Darwin on The Origin of Species
A Review Essay by Richard Owen
[This
electronic version of Owen's text has been prepared by Ian Johnston of
Malaspina University-College, Nanaimo. For comments please contact johnstoi@mala.bc.ca. The article was
published anonymously in the Edinburgh Review, April 1860, pages 487-532. The
essay begins with the list of titles given below. In this electronic version,
Owen's footnotes have been moved to the end of the document, with numerical
references in the text. The translations after the quotations from foreign
works (given in square brackets) are by Ian Johnston. This document is in the
public domain, released June 1999]
1. On
the Origin of Species by means of Natural Selection, or the Preservation of
Favoured Races in the Struggle for Life. By CHARLES DARWIN, M.A. 8vo. 1859
2. On
the Tendency of Varieties to Depart Indefinitely from the Original Type. By
ALFRED RUSSEL WALLACE. (February, 1858.) Proceedings of the Linnæan Society,
August, 1858.
3. BUFFON,
Histoire de ses Travaux et de ses Idées. Par P. FLOURENS, Sec. Perp. De
l'Académie des Sciences. 12mo. 1846.
4. Contributions
to the Natural History of the United States. By M. AGASSIZ 4to. Vol I. (I.
Essay on Classification.) 1857.
5. On
the Flora of Australia, &c. By Dr. JOSEPH D. HOOKER, F.R.S.
(Introductory Essay.) 4to. 1859.
6. Essays
on the Spirit of the Inductive Philosophy and the Philosophy of Creation.
By the Rev. BADEN POWELL. 12mo. 1855.
7. Hétérogénie,
ou Traité de la Génération Spontanée. By Professor V.A. POUCHET. 8vo.
Paris: 1855.
8. Recherches
sur l'Archetype et les Homogies du Squelette Vertebré. Par Professor R.
OWEN. 8vo. Paris: 1855.
9. Address
to the British Association, Leeds. By Professor R. OWEN. 8vo. 1858.
10.
Palæontology; or a Systematic Summary of Extinct Animals, 7c. By
Professor R. OWEN. 8vo. 1860.
In
the works above cited the question of the origin, succession, and extinction of
species is more or less treated of, but most fully and systematically by the
accomplished Naturalist who heads the list. Mr. Charles Darwin has long been
favourably known, not merely to the Zoological but to the Literary World, by
the charming style in which his original observations on a variety of natural
phenomena are recorded in the volume assigned to him in the narrative of the
circumnavigatory voyage of H.M.S Beagle, by Capt (now Admiral) Fitz Roy, F.R.S.
Mr Darwin earned the good opinion of geologists by the happy application of his
observations on coral reefs (1), made
during that voyage, to the explanation of some of the phenomena of the changes
of level of the earth's crust. He took high rank amongst the original explorers
of the minute organisation of the invertebrate animals, upon the appearance of his
monographs, in the publications by the Ray Society, on the Cirripedia,
Sub-classes Lepadidae (1851), and Balanidae (1854). Of
independent means, he has full command of his time for the prosecution of
original research: his tastes have led him to devote himself to Natural
History; and those who enjoy his friendship and confidence are aware that the
favourite subject of his observations and experiments for some years past has
been the nature and origin of the so-called species of plants and animals. The
octavo volume, of upwards of 500 pages, which made its appearance towards the
end of last year, has been received and perused with avidity, not only by the
professed naturalist, but by that far wider intellectual class which now takes
interest in the higher generalisations of all the sciences. The same pleasing
style which marked Mr. Darwin's earliest work, and a certain artistic
disposition and sequence of his principal arguments, have more closely recalled
the attention of thinking men to the hypothesis of the inconstancy and
transmutation of species, than had been done by the writings of previous
advocates of similar views. Thus several, and perhaps the majority, of our
younger naturalists have been seduced into the acceptance of the homoeopathic
form of the transmutative hypothesis now presented to them by Mr. Darwin, under
the phrase of 'natural selection.'
Dr.
Joseph Hooker, in his latest work, above cited, writes:--
'In
the Introductory Essay to the New Zealand Flora, I advance certain
general propositions as to the origin of species, which I refrained from
endorsing as articles of my own creed; amongst others was the still prevalent
doctrine that these are, in the ordinary acceptation of the term, created as
such, and are immutable. In the present essay I shall advance the opposite
hypothesis, that species are derivative and mutable, and this chiefly because,
whatever opinions a naturalist may have adopted with regard to the origin and
variation of species, every candid mind must admit that the facts and arguments
upon which he has grounded his convictions require revision, since the recent
publication by the Linnæan Society of the ingenious and original reasonings and
theories of Mr. Darwin and Mr. Wallace.' (P. ii)
Mr.
Darwin claims another convert in an older name of scientific note: in reference
to the immutability of species, he tells us 'I have reason to believe that one
great authority, Sir Charles Lyell, from further reflection, entertains grave
doubts on this subject.' For our own part, governed by the motto of the parent
society for the promotion of natural knowledge, 'nullius in verba' [there is
nothing in words], our attention was principally directed, in the first
perusal of Mr. Darwin's work, to the direct observations of nature which seemed
to be novel and original, and to the additional grounds, based on fact, on
which a more lasting superstructure of the theory of the mutability of species
might be raised. These observations, therefore, claim our notice before we
proceed to discuss the general theory of the work.
No
naturalist has devoted more painstaking attention to the structure of the
barnacles than Mr. Darwin. In reference to the transitions of organs, and the
probability of their conversion from one function to another, he states:--
'Pedunculated
cirripedes have two minute folds of skin, called by me the ovigerous frena,
which serve, through the means of a sticky secretion, to retain the eggs until
they are hatched within the sack. These cirripedes have no branchiae, the whole
surface of the body and sack, including the small frena, serving for
respiration. The Balanidae or sessile cirripedes, on the other hand, have no
ovigerous frena, the eggs lying loose at the bottom of the sack, in the
well-enclosed shell; but they have large folded branchiae. Now I think no one
will dispute that the ovigerous frena in the one family are strictly homologous
with the branchiae of the other family; indeed, they graduate into each other.'
(P. 191).
That
is, a series of modifications are affirmed to have been met with in different
species, changing a respiratory into an ovigerous organ. Should this graduation
of parts be confirmed, and the respiratory function of the folded membranes in Balanidae
be determined, Mr. Darwin will have contributed both an interesting
observation, and a valuable discovery. But neither in the present work, nor in
the two volumes published and illustrated at the cost of the Ray Society, are
those relations of the folded membranes in the Balanidae with the heart
or vascular system demonstrated, which would alone prove the respiratory
function of such membranes.
Mr.
Darwin has by no means limited himself to dissections of dead animals, but has
devoted much time to observation of the living. Desirous of testing the truth
of the assertions respecting the slave-making ants (Formica sanguinea),
he opened
fourteen
nests of that species and found a few slaves in all. Males and fertile females
of the slave species (Formica fusca) are found only in their proper
communities, and have never been observed in the nests of F. sanguinea.
The slaves are black, and not above half the size of their red masters, so that
the contrast in their appearance is very great. When the nest is slightly disturbed,
the slaves occasionally come out, and, like their masters, are much agitated
and defend the nest: when the nest is much disturbed and the larvae and pupae
are exposed, the slaves work energetically with their masters in carrying them
away to a place of safety. Hence, it is clear, that the slaves feel quite at
home. During the months of June and July, on three successive years, I have
watched for many hours several nests in Surrey and Sussex, and never saw a
slave either leave or enter a nest. During the present year, however, in the
month of July (1859), I came across a community with an unusually large stock
of slaves, and I observed a few slaves mingled with their masters leaving the
nest, and marching along the same road to a tall Scotch fir-tree, twenty-five
yards distant, which they ascended together, probably in search of aphides or
cocci. According to Huber, who had ample opportunities for observation, in
Switzerland, the slaves habitually work with their masters in making the nest,
and they alone open and close the doors in the morning and evening; and, as
Huber expressly states, their principal office is to search for aphides.
Another day my attention was struck by about a score of the slave-makers
haunting the same spot, and evidently not in search of food; they approached
and were vigorously repulsed by an independent community of the slave species (F.
fusca); sometimes as many as three of these ants clinging to the legs of
the slave-making F. sanguinea. The latter ruthlessly killed their small
opponents, and carried their dead bodies as food to their nest, twenty-nine
yards distant; but they were prevented from getting any pupae to rear as
slaves. I then dug up a small parcel of the pupae of F. fusca from
another nest, and put them down on a bare spot near the place of combat; they
were eagerly seized, and carried off by the tyrants, who perhaps fancied that,
after all, they had been victorious in their late combat.' (P. 221).
Many
other direct observations on the F. sanguinea of England are recounted,
and are contrasted with those first recorded by Huber, relative to the
slave-holding F. rufescens of Switzerland.
'Such
are the facts, though they did not need confirmation by me, in regard to the
wonderful instinct of making slaves. Let it be observed what a contrast the
instinctive habits of F. sanguinea present with those of the F.
rufescens. The latter does not build its own nest, does not determine its
own migrations, does not collect food for itself or its young, and cannot even
feed itself: it is absolutely dependent on its numerous slaves. F. sanguinea,
on the other hand, possesses much fewer slaves, and in the early part of the
summer extremely few. The masters determine when and where a new nest shall be
formed, and when they migrate the masters carry the slaves. Both in Switzerland
and England the slaves seem to have exclusive care of the larvae, and the
masters alone go on slave-making expeditions. In Switzerland the slaves and
masters work together, making and bringing materials for the nest: both, but
chiefly the slaves, tend, and milk, as it may be called, their aphides; and
thus both collect food for the community. In England the masters alone usually
leave the nest to collect building materials and food for themselves, their
slaves, and larvae. So that the masters in this country receive much less
service from their slaves than they do in Switzerland.' (P. 223)
The
instincts of the Bee have received no less attention from Mr. Darwin than those
of the Ant; and he has also enriched this interesting part of Natural History
by new and original remarks (2). Desirous of testing the
mechanical hypothesis for the formation of the hexagonal cell, out of an
original cylindrical form, by pressure of surrounding cylinders, Mr. Darwin
'separated
two combs, and put between them a long, thick, square (rectangular?) strip of
wax; the bees instantly began to excavate minute circular pits in it; and as
they deepened these little pits they made them wider and wider until they were
converted into shallow basins, appearing to the eye perfectly true or parts of
a sphere, and of about the diameter of a cell. It was most interesting to me to
observe that wherever several bees had begun to excavate these basins near
together, they had begun their work at such a distance from each other, that by
the time the basins had acquired the above stated width (i.e. about the width
of an ordinary cell), and were in depth about one-sixth of the diameter of the
sphere of which they formed a part; the rims of the basins intersected or broke
into each other. As soon as this occurred, the bees ceased to excavate, and
began to build up flat walls of wax on the lines of intersection between the
basins, so that each hexagonal prism was built upon the festooned edge of a
smooth basin, instead of on the straight edges of a three-sided pyramid as in
the case of ordinary cells.' (P. 228)
With
regard to the mechanical origin of the bee's cell, Mr. Darwin proceeds to
say:--
'In
one well-marked instance I put the comb back into the hive, and allowed the
bees to go on working for a short time, and again examined the cell, and I
found that the rhombic plate had been completed, and had become perfectly flat:
it was absolutely impossible, from the extreme thinness of the little rhombic
plate, that they could have effected this by gnawing away the convex side; and
I suspect that the bees in such cases stand in the opposed cells and push and
bend the ductile and warm wax (which, as I have tried, is easily done) into its
proper intermediate plane, and thus flatten it.
