Lamarck, the Founder of Evolution

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"Thirdly, when we enumerate the great changes produced in the
species of animals before their maturity, as, for example, when the
offspring reproduces the effects produced upon the parent by
accident or cultivation; or the changes produced by the mixture of
species, as in mules; or the changes produced probably by the
exuberance of nourishment supplied to the fetus, as in monstrous
births with additional limbs, many of these enormities of shape are
propagated and continued as a variety, at least, if not as a new
species of animal. I have seen a breed of cats with an additional
claw on every foot; of poultry also with an additional claw, and
with wings to their feet, and of others without rumps. Mr. Buffon
mentions a breed of dogs without tails, which are common at Rome and
Naples, which he supposes to have been produced by a custom, long
established, of cutting their tails close off. There are many kinds
of pigeons admired for their peculiarities which are more or less
thus produced and propagated."[154]

6. The means of procuring food has, he says, "diversified the forms of
all species of animals. Thus the nose of the swine has become hard for
the purpose of turning up the soil in search of insects and of roots.
The trunk of the elephant is an elongation of the nose for the purpose
of pulling down the branches of trees for his food, and for taking up
water without bending his knees. Beasts of prey have acquired strong
jaws or talons. Cattle have acquired a rough tongue and a rough palate
to pull off the blades of grass, as cows and sheep. Some birds have
acquired harder beaks to crack nuts, as the parrot. Others have acquired
beaks to break the harder seeds, as sparrows. Others for the softer
kinds of flowers, or the buds of trees, as the finches. Other birds have
acquired long beaks to penetrate the moister soils in search of insects
or roots, as woodcocks, and others broad ones to filtrate the water of
lakes and to retain aquatic insects. All which seem to have been
gradually produced during many generations by the perpetual endeavors of
the creature to supply the want of food, and to have been delivered to
their posterity with constant improvement of them for the purpose
required" (p. 238).

7. The third great want among animals is that of security, which seems
to have diversified the forms of their bodies and the color of them;
these consist in the means of escaping other animals more powerful than
themselves.[155] Hence some animals have acquired wings instead of legs,
as the smaller birds, for purposes of escape. Others, great length of
fin or of membrane, as the flying-fish and the bat. Others have acquired
hard or armed shells, as the tortoise and the Echinus marinus (p. 239).

"The colors of insects," he says, "and many smaller animals
contribute to conceal them from the dangers which prey upon them.
Caterpillars which feed on leaves are generally green; earthworms
the color of the earth which they inhabit; butterflies, which
frequent flowers, are colored like them; small birds which frequent
hedges have greenish backs like the leaves, and light-colored
bellies like the sky, and are hence less visible to the hawk, who
passes under them or over them. Those birds which are much amongst
flowers, as the goldfinch (_Fringilla carduelis_), are furnished
with vivid colors. The lark, partridge, hare, are the color of dry
vegetables or earth on which they rest. And frogs vary their color
with the mud of the streams which they frequent; and those which
live on trees are green. Fish, which are generally suspended in
water, and swallows, which are generally suspended in air, have
their backs the color of the distant ground, and their bellies of
the sky. In the colder climates many of these become white during
the existence of the snows. Hence there is apparent design in the
colors of animals, whilst those of vegetables seem consequent to
the other properties of the materials which possess them" (_The
Loves of the Plants_, p. 38, note).

In his _Zoonomia_ (Sec. xxxix., vi.) Darwin also speaks of the efficient
cause of the various colors of the eggs of birds and of the hair and
feathers of animals which are adapted to the purpose of concealment.
"Thus the snake, and wild cat, and leopard are so colored as to resemble
dark leaves and their light interstices" (p. 248). The eggs of
hedge-birds are greenish, with dark spots; those of crows and magpies,
which are seen from beneath through wicker nests, are white, with dark
spots; and those of larks and partridges are russet or brown, like their
nests or situations. He adds: "The final cause of their colors is easily
understood, as they serve some purpose of the animal, but the efficient
cause would seem almost beyond conjecture." Of all this subject of
protective mimicry thus sketched out by the older Darwin, we find no
hint or trace in any of Lamarck's writings.

8. Great length of time. He speaks of the "great length of time since
the earth began to exist, perhaps millions of ages before the
commencement of the history of mankind" (p. 240).

