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Darwiniana

T >> Thomas Henry Huxley >> Darwiniana




We have dwelt at length upon, this subject, because of its great general
importance, and because we believe that Professor Kölliker's criticisms on
this head are based upon a misapprehension of Mr. Darwin's
views--substantially they appear to us to coincide with his own. The other
objections which Professor Kölliker enumerates and discusses are the
following: [Footnote: Space will not allow us to give Professor Kölliker's
arguments in detail; our readers will find a full and accurate version of
them in the _Reader_ for August 13th and 20th, 1864.]--

"1. No transitional forms between existing species are known; and known
varieties, whether selected or spontaneous, never go so far as to establish
new species."

To this Professor Kölliker appears to attach some weight. He makes the
suggestion that the short-faced tumbler pigeon may be a pathological
product.

"2. No transitional forms of animals are met with among the organic remains
of earlier epochs."

Upon this, Professor Kölliker remarks that the absence of transitional
forms in the fossil world, though not necessarily fatal to Darwin's views,
weakens his case.

"3. The struggle for existence does not take place."

To this objection, urged by Pelzeln, Kölliker, very justly, attaches no
weight.

"4. A tendency of organisms to give rise to useful varieties, and a natural
selection, do not exist.

"The varieties which are found arise in consequence of manifold external
influences, and it is not obvious why they all, or partially, should be
particularly useful. Each animal suffices for its own ends, is perfect of
its kind, and needs no further development. Should, however, a variety be
useful and even maintain itself, there is no obvious reason why it should
change any further. The whole conception of the imperfection of organisms
and the necessity of their becoming perfected is plainly the weakest side
of Darwin's Theory, and a _pis aller_ (Nothbehelf) because Darwin
could think of no other principle by which to explain the metamorphoses
which, as I also believe, have occurred."

Here again we must venture to dissent completely from Professor Kölliker's
conception of Mr. Darwin's hypothesis. It appears to us to be one of the
many peculiar merits of that hypothesis that it involves no belief in a
necessary and continual progress of organisms.

Again, Mr. Darwin, if we read him aright, assumes no special tendency of
organisms to give rise to useful varieties, and knows nothing of needs of
development, or necessity of perfection. What he says is, in substance: All
organisms vary. It is in the highest degree improbable that any given
variety should have exactly the same relations to surrounding conditions as
the parent stock. In that case it is either better fitted (when the
variation may be called useful), or worse fitted, to cope with them. If
better, it will tend to supplant the parent stock; if worse, it will tend
to be extinguished by the parent stock.

If (as is hardly conceivable) the new variety is so perfectly adapted to
the conditions that no improvement upon it is possible,--it will persist,
because, though it does not cease to vary, the varieties will be inferior
to itself.

If, as is more probable, the new variety is by no means perfectly adapted
to its conditions, but only fairly well adapted to them, it will persist,
so long as none of the varieties which it throws off are better adapted
than itself.

On the other hand, as soon as it varies in a useful way, _i.e._ when
the variation is such as to adapt it more perfectly to its conditions, the
fresh variety will tend to supplant the former.

So far from a gradual progress towards perfection forming any necessary
part of the Darwinian creed, it appears to us that it is perfectly
consistent with indefinite persistence in one state, or with a gradual
retrogression. Suppose, for example, a return of the glacial epoch and a
spread of polar climatal conditions over the whole globe. The operation of
natural selection under these circumstances would tend, on the whole, to
the weeding out of the higher organisms and the cherishing of the lower
forms of life. Cryptogamic vegetation would have the advantage over
Phanerogamic; _Hydrozoa_ over Corals; _Crustacea_ over
_Insecta_, and _Amphipoda_ and _Isopoda_ over the higher
_Crustacea;_ Cetaceans and Seals over the _Primates_; the
civilisation of the Esquimaux over that of the European.

"5. Pelzeln has also objected that if the later organisms have proceeded
from the earlier, the whole developmental series, from the simplest to the
highest, could not now exist; in such a case the simpler organisms must
have disappeared."

To this Professor Kölliker replies, with perfect justice, that the
conclusion drawn by Pelzeln does not really follow from Darwin's premises,
and that, if we take the facts of Paleontology as they stand, they rather
support than oppose Darwin's theory.

"6. Great weight must be attached to the objection brought forward by
Huxley, otherwise a warm supporter of Darwin's hypothesis, that we know of
no varieties which are sterile with one another, as is the rule among
sharply distinguished animal forms.