'From
the experiment of the ridge of vermilion wax, we can clearly see that if the
bees were to build for themselves a thin wall of wax, they could make their
cells of the proper shape, by standing at the proper distance from each other,
by excavating at the same rate, and by endeavouring to make equal spherical
hollows, but never allowing the spheres to break into each other.' (P. 230)
Mr.
Darwin, while collecting objects of natural history in the rivers of Brazil,
was surprised at the similarity of the fresh-water insects, shells, &c.,
and at the dissimilarity of the surrounding terrestrial beings, compared with
the Fauna of Great Britain, and he was led to ponder on this power, as it
seemed, in fresh-water productions of ranging widely. He offers many ingenious
suggestions to account for the phenomena, and gives, what is of greater value,
the following original observation and experiment:--
'Two
facts which I have observed--and no doubt many others remain to be
observed--throw some light on this subject. When a duck suddenly emerges from a
pond covered with duckweed, I have twice seen these little plants adhering to
its back; and it has happened to me, in removing a little duckweed from one
aquarium to another, that I have quite unintentionally stocked the one with
fresh-water shells from the other. But another agency is perhaps more
effectual: I suspended a duck's feet, which might represent those of a bird
sleeping in a natural pond, in an aquarium, where many ova of fresh-water shells
were hatching; and I found that numbers of the extremely minute and just
hatched shells crawled on the feet, and clung to them so firmly that when taken
out of the water they could not be jarred off, though at a somewhat more
advanced age they would voluntarily drop off. These just-hatched molluscs,
though aquatic in their nature, survived on the duck's feet, in damp air, from
twelve to twenty hours; and in this length of time a duck or heron might fly at
least six or seven hundred miles, and would be sure to alight on a pool or
rivulet, if blown across sea to an oceanic island or to any other distant
point.' (P. 385)
The
mud adhering to the feet of wading birds may serve to transmit species of
aquatic plants far away from their native streams.
'I
do not believe (writes Mr. Darwin) that botanists are aware how charged the mud
of ponds is with seeds. I have tried several little experiments, but will here
give only the most striking case. I took, in February, three table-spoonfuls of
mud from three different points, beneath water, on the edge of a little pond.
This mud, when dry, weighed only 6 ounces. I kept it covered up in my study for
six months, pulling up and counting each plant as it grew. The plants were of
many kinds, and were altogether 537 in number; and yet the viscid mud was all
contained in a breakfast cup! Considering these facts, I think it would be an
inexplicable circumstance if water-birds did not transport the seeds of
fresh-water plants to vast distances, and if consequently the range of these
plants was not very great. The same agency may have come into play with the
eggs of some of the smaller fresh-water animals.' (P. 386)
Facing
the difficulty of the transport of fresh-water or land shell-fish across long
tracts of ocean, on the supposition of a transporting bird occasionally resting
on, or dipping in, the salt sea, or in case of such shells adhering to drifted
timber, Mr. Darwin made more experiments, and found--
'That
several species did in this state withstand uninjured an immersion in sea-water
during seven days: one of these shells was the Helix pomatia, and after
it had again hybernated I put it in sea-water for twenty days, and it perfectly
recovered. As this species has a thick calcareous operculum, I removed it, and
when it had formed a new membranous one, I immersed it for fourteen days in
sea-water, and it recovered and crawled away.' (P. 397)
Pigeons
being monogamous, and proverbial for their constancy, are peculiarly favourable
for experiments and practices establishing and propagating varieties. Such
varieties consequently have become, under the selective care of man, numerous
and extreme. Believing it to best, in reference to the question of the origin
of varieties, to study some special group, Mr. Darwin took up domestic pigeons,
associated himself with several eminent pigeon-fanciers, and joined two of the
London Pigeon Clubs. He gives descriptions of the leading varieties: and
amongst his own observations, the following, perhaps, conveys the newest
matter:--
'As
the evidence appears to me conclusive, that the several domestic breeds of
Pigeon have descended from one wild species,--the Rock-pigeon (Columbia
livia),--I compared young pigeons of various breeds, within twelve hours
after being hatched; I carefully measured the proportions (but will not here
give details) of the beak, width of mouth, length of nostril and of eyelid,
size of feet and length of leg, in the wild stock, in pouters, fantails, runts,
barbs, dragons, carriers, and tumblers. Now some of these birds, when mature,
differ so extraordinarily in length and form of beak, that they would, I cannot
doubt, be ranked in distinct genera, had they been natural productions. But
when the nesting birds of these several breeds were placed in a row, though
most of them could be distinguished from each other, yet their proportional
differences in the above specified several points were incomparably less than
in the full-grown birds. Some characteristic points of difference--for
instance, that of the width of mouth--could hardly be detected in the young.
But there was one remarkable exception to this rule, for the young of the
short-faced tumbler differed from the young of the wild rock-pigeon and of the
other breeds, in all its proportions, almost exactly as much as in the adult
state.' (P. 445)
These
are the most important original observations, recorded in the volume of 1859:
they are, in our estimation, its real gems,--few indeed and far apart, and
leaving the determination of the origin of species very nearly where the author
found it; but a rich mine of such researches is alluded to and promised by Mr.
Darwin, in a more voluminous collection of his researches, extending over a
period of eighteen years; and to these every naturalist now looks forward with
keen interest.
The
interdependencies of living beings of different kinds and grades, and the
injurious results of their interruption, have long attracted the attention of
observant and philosophic naturalists. An undue importance indeed was at one
time attached to this principle; it was deemed to be so absolute as that no one
species could be permitted to perish without endangering the whole fabric of
organisation. So Pope sang:--
'From
Nature's chain, whatever link you strike,
Tenth or ten thousandth, breaks the chain alike.'
Manifold
subsequent experience has led to a truer appreciation and a more moderate
estimate of the importance of the dependence of one living being upon another.
Mr. Darwin contributes some striking and ingenious instances of the way in
which the principle partially affects the chain, or rather network of life,
even to the total obliteration of certain meshes. And truly extinction has made
wide rents in the reticulation as now represented by the co-affinities of
living species!
'From
experiments which I have tried, I have found that the visits of bees, if not
indispensable, are at least highly beneficial to the fertilisation of our
clovers; but humble bees alone visit the common red clover (Trifolium
pratense), as other bees cannot reach the nectar. Hence I have very little
doubt, that if the whole genus of humble bees became extinct or very rare in
England, the heartsease and red clover would become very rare, or wholly
disappear. The number of humble-bees in any district depends in a great degree
on the number of field-mice, which destroy their combs and nests; and Mr. H.
Newman, who has long attended to the habits of humble-bees, believes "that
more than two-thirds of them are thus destroyed all over England." Now the
number of mice is largely dependent, as every one knows, on the number of cats;
and Mr. Newman says, "Near villages and small towns I have found the nests
of humble-bees more numerous than elsewhere, which I attribute to the number of
cats that destroy the mice." Hence it is quite credible that the presence
of a feline animal in large numbers in a district might determine, through the
intervention first of mice and then of bees, the frequency of certain flowers
in that district!' (P. 73)
This
is very characteristic of the ingenious turn of thought of our author; the more
sober, or perhaps duller, naturalist would, no doubt, appreciate more highly a
dry statement of investigation, suggested by the actual extinction of red clover,
and tracing that extinction inductively, by the ascertained absence of
humble-bees and mice, back to the want of cats in the neighbourhood. For the
direct observation, however, (if it should be confirmed), of the exclusive
relation of Bombus terrestris, as the mechanical fecundator of Trifolium
pratense, natural history may be indebted to Mr. Darwin. We wish we could
cite other instances augmenting this debt from the present work: its chief
part, however, is devoted to speculations on the origin of species; and its
main object is the advocacy of a view, which we find most clearly expressed in
the following passage. Mr. Darwin refers to the multitude of the individual of
every species, which, from one cause or another, perish either before, or soon
after attaining maturity.
'Owing
to this struggle for life, any variation, however slight and from whatever
cause proceeding, if it be in any degree profitable to an individual of any
species, in its infinitely complex relations to other organic beings and to external
nature, will tend to the preservation of that individual, and will generally be
inherited by its offspring. The offspring, also, will thus have a better chance
of surviving, for, of the many individuals of any species which are
periodically born, but a small number can survive. I have called this
principle, by which each slight variation, if useful, is preserved, by the term
of Natural Selection, in order to mark its relation to man's power of
selection. We have seen that man by selection can certainly produce great
results, and can adapt organic beings to his own uses, through the accumulation
of slight but useful variations, given to him by the hand of Nature. But
Natural Selection, as we shall hereafter see, is a power incessantly ready for
action, and is as immeasurably superior to man's feeble efforts, as the works
of Nature are to those of Art.' (P. 61)
The
scientific world has looked forward with great interest to the facts which Mr.
Darwin might finally deem adequate to the support of his theory on this supreme
question in biology, and to the course of inductive original research which
might issue in throwing light on 'that mystery of mysteries.' But having now
cited the chief, if not the whole, of the original observations adduced by its
author in the volume now before us, our disappointment may be conceived.
Failing the adequacy of such observations, not merely to carry conviction, but
to give a colour to the hypothesis, we were then left to confide in the
superior grasp of mind, strength of intellect, clearness and precision of
thought and expression, which raise one man so far above his contemporaries, as
to enable him to discern in the common stock of facts, of coincidences,
correlations and analogies in Natural History, deeper and truer conclusions
than his fellow-labourers had been able to reach.
These
expectations, we must confess, received a check on perusing the first sentence
in the book.
'When
on board H.M.S. "Beagle," as naturalist, I was much struck with
certain facts in the distribution of the inhabitants of South America, and in
the geological relations of the present to the past inhabitants of that
continent. These facts seemed to me to throw some light on the origin of
species--that mystery of mysteries, as it has been called by some of our
greatest philosophers.' (P.1)
What
is there, we asked ourselves, as we closed the volume to ponder on this
paragraph,--what can there possibly be in the inhabitants, we suppose he means
aboriginal inhabitants, of South America, or in their distribution on that
continent, to have suggested to any mind that man might be a transmuted ape, or
to throw any light on the origin of the human or other species? Mr. Darwin must
be aware of what is commonly understood by an 'uninhabited island;' he may,
however, mean by the inhabitants of South America, not the human kind only,
whether aboriginal or otherwise, but all the lower animals. Yet again, why are
the fresh-water polypes or sponges to be called 'inhabitants' more than the
plants? Perhaps what was meant might be, that the distribution and geological
relations of the organised beings generally in South America, had suggested
transmutational views. They have commonly suggested ideas as to the independent
origin of such localized kinds of plants and animals. But what the 'certain
facts' were, and what may be the nature of the light which they threw upon the
mysterious beginning of species, is not mentioned or further alluded to in the
present work.