In this connection it may be observed that Dr. Darwin emphatically
opposes the preformation views of Haller and Bonnet in these words:

"Many ingenious philosophers have found so great difficulty in
conceiving the manner of the reproduction of animals that they have
supposed all the numerous progeny to have existed in miniature in
the animal originally created, and that these infinitely minute
forms are only evolved or distended as the embryon increases in the
womb. This idea, besides being unsupported by any analogy we are
acquainted with, ascribes a greater tenuity to organized matter than
we can readily admit" (p. 317); and in another place he claims that
"we cannot but be convinced that the fetus or embryon is formed by
apposition of new parts, and not by the distention of a primordial
nest of germs included one within another like the cups of a
conjurer" (p. 235).

9. To explain instinct he suggests that the young simply imitate the
acts or example of their parents. He says that wild birds choose spring
as their building time "from the acquired knowledge that the mild
temperature of the air is more convenient for hatching their eggs;" and
further on, referring to the fact that seed-eating animals generally
produce their young in spring, he suggests that it is "part of the
traditional knowledge which they learn from the example of their
parents."[156]

10. Hybridity. He refers in a cursory way to the changes produced by the
mixture of species, as in mules.

Of these ten factors or principles, and other views of Dr. Darwin, some
are similar to those of Lamarck, while others are directly opposed.
There are therefore no good grounds for supposing that Lamarck was
indebted to Darwin for his views. Thus Erasmus Darwin supposes that the
formation of organs precedes their use. As he says, "The lungs must be
previously formed before their exertions to obtain fresh air can exist;
the throat or oesophagus must be formed previous to the sensation or
appetites of hunger and thirst" (_Zoonomia_, p. 222). Again (_Zoonomia_,
i., p. 498), "From hence I conclude that with the acquisition of new
parts, new sensations and new desires, as well as new powers, are
produced" (p. 226). Lamarck does not carry his doctrine of
use-inheritance so far as Erasmus Darwin, who claimed, what some still
maintain at the present day, that the offspring reproduces "the effects
produced upon the parent by accident or cultivation."

The idea that all animals have descended from a similar living filament
is expressed in a more modern and scientific way by Lamarck, who derived
them from monads.

The Erasmus Darwin way of stating that the transformations of animals
are in part produced by their own exertions in consequence of their
desires and aversions, etc., is stated in a quite different way by
Lamarck.

Finally the principle of law of battle, or the combat between the males
for the possession of the females, with the result "that the strongest
and most active animal should propagate the species," is not hinted at
by Lamarck. This view, on the contrary, is one of the fundamental
principles of the doctrine of natural selection, and was made use of by
Charles Darwin and others. So also Erasmus anticipated Charles Darwin in
the third great want of "security," in seeking which the forms and
colors of animals have been modified. This is an anticipation of the
principle of protective mimicry, so much discussed in these days by
Darwin, Wallace, and others, and which was not even mentioned by
Lamarck. From the internal evidence of Lamarck's writings we therefore
infer that he was in no way indebted to Erasmus Darwin for any hints or
ideas.[157]

FOOTNOTES:

[152] Vol. ii., 3d edition. Our references are to this edition.

[153] Krause, _The Scientific Works of Erasmus Darwin_, footnote on
p. 134: "See 'Athenaeum,' March, 1875, p. 423."

[154] _Zoonomia_, i., p. 505 (3d edition, p. 335).

[155] The subject of protective mimicry is more explicitly stated by
Dr. Darwin in his earlier book, _The Loves of the Plants_, and, as
Krause states, though Roesel von Rosenhof in his _Insekten-Belustigungen_
(Nurnberg, 1746) describes the resemblance which geometric caterpillars,
and also certain moths when in repose, present to dry twigs, and thus
conceal themselves, "this group of phenomena seems to have been first
regarded from a more general point of view by Dr. Darwin."

[156] _Zoonomia_, vol. i., p. 170.

[157] Mr. Samuel Butler, in his _Evolution, Old and New_, taking it for
granted that Lamarck was "a partisan of immutability till 1801,"
intimates that "the secret of this sudden conversion must be found in a
French translation by M. Deleuze of Dr. Darwin's poem, _The Loves of the
Plants_, which appeared in 1800. Lamarck--the most eminent botanist of
his time--was sure to have heard of and seen this, and would probably
know the translator, who would be able to give him a fair idea of the
_Zoonomia_" (p. 258).

