-lobes, nails, as in the human species; it
also lacks a suspensory ligament of the neck. Is it not astonishing that
man, endowed with wisdom, differs so little from such a disgusting
animal!"--_Linnæus_.
[197] Vol. i., chapter iv., pp. 135-151; ii., p. 372.
CHAPTER XIX
LAMARCK'S THOUGHTS ON MORALS, AND ON THE RELATION BETWEEN SCIENCE AND
RELIGION
One who has read the writings of the great French naturalist, who may be
regarded as the founder of evolution, will readily realize that
Lamarck's mind was essentially philosophic, comprehensive, and
synthetic. He looked upon every problem in a large way. His breadth of
view, his moral and intellectual strength, his equably developed nature,
generous in its sympathies and aspiring in its tendencies, naturally led
him to take a conservative position as to the relations between science
and religion. He should, as may be inferred from his frequent references
to the Author of nature, be regarded as a deist.
When a very young man, he was for a time a friend of the erratic and
gifted Rousseau, and was afterwards not unknown to Condorcet, the
secretary of the French Academy of Sciences, so liberal in his views and
so bitter an enemy of the Church; and though constantly in contact with
the radical views and burning questions of that day, Lamarck throughout
his life preserved his philosophic calm, and maintained his lofty tone
and firm temper. We find no trace in his writings of sentiments other
than the most elevated and inspiring, and we know that in character he
was pure and sweet, self-sacrificing, self-denying, and free from
self-assertion.
The quotations from his _Philosophie zoologique_, published in 1809,
given below, will show what were the results of his meditations on the
relations between science and religion. Had his way of looking at this
subject prevailed, how much misunderstanding and ill-feeling between
theologians and savants would have been avoided! Had his spirit and
breadth of view animated both parties, there would not have been the
constant and needless opposition on the part of the Church to the grand
results of scientific discovery and philosophy, or too hasty dogmatism
and scepticism on the part of some scientists.
In Lamarck, at the opening of the past century, we behold the spectacle
of a man devoting over fifty years of his life to scientific research in
biology, and insisting on the doctrine of spontaneous generation; of the
immense length of geological time, so opposed to the views held by the
Church; the evolution of plants and animals from a single germ, and even
the origin of man from the apes, yet as earnestly claiming that nature
has its Author who in the beginning established the order of things,
giving the initial impulse to the laws of the universe.
As Duval says, after quoting the passage given below: "Deux faits son à
noter dans ce passage: d'une part, les termes dignes et conciliants dans
lesquels Lamarck établit la part de la science et de la religion; cela
vaut, mieux, même en tenant compte des différences d'epoques, que les
abjurations de Buffon."[198]
The passage quoted by M. Duval is the following one:
"Surely nothing exists except by the will of the Sublime Author of
all things. But can we not assign him laws in the execution of his
will, and determine the method which he has followed in this
respect? Has not his infinite power enabled him to create an order
of things which has successively given existence to all that we see,
as well as to that which exists and that of which we have no
knowledge? As regards the decrees of this infinite wisdom, I have
confined myself to the limits of a simple observer of nature."[199]
In other places we find the following expressions:
"There is then, for the animals as for the plants, an order which
belongs to nature, and which results, as also the objects which this
order makes exist, from the power which it has received from the
SUPREME AUTHOR of all things. She is herself only the general and
unchangeable order that this Sublime Author has created throughout,
and only the totality of the general and special laws to which this
order is subject. By these means, whose use it continues without
change, it has given and will perpetually give existence to its
productions; it varies and renews them unceasingly, and thus
everywhere preserves the whole order which is the result of
it."[200]
~ ~ ~ ~ ~
"To regard nature as eternal, and consequently as having existed
from all time, is to me an abstract idea, baseless, limitless,
improbable, and not satisfactory to my reason. Being unable to know
anything positive in this respect, and having no means of reasoning
on this subject, I much prefer to think that _all nature_ is only a
result: hence, I suppose, and I am glad to admit it, a first cause,
in a word, a supreme power which has given existence to nature, and
which has made it in all respects what it is."[201]
~ ~ ~ ~ ~
"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 cause its existence, 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 is necessarily 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."[202]
Lamarck's work on general philosophy[203] was written near the end of
his life, in 1820. He begins his "Discours préliminaire" by referring to
the sudden loss of his eyesight, his work on the invertebrate animals
being thereby interrupted. The book was, he says, "rapidly" dictated to
his daughter, and the ease with which he dictated was due, he says, to
his long-continued habit of meditating on the facts he had observed.
In the "Principes primordiaux" he considers man as the only being who
has the power of observing nature, and the only one who has perceived
the necessity of recognizing a superior and only cause, creator of the
order of the wonders of the world of life. By this he is led to raise
his thoughts to the _Supreme Author_ of all that exists.
"In the creation of his works, and especially those we can observe,
this omnipotent Being has undoubtedly been the ruling power in
pursuing the method which has pleased him, namely, his will has
been:
"Either to create instantaneously and separately every particular
living being observed by us, to personally care for and watch over
them in all their changes, their movements, or their actions, to
unremittingly care for each one separately, and by the exercise of
his supreme will to regulate all their life;
"Or to reduce his creations to a small number, and among these, to
institute an order of things general and continuous, pervaded by
ceaseless activity (_mouvement_), especially subject to laws by
means of which all the organisms of whatever nature, all the changes
they undergo, all the peculiarities they present, and all the
phenomena that many of them exhibit, may be produced.
"In regard to these two modes of execution, if observation taught us
nothing we could not form any opinion which would be well grounded.
But it is not so; we distinctly see that there exists an order of
things truly created (_véritablement créé_), as unchangeable as its
author allows, acting on matter alone, and which possesses the power
of producing all visible beings, of executing all the changes, all
the modifications, even the extinctions, so also the renewals or
recreations that we observe among them. It is to this order of
things that we have given the name of _nature_. The Supreme Author
of all that exists is, then, the immediate creator of matter as also
of nature, but he is only indirectly the creator of what nature can
produce.
"The end that God has proposed to himself in creating matter, which
forms the basis of all bodies, and nature, which divides (_divise_)
this matter, forms the bodies, makes them vary, modifies them,
changes them, and renews them in different ways, can be easily known
to us; for the Supreme Being cannot meet with any obstacle to his
will in the execution of his works; the general results of these
works are necessarily the object he had in view. Thus this end could
be no other than the existence of nature, of which matter alone
forms the sphere, and should not be that causing the creation of any
special being.
"Do we find in the two objects created, _i.e._, _matter_ and
_nature_, the source of the good and evil which have almost always
been thought to exist in the events of this world? To this question
I shall answer that good and evil are only relative to particular
objects, that they never affect by their temporary existence the
general result expected (_prévu_), and that for the end which the
Creator designed, there is in reality neither good nor evil, because
everything in nature perfectly fulfils its object.