The
origin of species is the question of questions in Zoology; the supreme problem
which the most striking of our original labourers, the clearest zoological
thinkers, and the most successful generalisers, have never lost sight of,
whilst they have approached it with due reverence. We have a right to expect
that the mind proposing to treat of, and assuming to have solved, the problem,
should show its equality to the task. The signs of such intellectual power we
look for in clearness of expression, and in the absence of all ambiguous or
unmeaning terms. Now, the present work is occupied by arguments, beliefs, and
speculations on the origin of species, in which, as it seems to us, the
fundamental mistake is committed, of confounding the questions, of species
being the result of a secondary cause or law, and of the nature of that
creative law. Various have been the ideas promulgated respecting its mode of
operation; such as the reciprocal action of an impulse from within, and an
influence from without, upon the organization (Demaillet, Lamarck); premature
birth of an embryo at a phase of development, so distinct from that of the
parents, as, with the power of life and growth, under that abortive phase, to
manifest differences equivalent to specific (Vestiges of Creation); the
hereditary transmission of what are called 'accidental monstrosities;' the
principle of gradual transmutation by 'degeneration' (Buffon) as contrasted
with the 'progressional' view.
In
reference to the definition of species, Lamarck (3), in 1809, cited, as the most exact, that of 'a collection of
like (semblables) individuals produced by other individuals equally like them
(pareils à eux).' But the progress of discovery, especially, perhaps, in
palæontology, led him to affirm that species were not as ancient as Nature
herself, nor all of the same antiquity; that this alleged constancy was
relative to the circumstances and influences to which every individual was
subject, and that as certain individuals, subjected to certain influences,
varied so as to constitute races, such variations might and do graduate
(s'avacent) toward the assumption of characters which the naturalist would
arbitrarily regard, some as varieties, others as species. He comments in almost
the words of Mr. Darwin, on the embarrassment and confusion which the different
interpretation of the nature and value of such observed differences, in the
works of different naturalists, had occasioned (4). The true method of surveying the diversities of organisation
is from the simple to the compound forms, which course Lamarck affirms to be
graduated and regularly progressive, save where local circumstances, and others
influencing the mode of life, have occasioned anomalous diversities.
Cuvier
had preceded Lamarck in specifying the kinds and degrees of variation, which
his own observations and critical judgment of the reports of others led him to
admit. 'Although organisms produce only bodies similar to themselves, there are
circumstances which, in the succession of generations, alter to a certain point
their primitive form' (5). Here it may be
remarked, that the whole question at issue hinges upon the proof of the
determination of that limit of variety. Cuvier gives no proof that the
alteration stops 'at a certain point.' It merely appears from what follows,
that his means of knowing by his own and others' observations had not carried
him beyond the point in question, and he was not the man to draw conclusions
beyond his premises.
'Less
abundant food,' he goes on to say, 'makes the young acquire less size and
force. Climate more or less cold, air more or less moist, exposure to light
more or less continuous, produce analogous effects; but, above all, the pains
bestowed by man on the animal and vegetable productions which he raises for his
uses, the consecutive attention with which he restricts them in regard to
exercise, or to certain kinds of food, or to influences other than those to
which they would be subject in a state of nature, all tend to alter more quickly
and sensibly their properties.'
Cuvier
admits that the determination by experiment of these variable properties, of
the precise causes to which they are due, of the degree of variability and of
the powers of the modifying influences, is still very imperfect ('mais ce
travail est encore très-imparfait.') The most variable properties in organisms
are, according to Cuvier, size and colour.
'The
first mainly depends on abundance of food; the second on light and many other
causes so obscure that it seems to vary by chance. The length and strength of
the hairs are very variable. A villous plant, for example, transported to a
moist place, becomes smooth. Beasts lose hair in hot countries, but gain hair
in cold. Certain external parts, such as stamens, thorns, digits, teeth,
spines, are subject to variations of number both in the more and the less;
parts of minor importance, such as barbs of wheat, &c., vary as to their
proportions; homologous parts ('des parties de nature analogue') change one
into another, i.e., stamens into petals as in double flowers, wings into fins,
feet into jaws, and we might add, adhesive into breathing organs [as in the
case of the barnacles cited by Mr. Darwin].'
As
to the alleged test of the difference between a species and a variety by the
infecundity of the hybrid of two parents which may differ in a doubtful degree,
Cuvier, in reference to this being the case when the parents are of distinct
species, and not mere varieties, emphatically affirms, 'Cette assertion ne
repose sur aucune preuve' (p. 11) [this assertion does not rest on any proof];
it is at least constant that individuals of the same species, however
different, produce together; 'quelque différens qu'ils soient, peuvent toujours
produire ensemble.' But Cuvier warns us not to conclude, when individuals of
two different races produce an intermediate and fecund offspring, that they
must be of the same species, and that they have not been originally distinct.
(P. 13)
'"The
number of varieties, or amount of variation," says Cuvier, "relates
to geographical circumstances". At the present day, many such varieties
appear to have been confined around their primitive centre, either by seas
which they could neither traverse by swimming or by flight, or by temperatures
which they were not able to support, or by mountains which they could not
cross, &c.' (6)
Daily
observation, comparison, and reflection, on recent and extinct organisms,
pursued from the date of these remarks (1798) to the close of his career (1832)
failed to bring the requisite proof, or to impress the mind of Cuvier with any
amount of belief worth mentioning, as to the nature of the cause operative in
the production of the species of which he was the first to demonstrate the
succession.
Lamarck,
without contributing additional results from observation and experience,
affirms that the changes defined by Cuvier do not 'stop at a certain point,'
but progress with the continued operation of the causes producing them. That,
moreover, such changes of form and structure induce corresponding changes in
actions, and that a change of actions, growing to a habit, becomes another
cause of altered structure; that the more frequent employment of certain parts
or organs leads to a proportional increase of development of such parts; and
that, as the increased exercise of one part is usually accompanied by a
corresponding disuse of another part, this very disuse, by inducing a
proportional degree of atrophy, becomes another element in the progressive
mutation of organic forms (7).
These
principles seem entitled to be regarded as of the nature of those called 'verae
causae' [true causes] by Bacon, and they are agreeable with known powers
and properties of animated beings; only observation has not disclosed more than
a very limited extent of their operation,--limited both as to the time in which
that operation has been watched, and limited consequently as to the amount of
the change produced.
When
Cuvier affirms that such capacity to vary proceeds only to a certain point, he
may mean that it has not been watched and traced beyond such point. Cuvier
admits the tendency to hereditary transmission of characters of variation.
Neither he nor any other physiologist has demonstrated the organic condition or
principle that should operate so as absolutely to prevent the progress of
modification of form and structure correlatively with the operation of
modifying influences, in successive generations. But those who hastily or
prematurely assume an indefinite capacity to deviate from a specific form are
as likely to obstruct as to promote the solution of the question.
The
principles, based on rigorous and extensive observation, which have been
established since the time of Cuvier, and have tended to impress upon the minds
of the most exact reasoners in biology the conviction of a constantly operating
secondary creational law, are the following:--The law of irrelative or
vegetative repetition, referred to at p. 437. of Mr. Darwin's work; the law of
unity of plan or relations to an archetype; the analogies of transitory
embryonal stages in a higher animal to the matured forms of lower animals; the
phenomena of parthenogenesis; a certain parallelism in the laws governing the
succession of forms throughout time and space; the progressive departure from
type, or from the more generalised to more specialised structures, exemplified
in the series of species from their first introduction to the existing forms (8). In his last published work (9) Professor Owen does not hesitate to
state 'that perhaps the most important and significant result of
palæontological research has been the establishment of the axiom of the
continuous operation of the ordained becoming of living things.' The italics
are the author's. As to his own opinions regarding the nature or mode of that
'continuous creative operation,' the Professor is silent. He gives a brief
summary of the hypotheses of others, and as briefly touches upon the defects in
their inductive bases (10).
Elsewhere he has restricted himself to testing the idea of progressive
transmutation by such subjects of Natural History as he might have specially in
hand: as, e.g. the characters of the chimpanzee, gorilla, and some other
animals.
All
who have brought the transmutative speculations to the test of observed facts
and ascertained powers in organic life, and have published the results, usually
adverse to such speculations, are set down by Mr. Darwin as 'curiously
illustrating the blindness of preconceived opinion;' and whosoever may withhold
assent to his own or other transmutationists' views, is described as 'really
believing that at innumerable periods of the earth's history certain elemental
atoms suddenly flashed into living tissues.' (P. 483) Which, by the way, is but
another notion of the mode of becoming of a species as little in harmony with
observation as the hypothesis of natural selection by external influence, or of
exceptional birth or development. Nay, Mr. Darwin goes so far as to affirm--
'All
the most eminent palæontologists, namely, Cuvier, Owen, Agassiz, Barrande,
Falconer, E. Forbes, &c., and all our greatest geologists, as Lyell,
Murchison, Sedgwick, &c., have unanimously, often vehemently, maintained
the immutability of species.' (P. 310)
But
if by this is meant that they as unanimously reject the evidences of a
constantly operative secondary cause or law in the production of the succession
of specifically differing organisms, made known by Palaeontology, it betrays
not only the confusion of ideas as to the fact and the nature of the law, but
an ignorance or indifference to the matured thoughts and expressions of some of
those eminent authorities on this supreme question in Biology.
One
of the disciples would seem to be as short-sighted as the master in regard to
this distinction.
'It
has been urged,' writes Dr. Hooker, 'against the theory that existing species have
arisen through the variation of pre-existing ones and the destruction of
intermediate varieties, that it is a hasty inference from a few facts in the
life of a few variable plants, and is therefore unworthy of confidence; but it
appears to me that the opposite theory, which demands an independent creative
act for each species, is an equally hasty inference.' (Hooker, p. xxv.)
Here
it is assumed, as by Mr. Darwin, that no other mode of operation of a secondary
law in the foundation of a form with distinct specific characters, can have
been adopted by the Author of all creative laws that the one which the
transmutationists have imagined. Any physiologist who may find the Lamarckian,
or the more diffused and attenuated Darwinian, exposition of the law inapplicable
to a species, such as the gorilla, considered as a step in the transmutative
production of man, is forthwith clamoured against as one who swallows up every
fact and every phenomenon regarding the origin and continuance of species 'in
the gigantic conception of a power intermittently exercised in the development,
out of inorganic elements, of organisms the most bulky and complex, as well as
the most minute and simple.' Significantly characteristic of the partial view
of organic phenomena taken by the transmutationists, and of their inadequacy to
grapple with the working out and discovery of a great natural law, is their
incompetency to discern the indications of any other origin of one specific
form out of another preceding it, save by their way of gradual change through a
series of varieties assumed to have become extinct.
But
has the free-swimming medusa, which bursts its way out of the ovicapsule of a
campanularia, been developed out of inorganic particles? Or have certain
elemental atoms suddenly flashed up into acalephal form? Has the polype-parent
of the acalephe necessarily become extinct by virtue of such anomalous birth?
May it not, and does it not proceed to propagate its own lower species in
regard to form and organisation, notwithstanding its occasional production of
another very different and higher kind. Is the fact of one animal giving birth
to another not merely specifically, but generically and ordinally, distinct, a
solitary one? Has not Cuvier, in a score or more of instances, placed the
parent in one class, and the fruitful offspring in another class, of animals?
Are the entire series of parthenogenetic phenomena to be of no account in the
consideration of the supreme problem of the introduction of fresh specific
forms into this planet? Are the transmutationists to monopolise the privilege
of conceiving the possibility of the occurrence of unknown phenomena, to be the
exclusive propounders of beliefs and surmises, to cry down every kindred barren
speculation, and to allow no indulgence in any mere hypothesis save their own?