But this notion seems disproved by the fact that Lamarck delivered his
famous lecture, published in 1801, during the last of April or in the
first half of May, 1800. The views then presented must have been formed
in his mind at least for some time--perhaps a year or more--previous,
and were the result of no sudden inspiration, least of all from any
information given him by Deleuze, whom he probably never met. If Lamarck
had actually seen and read the _Zoonomia_ he would have been manly
enough to have given him credit for any novel ideas. Besides that, as we
have already seen, the internal evidence shows that Lamarck's views were
in some important points entirely different from those of Erasmus
Darwin, and were conceptions original with the French zooelogist.

Krause in his excellent essay on the scientific works of Erasmus Darwin
(1879) refers to Lamarck as "evidently a disciple of Darwin," stating
that Lamarck worked out "in all directions" Erasmus Darwin's principles
of "will and active efforts" (p. 212).

CHAPTER XV

WHEN DID LAMARCK CHANGE HIS VIEWS REGARDING THE MUTABILITY OF SPECIES?

Lamarck's mind was essentially philosophical. He was given to inquiring
into the causes and origin of things. When thirty-two years old he wrote
his "Researches on the Causes of the Principal Physical Facts," though
this work did not appear from the press until 1794, when he was fifty
years of age. In this treatise he inquires into the origin of compounds
and of minerals; also he conceived that all the rocks as well as all
chemical compounds and minerals originated from organic life. These
inquiries were reiterated in his "Memoirs on Physics and Natural
History," which appeared in 1797, when he was fifty-three years old.

The atmosphere of philosophic France, as well as of England and Germany
in the eighteenth century, was charged with inquiries into the origin of
things material, though more especially of things immaterial. It was a
period of energetic thinking. Whether Lamarck had read the works of
these philosophers or not we have no means of knowing. Buffon, we know,
was influenced by Leibnitz.

Did Buffon's guarded suggestions have no influence on the young Lamarck?
He enjoyed his friendship and patronage in early life, frequenting his
house, and was for a time the travelling companion of Buffon's son. It
should seem most natural that he would have been personally influenced
by his great predecessor, but we see no indubitable trace of such
influence in his writings. Lamarckism is not Buffonism. It comprises in
the main quite a different, more varied and comprehensive set of
factors.[158]

Was Lamarck influenced by the biological writings of Haller, Bonnet, or
by the philosophic views of Condillac, whose _Essai sur l'Origine des
Connaissances humaines_ appeared in 1786; or of Condorcet, whom he must
personally have known, and whose _Esquisse d'un Tableau historique des
Progres de l'Esprit humain_ was published in 1794?[159] In one case only
in Lamarck's works do we find reference to these thinkers.

Was Lamarck, as the result of his botanical studies from 1768 to 1793,
and being puzzled, as systematic botanists are, by the variations of the
more plastic species of plants, led to deny the fixity of species?

We have been unable to find any indications of a change of views in his
botanical writings, though his papers are prefaced by philosophical
reflections.

It would indeed be interesting to know what led Lamarck to change his
views. Without any explanation as to the reason from his own pen, we
are led to suppose that his studies on the invertebrates, his perception
of the gradations in the animal scale from monad to man, together with
his inherent propensity to inquire into the origin of things, also his
studies on fossils, as well as the broadening nature of his zooelogical
investigations and his meditations during the closing years of the
eighteenth century, must gradually have led to a change of views.

It was said by Isidore Geoffroy St. Hilaire that Lamarck was "long a
partisan of the immutability of species,"[160] but the use of the word
"partisan" appears to be quite incorrect, as he only in one instance
expresses such views.