"Has God limited his creations to the existence of only matter and
nature? This question is vain, and should remain without an answer
on our part; because, being reduced to knowing anything only through
observation, and to bodies alone, also to what concerns them, these
being for us the only observable objects, it would be rash to speak
affirmatively or negatively on this subject.
"What is a spiritual being? It is what, with the aid of the
imagination, one would naturally suppose (_l'on vaudra supposer_).
Indeed, it is only by means of opposing that which is material that
we can form the idea of spirit; but as this hypothetical being is
not in the category of objects which it is possible for us to
observe, we do not know how to take cognizance of it. The idea that
we have of it is absolutely without base.
"We only know physical objects and only objects relative to these
beings (_êtres_): such is the condition of our nature. If our
thoughts, our reasonings, our principles have been considered as
metaphysical objects, these objects, then, are not beings (_êtres_).
They are only relations or consequences of relations (_rapports_),
or only results of observed laws.
"We know that relations are distinguished as general and special.
Among these last are regarded those of nature, form, dimension,
solidity, size, quantity, resemblance, and difference; and if we add
to these objects the being observed and the consideration of known
laws, as also that of conventional objects, we shall have all the
materials on which our thoughts are based.
"Thus being able to observe only the phenomena of nature, as well as
the laws which regulate these phenomena, also the products of these
last, in a word, only bodies (_corps_) and what concerns them, all
that which immediately proceeds from supreme power is
incomprehensible to us, as it itself [_i.e._, supreme power] is to
our minds. To create, or to make anything out of nothing, this is an
idea we cannot conceive of, for the reason that in all that we can
know, we do not find any model which represents it. GOD alone, then,
can create, while nature can only produce. We must suppose that, in
his creations, the Divinity is not restricted to the use of any
time, while, on the other hand, nature can effect nothing without
the aid of long periods of time."
Without translating more of this remarkable book, which is very rare,
much less known than the _Philosophie zoologique_, the spirit of the
remainder may be imagined from the foregoing extracts.
The author refers to the numerous evils resulting from ignorance, false
knowledge, lack of judgment, abuse of power, demonstrating the necessity
of our confining ourselves within the circle of the objects presented by
nature, and never to go beyond them if we do not wish to fall into
error, because the profound study of nature and of the organization of
man alone, and the exact observation of facts alone, will reveal to us
"the truths most important for us to know," in order to avoid the
vexations, the perfidies, the injustices, and the oppressions of all
sorts, and "incalculable disorders" which arise in the social body. In
this way only shall we discover and acquire the means of obtaining the
enjoyment of the advantages which we have a right to expect from our
state of civilization. The author endeavors to state what science can
and should render to society. He dwells on the sources from which man
has drawn the knowledge which he possesses, and from which he can obtain
many others--sources the totality of which constitutes for him the field
of realities.
Lamarck also in this work has built up a system for moral philosophy.
Self-love, he says, perfectly regulated, gives rise:
1. To moral force which characterizes the laborious man, so that the
length and difficulties of a useful work do not repel him.
2. To the courage of him who, knowing the danger, exposes himself when
he sees that this would be useful.
3. To love of wisdom.
Wisdom, according to Lamarck, consists in the observance of a certain
number of rules or virtues. These we cite in a slightly abridged form.
Love of truth in all things; the need of improving one's mind;
moderation in desires; decorum in all actions; a wise reserve in
unessential wants; indulgence, toleration, humanity, good will towards
all men; love of the public good and of all that is necessary to our
fellows; contempt for weakness; a kind of severity towards one's self
which preserves us from that multitude of artificial wants enslaving
those who give up to them; resignation and, if possible, moral
impassibility in suffering reverses, injustices, oppression, and losses;
respect for order, for public institutions, civil authorities, laws,
morality, and religion.
The practice of these maxims and virtues, says Lamarck, characterizes
true philosophy.
And it may be added that no one practised these virtues more than
Lamarck. Like Cuvier's, his life was blameless, and though he lived a
most retired life, and was not called upon to fill any public station
other than his chair of zoölogy at the Jardin des Plantes, we may feel
sure that he had the qualities of courage, independence, and patriotism
which would have rendered such a career most useful to his country.
As Bourguin eloquently asserts: "Lamarck was the brave man who never
deserted a dangerous post, the laborious man who never hesitated to meet
any difficulty, the investigating spirit, firm in his convictions,
tolerant of the opinions of others, the simple man, moderate in all
things, the enemy of weakness, devoted to the public good, imperturbable
under the attaints of fortune, of suffering, and of unjust and
passionate attacks."
FOOTNOTES:
[198] Mathias Duval: "Le transformiste français Lamarck," _Bulletin de
la Société d'Anthropologie de Paris_, xii., 1889, p. 345.
[199] _Philosophie zoologique_, p. 56.
[200] _Loc. cit._, i., p. 113.
[201] _Loc. cit._, i., p. 361.
[202] _Loc. cit._, ii., p. 465.
[203] _Système analytique des Connaissances de l'Homme_, etc.
CHAPTER XX
THE RELATIONS BETWEEN LAMARCKISM AND DARWINISM; NEOLAMARCKISM
Since the appearance of Darwin's _Origin of Species_, and after the
great naturalist had converted the world to a belief in the general
doctrine of evolution, there has arisen in the minds of many working
naturalists a conviction that natural selection, or Darwinism as such,
is only one of other evolutionary factors; while there are some who
entirely reject the selective principle. Darwin, moreover, assumed a
tendency to fortuitous variation, and did not attempt to explain its
cause. Fully persuaded that he had discovered the most efficient and
practically sole cause of the origin of species, he carried the doctrine
to its extreme limits, and after over twenty years of observation and
experiment along this single line, pushing entirely aside the
Erasmus-Darwin and Lamarckian factors of change of environment, though
occasionally acknowledging the value of use and disuse, he triumphantly
broke over all opposition, and lived to see his doctrine generally
accepted. He had besides the support of some of the strongest men in
science: Wallace in a twin paper advocated the same views; Spencer,
Lyell, Huxley, Hooker, Haeckel, Bates, Semper, Wyman, Gray, Leidy, and
other representative men more or less endorsed Darwin's views, or at
least some form of evolution, and owing largely to their efforts in
scientific circles and in the popular press, the doctrine of descent
rapidly permeated every avenue of thought and became generally accepted.
Meanwhile, the general doctrine of evolution thus proved, and the
"survival of the fittest" an accomplished fact, the next step was to
ascertain "how," as Cope asked, "the fittest originated?" It was felt by
some that natural selection alone was not adequate to explain the first
steps in the origin of genera, families, orders, classes, and branches
or phyla. It was perceived by some that natural selection by itself was
not a _vera causa_, an efficient agent, but was passive, and rather
expressed the results of the operations of a series of factors. The
transforming should naturally precede the action of the selective
agencies.