"If Darwin is right, it must be demonstrated that forms may be produced by
selection, which, like the present sharply distinguished animal forms, are
infertile, when coupled with one another, and this has not been done."

The weight of this objection is obvious; but our ignorance of the
conditions of fertility and sterility, the want of carefully conducted
experiments extending over long series of years, and the strange anomalies
presented by the results of the cross-fertilisation of many plants, should
all, as Mr. Darwin has urged, be taken into account in considering it.

The seventh objection is that we have already discussed (_supra_ p.
82).

The eighth and last stands as follows:--

"8. The developmental theory of Darwin is not needed to enable us to
understand the regular harmonious progress of the complete series of
organic forms from the simpler to the more perfect.

"The existence of general laws of Nature explains this harmony, even if we
assume that all beings have arisen separately and independent of one
another. Darwin forgets that inorganic nature, in which there can be no
thought of genetic connexion of forms, exhibits the same regular plan, the
same harmony, as the organic world; and that, to cite only one example,
there is as much a natural system of minerals as of plants and animals."

We do not feel quite sure that we seize Professor Kölliker's meaning here,
but he appears to suggest that the observation of the general order and
harmony which pervade inorganic nature, would lead us to anticipate a
similar order and harmony in the organic world. And this is no doubt true,
but it by no means follows that the particular order and harmony observed
among them should be that which we see. Surely the stripes of dun horses,
and the teeth of the _foetal_ _Balæna_, are not explained by the
"existence of General laws of Nature." Mr. Darwin endeavours to explain the
exact order of organic nature which exists; not the mere fact that there is
some order.

And with regard to the existence of a natural system of minerals; the
obvious reply is that there may be a natural classification of any
objects--of stones on a sea-beach, or of works of art; a natural
classification being simply an assemblage of objects in groups, so as to
express their most important and fundamental resemblances and differences.
No doubt Mr. Darwin believes that those resemblances and differences upon
which our natural systems or classifications of animals and plants are
based, are resemblances and differences which have been produced
genetically, but we can discover no reason for supposing that he denies the
existence of natural classifications of other kinds.

And, after all, is it quite so certain that a genetic relation may not
underlie the classification of minerals? The inorganic world has not always
been what we see it. It has certainly had its metamorphoses, and, very
probably, a long "Entwickelungsgeschichte" out of a nebular blastema. Who
knows how far that amount of likeness among sets of minerals, in virtue of
which they are now grouped into families and orders, may not be the
expression of the common conditions to which that particular patch of
nebulous fog, which may have been constituted by their atoms, and of which
they may be, in the strictest sense, the descendants, was subjected?

It will be obvious from what has preceded, that we do not agree with
Professor Kölliker in thinking the objections which he brings forward so
weighty as to be fatal to Darwin's view. But even if the case were
otherwise, we should be unable to accept the "Theory of Heterogeneous
Generation" which is offered as a substitute. That theory is thus stated:--

"The fundamental conception of this hypothesis is, that, under the
influence of a general law of development, the germs of organisms produce
others different from themselves. This might happen (1) by the fecundated
ova passing, in the course of their development, under particular
circumstances, into higher forms; (2) by the primitive and later organisms
producing other organisms without fecundation, out of germs or eggs
(Parthenogenesis)."

In favour of this hypothesis, Professor Kölliker adduces the well-known
facts of Agamogenesis, or "alternate generation"; the extreme dissimilarity
of the males and females of many animals; and of the males, females, and
neuters of those insects which live in colonies: and he defines its
relations to the Darwinian theory as follows:--

"It is obvious that my hypothesis is apparently very similar to Darwin's,
inasmuch as I also consider that the various forms of animals have
proceeded directly from one another. My hypothesis of the creation of
organisms by heterogeneous generation, however, is distinguished very
essentially from Darwin's by the entire absence of the principle of useful
variations and their natural selection: and my fundamental conception is
this, that a great plan of development lies at the foundation of the origin
of the whole organic world, impelling the simpler forms to more and more
complex developments. How this law operates, what influences determine the
development of the eggs and germs, and impel them to assume constantly new
forms, I naturally cannot pretend to say; but I can at least adduce the
great analogy of the alternation of generations. If a _Bipinnaria_, a
_Brachiolaria_, a _Pluteus_, is competent to produce the
Echinoderm, which is so widely different from it; if a hydroid polype can
produce the higher Medusa; if the vermiform Trematode 'nurse' can develop
within itself the very unlike _Cercaria_, it will not appear
impossible that the egg, or ciliated embryo, of a sponge, for once, under
special conditions, might become a hydroid polype, or the embryo of a
Medusa, an Echinoderm."