The only place where we have seen any statement of Lamarck's earlier
opinions is in his _Recherches sur les Causes des principaux Faits
physiques_, which was written, as the "advertisement" states, "about
eighteen years" before its publication in 1794. The treatise was
actually presented April 22, 1780, to the Academie des Sciences.[161] It
will be seen by the following passages, which we translate, that, as
Huxley states, this view presents a striking contrast to those to be
found in the _Philosophie zoologique_:

"685. Although my sole object in this article [article premier,
p. 188] has only been to treat of the physical cause of the
maintenance of life of organic beings, still I have ventured to urge
at the outset that the existence of these astonishing beings by no
means depends on nature; that all which is meant by the word nature
cannot give life--namely, that all the faculties of matter, added to
all possible circumstances, and even to the activity pervading the
universe, cannot produce a being endowed with the power of organic
movement, capable of reproducing its like, and subject to death.

"686. All the individuals of this nature which exist are derived
from similar individuals, which, all taken together, constitute the
entire species. However, I believe that it is as impossible for man
to know the physical origin of the first individual of each species
as to assign also physically the cause of the existence of matter or
of the whole universe. This is at least what the result of my
knowledge and reflection leads me to think. If there exist any
varieties produced by the action of circumstances, these varieties
do not change the nature of the species (_ces varietes ne denaturent
point les especes_); but doubtless we are often deceived in
indicating as a species what is only a variety; and I perceive that
this error may be of consequence in reasoning on this subject"
(tome ii., pp. 213-214).

It must apparently remain a matter of uncertainty whether this opinion,
so decisively stated, was that of Lamarck at thirty-two years of age,
and which he allowed to remain, as then stated, for eighteen years, or
whether he inserted it when reading the proofs in 1794. It would seem as
if it were the expression of his views when a botanist and a young man.

In his _Memoires de Physique et d'Histoire naturelle_, which was
published in 1797, there is nothing said bearing on the stability of
species, and though his work is largely a repetition of the
_Recherches_, the author omits the passages quoted above. Was this
period of six years, between 1794 and 1800, given to a reconsideration
of the subject resulting in favor of the doctrine of descent?

Huxley quotes these passages, and then in a footnote (p. 211), after
stating that Lamarck's _Recherches_ was not published before 1794, and
stating that at that time it presumably expressed Lamarck's mature
views, adds: "It would be interesting to know what brought about the
change of opinion manifested in the _Recherches sur l'Organisation des
Corps vivans_, published only seven years later."

In the appendix to this book (1802) he thus refers to his change of
views: "I have for a long time thought that _species_ were constant in
nature, and that they were constituted by the individuals which belong
to each of them. I am now convinced that I was in error in this respect,
and that in reality only individuals exist in nature" (p. 141).

Some clew in answer to the question as to when Lamarck changed his views
is afforded by an almost casual statement by Lamarck in the addition
entitled _Sur les Fossiles_ to his _Systeme des Animaux sans Vertebres_
(1801), where, after speaking of fossils as extremely valuable monuments
for the study of the revolutions the earth has passed through at
different regions on its surface, and of the changes living beings have
there themselves successively undergone, he adds in parenthesis: "_Dans
mes lecons j'ai toujours insiste sur ces considerations._" Are we to
infer from this that these evolutionary views were expressed in his
first course, or in one of the earlier courses of zooelogical
lectures--_i.e._, soon after his appointment in 1793--and if not then,
at least one or two, or perhaps several, years before the year 1800? For
even if the change in his views were comparatively sudden, he must have
meditated upon the subject for months and even, perhaps, years, before
finally committing himself to these views in print. So strong and bold a
thinker as Lamarck had already shown himself in these fields of thought,
and one so inflexible and unyielding in holding to an opinion once
formed as he, must have arrived at such views only after long
reflection. There is also every reason to suppose that Lamarck's theory
of descent was conceived by himself alone, from the evidence which lay
before him in the plants and animals he had so well studied for the
preceding thirty years, and that his inspiration came directly from
nature and not from Buffon, and least of all from the writings of
Erasmus Darwin.

FOOTNOTES:

[158] See the comparative summary of the views of the founders of
evolution at the end of Chapter XVII.

[159] While Rousseau was living at Montmorency "his thought wandered
confusedly round the notion of a treatise to be called 'Sensitive
Morality or the Materialism of the Age,' the object of which was to
examine the influence of external agencies, such as light, darkness,
sound, seasons, food, noise, silence, motion, rest, on our corporeal
machine, and thus, indirectly, upon the soul also."--_Rousseau_, by John
Morley (p. 164).

[160] Butler's _Evolution, Old and New_ (p. 244), and Isidore Geoffroy
St. Hilaire's _Histoire naturelle generale_, tome ii., p. 404 (1859).