We were, then, in our quest for the factors of organic evolution,
obliged to fall back on the action of the physico-chemical forces such
as light, or its absence, heat, cold, change of climate; and the
physiological agencies of food, or in other words on changes in the
physical environment, as well as in the biological environment. Lamarck
was the first one who, owing to his many years' training in systematic
botany and zoölogy, and his philosophic breadth, had stated more fully
and authoritatively than any one else the results of changes in the
action of the primary factors of evolution. Hence a return on the part
of many in Europe, and especially in America, to Lamarckism or its
modern form, Neolamarckism. Lamarck had already, so far as he could
without a knowledge of modern morphology, embryology, cytology, and
histology, suggested those fundamental principles of transformism on
which rests the selective principle.
Had his works been more accessible, or, where available, more carefully
read, and his views more fairly represented; had he been favored in his
lifetime by a single supporter, rather than been unjustly criticised by
Cuvier, science would have made more rapid progress, for it is an
axiomatic truth that the general acceptance of a working evolutionary
theory has given a vast impetus to biology.
We will now give a brief historical summary of the history of opinion
held by Lamarckians regarding the causes of the "origin of the fittest,"
the rise of variations, and the appearance of a population of plant and
animal forms sufficiently extensive and differentiated to allow for the
play of the competitive forces, and of the more passive selective
agencies which began to operate in pre-cambrian times, or as soon as the
earth became fitted for the existence of living beings.
The first writer after Lamarck to work along the lines he laid down was
Mr. Herbert Spencer. In 1866-71, in his epochal and remarkably
suggestive _Principles of Biology_, the doctrine of use and disuse is
implicated in his statements as to the effects of motion on structure in
general;[204] and in his theory as to the origin of the notochord, and
of the segmentation of the vertebral column and the segmental
arrangement of the muscles by muscular strains,[205] he laid the
foundations for future work along this line. He also drew attention in
the same work to the complementary development of parts, and likewise
instanced the decreased size of the jaws in the civilized races of
mankind, as a change not accounted for by the natural selection of
favorable variations.[206] In fact, this work is largely based on the
Lamarckian principles, as affording the basis for the action of natural
selection, and thirty years later we find him affirming: "The direct
action of the medium was the primordial factor of organic
evolution."[207] In his well-known essay on "The Inadequacy of Natural
Selection" (1893) the great philosopher, with his accustomed vigor and
force, criticises the arguments of those who rely too exclusively on
Darwinism alone, and especially Neodarwinism, as a sufficient factor to
account for the origin of special structures as well as species.
The first German author to appreciate the value of the Lamarckian
factors was that fertile and comprehensive philosopher and investigator
Ernst Haeckel, who also harmonized Lamarckism and Darwinism in these
words:
"We should, on account of the grand proofs just enumerated, have to
adopt Lamarck's Theory of Descent for the explanation of biological
phenomena, even if we did not possess Darwin's Theory of Selection.
The one is so completely and _directly proved_ by the other, and
established by mechanical causes, that there remains nothing to be
desired. The laws of _Inheritance_ and _Adaptation_ are universally
acknowledged physiological facts, the former traceable to
propagation, the latter to the _nutrition_ of organisms. On the
other hand, the _struggle for existence_ is a _biological_ fact,
which with mathematical necessity follows from the general
disproportion between the average number of organic individuals and
the numerical excess of their germs."[208]
A number of American naturalists at about the same date, as the result
of studies in different directions, unbiassed by a too firm belief in
the efficacy of natural selection, and relying on the inductive method
alone, worked away at the evidence in favor of the primary factors of
evolution along Lamarckian lines, though quite independently, for at
first neither Hyatt nor Cope had read Lamarck's writings.
In 1866 Professor A. Hyatt published the first of a series of classic
memoirs on the genetic relations of the fossil cephalopods. His labors,
so rich in results, have now been carried on for forty years, and are
supplemented by careful, prolonged work on the sponges, on the tertiary
shells of Steinheim, and on the land shells of the Hawaiian Islands.
His first paper was on the parallelism between the different stages of
life in the individual and those of the ammonites, carrying out
D'Orbigny's discovery of embryonic, youthful, adult, and old-age stages
in ammonites,[209] and showing that these forms are due to an
acceleration of growth in the mature forms, and a retardation in the
senile forms.
In a memoir on the "Biological Relations of the Jurassic
Ammonites,"[210] he assigns the causes of the progressive changes in
these forms, the origination of new genera, and the production of young,
mature, and senile forms to "the favorable nature of the physical
surroundings, primarily producing characteristic changes which become
perpetuated and increased by inheritance within the group."
The study of the modifications of the tertiary forms of Planorbis at
Steinheim, begun by Hilgendorf, led among others (nine in all) to the
following conclusions:
"First, that the unsymmetrical spiral forms of the shells of these
and of all the Mollusca probably resulted from the action of the
laws of heredity, modified by gravitation.
"Second, that there are many characteristics in these shells and in
other groups, which are due solely to the uniform action of the
physical influence of the immediate surroundings, varying with every
change of locality, but constant and uniform within each locality.
"Third, that the Darwinian law of Natural Selection does not explain
these relations, but applies only to the first stages in the
establishment of the differences between forms or species in the
same locality. That its office is to fix these in the organization
and bring them within the reach of the laws of heredity."
These views we find reiterated in his later palæontological papers.
Hyatt's views on acceleration were adopted by Neumayr.[211] Waagen,[212]
from his studies on the Jurassic cephalopods, concludes that the factors
in the evolution of these forms were changes in external conditions,
geographical isolation, competition, and that the fundamental law was
not that of Darwin, but "the law of development." Hyatt has also shown
that at first evolution was rapid. "The evolution is a purely mechanical
problem in which the action of the habitat is the working agent of all
the major changes; first acting upon the adult stages, as a rule, and
then through heredity upon the earlier stages in successive
generations." He also shows that as the primitive forms migrated and
occupied new, before barren, areas, where they met with new conditions,
the organisms "changed their habits and structures rapidly to accord
with these new conditions."[213]
While the palæontological facts afford complete and abundant proofs of
the modifying action of changes in the environment, Hyatt, in 1877, from
his studies on sponges,[214] shows that the origin of their endless
forms "can only be explained by the action of physical surroundings
directly working upon the organization and producing by such direct
action the modifications or common variations above described."
Mr. A. Agassiz remarks that the effect of the nature of the bottom of
the sea on sponges and rhizopods "is an all-important factor in
modifying the organism."[215]
While Hyatt's studies were chiefly on the ammonites, molluscs, and
existing sponges, Cope was meanwhile at work on the batrachians. His
_Origin of Genera_ appeared shortly after Hyatt's first paper, but in
the same year (1866). This was followed by a series of remarkably
suggestive essays based on his extensive palæontological work, which are
in part reprinted in his _Origin of the Fittest_ (1887); while in his
epoch-making book, _The Primary Factors of Organic Evolution_ (1896), we
have in a condensed shape a clear exposition of some of the Lamarckian
factors in their modern Neolamarckian form.