Is it to be endured that every observer who points out a case to which
transmutation, under whatever term disguised, is inapplicable, is to be set
down by the refuted theorist as a believer in a mode of manufacturing a species
which he never did believe in, and which may be inconceivable?
We
would ask Mr. Darwin and Dr. Hooker to give some thought to these queries, and
if they should see the smallest meaning in them, to reconsider their future
awards of the alternative which they may be pleased to grant to a
fellow-labourer, hesitating to accept the proposition, either that life
commenced under other than actually operating laws, or that 'all the beings
that every lived on this earth have descended,' by the way of 'natural
selection,' from a hypothetical unique instance of a miraculously created
primordial form.
We
are aware that Professor Owen and others, who have more especially studied the
recently discovered astounding phenomena of generation summed up under the terms
Parthenogenesis and Alternation of Generations, have pronounced against those
phenomena have, as yet, helped us 'to penetrate the mystery of the origin of
different species of animals,' and have affirmed, at least so far as
observation has yet extended, that 'the cycle of changes is definitely closed;'
that is, that when the ciliated 'monad' has given birth to the 'gregarina,' and
this to the 'cercaria,' and the 'cercaria' to the 'distoma,'--that the
fertilised egg of the fluke-worm again excludes the progeny under the
infusorial or monadic form, and the cycle again recommences (11). But circumstances are
conceivable,-- changes of surrounding influences, the operation of some
intermittent law at long intervals, like that of the calculating-machine quoted
by the author of 'Vestiges,'-under which the monad might go on splitting up
into monads, the gregarina might go on breeding gregarinae, the cercaria
cercariae, &c., and thus four or five not merely different specific,
but different generic, and ordinal forms, zoologically viewed, might all
diverge from an antecedent quite distinct form. For how many years, and by how
many generations, did the captive polype-progeny of the Medusa aurita go
on breeding polypes of their species (Hydra tuba), without resolving
themselves into any higher form, in Sir John Dalyell's aquarium! (12). The natural phenomena already
possessed by science are far from being exhausted on which hypotheses, other
than transmutative, of the production of species by law might be based, and on
a foundation at least as broad as that which Mr. Darwin has exposed in this
Essay.
We
do not advocate any of these hypotheses in preference to the one of 'natural
selection,' we merely affirm that this at present rests on as purely a
conjectural basis. The exceptions to that and earlier forms of transmutationism
which rise up in the mind of the working naturalist and original observer, are
so many and so strong, as to have left the promulgation and advocacy of the
hypothesis, under any modification, at all times to individuals of more
imaginative temperament; such as Demaillet in the last century, Lamarck in the
first half the present, Darwin in the second half. The great names to which the
steady inductive advance of zoology has been due during those periods, have
kept aloof from any hypothesis on the origin of species. One only, in connexion
with his palæontological discoveries, with his development of the law of
irrelative repetition and of homologies, including the relation of the latter
to an archetype, has pronounced in favour of the view of the origin of species
by a continuously operative creational law; but he, at the same time, has set
forth some of the strongest objections or exceptions to the hypothesis of the
nature of that law as a progressively and gradually transmutational one.
Mr.
Darwin rarely refers to the writings of his predecessors, from whom, rather
than from the phenomena of the distribution of the inhabitants of South
America, he might be supposed to have derived his ideas as to the origin of
species. When he does allude to them, their expositions on the subject are
inadequately represented. Every one studying the pages of Lamarck's original
chapters (iii. vi. vii., vol. I., and the supplemental chapter of 'additions'
to vol. ii. Of the 'Philosophie Zoologique'), will see how much weight
he gives to inherent constitutional adaptability, to hereditary influences, and
to the operation of long lapses of time on successive generations, in the
course of transmuting a species. The common notion of Lamarck's philosophy,
drawn from the tirades which a too figurative style of illustrating the
reciprocal influence of innate tendencies and outward influences have drawn
upon the blind philosopher, is incorrect and unjust. Darwin writes:--
'Naturalists
continually refer to external conditions, such as climate, food, &c., as
the only possible cause of variation. In one very limited sense, as we shall
hereafter see, this may be true; but it is preposterous to attribute to mere
external conditions, the structure, for instance, of the woodpecker, with its
feet, tail, beak, and tongue, so admirably adapted to catch insects under the
bark of trees. In the case of the misseltoe, which draws its nourishment from
certain trees, which has seeds that must be transported by certain birds, and
which has flowers with separate sexes absolutely requiring the agency of
certain insects to bring pollen from one flower to the other; it is equally
preposterous to account for the structure of this parasite, with its relations
to several distinct organic beings, by the effects of external conditions, or
of habit, or of the volition of the plant itself.
'The
author of the Vestiges of Creation would, I presume, say that, after a
certain unknown number of generations, some bird had given birth to a
woodpecker, and some plant to the misseltoe, and that these had been produced
perfect as we now see them; but this assumption seems to me to be no
explanation, for it leaves the case of the coadaptations of organic beings to
each other and to their physical conditions of life untouched and unexplained.'
(P. 3)
The
last cited ingenious writer came to the task of attempting to unravel the
'mystery of mysteries,' when a grand series of embryological researches had
brought to light the extreme phases of form that the higher animals passed
through in the course of foetal development, and the striking analogies which
transitory embryonal phases of a higher species presented to series of lower
species in their permanent or completely developed state. He also instances the
abrupt departure from the specific type manifested by a malformed or monstrous
offspring, and called to mind the cases in which such malformations had lived
and propagated the deviating structure. The author of Vestiges,
therefore, speculates--and we think not more rashly or unlawfully than his
critic has done--on other possibilities, other conditions of change, than the
Lamarckian ones; as, for example, on the influence of premature birth and of
prolonged foetation in establishing the beginning of a specific form different
from that of the parent. And does not the known history of certain varieties,
such as that of M. Graux's cachemir-wooled sheep, which began suddenly by malformation,
show the feasibility of this view? (13) 'The whole train of animated beings,' writes the author of Vestiges
of Creation, 'are the results first, of an inherent impulse in the forms of
life to advance, in definite times, through grades of organisation terminating
in the highest dicotyledons and mammals; second, of external physical
circumstances, operating reactively upon the central impulse to produce the
requisite peculiarities of exterior organisation,--the adaptation of the
natural theologian.' But he, likewise, requires the same additional element
which Mr. Darwin so freely invokes. 'The gestation of a single organism is the
work of but a few days, weeks, or months; but the gestation (so to speak) of a
whole creation is a matter involving enormous spaces of time.' . . . . 'Though
distinctions admitted as specific are not now, to ordinary observation,
superable, time may have a power over these.' . . . . 'Geology shows
successions of forms, and grants enormous spaces of time within which we may
believe them to have changed from each other by the means which we see
producing varieties. Brief spaces of time admittedly sufficing to produce these
so-called varieties, is it unreasonable to suppose that large spaces of time
would effect mutations somewhat more decided, but of the same character?' (14).
Unquestionably
not, replies Mr. Darwin:--
'To
give an imaginary example from changes in progress on an island: let the
organisation of a canine animal which preyed chiefly on rabbits, but sometimes
on hares, become slightly plastic; let these same changes cause the number of
rabbits very slowly to decrease, and the number of hares to increase; the
effect of this would be that the fox or dog would be driven to try to catch
more hares; his organisation, however, being slightly plastic, those
individuals with the lightest forms, longest limbs, and best eyesight, let the
difference be ever so small, would be slightly favoured, and would tend to live
longer, and to survive during that time of the year when food was scarcest;
they would also rear more young, which would tend to inherit these slight
peculiarities. The less fleet ones would be rigidly destroyed. I can see no
more reason to doubt that these causes in a thousand generations would produce
a marked effect, and adapt the form of the fox or dog to the catching of hares
instead of rabbits, than that greyhounds can be improved by selection and
careful breeding.' (15)
Of
course, prosaic minds are apt to bore one by asking for our proofs, and one
feels almost provoked, when seduced to the brink of such a draught of forbidden
knowledge as the transmutationists offer, to have the Circean cup dashed away
by the dry remark of a President of the British Association:--
'Observation
of animals in a state of nature is required to show their degree of plasticity,
or the extent to which varieties do arise: whereby grounds may be had for
judging of the probability of the elastic ligaments and joint-structures of a
feline foot, for example, being superinduced upon the more simple structure of
the toe with the non-retractile claw, according to the principle of a
succession of varieties in time.' (16)
This
very writer has, however, himself suggested an operative cause in the
development of organised beings of a different and opposite character to that
conceived by 'Vestiges,' to produce the teleological adaptations. Professor
Owen has pointed out the numerous instances in the animal kingdom of a
principle of structure prevalent throughout the vegetable kingdom, exemplified
by the multiplication of organs in one animal performing the same function, and
not related to each other by combination of powers for the performance of a
higher function. The Invertebrate animals, according to the Professor, afford
the most numerous and striking illustration of the principles which he has
generalised as the 'Law of Irrelative Repetition.'
'We
perceive,' says he, 'in the fact of the endoskeleton consisting of a succession
of segments similarly composed--in the very power of enunciating special,
general, and serial homologies--an illustration of that law of vegetative or
irrelative repetition, which is so much more conspicuously manifested by the
segments of the exoskeleton of the Invertebrata: as, for example, in the rings
of the centipede and worm, and in the more multiplied parts of the skeleton of
the Echinoderms. The repetition of similar segments in the spinal column, and
of similar elements in a vertebral segment, is analogous to the repetition of
similar crystals, as the result of the polarising force in the growth of an
inorganic body. Not only does the principle of vegetative repetition prevail
more and more as we descend in the scale of animal life, but the forms of the
repeated parts of the skeleton approach more and more to geometrical figures;
as we see, for example, in the external skeletons of the echini and
star-fishes: nay, the calcifying salt assumes the same crystalline figures
which characterise it, when deposited and subject to the general polarising
force out of the organised body. Here, therefore, we have direct proof of the
concurrence of such general all-pervading polarising force, with the adaptive
or special organising force, in the development of an animal body.'
In
addition, therefore, to the organising principle, however explained, producing
the special 'adaptations,' and admitted as the 'second' power in the production
of species by Vestiges, Professor Owen states--
'There
appears also to be in counter-operation during the building up of such bodies,
a general polarising force, to the operation of which the similarity of forms,
the repetition of parts, the signs of the unity of organisation may be mainly
ascribed; the platonic or specific organising principle would seem,' he adds,'
to be in antagonism with the general polarising force, and to subdue and mould
it in subserviency to the exigencies of the resulting specific form.' (17)
An
index of the degree in which the polaric or irrelative repetitive force has
operated is given by that character of the animal's organisation which is
expressed by the term of 'a more generalised structure.' V. Baer pointed out
that the structure was 'more generalised,' in the ratio of the proximity of the
individual to the starting point of its existence. In proportion as the
individual is subject to the action and reaction of surrounding influences, in
other words, as it advances in life, does it acquire a more specialised
structure--more decided specific and individual characters (18). Owen has shown that the
more generalised structure is, in a very significant degree, a characteristic
of many extinct as compared with recent animals; and it may be readily
conceived that specialisation of structure would be the result of the
progressive modification of any organ applied to a special purpose in the
animal economy.
