Lamarck, the Founder of Evolution

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1. Mollusca. I. _Mollusca._

2. Crustacea. II. _Insectes et Vers._

3. Arachnides (comprising 1. Insectes.
the Myriapoda). 2. Vers.

4. Insectes. III. _Zoophytes._

5. Vers. 1. Echinodermes.
2. Meduses, Animaux
6. Radiaires. infusorines, Rotifer,
Vibrio, Volvox.
7. Polypes. 3. Zoophytes proprement
dits.

Of these, four were for the first time defined, and the others
restricted. It will be noticed that he separates the Radiata
(_Radiaires_) from the Polypes. His "Radiaires" included the
Echinoderms (the _Vers echinoderms_ of Bruguiere) and the Medusae (his
_Radiaires molasses_), the latter forming the Discophora and
Siphonophora of present zooelogists. This is an anticipation of the
division by Leuckart in 1839 of the Radiata of Cuvier into
Coelenterata and Echinodermata.

The "Polypes" of Lamarck included not only the forms now known as such,
but also the Rotifera and Protozoa, though, as we shall see, he
afterwards in his course of 1807 eliminated from this heterogeneous
assemblage the Infusoria.

Comparing this classification with that of Cuvier[121] published in
1798, we find that in the most important respects, _i.e._, the
foundation of the classes of Crustacea, Arachnida, and Radiata, there is
a great advance over Cuvier's system. In Cuvier's work the molluscs are
separated from the worms, and they are divided into three groups,
Cephalopodes, Gasteropodes, and Acephales--an arrangement which still
holds, that of Lamarck into Mollusques cephales and Mollusques acephales
being much less natural. With the elimination of the Mollusca, Cuvier
allowed the Vers or Vermes of Linne to remain undisturbed, except that
the Zooephytes, the equivalent of Lamarck's Polypes, are separately
treated.

He agrees with Cuvier in placing the molluscs at the head of the
invertebrates, a course still pursued by some zooelogists at the present
day. He states in the _Philosophie Zoologique_[122] that in his course
of lectures of the year 1799 he established the class of Crustacea, and
adds that "although this class is essentially distinct, it was not until
six or seven years after that some naturalists consented to adopt it."
The year following, or in his course of 1800, he separated from the
insects the class of Arachnida, as "easy and necessary to be
distinguished." But in 1809 he says that this class "is not yet admitted
into any other work than my own."[123] As to the class of Annelides, he
remarks: "Cuvier having discovered the existence of arterial and venous
vessels in different animals which have been confounded under the name
of worms (_Vers_) with other animals very differently organized, I
immediately employed the consideration of this new fact in rendering my
classification more perfect, and in my course of the year 10 (1802) I
established the class of Annelides, a class which I have placed after
the molluscs and before the crustaceans, as their known organization
requires." He first established this class in his _Recherches sur les
corps vivans_ (1802), but it was several years before it was adopted by
naturalists.

The next work in which Lamarck deals with the classification of the
invertebrates is his _Discours d'ouverture du Cours des Animaux sans
Vertebres_, published in 1806.

On page 70 he speaks of the animal chain or series, from the monad to
man, ascending from the most simple to the most complex. The monad is
one of his _Polypes amorphs_, and he says that it is the most simple
animal form, the most like the original germ (_ebauche_) from which
living bodies have descended. From the monad nature passes to the
Volvox, Proteus (Amoeba), and Vibrio. From them are derived the
_Polypes rotiferes_ and other "Radiaires," and then the Vers,
Arachnides, and Crustacea. On page 77 a tabular view is presented, as
follows:

1. _Les Mollusques._
2. _Les Cirrhipedes._
3. _Les Annelides._
4. _Les Crustaces._
5. _Les Arachnides._
6. _Les Insectes._
7. _Les Vers._
8. _Les Radiaires._
9. _Les Polypes._

It will be seen that at this date two additional classes are proposed
and defined--_i.e._, the Annelides and the Cirrhipedes, though the class
of Annelida was first privately characterized in his lectures for 1802.

The elimination of the barnacles or Cirrhipedes from the molluscs was a
decided step in advance, and was a proof of the acute observation and
sound judgment of Lamarck. He says that this class is still very
imperfectly known and its position doubtful, and adds: "The Cirrhipedes
have up to the present time been placed among the molluscs, but
although certain of them closely approach them in some respects, they
have a special character which compels us to separate them. In short, in
the genera best known the feet of these animals are distinctly
articulated and even crustaceous (_crustaces_)." He does not refer to
the nervous system, but this is done in his next work. It will be
remembered that Cuvier overlooked this feature of the jointed limbs, and
also the crustaceous-like nervous system of the barnacles, and allowed
them to remain among the molluscs, notwithstanding the decisive step
taken by Lamarck. It was not until many years after (1830) that Thompson
proved by their life-history that barnacles are true crustacea.