In the Introduction, p. 9, he remarks:
"In these papers by Professor Hyatt and myself is found the first
attempt to show by concrete examples of natural taxonomy that the
variations that result in evolution are not multifarious or
promiscuous, but definite and direct, contrary to the method which
seeks no origin for variations other than natural selection. In
other words, these publications constitute the first essays in
systematic evolution that appeared. By the discovery of the
paleontologic succession of modifications of the articulations of
the vertebrate, and especially mammalian, skeleton, I first
furnished an actual demonstration of the reality of the Lamarckian
factor of use, or motion, as friction, impact, and strain, as an
efficient cause of evolution."[216]
The discussion in Cope's work of kinetogenesis, or of the effects of use
and disuse, affords an extensive series of facts in support of these
factors of Lamarck's. As these two books are accessible to every one, we
need only refer the reader to them as storehouses of facts bearing on
Neolamarckism.
The present writer, from a study of the development and anatomy of
Limulus and of Arthropod ancestry, was early (1870)[217] led to adopt
Lamarckian views in preference to the theory of Natural Selection, which
never seemed to him adequate or sufficiently comprehensive to explain
the origin of variations.
In the following year,[218] from a study of the insects and other
animals of Mammoth Cave, we claimed that "the characters separating the
genera and species of animals are those inherited from adults, modified
by their physical surroundings and adaptations to changing conditions of
life, inducing certain alterations in parts which have been transmitted
with more or less rapidity, and become finally fixed and habitual."
In an essay entitled "The Ancestry of Insects"[219] (1873) we adopted
the Lamarckian factors of change of habits and environment, of use and
disuse, to account for the origin of the appendages, while we attributed
the origin of the metamorphoses of insects to change of habits or of the
temperature of the seasons and of climates, particularly the change in
the earth's climates from the earlier ages of the globe, "when the
temperature of the earth was nearly the same the world over, to the
times of the present distribution of heat and cold in zones."
From further studies on cave animals, published in 1877,[220] we wrote
as follows:
"In the production of these cave species, the exceptional phenomena
of darkness, want of sufficient food, and unvarying temperature,
have been plainly enough _veræ causæ_. To say that the principle of
natural selection accounts for the change of structure is no
explanation of the phenomena; the phrase has to the mind of the
writer no meaning in connection with the production of these cave
forms, and has as little meaning in accounting for the origination
of species and genera in general. Darwin's phrase 'natural
selection,' or Herbert Spencer's term 'survival of the fittest,'
expresses simply the final result, while the process of the
origination of the new forms which have survived, or been selected
by nature, is to be explained by the action of the physical
environments of the animals coupled with inheritance-force. It has
always appeared to the writer that the phrases quoted above have
been misused to state the cause, when they simply express the result
of the action of a chain of causes which we may, with Herbert
Spencer, call the 'environment' of the organism undergoing
modification; and thus a form of Lamarckianism, greatly modified by
recent scientific discoveries, seems to meet most of the
difficulties which arise in accounting for the origination of
species and higher groups of organisms. Certainly 'natural
selection' or the 'survival of the fittest' is not a _vera causa_,
though the 'struggle for existence' may show us the causes which
have led to the _preservation_ of species, while changes in the
environment of the organism may satisfactorily account for the
original tendency to variation assumed by Mr. Darwin as the
starting-point where natural selection begins to act."
In our work on _The Cave Animals of North America_,[221] after stating
that Darwin in his _Origin of Species_ attributed the loss of eyes
"wholly to disuse," remarking (p. 142) that after the more or less
perfect obliteration of the eyes, "natural selection will often have
effected other changes, such as an increase in the length of the antennæ
or palpi, as a compensation for blindness," we then summed up as follows
the causes of the production of cave faunæ in general:
"1. Change in environment from light, even partial, to twilight or
total darkness, and involving diminution of food, and compensation
for the loss of certain organs by the hypertrophy of others.
"2. Disuse of certain organs.
"3. Adaptation, enabling the more plastic forms to survive and
perpetuate their stock.
"4. Isolation, preventing intercrossing with out-of-door forms,
thus insuring the permanency of the new varieties, species, or
genera.
"5. Heredity, operating to secure for the future the permanence of
the newly originated forms as long as the physical conditions remain
the same.
"Natural selection perhaps expresses the total result of the working
of these five factors rather than being an efficient cause in
itself, or at least constitutes the last term in a series of causes.
Hence Lamarckism in a modern form, or as we have termed it,
Neolamarckism, seems to us to be nearer the truth than Darwinism
proper or natural selection."[222]
In an attempt to apply Lamarck's principle of the origin of the spines
and horns of caterpillars and other insects as well as other animals to
the result of external stimuli,[223] we had not then read what he says
on the subject. (See p. 316.) Having, however, been led to examine into
the matter, from the views held by recent observers, especially Henslow,
and it appearing that Lamarck was substantially correct in supposing
that the blood (his "fluids") would flow to parts on the exposed
portions of the body and thus cause the origin of horns, on the
principle of the saying, "_ubi irritatio, ibi affluxus_," we came to the
following conclusions:
"The Lamarckian factors (1) change (both direct and indirect) in the
_milieu_, (2) need, and (3) habit, and the now generally adopted
principle that a change of function induces change in organs,[224]
and in some or many cases actually induces the hypertrophy and
specialization of what otherwise would be indifferent parts or
organs;--these factors are all-important in the evolution of the
colors, ornaments, and outgrowths from the cuticle of caterpillars."
Our present views as to the relations between the Lamarckian factors and
the Darwinian one of natural selection are shown by the following
summary at the end of this essay.
"1. The more prominent tubercles, and spines or bristles arising
from them, are hypertrophied piliferous warts, the warts, with the
seta or hair which they bear, being common to all caterpillars.
"2. The hypertrophy or enlargement was probably [we should rather
say _possibly_] primarily due to a change of station from herbs to
trees, involving better air, a more equable temperature, perhaps a
different and better food.
"3. The enlarged and specialized tubercles developed more rapidly on
certain segments than on others, especially the more prominent
segments, because the nutritive fluids would tend more freely to
supply parts most exposed to external stimuli.
"4. The stimuli were in great part due to the visits of insects and
birds, resulting in a mimicry of the spines and projections on the
trees; the colors (lines and spots) were due to light or shade,
with the general result of protective mimicry, or adaptation to
tree-life.
"5. As the result of some unknown factor some of the hypodermic
cells at the base of the spines became in certain forms specialized
so as to secrete a poisonous fluid.
"6. After such primitive forms, members of different families, had
become established on trees, a process of arboreal segregation or
isolation would set in, and intercrossing with low-feeders would
cease.
"7. Heredity, or the unknown factors of which heredity is the
result, would go on uninterruptedly, the result being a succession
of generations perfectly adapted to arboreal life.
"8. Finally the conservative agency of natural selection operates
constantly, tending towards the preservation of the new varieties,
species, and genera, and would not cease to act, in a given
direction, so long as the environment remained the same.
"9. Thus in order to account for the origin of a species, genus,
family, order, or even a class, the first steps, causing the
origination of variations, were in the beginning due to the primary
(direct and indirect) factors of evolution (Neolamarckism), and the
final stages were due to the secondary factors, segregation and
natural selection (Darwinism)."