We
have cited these attempts to elucidate the nature of the organising forces, to
show the prevalent condition of the most advanced physiological minds in regard
to the cause of the successive introduction of distinct species of plants and
animals. Demaillet invoked the operation of the external influences or
conditions of life, with the consentaneous volitional efforts, in order to
raise species in the scale, as the fish, e.g., into the bird (19). Buffon called in the same
agency to lower the species, by way of degeneration, as the bear, e.g., into
the seal, and this into the whale (20). Lamarck added to these outward influences the effects of
increased or decreased use or action of parts. The Author of Vestiges,
availing himself of the ingenious illustration of a pre-ordained exception,
occurring at remote intervals, to the ordinary course, derived by Babbage from
the working of his Calculating Engine, threw out the suggestion of a like rare
exception in the character of the offspring of a known species, and he cites
the results of embryological studies, to show how such 'monster,' either by
excess or defect, by arrest or prolongation of development, might be no monster
in fact, but one of the preordained exceptions in the long series of natural
operations, giving rise to the introduction of a new species. Owen has not
failed to apply the more recent discoveries of Parthenogenesis to the same
mysterious problem. A polype, e.g., breaks up into a pile of medusae;
'the indirect or direct action of the conditions of life' might tend to harden
the integument and change the medusa into a star-fish. But he resists the
seduction of possibilities, and governed by the extent of actual observation,
says:--'The first acquaintance with these marvels excited the hope that we were
about to penetrate the mystery of the origin of species; but, as far as
observation has yet extended, they cycle of changes is definitely closed.' (21)
Mr.
Wallace calls attention to the 'tremendous rate of increase in a few years from
a single pair of birds producing two young ones each year, and this only four
times in their life; in fifteen years such pair would have increased to nearly
ten millions!' (22) The
passenger-pigeon of the United States exemplifies such rate of increase, where
congenial food abounds. But, as a general rule, the animal population of a
country is stationary, being kept down by a periodical deficiency of food and
other checks. Hence the struggle for existence; and the successful result of
adapted organisation and powers in a well developed variety, which Mr. Darwin
generalises as 'Natural Selection,' and which Mr. Wallace (23) illustrates as
follows:--
'An
antelope with shorter or weaker legs must necessarily suffer more from the
attacks of the feline carnivora; the passenger-pigeon with less powerful wings,
would sooner or later be affected in its powers of procuring a regular supply
of food.' (24) If, on
the other hand, 'any species should produce a variety having slightly increased
powers of preserving existence, that variety must inevitably in time acquire a
superiority in numbers.' 'During any change tending to render existence more
difficult to a species, tasking its utmost powers to avoid complete
extermination, those individuals forming the most feebly organised variety
would suffer first; the same causes continuing, the parent species would next
suffer, would gradually diminish in numbers, and with a recurrence of similar
unfavourable conditions, must soon become extinct. The superior variety would
then alone remain, and on a return to favourable circumstances would rapidly
increase in numbers and occupy the place of the extinct species and variety.
The variety would now have replaced the species, of which it would be a more
perfectly developed and a more highly organised from.' (25)
Buffon
regarded varieties as particular alterations of species, as supporting and
illustrating a most important principle--the mutability of species themselves.
The so-called varieties of a species, species of a genus, genera of a family,
&c., were, with him, so many evidences of the progressive amount or degrees
of change which had been superinduced by time and generations upon a primordial
type of animal. Applying this principle to the two hundred mammalian species of
which he had given a history in his great work, he believed himself able to
reduce them to a very small number of primitive stocks or families (26). Of these he enumerates
fifteen: besides which, Buffon specifies certain isolated forms, which
represent, as he forcibly and truly expresses it, both species and genus (27): such are the
elephant, rhinoceros, hippopotamus, giraffe, camel, lion, bear, and mole (28). Palæontology has
since revealed the evidences of the true nature and causes of the present seeming
isolation of some of these forms.
Such
evidences have been mainly operative with the later adopters and diffusers of
Buffon's principle in the reduction of the number of primitive sources of
existing species, and the contraction of the sphere of direct creative acts.
Thus Lamarck (29) reduces
the primordial forms or prototypes of animals to two, viz. the worm (vers),
and the monad (infusoires); the principles which in the course of
illimited time operated, on his hypothesis, to produce the present groups of
animals led from the vibrio, through the annelids, cirripeds, and molluscs to
fishes, and there met the other developmental route by way of rotifers,
polypes, radiaries, insects, arachnides, and crustacea. The class of fishes,
deriving its several forms from combinations of transmuted squids and crabs,
then proceeded through the well-defined vertebrate pattern up to man. With a
philosophic consistency, wanting in his latest follower, Lamarck sums up:
'Cette série d'animaux commençant par deux branches où se trouvent les plus
imparfaits, les premiers de chacune de ces branches ne reçoivent l'existence
que par génération directe ou spontanée.' (30) [This series of animals beginning with two branches where
the most imperfect are found; the first members of each of these branches do
not acquire existence except by direct or spontaneous generation].
Mr.
Darwin, availing himself of the more exact ideas of the affinities and
relationships of animal groups obtained by subsequent induction, says: 'I
believe that animals have descended from at most only four or five
progenitors,' [evidently meaning, or answering to, the type-forms of the four
or five 'sub-kingdoms' in modern zoology], 'and plants from an equal or lesser
number.'
But
if the means which produce varieties have operated 'through the enormous
species of time, within which species are changed,' (31)
the minor modifications which produce, under our brief
scope of observation, so-called varieties, might well amount to differences
equivalent to those now separating sub-kingdoms; and, accordingly, 'analogy,'
Mr. Darwin logically admits, 'would lead us one stop further, namely, to the belief
that all animals and plants have descended from some one prototype;' (32) and, summing up the
conditions which all living things have in common, this writer infers from that
analogy, 'that probably all the organic beings which have ever lived on this
earth, have descended from some one primordial form, into which life was first
breathed.' (33)
By
the latter scriptural phrase, it may be inferred that Mr. Darwin formally
recognises, in the so-limited beginning, a direct creative act, something like
that supernatural or miraculous one which, in the preceding page, he defines,
as 'certain elemental atoms which have been commanded suddenly to flash into
living tissues.' He has, doubtless, framed in his imagination some idea of the
common organic prototype; but he refrains from submitting it to criticism. He
leaves us to imagine our globe, void, but so advanced as to be under the
conditions which render life possible; and he then restricts the Divine power
of breathing life into organic form to its minimum of direct operation. All
subsequent organisms henceforward result from properties imparted to the
organic elements at the moment of their creation, pre-adapting them to the
infinity of complications and their morphological results, which now try to the
utmost the naturalist's faculties to comprehend and classify. And we admit,
with Buckland, that such an aboriginal constitution, 'far from superseding an
intelligent agent, would only exalt our conceptions of the consummate skill and
power, that could comprehend such an infinity of future uses, under future
systems, in the original groundwork of his creation.' We would accordingly
assure Professor Owen that he 'may conceive the existence of such ministers,
personified as Nature, without derogation of the Divine power;' and that he,
with other inductive naturalists, may confidently advance in the investigation
of those 'natural laws or secondary causes to which the orderly succession and
progression of organic phenomena have been committed.' (34)
We have no sympathy whatever with Biblical objectors to
creation by law, or with the sacerdotal revilers of those who would explain
such law. Literal scripturalism in the time of Lactantius, opposed and reviled
the demonstrations of the shape of the earth; in the time of Galileo it reviled
and persecuted the demonstrations of the movements of the earth; in the time of
Dean Cockburn of York, it anathematised the demonstrations of the antiquity of
the earth; and the eminent geologist who then personified the alleged
anti-scriptural heresy, has been hardly less emphatic than his theological
assault, in his denunciations of some of the upholders of the 'becoming and
succession of species by natural law,' or by 'a continuously operating creative
force.' What we have here to do, is to express our views of the hypothesis as
to the nature and mode of operation of the creative law, which has been
promulgated by Messrs. Wallace and Darwin.
The
author of the volume 'On the Origin of Species,' starts from a single
supernaturally created form. He does not define it; it may have been beyond his
power of conception. It is, however, eminently plastic, is modified by the
influence of external circumstances, and propagates such modifications by
generation. Where such modified descendant find favourable conditions of
existence, there they thrive; where otherwise they perish. In the first state
of things, the result is so analogous to that which man brings about, in
establishing a breed of domestic animals from a selected stock, that it
suggested the phrase of 'Natural Selection;' and we are appealed to, or at
least 'the young and rising naturalists with plastic minds' (35), are adjured, to believe
that the reciprocal influences so defined have operated, through divergence of
character and extinction, on the descendants of a common parent, so as to
produce all the organic beings that live, or have ever lived, on our planet.
Now
we may suppose that the primeval prototype began by producing, in the legal
generative way, creatures like itself, or so slightly affected by external
influences, as at first to be scarcely distinguishable from their parent. When,
as the progeny multiplied and diverged, they came more and more under the
influence of 'Natural Selection' so, through countless ages of this law's
operation, they finally rose to man. But, we may ask, could any of the
prototype's descendants utterly escape the surrounding influences? To us such
immunity, in the illimitable period during which the hypothesis of Natural
Selection requires it to have operated, is inconceivable. No living being,
therefore, can now manifest the mysterious primeval form to which Darwin restricts
the direct creative act; and we may presume that this inevitable consequence of
his hypothesis, became to him an insuperable bar to the definition of that
form.
But
do the facts of actual organic nature square with the Darwinian hypothesis? Are
all the recognised organic forms of the present date, so differentiated, so
complex, so superior to conceivable primordial simplicity of form and
structure, as to testify to the effects of Natural Selection continuously
operating through untold time? Unquestionably not. The most numerous living
beings now on the globe are precisely those which offer such a simplicity of
form and structure, as best agrees, and we take leave to affirm can only agree,
with that ideal prototype from which, by any hypothesis of natural law, the
series of vegetable and animal life might have diverged.
If
by the patient and honest study and comparison of plants and animals, under
their manifold diversities of matured form, and under every step of development
by which such form is attained, any idea may be gained of a hypothetical
primitive organism,--if its nature is not to be left wholly to the unregulated
fancies of dreamy speculation--we should say that the form and condition of
life which are common, at one period of existence, to every known kind and
grade of organism, would be the only conceivable form and condition of the one
primordial being from which 'Natural Selection' infers that all the organisms
which have ever lived on this earth have descended.
Now
the form in question is the nucleated cell, having the powers of receiving
nutritive matter from without, of assimilating such nutriment, and of
propagating its kind by spontaneous fission. These powers are called 'vital,'
because as long as they are continued the organism is said to live. The most
numerous and most widely diffused of living beings present this primitive grade
of structure and vital force, which grade is inferior to that of the truly
definable 'plant' or 'animal,' but is a grade represented and passed through by
the term of every, even the highest, class of animals, in the course of
embryonic development. The next stages of differentiated or advanced
organisation are defined as follows in Professor Owen's last publication:--
'When
the organism is rooted, has neither mouth nor stomach, exhales oxygen, and has
tissues composed of "cellulose" or of binary or ternary compounds, it
is called a "plant." When the organism can move, when it receives the
nutritive matter by a mouth, inhales oxygen, and exhales carbonic acid, and
developes tissues, the proximate principles of which are quaternary compounds
of carbon, hydrogen, oxygen, and nitrogen, it is called an "animal."