It is obvious, from, these extracts, that Professor Kölliker's hypothesis
is based upon the supposed existence of a close analogy between the
phænomena of Agamogenesis and the production of new species from
pre-existing ones. But is the analogy a real one? We think that it is not,
and, by the hypothesis cannot be.

For what are the phænomena of Agamogenesis, stated generally? An
impregnated egg develops into a sexless form, A; this gives rise,
non-sexually, to a second form or forms, B, more or less different from A.
B may multiply non-sexually again; in the simpler cases, however, it does
not, but, acquiring sexual characters, produces impregnated eggs from
whence A, once more, arises.

No case of Agamogenesis is known in which _when A differs widely from
B_, it is itself capable of sexual propagation. No case whatever is
known in which the progeny of B, by sexual generation, is other than a
reproduction of A.

But if this be a true statement of the nature of the process of
Agamogenesis, how can it enable us to comprehend the production of new
species from already existing ones? Let us suppose Hyænas to have preceded
Dogs, and to have produced the latter in this way. Then the Hyæna will
represent A, and the Dog, B. The first difficulty that presents itself is
that the Hyæna must be non-sexual, or the process will be wholly without
analogy in the world of Agamogenesis. But passing over this difficulty, and
supposing a male and female Dog to be produced at the same time from the
Hyæna stock, the progeny of the pair, if the analogy of the simpler kinds
of Agamogenesis [Footnote: If, on the contrary, we follow the analogy of
the more complex forms of Agamogenesis, such as that exhibited by some
_Trematoda_ and by the _Aphides_, the Hyæna must produce,
non-sexually, a brood of sexless Dogs, from which other sexless Dogs must
proceed. At the end of a certain number of terms of the series, the Dogs
would acquire sexes and generate young; but these young would be, not Dogs,
but Hyænas. In fact, we have demonstrated, in Agamogenetic phænomena, that
inevitable recurrence to the original type, which is asserted to be true of
variations in general, by Mr. Darwin's opponents; and which, if the
assertion could be changed into a demonstration, would, in fact, be fatal
to his hypothesis.] is to be followed, should be a litter, not of puppies,
but of young Hyænas. For the Agamogenetic series is always, as we have
seen, A:B:A:B, &c.; whereas, for the production of a new species, the
series must be A:B:B:B, &c. The production of new species, or genera, is
the extreme permanent divergence from the primitive stock. All known
Agamogenetic processes, on the other hand, end in a complete return to the
primitive stock. How then is the production of new species to be rendered
intelligible by the analogy of Agamogenesis?

The other alternative put by Professor Kölliker--the passage of fecundated
ova in the course of their development into higher forms--would, if it
occurred, be merely an extreme case of variation in the Darwinian sense,
greater in degree than, but perfectly similar in kind to, that which
occurred when the well-known Ancon Ram was developed from an ordinary Ewe's
ovum. Indeed we have always thought that Mr. Darwin has unnecessarily
hampered himself by adhering so strictly to his favourite "Natura non facit
saltum." We greatly suspect that she does make considerable jumps in the
way of variation now and then, and that these saltations give rise to some
of the gaps which appear to exist in the series of known forms.

Strongly and freely as we have ventured to disagree with Professor
Kölliker, we have always done so with regret, and we trust without
violating that respect which is due, not only to his scientific eminence
and to the careful study which he has devoted to the subject, but to the
perfect fairness of his argumentation, and the generous appreciation of the
worth of Mr. Darwin's labours which he always displays. It would be
satisfactory to be able to say as much for M. Flourens.

But the Perpetual Secretary of the French Academy of Sciences deals with
Mr. Darwin as the first Napoleon would have treated an "idéologue;" and
while displaying a painful weakness of logic and shallowness of
information, assumes a tone of authority, which always touches upon the
ludicrous, and sometimes passes the limits of good breeding.

For example (p. 56):--

"M. Darwin continue: 'Aucune distinction absolue n'a été et ne peut être
établie entre les espèces et les variétés.' Je vous ai déjà dit que vous
vous trompiez; une distinction absolue sépare les variétés d'avec les
espèces."