From a late essay[225] we take the following extracts explaining our
views:
"In seeking to explain the causes of a metamorphosis in animals, one
is compelled to go back to the primary factors of organic
evolution, such as the change of environment, whether the factors be
cosmical (gravity), physical changes in temperature, effects of
increased or diminished light and shade, under- or over-nutrition,
and the changes resulting from the presence or absence of enemies,
or from isolation. The action of these factors, whether direct or
indirect, is obvious, when we try to explain the origin or causes of
the more marked metamorphoses of animals. Then come in the other
Lamarckian factors of use and disuse, new needs resulting in new
modes of life, habits, or functions, which bring about the
origination, development, and perfection of new organs, as in new
species and genera, etc., or which in metamorphic forms may result
in a greater increase in the number of, and an exaggeration of the
features characterizing the stages of larval life.
"VI. _The Adequacy of Neolamarckism_.
"It is not to be denied that in many instances all through the
ceaseless operation of these fundamental factors there is going on a
process of sifting or of selection of forms best adapted to their
surroundings, and best fitted to survive, but this factor, though
important, is quite subordinate to the initial causes of variation,
and of metamorphic changes.
"Neolamarckism,[226] as we understand this doctrine, has for its
foundation a combination of the factors suggested by the Buffon and
Geoffroy St. Hilaire school, which insisted on the direct action of
the _milieu_, and of Lamarck, who relied both on the direct (plants
and lowest animals) and on the indirect action of the environment,
adding the important factors of need and of change of habits
resulting either in the atrophy or in the development of organs by
disuse or use, with the addition of the hereditary transmission of
characters acquired in the lifetime of the individual.
"Lamarck's views, owing to the early date of his work, which was
published in 1809, before the foundation of the sciences of
embryology, cytology, palæontology, zoögeography, and in short all
that distinguishes modern biology, were necessarily somewhat crude,
though the fundamental factors he suggested are those still invoked
by all thinkers of Lamarckian tendencies.
"Neolamarckism gathers up and makes use of the factors both of the
St. Hilaire and Lamarckian schools, as containing the more
fundamental causes of variation, and adds those of geographical
isolation or segregation (Wagner and Gulick), the effects of
gravity, the effects of currents of air and of water, of fixed or
sedentary as opposed to active modes of life, the results of strains
and impacts (Ryder, Cope, and Osborn), the principle of change of
function as inducing the formation of new structures (Dohrn), the
effects of parasitism, commensalism, and of symbiosis--in short, the
biological environment; together with geological extinction, natural
and sexual selection, and hybridity.
"It is to be observed that the Neolamarckian in relying mainly on
these factors does not overlook the value of natural selection as a
guiding principle, and which began to act as soon as the world
became stocked with the initial forms of life, but he simply seeks
to assign this principle to its proper position in the hierarchy of
factors.
"Natural selection, as the writer from the first has insisted, is
not a _vera causa_, an initial or impelling cause in the origination
of new species and genera. It does not start the ball in motion; it
only, so to speak, guides its movements down this or that incline.
It is the expression, like that of "the survival of the fittest" of
Herbert Spencer, of the results of the combined operation of the
more fundamental factors. In certain cases we cannot see any room
for its action; in some others we cannot at present explain the
origin of species in any other way. Its action increased in
proportion as the world became more and more crowded with diverse
forms, and when the struggle for existence had become more unceasing
and intense. It certainly cannot account for the origination of the
different branches, classes, or orders of organized beings. It in
the main simply corresponds to artificial selection; in the latter
case, man selects forms already produced by domestication, the
latter affording sports and varieties due to change in the
surroundings, that is, soil, climate, food, and other physical
features, as well as education.
"In the case also of heredity, which began to operate as soon as the
earliest life forms appeared, we have at the outset to invoke the
principle of the heredity of characters acquired during the lifetime
of lowest organisms.
"Finally, it is noticeable that when one is overmastered by the
dogma of natural selection he is apt, perhaps unconsciously, to give
up all effort to work out the factors of evolution, or to seek to
work out this or that cause of variation. Trusting too implicitly to
the supposed _vera causa_, one may close his eyes to the effects of
change of environment or to the necessity of constant attempts to
discover the real cause of this or that variation, the reduction or
increase in size of this or that organ; or become insensible to the
value of experiments. Were the dogma of natural selection to become
universally accepted, further progress would cease, and biology
would tend to relapse into a stage of atrophy and degeneration. On
the other hand, a revival of Lamarckism in its modern form, and a
critical and doubting attitude towards natural selection as an
efficient cause, will keep alive discussion and investigation, and
especially, if resort be had to experimentation, will carry up to a
higher plane the status of philosophical biology."
Although now the leader of the Neodarwinians, and fully assured of the
"all-sufficiency" of natural selection, the veteran biologist Weismann,
whose earlier works were such epoch-making contributions to insect
embryology, was, when active as an investigator, a strong advocate of
the Lamarckian factors. In his masterly work, _Studies in the Theory of
Descent_[227] (1875), although accepting Darwin's principle of natural
selection, he also relied on "the transforming influence of direct
action as upheld by Lamarck," although he adds, "its extent cannot as
yet be estimated with any certainty." He concluded from his studies in
seasonal dimorphism, "that differences of specific value can originate
through the direct action of external conditions of life only." While
conceding that sexual selection plays a very important part in the
markings and coloring of butterflies, he adds "that a change produced
directly by climate may be still further increased by sexual selection."
He also inquired into the origin of variability, and held that it can be
elucidated by seasonal dimorphism. He thus formulated the chief results
of his investigations: "A species is only caused to change through the
influence of changing external conditions of life, this change being in
a fixed direction which entirely depends on the physical nature of the
varying organism, and is different in different species or even in the
two sexes of the same species."
The influence of changes of climate on variation has been studied to
especial advantage in North America, owing to its great extent, and to
the fact that its territory ranges from the polar to the tropical
regions, and from the Atlantic to the Pacific Ocean. As respects
climatic variation in birds, Professor Baird first took up the inquiry,
which was greatly extended, with especial relation to the formation of
local varieties, by Dr. J. A. Allen,[228] who was the first to ascertain
by careful measurements, and by a study of the difference in plumage and
pelage of individuals inhabiting distant portions of a common habitat,
the variations due to climatic and local causes.
"That varieties," he says, "may and do arise by the action of climatic
influences, and pass on to become species; and that species become, in
like manner, differentiated into genera, is abundantly indicated by the
facts of geographical distribution, and the obvious relation of local
forms to the conditions of environment. The present more or less
unstable condition of the circumstances surrounding organic beings,
together with the known mutations of climate our planet has undergone in
past geological ages, point clearly to the agency of physical conditions
as one of the chief factors in the evolution of new forms of life. So
long as the environing conditions remain stable, just so long will
permanency of character be maintained; but let changes occur, however
gradual or minute, and differentiations begin." He inclines to regard
the modifications as due rather to the direct action of the conditions
of environment than to "the round-about process of natural selection."