In the _Philosophie zoologique_ the ten classes of the invertebrates are
arranged in the following order:

_Les Mollusques._
_Les Cirrhipedes._
_Les Annelides._
_Les Crustaces._
_Les Arachnides._
_Les Insectes._
_Les Vers._
_Les Radiaires._
_Les Polypes._
_Les Infusoires._

At the end of the second volume Lamarck gives a tabular view on a page
by itself (p. 463), showing his conception of the origin of the
different groups of animals. This is the first phylogeny or genealogical
tree ever published.

TABLEAU

Servant a montrer l'origine des differens animaux.

Vers. Infusoires.
. Polypes.
. Radiaires.
.
. .
. .
. .
. Insectes.
. Arachnides.
Annelides. Crustaces.
Cirrhipedes.
Mollusques.
.
.
.
Poissons.
Reptiles.
.
. .
. .
Oiseaux. .
. .
. .
Monotremes. M. Amphibies.
.
. .
. .
. . M. Cetaces.
. .
. M. Ongules.
M. Onguicules.

The next innovation made by Lamarck in the _Extrait du Cours de
Zoologie_, in 1812, was not a happy one. In this work he distributed the
fourteen classes of the animal kingdom into three groups, which he named
_Animaux Apathiques_, _Sensibles_, and _Intelligens_. In this
physiologico-psychological base for a classification he unwisely
departed from his usual more solid foundation of anatomical structure,
and the results were worthless. He, however, repeats it in his great
work, _Histoire naturelle des Animaux sans Vertebres_ (1815-1822).

The sponges were by Cuvier, and also by Lamarck, accorded a position
among the Polypes, near Alcyonium, which represents the latter's
_Polypiers empates_; and it is interesting to notice that, for many
years remaining among the Protozoa, meanwhile even by Agassiz regarded
as vegetables, they were by Haeckel restored to a position among the
Coelenterates, though for over twenty years they have by some American
zooelogists been more correctly regarded as a separate phylum.[124]
Lamarck also separated the seals and morses from the cetacea. Adopting
his idea, Cuvier referred the seals to an order of carnivora.

Another interesting matter, to which Professor Lacaze-Duthiers has
called attention in his interesting letter on p. 77, is the position
assigned _Lucernaria_ among his _Radiaires molasses_ near what are now
Ctenophora and Medusae, though one would have supposed he would, from
its superficial resemblance to polyps, have placed it among the polyps.
To Lamarck we are also indebted for the establishment in 1818 of the
molluscan group of Heteropoda.

Lamarck's acuteness is also shown in the fact that, whereas Cuvier
placed them among the acephalous molluscs, he did not regard the
ascidians as molluscs at all, but places them in a class by themselves
under the name of _Tunicata_, following the Sipunculus worms. Yet he
allowed them to remain near the Holothurians (then including Sipunculus)
in his group of _Radiaires echinodermes_, between the latter and the
Vers. He differs from Cuvier in regarding the tunic as the homologue of
the shell of Lamellibranches, remarking that it differs in being
muscular and contractile.

Lamarck's fame as a zooelogist rests chiefly on this great work. It
elicited the highest praise from his contemporaries. Besides containing
the innovations made in the classification of the animal kingdom, which
he had published in previous works, it was a summary of all which was
then known of the invertebrate classes, thus forming a most convenient
hand-book, since it mentioned all the known genera and all the known
species except those of the insects, of which only the types are
mentioned. It passed through two editions, and still is not without
value to the working systematist.

In his _Histoire des Progres des Sciences naturelles_ Cuvier does it
justice. Referring to the earlier volume, he states that "it has
extended immensely the knowledge, especially by a new distribution, of
the shelled molluscs ... M. de Lamarck has established with as much
care as sagacity the genera of shells." Again he says, in noticing the
three first volumes: "The great detail into which M. de Lamarck has
entered, the new species he has described, renders his work very
valuable to naturalists, and renders most desirable its prompt
continuation, especially from the knowledge we have of means which this
experienced professor possesses to carry to a high degree of perfection
the enumeration which he will give us of the shells" (_Oeuvres
completes de Buffon_, 1828, t. 31, p. 354).