[161] After looking in vain through both volumes of the _Recherches_ for
some expression of Lamarck's earlier views, I found a mention of it in
Osborn's _From the Greeks to Darwin_, p. 152, and reference to Huxley's
_Evolution in Biology_, 1878 ("Darwiniana," p. 210), where the
paragraphs translated above are quoted in the original.

CHAPTER XVI

THE STEPS IN THE DEVELOPMENT OF LAMARCK'S VIEWS ON EVOLUTION BEFORE THE
PUBLICATION OF HIS _PHILOSOPHIE ZOOLOGIQUE_

I. _From the Systeme des Animaux sans Vertebres_ (1801).

The first occasion on which, so far as his published writings show,
Lamarck expressed his evolutional views was in the opening lecture[162]
of his course on the invertebrate animals delivered in the spring of
1800, and published in 1801 as a preface to his _Systeme des Animaux
sans Vertebres_, this being the first sketch or prodromus of his later
great work on the invertebrate animals. In the preface of this book,
referring to the opening lecture, he says: "I have glanced at some
important and philosophic views that the nature and limits of this work
do not permit me to develop, but which I propose to take up elsewhere
with the details necessary to show on what facts they are based, and
with certain explanations which would prevent any one from
misunderstanding them." It may be inferred from this that he had for
some time previous meditated on this theme. It will now be interesting
to see what factors of evolution Lamarck employed in this first sketch
of his theory.

After stating the distinctions existing between the vertebrate and
invertebrate animals, and referring to the great diversity of animal
forms, he goes on to say that Nature began with the most simply
organized, and having formed them, "then with the aid of much time and
of favorable circumstances she formed all the others."

"It appears, as I have already said, that _time_ and _favorable
conditions_ are the two principal means which nature has employed in
giving existence to all her productions. We know that for her time
has no limit, and that consequently she has it always at her
disposal.

"As to the circumstances of which she has had need and of which she
makes use every day in order to cause her productions to vary, we
can say that they are in a manner inexhaustible.

"The essential ones arise from the influence and from all the
environing media (_milieux_), from the diversity of local causes
(_diversite des lieux_), of habits, of movements, of action, finally
of means of living, of preserving their lives, of defending
themselves, of multiplying themselves, etc. Moreover, as the result
of these different influences the faculties, developed and
strengthened by use (_usage_), became diversified by the new habits
maintained for long ages, and by slow degrees the structure, the
consistence, in a word the nature, the condition of the parts and of
the organs consequently participating in all these influences,
became preserved and were propagated by generation.[163]

"The bird which necessity (_besoin_) drives to the water to find
there the prey needed for its subsistence separates the toes of its
feet when it wishes to strike the water[164] and move on its
surface. The skin, which unites these toes at their base, contracts
in this way the habit of extending itself. Thus in time the broad
membranes which connect the toes of ducks, geese, etc., are formed
in the way indicated.

"But one accustomed to live perched on trees has necessarily the end
of the toes lengthened and shaped in another way. Its claws are
elongated, sharpened, and are curved and bent so as to seize the
branches on which it so often rests.

"Likewise we perceive that the shore bird, which does not care to
swim, but which, however, is obliged (a _besoin_) to approach the
water to obtain its prey, will be continually in danger of sinking
in the mud, but wishing to act so that its body shall not fall into
the liquid, it will contract the habit of extending and lengthening
its feet. Hence it will result in the generations of these birds
which continue to live in this manner, that the individuals will
find themselves raised as if on stilts, on long naked feet; namely,
denuded of feathers up to and often above the thighs.

"I could here pass in review all the classes, all the orders, all
the genera and species of animals which exist, and make it apparent
that the conformation of individuals and of their parts, their
organs, their faculties, etc., is entirely the result of
circumstances to which the race of each species has been subjected
by nature.

"I could prove that it is not the form either of the body or of its
parts which gives rise to habits, to the mode of life of animals,
but, on the contrary, it is the habits, the mode of life, and all
the influential circumstances which have, with time, made up the
form of the body and of the parts of animals. With the new forms new
faculties have been acquired, and gradually nature has reached the
state in which we actually see her" (pp. 12-15).

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