He also admits that change of habits and food, use and disuse, are
factors.
The same kind of inquiry, though on far less complete data, was extended
by the present writer[229] in 1873 to the moths, careful measurements of
twenty-five species of geometrid moths common to the Atlantic and
Pacific coasts of North America showing that there is an increase in
size and variation in shape of the wings, and in some cases in color, in
the Pacific Coast over Eastern or Atlantic Coast individuals of the same
species, the differences being attributed to the action of climatic
causes. The same law holds good in the few Notodontian moths common to
both sides of our continent. Similar studies, the results depending on
careful measurements of many individuals, have recently been made by
C. H. Eigenmann (1895-96), W. J. Moenkhaus (1896), and H. C. Bumpus
(1896-98).
The discoveries of Owen, Gaudry, Huxley, Kowalevsky, Cope, Marsh,
Filhol, Osborn, Scott, Wortmann, and many others, abundantly prove that
the lines of vertebrate descent must have been the result of the action
of the primary factors of organic evolution, including the principles of
migration, isolation, and competition; the selective principle being
secondary and preservative rather than originative.
Important contributions to dynamic evolution or kinetogenesis are the
essays of Cope, Ryder, Dall, Osborn, Jackson, Scott, and Wortmann.
Ryder began in 1877 to publish a series of remarkably suggestive essays
on the "mechanical genesis," through strains, of the vertebrate limbs
and teeth, including the causes of the reduction of digits. In
discussing the origin of the great development of the incisor teeth of
rodents, he suggested that "the more severe strains to which they were
subjected by enforced or intelligently assumed changes of habit, were
the initiatory agents in causing them to assume their present forms,
such forms as were best adapted to resist the greatest strains without
breaking."[230]
He afterwards[231] claimed that the articulations of the cartilaginous
fin-rays of the trout (_Salmo fontinalis_) are due to the mechanical
strains experienced by the rays in use as motors of the body of the fish
in the water.
In the line of inquiry opened up by Cope and by Ryder are the essays of
Osborn[232] on the mechanical causes for the displacement of the
elements of the feet in the mammals, and the phylogeny of the teeth.
Also Professor W. B. Scott thus expresses the results of his
studies:[233]
"To sum up the results of our examination of certain series of
fossil mammals, one sees clearly that transformation, whether in the
way of the addition of new parts or the reduction of those already
present, acts just _as if_ the direct action of the environment and
the habits of the animal were the efficient cause of the change, and
any explanation which excludes the direct action of such agencies is
confronted by the difficulty of an immense number of the most
striking coincidences.... So far as I can see, the theory of
determinate variations and of use-inheritance is not antagonistic
but supplementary to natural selection, the latter theory attempting
no explanation of the _causes_ of variation. Nor is it pretended for
a moment that use and disuse are the sole or even the chief factors
in variation."
As early as 1868 the Lamarckian factor of isolation, due to migration
into new regions, was greatly extended, and shown by Moritz Wagner[234]
to be a most important agent in the limitation and fixation of varieties
and species.
"Darwin's work," he says, "neither satisfactorily explains the
external cause which gives the first impulse to increased individual
variability, and consequently to natural selection, nor that
condition which, in connection with a certain advantage in the
struggle for life, renders the new characteristics indispensable.
The latter is, according to my conviction, solely fulfilled by the
voluntary or passive migration of organisms and colonization, which
depends in a great measure upon the configuration of the country; so
that only under favorable conditions would the home of a new species
be founded."
This was succeeded by Rev. J. T. Gulick's profound essays "On Diversity
of Evolution under One Set of External Conditions"[235] (1872), and on
"Divergent Evolution through Cumulative Segregation"[236] (1887).
These and later papers are based on his studies on the land shells of
the Hawaiian Islands. The cause of their extreme diversity of local
species is, he claims, not due to climatic conditions, food, enemies, or
to natural selection, but to the action of what he calls the "law of
segregation."
Fifteen years later Mr. Romanes published his theory of physiological
selection, which covered much the same ground.
A very strong little book by an ornithologist of wide experience,
Charles Dixon,[237] and refreshing to read, since it is packed with
facts, is Lamarckian throughout. The chief factor in the formation of
local species is, he thinks, isolation; the others are climatic
influences (especially the glacial period), use and disuse, and sexual
selection as well as chemical agency. Dixon insists on the "vast
importance of isolation in the modification of many forms of life,
without the assistance of natural selection." Again he says: "Natural
selection, as has often been remarked, can only preserve a beneficial
variation--it cannot originate it, it is not a cause of variation; on
the other hand, the use or disuse of organs is a direct cause of
variation, and can furnish natural selection with abundance of material
to work upon" (p. 49). The book, like the papers of Allen, Ridgway,
Gulick, and others, shows the value of isolation or segregation in
special areas as a factor in the origination of varieties and species,
the result being the prevention of interbreeding, which would otherwise
swamp the incipient varieties.
Here might be cited Delboeuf's law:[238]
"When a modification is produced in a very small number of
individuals, this modification, even were it advantageous, would be
destroyed by heredity, as the favored individuals would be obliged
to unite with the unmodified individuals. _Il n'en est rien,
cependant._ However great may be the number of forms similar to it,
and however small may be the number of dissimilar individuals which
would give rise to an isolated individual, we can always, while
admitting that the different generations are propagated under the
same conditions, meet with a number of generations at the end of
which the sum total of the modified individuals will surpass that of
the unmodified individuals." Giard adds that this law is capable of
mathematical demonstration. "Thus the continuity or even the
periodicity of action of a primary factor, such, for example, as a
variation of the _milieu_, shows us the necessary and sufficient
condition under which a variety or species originates without the
aid of any secondary factor."
Semper,[239] an eminent zoölogist and morphologist, who also was the
first (in 1863) to criticise Darwin's theory of the mode of formation of
coral atolls, though not referring to Lamarck, published a strong,
catholic, and original book, which is in general essentially Lamarckian,
while not undervaluing Darwin's principle of natural selection. "It
appears to me," he says, in the preface, "that of all the properties of
the animal organism, Variability is that which may first and most easily
be traced by exact investigation to its efficient causes."
"By a rearrangement of the materials of his argument, however, we
obtain, as I conceive, convincing proof that external conditions can
exert not only a very powerful selective force, but a transforming
one as well, although it must be the more limited of the two.
"An organ no longer needed for its original purpose may adapt itself
to the altered circumstances, and alter correspondingly if it
contains within itself, as I have explained above, the elements of
such a change. Then the influence exerted by the changed conditions
will be _transforming_, not _selective_.
"This last view may seem somewhat bold to those readers who know
that Darwin, in his theory of selection, has almost entirely set
aside the direct transforming influence of external circumstances.