"His excellences," says Cleland, speaking of Lamarck as a scientific
observer, "were width of scope, fertility of ideas, and a preeminent
faculty of precise description, arising not only from a singularly terse
style, but from a clear insight into both the distinctive features and
the resemblance of forms" (_Encyc. Britannica_, Art. LAMARCK).

The work, moreover, is remarkable for being the first one to begin with
the simplest and to end with the most highly developed forms.

Lamarck's special line of study was the Mollusca. How his work is still
regarded by malacologists is shown by the following letter from our
leading student of molluscs, Dr. W. H. Dall:

"SMITHSONIAN INSTITUTION,
"UNITED STATES NATIONAL MUSEUM, WASHINGTON, D. C.,
"_November 4, 1899._

"Lamarck was one of the best naturalists of his time, when geniuses
abounded. His work was the first well-marked step toward a natural
system as opposed to the formalities of Linne. He owed something to
Cuvier, yet he knew how to utilize the work in anatomy offered by
Cuvier in making a natural classification. His failing eyesight,
which obliged him latterly to trust to the eyes of others; his
poverty and trials of various kinds, more than excuse the occasional
slips which we find in some of the later volumes of the _Animaux
sans Vertebres_. These are rather of the character of typographical
errors than faults of scheme or principle.

"The work of Lamarck is really the foundation of rational natural
malacological classification; practically all that came before his
time was artificial in comparison. Work that came later was in the
line of expansion and elaboration of Lamarck's, without any change
of principle. Only with the application of embryology and
microscopical work of the most modern type has there come any
essential change of method, and this is rather a new method of
getting at the facts than any fundamental change in the way of using
them when found. I shall await your work on Lamarck's biography with
great interest.

"I remain,
"Yours sincerely,
"WILLIAM H. DALL."

FOOTNOTES:

[119] During the same period (1803-1829) Russia sent out expeditions to
the North and Northeast, accompanied by the zooelogists Tilesius,
Langsdorff, Chamisso, Eschscholtz, and Brandt, all of them of German
birth and education. From 1823 to 1850 England fitted up and sent out
exploring expeditions commanded by Beechey, Fitzroy, Belcher, Ross,
Franklin, and Stanley, the naturalists of which were Bennett, Owen,
Darwin, Adams, and Huxley. From Germany, less of a maritime country, at
a later date, Humboldt, Spix, Prince Wied-Neuwied, Natterer, Perty, and
others made memorable exploring expeditions and journeys.

[120] These papers have been mercilessly criticised by Blainville in his
"Cuvier et Geoffroy St. Hilaire." In the second article--_i.e._, on the
anatomy of the limpet--Cuvier, in considering the organs, follows no
definite plan; he gives a description "_tout-a-fait fantastique_" of the
muscular fibres of the foot, and among other errors in this first essay
on comparative anatomy he mistakes the tongue for the intromittent
organ; the salivary glands, and what is probably part of the brain,
being regarded as the testes, with other "_erreurs materielles
inconcevables, meme a l'epoque ou elle fut redigee_." In his first
article he mistakes a species of the myriapod genus Glomeris for the
isopod genus Armadillo. In this he is corrected by the editor (possibly
Lamarck himself), who remarks in a footnote that the forms to which
M. Cuvier refers under the name of Armadillo are veritable species of
Julus. We have verified these criticisms of Cuvier by reference to his
papers in the "Journal." It is of interest to note, as Blainville does,
that Cuvier at this period admits that there is a passage from the
Isopoda to the armadilloes and Julus. Cuvier, then twenty-three years
old, wrote: "_Nous sommes donc descendus par degres, des Ecrevisses aux
Squilles, de celles-ci aux Aselles, puis aux Cloportes, aux Armadilles
et aux Iules_" (_Journal d'Hist. nat._, tom. ii., p. 29, 1792). These
errors, as regards the limpet, were afterwards corrected by Cuvier
(though he does not refer to his original papers) in his _Memoires pour
servir a l'Histoire et a l'Anatomie des Mollusques_ (1817).

[121] _Tableau elementaire de l'Histoire naturelle des Animaux._ Paris,
An VI. (1798). 8vo, pp. 710. With 14 plates.

[122] Tome i., p. 123.

