to those passages specially cited by Professor Kölliker, we cannot admit
that they bear the interpretation he puts upon them. Darwin, if we read
him rightly, does _not_ affirm that every detail in the structure of an
animal has been created for its benefit. His words are (p. 199):--
"The foregoing remarks lead me to say a few words on the protest
lately made by some naturalists against the utilitarian doctrine
that every detail of structure has been produced for the good of
its possessor. They believe that very many structures have been
created for beauty in the eyes of man, or for mere variety. This
doctrine, if true, would be absolutely fatal to my theory--yet I
fully admit that many structures are of no direct use to their
possessor."
And after sundry illustrations and qualifications, he concludes (p.
200):--
"Hence every detail of structure in every living creature (making
some little allowance for the direct action of physical conditions)
may be viewed either as having been of special use to some
ancestral form, or as being now of special use to the descendants
of this form--either directly, or indirectly, through the complex
laws of growth."
But it is one thing to say, Darwinically, that every detail observed in
an animal's structure is of use to it, or has been of use to its
ancestors; and quite another to affirm, teleologically, that every
detail of an animal's structure has been created for its benefit. On the
former hypothesis, for example, the teeth of the foetal _Balæna_ have
a meaning; on the latter, none. So far as we are aware, there is not a
phrase in the "Origin of Species," inconsistent with Professor
Kölliker's position, that "varieties arise irrespectively of the notion
of purpose, or of utility, according to general laws of Nature, and may
be either useful, or hurtful, or indifferent."
On the contrary, Mr. Darwin writes (Summary of Chap. V.):--
"Our ignorance of the laws of variation is profound. Not in one
case out of a hundred can we pretend to assign any reason why this
or that part varies more or less from the same part in the
parents.... The external conditions of life, as climate and food,
&c. seem to have induced some slight modifications. Habit, in
producing constitutional differences, and use, in strengthening,
and disuse, in weakening and diminishing organs, seem to have been
more potent in their effects."
And finally, as if to prevent all possible misconception, Mr. Darwin
concludes his Chapter on Variation with these pregnant words:--
"Whatever the cause may be of each slight difference in the
offspring from their parents--and a cause for each must exist--it
is the steady accumulation, through natural selection of such
differences, when beneficial to the individual, that gives rise to
all the more important modifications of structure, by which the
innumerable beings on the face of the earth are enabled to struggle
with each other, and the best adapted to survive."
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:[66]--
"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 civilization 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 Palæontology 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-fertilization 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 (_suprà_, p.
329).
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 a 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 _Brachialaria_, 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 an asexual form, A; this gives rise,
asexually, to a second form or forms, B, more or less different from A.
B may multiply asexually 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 asexual, 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[67] 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 que 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 personifications puériles et surannées! O lucidité! O
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 organísé, 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'election naturelle_
est cette _forme substantielle_ dont on jonait 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'election 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 organized being, Nature is only
organization, neither more nor less."
Organized 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 "organization chooses and selects
organization."
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 contre-sens
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 xix^e ne fait plus de
personnifications." (P. 53.)