Yet he seems latterly to be disposed to admit that he had
undervalued the transforming as well as the selective influence of
external conditions; and it seems to me that his objection to the
idea of such an influence rested essentially on the method of his
argument, which seemed indispensable for setting his theory of
selection and his hypothesis as to the transformation of species in
a clear light and on a firm footing" (p. 37).
Dr. H. de Varigny has carried on much farther the kind of experiments
begun by Semper. In his _Experimental Evolution_ he employs the
Lamarckian factors of environment and use and disuse, regarding the
selective factors as secondary.
The Lamarckian factors are also depended upon by the late Professor
Eimer in his works on the variation of the wall-lizard and on the
markings of birds and mammals (1881-88), his final views being comprised
in his general work.[240] The essence of his point of view may be seen
by the following quotation:
"According to my conception, the physical and chemical changes which
organisms experience during life through the action of the
environment, through light or want of light, air, warmth, cold,
water, moisture, food, etc., and which they transmit by heredity,
are the primary elements in the production of the manifold variety
of the organic world, and in the origin of species. From the
materials thus supplied the struggle for existence makes its
selection. These changes, however, express themselves simply as
growth" (p. 22).
In a later paper[241] Eimer proposes the term "orthogenesis," or direct
development, in rigorous conformity to law, in a few definite
directions. Although this is simply and wholly Lamarckism, Eimer claims
that it is not, "for," he strangely enough says, "Lamarck ascribed no
efficiency whatever to the effects of outward influences on the animal
body, and very little to their effects upon vegetable organisms."
Whereas if he had read his Lamarck carefully, he would have seen that
the French evolutionist distinctly states that the environment acts
directly on plants and the lower animals, but indirectly on those
animals with a brain, meaning the higher vertebrates. The same
anti-selection views are held by Eimer's pupil, Piepers,[242] who
explains organic evolution by "laws of growth, ... uncontrolled by any
process of selection."
Dr. Cunningham likewise, in the preface to his translation of Eimer's
work, gives his reasons for adopting Neolamarckian views, concluding
that "the theory of selection can never get over the difficulty of the
origin of entirely new characters;" that "selection, whether natural or
artificial, could not be the essential cause of the evolution of
organisms." In an article on "The New Darwinism" (_Westminster Review_,
July, 1891) he claims that Weismann's theory of heredity does not
explain the origin of horns, venomous teeth, feathers, wings of insects,
or mammary glands, phosphorescent organs, etc., which have arisen on
animals whose ancestors never had anything similar.
Discussing the origin of whales and other aquatic mammals, W. Kükenthal
suggests that the modifications are partially attributable to mechanical
principles. (_Annals and Mag. Nat. Hist._, February, 1891.)
From his studies on the variation of butterflies, Karl Jordan[243]
proposes the term "mechanical selection" to account for them, but he
points out that this factor can only work on variations produced by
other factors. Certain cases, as the similar variation in the same
locality of two species of different families, but with the same wing
pattern, tell in favor of the direct action of the local surroundings on
the markings of the wings.
In the same direction are the essays of Schroeder[244] on the markings
of caterpillars, which he ascribes to the colors of the surroundings; of
Fischer[245] on the transmutations of butterflies as the result of
changes of temperature, and also Dormeister's[246] earlier paper.
Steinach[247] attributes the color of the lower vertebrates to the
direct influence of the light on the pigment cells, as does
Biedermann.[248]
In his address on evolution and the factors of evolution, Professor A.
Giard[249] has given due credit to Lamarck as "the creator of
transformism," and to the position to be assigned to natural selection
as a secondary factor. He quotes at length Lamarck's views published in
1806. After enumerating the primary factors of organic evolution, he
places natural selection among his secondary factors, such as heredity,
segregation, amixia, etc. On the other hand, he states that Lamarck was
not happy in the choice of the examples which he gave to explain the
action of habits and use of parts. "Je ne rappellerai par l'histoire
tant de fois critique du cou de la giraffe et des cornes de l'escargot."
Another important factor in the evolution of the metazoa or many-celled
animals, from the sponges and polyps upward from the one-celled forms or
protozoa, is the principle of animal aggregation or colonization
advanced by Professor Perrier. As civilization and progressive
intelligence in mankind arose from the aggregation of men into tribes or
peoples which lived a sedentary life, so the agricultural, building, and
other arts forthwith sprang up; and as the social insects owe their
higher degree of intelligence to their colonial mode of life, so as soon
as unicellular organisms began to become fixed, and form aggregates, the
sponge and polyp types of organization resulted, this leading to the
gastræa, or ancestral form from which all the higher phyla may have
originated.
M. Perrier appears to fully accept Lamarck's views, including his
speculations as to wants, and use and disuse. He, however, refuses to
accept Lamarck's extreme view as to the origin through effort of
entirely new organs. As he says: "Unfortunately, if Lamarck succeeded in
explaining in a plausible way the modification of organs already
existing, their adaptation to different uses, or even their
disappearance from disuse, in regard to the appearance of new organs he
made hypotheses so venturesome that they led to the momentary
forgetfulness of his other forceful conceptions."[250]
The popular idea of Lamarckism, and which from the first has been
prejudicial to his views, is that an animal may acquire an organ by
simply wishing for or desiring it, or, as his French critics put it, "Un
animal finit toujours par posséder un organe quand il le veut." "Such,"
says Perrier,[251] "is not the idea of Lamarck, who simply attributes
the transformations of species to the stimulating action of external
conditions, construing it under the expression of wants (_besoins_), and
explaining by that word what we now call _adaptations_. Thus the long
neck of the giraffe results from the fact that the animal inhabits a
country where the foliage is situated at the tops of high trees; the
long legs of the wading birds have originated from the fact that these
birds are obliged to seek their food in the water without wetting
themselves," etc. (See p. 350.)
"Many cases," says Perrier, "may be added to-day to those which
Lamarck has cited to support his first law [pp. 303, 346]; the only
point which is open to discussion is the extent of the changes which
an organ may undergo, through the use it is put to by the animal. It
is a simple question of measurement. The possibility of the creation
of an organ in consequence of external stimuli is itself a matter
which deserves to be studied, and which we have no right to reject
without investigation, without observations, or to treat as a
ridiculous dream; Lamarck would doubtless have made it more readily
accepted, if he had not thought it well to pass over the
intermediate steps by means of wants. It is incontestable that by
lack of exercise organs atrophy and disappear."
Finally, says Perrier: "Without doubt the real mechanism of the
improvement (_perfectionnement_) of organisms has escaped him
[Lamarck], but neither has Darwin explained it. The law of natural
selection is not the indication of a process of transformation of
animals; it is the expression of the total results. It states these
results without showing us how they have been brought about. We
indeed see that it tends to the preservation of the most perfect
organisms; but Darwin does not show us how the organisms themselves
originated. This is a void which we have only during these later
years tried to fill" (p. 90).