But the two divisions of organisms called "plants" and
"animals" are specialised members of the great natural groups of
living things; and there are numerous organisms, mostly of minute size and
retaining the form of nucleated cells, which manifest the common organic
characters, but without the distinctive superadditions of true plants or
animals. Such organisms are called "Protozoa," and include the
sponges or Amorphozoa, the Foraminifera or Rhizopods, the Polycystineæ, the
Diatomaceæ, Desmidiæ, Gregarinæ, and most of the so-called Polygastria of
Ehrenberg, or infusorial animalcules of older authors.' (36)
All
these would be interpreted as the earliest evidences of the modifying and
species-changing influences, according to the hypothesis of Lamarck. They are the
organisms respecting which the first living physiologists hesitate to apply the
Harveian axiom omne vivum ab ovo [everything living is from the egg],
believing the possibility of their spontaneous origin to be by no means
experimentally disproved. The prevalence of the essential first step in the
production of all higher organisms, viz. through the combined matter of the
'germ-cell' and 'sperm-cell,' has no doubt strongly inclined physiologists to
believe impregnation to be an absolute condition of the beginning of all
existing organisms. But, as the President of the British Association stated, in
his 'Address' at Leeds:--
'In
regard to lower living things, analogy is but hazardous ground for conclusions.
The single-celled organisms, such as many of the so-called animalcules of
infusions, which are at a stage of organisation too low for a definite transfer
to either the vegetable or animal kingdoms, offer a field of observation and
experiment which may yet issue in giving us a clearer insight into the development
of the organic living cell.'--'Whether an independent free-moving and
assimilating organism, of a grade of structure similar to, and scarcely higher
than, the "germ-cell," may not arise by a collocation of particles,
through the operation of a force analogous to that which originally formed the
germ-cell in the ovarian stroma, is a question which cannot be answered until
every possible care and pains have been applied to its solution.' (P. 28)
Professor
Pouchet believes that he is authorised by the results of his experiments to
answer that question in the affirmative. It is one of supreme importance, and
which has, hitherto, never received such an amount of painstaking experimental
research as it merits; and the best observations, the most carefully conducted
and ingeniously devised arrangements for insuring success, are undoubtedly
those of the patiently observant Professor of Zoology in the Ecole de
Médecine,' and Ecole supérieure des Sciences,' at Rouen (37). This, at least, may
be affirmed, that the inductive groundwork of his opponents is by no means such
as can justify any dogmatic negation of Heterogeny as applicable to the
simplest Protozoa.
On
the basis, therefore, of analogical probability, it may be inferred:--that the
primordial as well as all other forms of organic beings, originate, and have
ever originated, from the operation of secondary and continuously operating
creative laws: and that the various grades of organisms now in being, from the
microscopic monad upwards, indicate the various periods in time at which the
first step of the series they respectively terminate began. The monad that by
'natural selection' has ultimately become man, dates from the farthest point in
the remote past, upon which our feigners of developmental hypotheses can draw
with unlimited credit: the monad which by its superficial vibratile cilia
darted across the field of the microscope we were looking through this morning,
is the result of the collocation of particles which, without 'sudden flash,'
took place under the operation of the heterogeneous organising force of
yesterday.
Accordingly
we find that every grade of structure, from the lowest to the highest, from the
most simple to the most complex, is now in being,--a result which it is
impossible to reconcile with the Darwinian hypothesis of the one and once only
created primordial form, the parent of all subsequent living things. The
changes which our planet has undergone in the course of geological time have
been accompanied by the loss of many minor links which connected together the
existing evidences of gradational structure; but the general laws regulating
the progress and diversity of organic forms, having been the same throughout
all time, so it happens, according to the testimony of the most experienced
palæontologists, that--
'Every
known fossil belongs to some one or other of the existing classes, and that the
organic remains of the most ancient fossiliferous strata do not indicate or
suggest that any earlier and different group of beings remains to be
discovered, or has been irretrievably lost in the universal metamorphism of the
oldest rocks. (38)
That
forms, recognised as species by their distinctive characters and the power of
propagating them, have ceased to exist, and have successively passed away, is a
fact now unquestioned; that they have been exterminated by exceptional
cataclysmal changes of the earth's surface, as was surmised at the first
acceptance of the fact of extinction, has not been proved; that their
limitation in time may, in some instance, or in some degree, be due to
constitutional changes, accumulating by slow degrees in the long course of
generations, is possible: but all the traceable and observed causes of extirpation
point either to continuous slowly operating geological changes, or to no
greater sudden cause than the apparition of mankind on a limited tract of land
not before inhabited. It is now, therefore, generally inferred that the
extinction of species, prior to man's existence, has been due to ordinary
causes--ordinary in the sense of agreement with the great laws of never-ending
mutation of geographical and climatal conditions on the earth's surface. The
individuals of species least adapted to bear such influences and incapable of
modifying their organisation in harmony therewith, have perished. Extinction,
therefore, on this hypothesis, is due to the want of self-adjusting,
self-modifying power in the individuals of the species.
In
a joint paper on the tendency of varieties to form species by natural means of
selection (39), one of
the authors writes:--
'Any
minute variation in structure, habits, or instincts, adapting the individual
better to the new conditions, would tell upon its vigour and health. In the
struggle it would have a better chance of surviving, and those of its offspring
which inherited the variation would also have a better chance. Let this work go
on for a thousand generations, and who will pretend to affirm,' asks Mr.
Darwin, 'that a new species might not be the result?'
Thereupon
is adduced the imaginary example of dogs and rabbits on an island, which we
have already cited.
Now
this, we take leave to say, is no very profound or recondite surmise; it is just
one of those obvious possibilities that might float through the imagination of
any speculative naturalist; only, the sober searcher after truth would prefer a
blameless silence to sending the proposition forth as explanatory of the origin
of species, without its inductive formation.
In
the degeneration-theory of Buffon, man is one of the primitive types,--the
created apes and monkeys are derivatives. He might have illustrated it as
follows:--
To
give an imaginary example from changes in progress on an island: let the
organisation of a wild man feeding chiefly on fruits become slightly plastic;
let corresponding changes cause the sources of food on the ground very slowly
to decrease, and those on the trees to increase: the effect of this would be
that the man would try to climb more for food. Suppose also that a tiger or
like destructive carnivore should swim over and settle in the island, which
happened to be destitute of flints for weapons. The human organisation being
slightly plastic, those individual with the longest and strongest arms, and
with the most prehensile use of the great toe, let the difference be every so
small, would be slightly favoured, would survive during the time of the year
when food was scarcest on the ground, but ripe and ready on certain trees; they
would also rear more young which would tend to inherit these slight
peculiarities. The best climbers would escape the tigers, the worst would be
rigidly destroyed.
Buffon
would have seen no more reason to doubt that these causes, in a thousand
generations, would produce a marked effect, and adapt the form of the wild man
to obtain fruits rather than grains, than Darwin now believes that man can be
improved by selection and careful interbreeding into a higher, more heroic,
more angelic form! The advocate of Buffon's hypothesis might point out that it
is on islands, as Borneo and Sumatra, for example, where the orang-utan--the
obvious result of such 'degradation by natural selection'--is exclusively
found. And is it not there also, and in some other islands of the Malayan
Archipelago, where the next step in the scale of 'degeneration' is exhibited in
the still longer-armed Ungkas and other tail-less Hylobates? And though we call
them 'tail-less' yet they have the 'os coccygis;' and this being a
terminal appendage of stunted vertebrates, offers the very condition for the
manifestation of an occasional developmental variety. If cats, after accidental
mutilation or malformation, can propagate a tail-less breed, why may not apes
produce a tailed variety, and by natural selection in a long course of ages,
degenerate into endless incipient species of 'baboons and monkeys'?
But
Mr. Darwin, it may be said, repudiates the coarse transmutational conditions
and operations of Buffon and Lamarck; or, if there be any parallel between his
and Buffon's illustration of the changing of species, at all events such
parallels must run in opposite directions. Mr. Darwin starts from a single
created prototype, from which it is difficult to conceive he can mean any other
course of organic progress than an ascensive one. But of this, in the absence
of a definition of the starting point, we cannot be perfectly sure. 'Natural
selection' may operate in both directions. The following, for example, would
have been cordially welcomed by Buffon as a testimony in favour of his
'dégénération' hypothesis:--
'In
North America the black bear was seen by Hearne swimming for hours with widely
open mouth, thus catching, like a whale, insects in the water. Even in so
extreme a case as this, if the supply of insects were constant, and if better
adapted competitors did not already exist in the country, I can see no
difficulty in a race of bears being rendered, by natural selection, more and
more aquatic in their structure and habits, with larger and larger mouths, till
a creature was produced as monstrous as a whale.' (40)
If
the ursine species had not been restricted to northern latitudes, we might have
surmised this to have been one of the facts connected with 'the distribution of
the inhabitants of South America,' which seemed to Mr. Darwin, when naturalist
on board H. M. S. Beagle, 'to throw some light on the origin of species.' (41) But the close resemblance of
the style, and of the tone and frame of mind which could see no difficulty in
the adequacy of the above-cited circumstances of 'external conditions, of
habit, of volition,' to change a bear into a whale, to those exemplified in the
Philosophie Zoologique, point strongly to the writings of Lamarck as the
true suggestor of Mr. Darwin's views of animated nature. We look, however, in
vain for any instance of hypothetical transmutation in Lamarck so gross as the
one above cited; we must descend to older illustrators of the favourite idea,
to find an equivalent case of the bear in pursuit of water-insects, and we find
one in the following:--
'Car
il peut arriver, comme nous sçavons qu'en effet il arrive assez souvent, que
les poissons aîlés et volans chassant ou étant chassés dans la mer, emportés du
desir de la proie ou de la crainte de la mort, ou bien poussés peut-être à
quelques pas du rivage par des vagues qu'excitoit une tempête, soient tombés
dans des roseaux ou dans des herbages, d'où ensuite il ne leur fut pas possible
de reprendre vers la mer l'essor qui les en avoit tirés, et qu'en cet état ils
ayent contracté une plus grande faculté de voler. Alors leurs nageoires n'étant
plus baignées des eaux de la mer, se fendirent et se déjettèrent par la
sécheresse. Tandis qu'ils trouvèrent dans les roseaux et les herbages dans
lesquels ils étoient tombés, quelques alimens pour se soutenir, les tuyaux de
leurs nageoires, séparés les uns des autres, se prolongèrent et se revêtirent
de barbes; ou, pour parler plus juste, les membranes qui auparavant les avoient
tenus collés les uns aux autres se métamorphosèrent. La barbe formée de ces
pellicules déjetées s'allongea elle-même; la peau de ces animaux se revêtit
insensiblement d'un duvet de la même couleur dont elle étoit peinte, et ce duvet
grandit. Les petits aîlerons qu'ils avoient sous le ventre, et qui comme leurs
nageoires, leur avoient aidé à se promener dans la mer, devinrent des pieds, et
leur servirent à marcher sur la terre. Il se fit encore d'autres petits
changemens dans leur figure. Le bec et le col des uns s'allongèrent; ceux des
autres se racourçirent: il en fut de même du reste du corps. Cependant la
conformité de la première figure subsiste dans le total; et elle est et sera
toujours aisée à reconnoître.