[123] In his _Histoire des Progres des Sciences naturelles_ Cuvier takes
to himself part of the credit of founding the class Crustacea, stating
that Aristotle had already placed them in a class by themselves, and
adding, "_MM. Cuvier et de Lamarck les en out distingues par des
caracteres de premier ordre tires de leur circulation._" Undoubtedly
Cuvier described the circulation, but it was Lamarck who actually
realized the taxonomic importance of this feature and placed them in a
distinct class.

[124] See A. Hyatt's _Revision of North American Poriferae_, Part II.
(Boston, 1877, p. 11); also the present writer in his _Text-book of
Zooelogy_ (1878).

CHAPTER XIII

THE EVOLUTIONARY VIEWS OF BUFFON AND OF GEOFFROY ST. HILAIRE

Of the French precursors of Lamarck there were four--Duret (1609), De
Maillet (1748), Robinet (1768), and Buffon. The opinions of the first
three could hardly be taken seriously, as they were crude and fantastic,
though involving the idea of descent. The suggestions and hypotheses of
Buffon and of Erasmus Darwin were of quite a different order, and
deserve careful consideration.

[Illustration: MAISON DE BUFFON, IN WHICH LAMARCK LIVED, 1793-1829]

George Louis Leclerc, Comte de Buffon, was born in 1707 at Montbard,
Burgundy, in the same year as Linne. He died at Paris in 1788, at the
age of eighty-one years. He inherited a large property from his father,
who was a councillor of the parliament of Burgundy. He studied at Dijon,
and travelled abroad. Buffon was rich, but, greatly to his credit,
devoted all his life to the care of the Royal Garden and to writing his
works, being a most prolific author. He was not an observer, not even a
closet naturalist. "I have passed," he is reported to have said, "fifty
years at my desk." Appointed in 1739, when he was thirty-two years old,
Intendant of the Royal Garden, he divided his time between his retreat
at Montbard and Paris, spending four months in Paris and the remainder
of the year at Montbard, away from the distractions and dissipations of
the capital. It is significant that he wrote his great _Histoire
naturelle_ at Montbard and not at Paris, where were the collections of
natural history.

His biographer, Flourens, says: "What dominates in the character of
Buffon is elevation, force, the love of greatness and glory; he loved
magnificence in everything. His fine figure, his majestic air, seemed to
have some relation with the greatness of his genius; and nature had
refused him none of those qualities which could attract the attention of
mankind.

"Nothing is better known than the _naivete_ of his self-esteem; he
admired himself with perfect honesty, frankly, but good-naturedly."

He was once asked how many great men he could really mention; he
answered: "Five--Newton, Bacon, Leibnitz, Montesquieu, and myself." His
admirable style gained him immediate reputation and glory throughout the
world of letters. His famous epigram, "_Le style est l'homme meme_" is
familiar to every one. That his moral courage was scarcely of a high
order is proved by his little affair with the theologians of the
Sorbonne. Buffon was not of the stuff of which martyrs are made.

His forte was that of a brilliant writer and most industrious compiler,
a popularizer of science. He was at times a bold thinker; but his
prudence, not to say timidity, in presenting in his ironical way his
thoughts on the origin of things, is annoying, for we do not always
understand what Buffon did really believe about the mutability or the
fixity of species, as too plain speaking in the days he wrote often led
to persecution and personal hazard.[125]

His cosmological ideas were based on those of Burnet and Leibnitz. His
geological notions were founded on the labors of Palissy, Steno,
Woodward, and Whiston. He depended upon his friend Daubenton for
anatomical facts, and on Gueneau de Montbeliard and the Abbe Bexon for
his zooelogical data. As Flourens says, "Buffon was not exactly an
observer: others observed and discovered for him. He discovered,
himself, the observations of others; he sought for ideas, others sought
facts for him." How fulsome his eulogists were is seen in the case of
Flourens, who capped the climax in exclaiming, "Buffon is Leibnitz with
the eloquence of Plato;" and he adds, "He did not write for savants: he
wrote for all mankind." No one now reads Buffon, while the works of
Reaumur, who preceded him, are nearly as valuable as ever, since they
are packed with careful observations.

The experiments of Redi, of Swammerdam, and of Vallisneri, and the
observations of Reaumur, had no effect on Buffon, who maintained that,
of the different forms of genesis, "spontaneous generation" is not only
the most frequent and the most general, but the most ancient--namely,
the primitive and the most universal.[126]

Buffon by nature was unsystematic, and he possessed little of the spirit
or aim of the true investigator. He left no technical papers or memoirs,
or what we would call contributions to science. In his history of
animals he began with the domestic breeds, and then described those of
most general, popular interest, those most known. He knew, as
Malesherbes claimed, little about the works even of Linne and other
systematists, neither grasping their principles nor apparently caring to
know their methods. His single positive addition to zooelogical science
was generalizations on the geographical distribution of animals. He
recognized that the animals of the tropical and southern portions of the
old and new worlds were entirely unlike, while those of North America
and northern Eurasia were in many cases the same.