"_Je vous ai déjà dit_; moi, M. le Secrétaire perpétuel de l'Académie
des Sciences: et vous

"'Qui n'êtes rien,
Pas même Académicien;'

what do you mean by asserting the contrary?" Being devoid of the blessings
of an Academy in England, we are unaccustomed to see our ablest men treated
in this fashion, even by a "Perpetual Secretary."

Or again, considering that if there is any one quality of Mr. Darwin's work
to which friends and foes have alike borne witness, it is his candour and
fairness in admitting and discussing objections, what is to be thought of
M. Flourens' assertion, that

"M. Darwin ne cite que les auteurs qui partagent ses opinions." (P. 40.)

Once more (p. 65):--

"Enfin l'ouvrage de M. Darwin a paru. On ne peut qu'être frappé du talent
de l'auteur. Mais quo d'idées obscures, que d'idées fausses! Quel jargon
métaphysique jeté mal à propos dans l'histoire naturelle, qui tombe dans le
galimatias dès qu'elle sort des idées claires, des idées justes! Quel
langage prétentieux et vide! Quelles personnifications puériles et
surannées! O lucidité! 0 solidité de l'esprit Français, que devenez-vous?"

"Obscure ideas," "metaphysical jargon," "pretentious and empty language,"
"puerile and superannuated personifications." Mr. Darwin has many and hot
opponents on this side of the Channel and in Germany, but we do not
recollect to have found precisely these sins in the long catalogue of those
hitherto laid to his charge. It is worth while, therefore, to examine into
these discoveries effected solely by the aid of the "lucidity and solidity"
of the mind of M. Flourens.

According to M. Flourens, Mr. Darwin's great error is that he has
personified Nature (p. 10), and further that he has

"imagined a natural selection: he imagines afterwards that this power of
selecting (_pouvoir d'élire_) which he gives to Nature is similar to
the power of man. These two suppositions admitted, nothing stops him: he
plays with Nature as he likes, and makes her do all he pleases." (P. 6.)

And this is the way M. Flourens extinguishes natural selection:

"Voyons donc encore une fois, ce qu'il peut y avoir de fondé dans ce qu'on
nomme _élection naturelle_.

"_L'élection naturelle_ n'est sous un autre nom que la nature. Pour un
être organisé, la nature n'est que l'organisation, ni plus ni moins.

"Il faudra donc aussi personnifier _l'organisation,_ et dire que
_l'organisation_ choisit _l'organisation. L'élection naturelle_
est cette _forme substantielle_ dont on jouait autrefois avec tant de
facilité. Aristote disait que 'Si l'art de bâtir était dans le bois, cet
art agirait comme la nature.' A la place de _l'art de bâtir_ M. Darwin
met _l'élection naturelle,_ et c'est tout un: l'un n'est pas plus
chimérique que l'autre." (P. 31.)

And this is really all that M. Flourens can make of Natural Selection. We
have given the original, in fear lest a translation should be regarded as a
travesty; but with the original before the reader, we may try to analyse
the passage. "For an organised being, Nature is only organisation, neither
more nor less."

Organised beings then have absolutely no relation to inorganic nature: a
plant does not depend on soil or sunshine, climate, depth in the ocean,
height above it; the quantity of saline matters in water have no influence
upon animal life; the substitution of carbonic acid for oxygen in our
atmosphere would hurt nobody! That these are absurdities no one should know
better than M. Flourens; but they are logical deductions from the assertion
just quoted, and from the further statement that natural selection means
only that "organisation chooses and selects organisation."

For if it be once admitted (what no sane man denies) that the chances of
life of any given organism are increased by certain conditions (A) and
diminished by their opposites (B), then it is mathematically certain that
any change of conditions in the direction of (A) will exercise a selective
influence in favour of that organism, tending to its increase and
multiplication, while any change in the direction of (B) will exercise a
selective influence against that organism, tending to its decrease and
extinction.

Or, on the other hand, conditions remaining the same, let a given organism
vary (and no one doubts that they do vary) in two directions: into one form
(_a_) better fitted to cope with these conditions than the original
stock, and a second (_b_) less well adapted to them. Then it is no
less certain that the conditions in question must exercise a selective
influence in favour of (_a_) and against (_b_), so that
(_a_) will tend to predominance, and (_b_) to extirpation.