Examainez
en effet toutes les espèces de poules, grosses et petites, même celles des
Indes, celles qui sont huppées, ou celles qui ne le sont pas; celles dont les
plumes sont à rebours telles qu'on en voit à Damiette, c'est-à-dire, dont le
plumage est couché de la queue à la tête; vous trouverez dans la mer des
espèces de perroquets dont les plumages sont si divers, les oiseaux les plus
rares et les plus singulièrement marquetés sont conformes à des poissons
peints, comme eux, de noir, de brun, de gris, de jaune, de verd, de rouge, de
violet, de couleur d'or et d'azur; et cela précisément dans les mêmes parties
où les plumages de ces mêmes oiseaux sont diversifiés d'une manière si
bizarre.' (42)
[For
it can happen, as we know in fact it happens often enough, that the winged and
flying fish which hunt or are hunted in the sea, filled with the desire for
their prey or with fear of death, or else pushed perhaps a few paces from the
shore by waves stirred up by a storm, have fallen in the reeds or in the
vegetation, where later it was not possible for them to reharness the energy
which had pulled them from the sea in order to get back to it, and that in this
condition they acquired a greater ability to fly. Once their fins were no
longer immersed in the waters of the sea, they cracked and became deformed by
drying out. While they found in the reeds and vegetation into which they had
fallen some food to sustain themselves, the tubes of their fins separated from
each other, grew longer and became covered with barbs; or, to speak more
precisely, the membranes which had previously held them together underwent a
change. The barb formed of these warped layers itself grew longer; the skin of
these animals very gradually became covered with a down of the same colour as
the skin, and this down grew. The small fins which they had under their belly,
which like their large fins had assisted them to move in the sea, became feet,
and served for their movement on the land. There were still other small changes
in their shape. The nose and the neck grew longer in some; in others they
decreased in size. So it went with the rest of the body. However, the
conformity with the first shape remains in all of them, and that is and always
will be easy to recognize.
Consider,
in fact, all the species of hens, large and small, even those of India, those
which are crested and those which are not, those in whom the feathers are aligned
the wrong way (the sort one sees in Damietta), that is to say, in whom the
plumage runs from the tail to the head. You will find in the sea species of
parrots whose plumage is so varied, the very rarest of birds and the most
singularly marked, and they conform to fish coloured like them, black, brown,
grey, yellow, green, red, violet, gold and blue coloured, and precisely in the
same places where the plumages of these same birds are diversified in such a
bizarre way.]
Demaillet,
it must be admitted, enters more fully into the details of the operation of
'natural selection,' in changing the fish into the bird; and it is, perhaps,
from this very 'naïveté' in the exposition of his theory, that its weakness has
been made so obvious to later zoologists and comparative anatomists. Mr. Darwin
rarely shows a fair front to these searching tests; the facts of the manner of
transmutation, as they might have presented themselves to his fancy, are not
stated with the 'abandon' of the old French philosopher. Vague and general as
is the illustration based upon Hearne's remark, it is made still more vague in
a later reprint of the volume On the Origin of Species. It now reads,
'In North America the black bear was seen by Hearne swimming for hours with
widely opened mouth, thus catching, almost like a whale, insects in the water.'
(Ed. 1860, p. 184.)
'Individuals,
it is said, of every species, in a state of nature annually perish,' and 'the
survivors will be, for the most part, those of the strongest constitutions and
the best adapted to provide for themselves and offspring, under the
circumstances in which they exist.' Now, let us test the applicability of this
postulate to the gradual mutation of a specific form by some instance in
Natural History eminently favourable for the assumed results. In many species
nature has superadded to general health and strength particular weapons and
combative instincts, which, as, e.g., in the deer-tribe, insure to the
strongest, to the longest-winded, the largest-antlered, and the sharpest-snagged
stages, the choice of the hinds and the chief share in the propagation of the
next generation. In such peculiarly gifted species we have the most favourable
conditions for testing one of the conclusions drawn by Messrs. Darwin and
Wallace from this universally recognised 'struggle for the preservation of life
and kind.' If the offspring inheriting the advantages of their parents, did in
their turn, however slightly and gradually, increase those advantages and give
birth to a still more favoured progeny, with repetition of the result to the
degree required by 'natural selection,'-then, according to the rate of
modification experimentally proved in pigeons, we ought to find evidence of
progressive increase in the combative qualities of antlers in those deer that
for centuries have been under observation in our parks, and still more so in
those that have fought and bred from the earliest historical times in the
mountain wilds of Scotland. The element of 'natural selection' above
illustrated, either is, or is not, a law of nature. If it be one, the results
should be forthcoming; more especially in those exceptional cases in which
nature herself has superadded structures, as it were expressly to illustrate
the consequences of such 'general struggle of the life of the individual and
the continuance of the race.' (43) The antlers of deer are expressly given to the male, and
permitted to him, in fighting trim, only at the combative sexual season; they
fall and are renewed annually; they belong moreover to the most plastic and
variable parts or appendages of the quadruped. Is it then a fact that the
fallow-deer propagated under these influences in Windsor Forest, since the
reign of William Rufus, now manifest in the superior condition of the antlers,
as weapons, that amount and kind of change which the succession of generations
under the influence of 'natural selection' ought to have produced? Do the
crowned antlers of the red deer of the nineteenth century surpass those of the
turbaries and submerged forest-lands which date back long before the beginning
of our English History? Does the variability of the artificially bred pigeon or
of the cultivated cabbage outweigh, in a philosophical consideration of the
origin of species, those obstinate evidences of persistence of specific types
and of inherent limitation of change of character, however closely the seat of
such characters may be connected with the 'best chance of taking care of self
and of begetting offspring?' If certain bounds to the variability of specific
characters be a law in nature, we then can see why the successive progeny of
the best antlered deer, proved to be best by wager of battle, should never have
exceeded the specific limit assigned to such best possible antlers under that
law of limitation. If unlimited variability by 'natural selection' be a law, we
ought to see some degree of its operation in the peculiarly favourable
test-instance just quoted.
That
the variability of an organism to a certain extent is a constant and certain
condition of life we admit, otherwise there would be no distinguishable
individuals of a species. The forester, by the operation of this law of
variability, is able to distinguish his individual oaks, the shepherd his
particular sheep, the teacher his several scholars. This true and proved law of
variability is, in fact, the essential condition of individuality itself. We
have searched in vain, from Demaillet to Darwin, for the evidence or the proof,
that it is only necessary for one individual to vary, be it ever so little, in
order to [sic] the conclusion that the variability is progressive and
unlimited, so as, in the course of generations, to change the species, the
genus, the order, or the class. We have no objection to this result of 'natural
selection' in the abstract; but we desire to have reason for our faith. What we
do object to is, that science should be compromised through the assumption of
its true character by mere hypotheses, the logical consequences of which are of
such deep importance.
The
powers, aspirations, and mission of man are such as to raise the study of his
origin and nature, inevitably and by the very necessity of the case, from the
mere physiological to the psychological stage of scientific operations. Every
step in the progress of this study has tended to obliterate the technical
barriers by which logicians have sought to separate the inquiries relating to
the several parts of man's nature. The considerations involved in the attempt
to disclose the origin of the worm are inadequate to the requirements of the
higher problem of the origin of man; and it may be that the conditions of that
problem are beyond our present powers of acquiring certain knowledge.
To
him, indeed, who may deem himself devoid of soul and as the brute that
perisheth, any speculation, pointing, with the smallest feasibility, to an
intelligible notion of the way of coming in of a lower organised species, may
be sufficient, and he need concern himself no further about his own relations
to a Creator. But when the members of the Royal Institution of Great Britain
are taught by their evening lecturer that such a limited or inadequate view and
treatment of the great problem exemplifies that application of science to which
England owes her greatness, we take leave to remind the managers that it more
truly parallels the abuse of science to which a neighbouring nation, some
seventy years since, owed its temporary degradation. By their fruits may the
promoters of true and false philosophy be known. We gazed with amazement at the
audacity of the dispenser of the hour's intellectual amusement, who, availing
himself of the technical ignorance of the majority of his auditors, sought to
blind them as to the frail foundations of 'natural selection' by such illustrations
as the subjoined:--
|
Hyrax Rhinoceros
Tapir Horse |
Tumbler Runt Pouter
Fantail |
The
above diagrams were set before an intelligent audience by a professor, in whom they
naturally repose confidence as to facts specially belonging to his science, as
parallel instances of departure from type: the one illustrating the extent and
directions in which varieties diverge from a type form, in long course of time,
by 'natural selection;' the other showing the correlative examples of such
divergence, in a short course of time, through human selection. He told them
that, in the latter series, the skeleton varied in regard to the number of
vertebræ; but did not remark that it was in the variable region of the tail, on
which no ornithologist ever depended for a specific character, neither did he
state that the alleged difference in the number of dorsal vertebræ (44) was one that is merely
simulated by a greater or less extent of the process of anchylosis over a
region of the spinal column in which every vertebra was originally distinct.
With regard to the parallel diagram, no allusion was made to such differences
in the relative position of the cranial bones as the following:--viz., that in
the palæotherium, as in the tapir, the maxillary bones intervene between
and separate the nasal bones from the intermaxillary bones; whilst in the
horse, as in the hyrax, the nasal and the intermaxillary bones are united as
far as their extremities; that, consequently, the external nostril is bounded
by four bones in the horse, but by six in its implied progenitor; that there is
as marked a difference in the conformation of the orbit, which is encircled by
the union of the malar with the frontal bone in the horse, but is left widely
open or incomplete, by the want of such union in the same two cranial bones of
the palæothere. The advocate of the 'natural selection' view exaggerated
resemblances and glossed over discrepancies of structure. The resemblance of
the Palæothere to its four hypothetical descendants, in respect of their
more generalised or more specialised structures, was flippantly affirmed to be
as that of a father to his four sons! (45) Nothing was said to give his hearers a notion of the
important difference between the horse and palæothere in the structure
and implantation of the whole dental system. Yet the horse resembles the
elephant in having a long mass of complexly interblended dental substances
deeply implanted in a large simple socket; whilst the palæothere differs
from both in having a short mass or crown of differently disposed dental
substances implanted by several long fangs in a correspondingly complex socket.
To the competent anatomist a score of such anatomical differences would be
present to the memory in contrasting the two alleged parallel series of
differences from selection natural and human; to which differences in the
palæontological series nothing comparable in essential value has been pointed
out in the varieties of Columbia livia. The competent palæontologist,
moreover, would detect the superficial character of the knowledge that would
interpose the tapir in any series leading from palæotherium: he would point
to the eocene lophiodon as the true ancestor of the tapir on the
derivative hypothesis.
Neither
zoology nor physiology as yet, however, possess a single fact to support the
idea that six incisor and two canine teeth, as in the palæothere, could
be blended or changed, by progressive transmutation, into the pair of large
scalpriform teeth that projects from the fore part of the lower jaw in the
hyrax or scriptural coney. The genuine cultivator of science and true
representative of the minds on which the glory and greatness of nations depend,
would feel bound to illustrate any series of observed varieties of a species by
a true parallel. The hoofed mammals which afford this parallel with the
diverging series of pigeons, are the following:--
|
Tumbler Runt Pouter
Fantail |
Racer Dray-Horse
Barb Galloway |
Here
the differences in regard to size, colour, development of tegumentary
appendages, number of caudal vertebræ, length or stuntedness of muzzle,
relative length of limb to body, &c., are closely analogous with the
diversities which Mr. Darwin has dwelt upon in the first chapter of his work.