We will first bring together, as Flourens and also Butler have done, his
scattered fragmentary views, or rather suggestions, on the fixity of
species, and then present his thoughts on the mutability of species.
"The species" is then "an abstract and general term."[127] "There only
exist individuals and _suites_ of individuals, that is to say,
species."[128] He also says that Nature "imprints on each species its
unalterable characters;" that "each species has an equal right to
creation;"[129] that species, even those nearest allied, "are separated
by an interval over which nature cannot pass;"[130] and that "each
species having been independently created, the first individuals have
served as a model for their descendants."[131]

Buffon, however, shows the true scientific spirit in speaking of final
causes.

"The pig," he says, "is not formed as an original, special, and
perfect type; its type is compounded of that of many other animals.
It has parts which are evidently useless, or which, at any rate, it
cannot use." ... "But we, ever on the lookout to refer all parts to
a certain end--when we can see no apparent use for them, suppose
them to have hidden uses, and imagine connections which are without
foundation, and serve only to obscure our perception of Nature as
she really is: we fail to see that we thus rob philosophy of her
true character, which is to inquire into the 'how' of these
things--into the manner in which Nature acts--and that we substitute
for this true object a vain idea, seeking to divine the 'why'--the
ends which she has proposed in acting" (tome v., p. 104, 1755, _ex_
Butler).

The volumes of the _Histoire naturelle_ on animals, beginning with
tome iv., appeared in the years 1753 to 1767, or over a period of
fourteen years. Butler, in his _Evolution, Old and New_, effectually
disposes of Isidore Geoffroy St. Hilaire's statement that at the
beginning of his work (tome iv., 1753) he affirms the fixity of species,
while from 1761 to 1766 he declares for variability. But Butler asserts
from his reading of the first edition that "from the very first chapter
onward he leant strongly to mutability, even if he did not openly avow
his belief in it.... The reader who turns to Buffon himself will find
that the idea that Buffon took a less advanced position in his old age
than he had taken in middle life is also without foundation"[132]
(p. 104).

But he had more to say on the other side, that of the mutability of
species, and it is these tentative views that his commentators have
assumed to have been his real sentiments or belief, and for this reason
place Buffon among the evolutionists, though he had little or no idea of
evolution in the enlarged and thoroughgoing sense of Lamarck.

He states, however, that the presence of callosities on the legs of the
camel and llama "are the unmistakable results of rubbing or friction; so
also with the callosities of baboons and the pouched monkeys, and the
double soles of man's feet."[133] In this point he anticipates Erasmus
Darwin and Lamarck. As we shall see, however, his notions were much less
firmly grounded than those of Erasmus Darwin, who was a close observer
as well as a profound thinker.

In his chapter on the _Degeneration des Animaux_, or, as it is
translated, "modification of animals," Buffon insists that the three
causes are climate, food, and domestication. The examples he gives are
the sheep, which having originated, as he thought, from the mufflon,
shows marked changes. The ox varies under the influence of food; reared
where the pasturage is rich it is twice the size of those living in a
dry country. The races of the torrid zones bear a hump on their
shoulders; "the zebu, the buffalo, is, in short, only a variety, only a
race of our domestic ox." He attributed the camel's hump to domesticity.
He refers the changes of color in the northern hare to the simple change
of seasons.

He is most explicit in referring to the agency of climate, and also to
time and to the uniformity of nature's processes in causing variation.
Writing in 1756 he says:

"If we consider each species in the different climates which it
inhabits we shall find perceptible varieties as regards size and
form; they all derive an impress to a greater or less extent from
the climate in which they live. These changes are only made slowly
and imperceptibly. Nature's great workman is time. He marches ever
with an even pace and does nothing by leaps and bounds, but by
degrees, gradations, and succession he does all things; and the
changes which he works--at first imperceptible--become little by
little perceptible, and show themselves eventually in results about
which there can be no mistake. Nevertheless, animals in a free, wild
state are perhaps less subject than any other living beings, man not
excepted, to alterations, changes, and variations of all kinds.
Being free to choose their own food and climate, they vary less than
domestic animals vary."[134]

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