That M. Flourens should be unable to perceive the logical necessity of
these simple arguments, which lie at the foundation of all Mr. Darwin's
reasoning; that he should confound an irrefragable deduction from the
observed relations of organisms to the conditions which lie around them,
with a metaphysical "forme substantielle," or a chimerical personification
of the powers of Nature, would be incredible, were it not that other
passages of his work leave no room for doubt upon the subject.

"On imagine une _élection naturelle_ que, pour plus de ménagement, on
me dit être _inconsciente_, sans s'apercevoir que le contresens
littéral est précisément là: _élection inconsciente_." (P. 52.)

"J'ai déjà dit ce qu'il faut penser de _l'élection naturelle_. Ou
_l'élection naturelle_ n'est rien, ou c'est la nature: mais la nature
douée _d'élection_, mais la nature personnifiée: dernière erreur du
dernier siècle: Le XIXe ne fait plus de personnifications." (P. 53.)

M. Flourens cannot imagine an unconscious selection--it is for him a
contradiction in terms. Did M. Flourens ever visit one of the prettiest
watering-places of "la belle France," the Baie d'Arcachon? If so, he will
probably have passed through the district of the Landes, and will have had
an opportunity of observing the formation of "dunes" on a grand scale. What
are these "dunes"? The winds and waves of the Bay of Biscay have not much
consciousness, and yet they have with great care "selected," from among an
infinity of masses of silex of all shapes and sizes, which have been
submitted to their action, all the grains of sand below a certain size, and
have heaped them by themselves over a great area. This sand has been
"unconsciously selected" from amidst the gravel in which it first lay with
as much precision as if man had "consciously selected" it by the aid of a
sieve. Physical Geology is full of such selections--of the picking out of
the soft from the hard, of the soluble from the insoluble, of the fusible
from the infusible, by natural agencies to which we are certainly not in
the habit of ascribing consciousness.

But that which wind and sea are to a sandy beach, the sum of influences,
which we term the "conditions of existence," is to living organisms. The
weak are sifted out from the strong. A frosty night "selects" the hardy
plants in a plantation from among the tender ones as effectually as if it
were the wind, and they, the sand and pebbles, of our illustration; or, on
the other hand, as if the intelligence of a gardener had been operative in
cutting the weaker organisms down. The thistle, which has spread over the
Pampas, to the destruction of native plants, has been more effectually
"selected" by the unconscious operation of natural conditions than if a
thousand agriculturists had spent their time in sowing it.

It is one of Mr. Darwin's many great services to Biological science that he
has demonstrated the significance of these facts. He has shown that given
variation and given change of conditions the inevitable result is the
exercise of such an influence upon organisms that one is helped and another
is impeded; one tends to predominate, another to disappear; and thus the
living world bears within itself, and is surrounded by, impulses towards
incessant change.

But the truths just stated are as certain as any other physical laws, quite
independently of the truth, or falsehood, of the hypothesis which Mr.
Darwin has based upon them; and that Mr. Flourens, missing the substance
and grasping at a shadow, should be blind to the admirable exposition of
them, which Mr. Darwin has given, and see nothing there but a "dernière
erreur du dernier siècle"--a personification of Nature--leads us indeed to
cry with him: "O lucidité! O solidité de l'esprit Français, que
devenez-vous?"

M. Flourens has, in fact, utterly failed to comprehend the first principles
of the doctrine which he assails so rudely. His objections to details are
of the old sort, so battered and hackneyed on this side of the Channel,
that not even a Quarterly Reviewer could be induced to pick them up for the
purpose of pelting Mr. Darwin over again. We have Cuvier and the mummies;
M. Roulin and the domesticated animals of America; the difficulties
presented by hybridism and by Palæontology; Darwinism a
_rifacciamento_ of De Maillet and Lamarck; Darwinism a system without
a commencement, and its author bound to believe in M. Pouchet, &c. &c. How
one knows it all by heart, and with what relief one reads at p. 65--

"Je laisse M. Darwin!"

But we cannot leave M. Flourens without calling our readers' attention to
his wonderful tenth chapter, "De la Préexistence des Germes et de
l'Epigénèse," which opens thus:--

"Spontaneous generation is only a chimaera. This point established, two
hypotheses remain: that of _pre-existence_ and that of
_epigenesis_. The one of these hypotheses has as little foundation as
the other." (p. 163.)

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