Dr. J. A. Jeffries, author of an essay "On the Epidermal System of
Birds," in a later paper[252] thus frankly expresses his views as to the
relations of natural selection to the Lamarckian factors. Referring to
Darwin's case of the leg bones of domestic ducks compared with those of
wild ducks, and the atrophy of disused organs, he adds:
"In this case, as with most of Lamarck's laws, Darwin has taken them
to himself wherever natural selection, sexual selection, and the
like have fallen to the ground.
"Darwin's natural selection does not depend, as is popularly
supposed, on direct proof, but is adduced as an hypothesis which
gains its strength from being compatible with so many facts of
correlation between an organism and its surroundings. Yet the same
writer who considers natural selection proved will call for positive
experimental proof of Lamarck's theory, and refuse to accept its
general compatibility with the facts as support. Almost any case
where natural selection is held to act by virtue of advantage gained
by use of a part is equally compatible with Lamarck's theory of use
and development. The wings of birds of great power of flight, the
relations of insects to flowers, the claws of beasts of prey, are
all cases in point."
Professor J. A. Thomson's useful _Synthetic Summary of the Influence of
the Environment upon the Organism_ (1887) takes for its text Spencer's
aphorism, that the direct action of the medium was the primordial factor
of organic evolution. Professor Geddes relies on the changes in the soil
and climate to account for the origin of spines in plants.
The botanist Sachs, in his _Physiology of Plants_ (1887), remarks: "A
far greater portion of the phenomena of life are [is] called forth by
external influences than one formerly ventured to assume."
Certain botanists are now strong in the belief that the species of
plants have originated through the direct influence of the environment.
Of these the most outspoken is the Rev. Professor G. Henslow. His view
is that self-adaptation, by response to the definite action of changed
conditions of life, is the true origin of species. In 1894[253] he
insisted, "_in the strictest sense of the term_, that natural selection
is not wanted as an 'aid' or a 'means' in originating species." In a
later paper[254] he reasserts that all variations are definite, that
there are no indefinite variations, and that natural selection "can take
no part in the origination of varieties." He quotes with approval the
conclusion of Mr. Herbert Spencer in 1852, published
"seven years before Darwin and Dr. Wallace superadded natural
selection as an aid in the origin of species. He saw no necessity
for anything beyond the natural power of change with adaptation; and
I venture now to add my own testimony, based upon upwards of a
quarter of a century's observations and experiments, which have
convinced me that Mr. Spencer was right and Darwin was wrong. His
words are as follows: 'The supporters of the development hypothesis
can show ... that any existing species, animal or vegetable, when
placed under conditions different from its previous ones,
immediately begins to undergo certain changes of structure fitting
it for the new conditions; ... that in the successive generations
these changes continue until ultimately the new conditions become
the natural ones.... They can show that throughout all organic
nature there is at work a modifying influence of the kind they
assign as the causes of specific differences; an influence which,
though slow in its action, does in time, if the circumstances demand
it, produce marked changes.'"[255]
Mr. Henslow adduces observations and experiments by Buckman, Bailey,
Lesage, Lothelier, Costantin, Bonnier, and others, all demonstrating
that the environment acts directly on the plant.
Henslow also suggests that endogens have originated from exogenous
plants through self-adaptation to an aquatic habit,[256] which is in
line with our idea that certain classes of animals have diverged from
the more primitive ones by change of habit, although this has led to the
development of new class-characteristics by use and disuse, phenomena
which naturally do not operate in plants, owing to their fixed
conditions.
Other botanists--French, German, and English--have also been led to
believe in the direct influence of the _milieu_, or environment. Such
are Viet,[257] and Scott Elliot,[258] who attributes the growth of bulbs
to the "direct influence of the climate."
In a recent work Costantin[259] shares the belief emphatically held by
some German botanists in the direct influence of the environment not
only as modifying the form, but also as impressing, without the aid of
natural selection, that form on the species or part of its inherited
stock; and one chapter is devoted to an attempt to establish the thesis
that acquired characters are inherited.
In his essay "On Dynamic Influences in Evolution" W. H. Dall[260] holds
the view that--
"The environment stands in a relation to the individual such as the
hammer and anvil bear to the blacksmith's hot iron. The organism
suffers during its entire existence a continuous series of
mechanical impacts, none the less real because invisible, or
disguised by the fact that some of them are precipitated by
voluntary effort of the individual itself.... It is probable that
since the initiation of life upon the planet no two organisms have
ever been subjected to exactly the same dynamic influences during
their development.... The reactions of the organism against the
physical forces and mechanical properties of its environment are
abundantly sufficient, if we are granted a single organism, with a
tendency to grow, to begin with; time for the operation of the
forces; and the principle of the survival of the fittest."
In his paper on the hinge of Pelecypod molluscs and its development, he
has pointed out a number of the particular ways in which the dynamics of
the environment may act on the characters of the hinge and shell of
bivalve molluscs. He has also shown that the initiation and development
of the columellar plaits in Voluta, Mitra, and other gasteropod molluscs
"are the necessary mechanical result of certain comparatively simple
physical conditions; and that the variations and peculiarities connected
with these plaits perfectly harmonize with the results which follow
within organic material subjected to analogous stresses."
In the same line of study is Dr. R. T. Jackson's[261] work on the
mechanical origin of characters in the lamellibranch molluscs. "The
bivalve nature of the shell doubtless arose," he says, "from the
splitting on the median line of a primitive univalvular ancestor;" and
he adds: "A parallel case is seen in the development of a bivalve shell
in ancient crustaceans;" in both types of shells "the form is induced by
the mechanical conditions of the case." The adductor muscles of bivalve
molluscs and crustaceans are, he shows plainly, the necessary
consequence of the bivalvular condition.
In his theory as to the origin of the siphon of the clam (_Mya
arenaria_), he explains it in a manner identical with Lamarck's
explanations of the origin of the wading and swimming birds, etc., even
to the use of the words "effort" and "habit."
"In _Mya arenaria_ we find a highly elongated siphon. In the young
the siphon hardly extends beyond the borders of the valves, and then
the animal lives at or close to the surface. In progressive growth,
as the animal burrows deeper, the siphon elongates, until it attains
a length many times the total length of the valves.
"The ontogeny of the individual and the paleontology of the family
both show that Mya came from a form with a very abbreviated siphon,
and it seems evident that the long siphon of this genus was brought
about by the effort to reach the surface induced by the habit of
deep burial."
"The tendency to equalize the form of growth in a horizontal plane,
or the geomalic tendency of Professor Hyatt,[262] is seen markedly
in pelecypods. In forms which crawl on the free borders of the
valves, the right and left growth in relation to the perpendicular
is obvious, and agrees with the right and left sides of the animal.
In Pecten the animal at rest lies on the right valve, and swims or
flies with the right valve lowermost. Here equalization to the right
and left of the perpendicular line passing through the centre of
gravity is very marked (especially in the Vola division of the
group); but the induced right and left aspect corresponds to the
dorsal and ventral sides of the animal, not the right and left
sides, as in the former case. Lima, a near ally of Pecten, swims
with the edges of the valves perpendicular. In this case the
geomalic growth corresponds to the right and left sides of the
animal.