And not only are the subjects of the above diagrams morphologically but
physiologically alike; not merely are the differences of form and structure
similar and equivalent, but the powers of procreation are the same. 'The
hybrids or mongrels from between all the domestic breeds of pigeons are
perfectly fertile;' (46) so,
likewise are the hybrids or mongrels from between all the domestic breeds of
the horse. Now, as this is not the case with the hybrid between any variety of
the horse and of the ass, it may be inferred that the physiological distinction
would be, at least, as great, or more insuperable, between the horse and the
tapir, or the rhinoceros, or the palæotherium. The infertility, or very
rare fertility, of the solipedous mule, even when paired with a true horse or
ass, and the absolute infertility of such hybrids inter se, are facts so
notorious, that the professional advocate of 'natural selection' was compelled
to admit that his alleged parallel broke down at the physiological test,--the
most important element of the comparison.
It
is assumed by Mr. Darwin that variations, useful in some way to each being,
occur naturally in the course of thousands of generations (p. 80), that such
variations are reproduced in the offspring, and, if in harmony with external
circumstances, may be heightened in still further modified descendants of the
species. The transmission and exaggeration of a variety, step by step, in the
generative series, essential to the theory of 'natural selection,' implies the
fertility of the individuals constituting the several steps of the series of
transmutation. But numerous instances, familiar to every zoologist, suggest an
objection which seems fatal to the theory, since they show extreme
peculiarities of structure and instinct in individuals that cannot transmit
them, because they are doomed to perpetual sterility.
The
most numerous and important members of the hive, which collect the pollen on
their peculiarly expanded thighs, and the honey in their peculiarly valvular
crop or 'honey-bag,' and which, in the construction of cells of a shape adapted
to contain the greatest possible quantity of honey with least possible
consumption of wax, have practically solved a recondite mathematical problem,
are the neuters, or females with abortive sexual organs,--'non-breeding
females' of our great physiologist Hunter. From the hypothetical protoplastic
progenitor of all animal species, what an enormous series of 'slight
modifications of structure and instinct' must have rolled, snow-ball like,
along the articulate line of departure, to have accumulated, according to
'natural selection,' in the Apis mellifica, which in the days of Moses
exercised as now their structures and instincts in the 'land flowing with milk
and honey!'
So
also in the family of ants, the neuters or sterile females form, in certain species,
two, or even three castes,--soldiers, workers, nurses. In Cryptocerus
the workers of one caste 'carry a wonderful sort of shield on their heads;' in
the Mexican genus, Myrmococystus, the workers of one caste are fed by
the workers of another caste, and have an enormously expanded abdomen where a
sort of honey is secreted and stored, which, like domestic cattle, they supply
to the rest of the community. Mr. Darwin, with one of his usual happy
illustrations, compares the workers of the 'driver ant' (Anomma), to a
'set of workmen building a house, of whom many were five feet four inches high,
and many sixteen feet high; but we must suppose that the larger workmen had
heads four instead of three times as big as those of the smaller men, and jaws
nearly five times as big;' in short, the most grotesque and extravagant scene
in a pantomime is realised in the industrial community of a West African ant.
Yet
all these instances of exaggerated peculiarities of structure and instinct are manifested
in individuals which never could have transmitted them.
No
zoologist, perhaps, is better acquainted with these fatal exceptions to his
principle of the organisation of species by hereditary transmission of
variation-characters, than Mr. Darwin. He could not, with any pretension to
free and candid discussion, pass over the chief instances which have checked
the natural disposition of all zoologists to obtain inductively an infallible
idea of the most mysterious phenomena of their science. But the barrier at
which Cuvier hesitated, Mr. Darwin rushes through, and thus he disposes of the
difficulty:--
'We
have even slight differences in the horns of different breeds of cattle in
relation to an artificially imperfect state of the male sex; for oxen of certain
breeds have longer horns than in other breeds, in comparison with the horns of
the bulls or cows of the same breeds. Hence I can see no real difficulty in any
character having become correlated with the sterile condition of certain
members of insect-communities: the difficulty lies in understanding how such
correlated modifications of structure could have been slowly accumulated by
natural selection.
'I
have such faith in the powers of selection, that I do not doubt that a breed of
cattle, always yielding oxen with extraordinarily long horns, could be slowly
formed by carefully watching which individual bulls and cows, when matched,
produce oxen with the longest horns; and yet no one ox could ever have
propagated its kind. Thus I believe it has been with social insects: a slight
modification of structure, or instinct, correlated with the sterile condition
of certain members of the community, has been advantageous to the community:
consequently the fertile males and females of the same community flourished,
and transmitted to their fertile offspring a tendency to produce sterile
members having the same modification.' (P. 238)
It
is a notorious and constant fact, that the castrate bovine has longer horns
than either the prefect male or female. The progressively elongating result in
the case of the oxen, about which our theorist does not doubt, has not been
proved experimentally. It is capable of proof or disproof. In scientific
questions of far less import than the origin of animal species, involving our own,
small value, if any, is attached to supposititious cases.
It
is, doubtless, by no means necessary that we should sow a seed of the very
cauliflower we eat in order to get more cauliflowers; seed of other individuals
of the same stock will suffice. So the bee-keeper feels satisfied that the
progeny of the impregnated young queen will exercise all the wonderful
instincts which result in the production of wax and honey, as effectively as
the virgin-sisters of the queen mother, who were destroyed in the preceding
winter. And our readers may well wonder what all this has to do with the
explanation of the acquisition of the adaptive structures and instincts of
neuter bees, by homoeopathic doses of Lamarckian transmutation, accumulating
through a long series of hereditary transmissions? We cannot reply; we can only
quote, with no less amazement, our author:--
'This
difficulty, though appearing insuperable, is lessened, or, as I believe,
disappears, when it is remembered that selection may be applied to the family,
as well as to the individual, and may thus gain the desired end. Thus, a
well-flavoured vegetable is cooked, and the individual is destroyed; but the
horticulturist sows seed of the same stock, and confidently expects to get
nearly the same variety; breeders of cattle wish the flesh and fat to be well
marbled together; the animal has been slaughtered, but the breeder goes with
confidence to the same family.' (P. 237)
Now
every step in the production of the breed or family of cattle may have been
observed and recorded; and many of the incidents of the transmutative journey
of the edible variety of cabbage from the wild stock may be similarly known;
but this is just the knowledge that we desiderate in regard to the creation of
the honey-bee by the way of 'natural selection;' and, instead of satisfying our
craving with the mature fruit of inductive research, Mr. Darwin offers us the
intellectual husks above quoted, endorsed by his firm belief in their nutritive
sufficiency!
To
more intelligible propositions in support of his hypothesis, we marginally
noted, as we perused them, the difficulties or exceptions which rose in our
mind. We have still room for a few of these illustrations of the groundwork of
'natural selection.'
'From
looking at species as only strongly-marked and well-defined varieties, I was
led to anticipate that the species of the larger genera in each country would
oftener present varieties, than the species of the smaller genera. To test the
truth of this anticipation I have arranged the plants of twelve countries, and
the coleopterous insects of two districts, into two nearly equal masses, the
species of the larger genera on one side, and those of the smaller genera on
the other side, and it has invariably proved to be the case that a larger proportion
of the species on the side of the larger genera present varieties, than on the
side of the smaller genera.' (P. 55)
The
elephant is, however, a small genus, indeed one of the smallest in the sense of
the number of species composing it, which are indeed but two, the Elephas
Indiens and Elephas Africanus of Cuvier. But the range of variety in
both African and Indian kinds is by no means inconsiderable. Livingstone adds
instances in the elephants of the Zambesi, and the terms 'Dauntelah,'
'Mooknah,' &c., applied by the Indians and Singhalese entrappers of the
wild proboscidians to the different varieties that are captured, still more
exemplify this tendency to vary in individuals of a 'small genus.' Another
exception to Mr. Darwin's rule as strongly and quickly suggests itself in the
genus Pithecus. Naturalists seem unwilling to admit more species that the
Bornean Pongo (Pithecus Wurmbii, seu Satyrus of Wurmb), and the
smaller orang (P. morio), since established by Owen. But the varieties
in regard to the cranial crests, to colour, to relative length of arms, appears
by a memoir from the pen of the latter naturalist (47), to be both numerous and well marked. On the other hand,
the species of the antelope genus have not hitherto presented any notable
varieties to the observation of naturalists; and yet the genus, in respect to
the number of these species, is one of the largest in the mammalian class.
There may be, of course, a difference in different classes of organisms in this
respect. Plants and invertebrates may better exemplify Mr. Darwin's proposition
than fishes, reptiles, or quadrupeds. But an hypothesis applied to all living
things can only be sustained by laws and rules of a like generality of
application.
Mr.
Darwin's argument for a common origin of all the varieties of dovecot pigeon,
leads him to affirm, 'all recent experience shows that it is most difficult to
get any wild animal to breed freely under domestication.' (P. 24) But the
recent experience at the Zoological Gardens of London tells a different story.
Three young individuals, two males and one female, of those most strange exotic
quadrupeds, the giraffe, were transported from their African wilderness to the
menagerie in Regent's Park in 1836. No sooner had they attained their proper
age in 1838 than they bred; and there has been no other interval in the
repetition of the act that that which the phenomena of a fifteen months'
gestation and seven months' suckling necessarily interpose. 'Nine fawns have been
produced without any casualty.' (48) A pair of the largest and wildest of antelopes (the Eland,
A. Oreas) is transported from the boundless sunny plains of South Africa to the
confinement of a park in cloudy and rainy Lancashire; they breed freely there,
and become the parents of elands now widely distributed over Great Britain, and
promising in another century to be as common in our parks as fallow deer. (49) What conditions might seem
more adverse to health and procreative power than such as are exemplified by
the contrast of the den and the pond appropriated to the hippopotamus in the
Jardin des Plantes, with that noble river where these most uncouth of African
wild beasts disported themselves prior to their capture? Before two years
elapse after the arrival of the young male and female, they produce a fine
offspring.
Such
are the signs of defective information which contribute, almost at each
chapter, to check our confidence in the teachings and advocacy of the
hypothesis of 'Natural Selection.' But, as we have before been led to remark,
most of Mr. Darwin's statements elude, by their vagueness and incompleteness,
the test of Natural History facts. Thus he says:--
'I
think it highly probable that our domestic dogs have descended from several
wild species.' It may be so; but what are the species here referred to? Are
they known, or named, or can they be defined? If so, why are they not
indicated, so that the naturalist might have some means of judging of the
degree of probability, or value of the surmise, and of its bearing on the
hypothesis?
'Isolation,
also,' says Mr. Darwin, is an important element in the process of natural
selection.' But how can one select if a thing be 'isolated'? Even using the
word in the sense of a confined area, Mr. Darwin admits that the conditions of
life 'throughout such area, will tend to modify all the individuals of a
species in the same manner, in relation to the same conditions.' (P. 104.) No
evidence, however, is given of a species having ever been created in that way;
but granting the hypothetical influence and transmutation, there is no
selection here. The author adds, 'Although I do not doubt that isolation is of
considerable importance in the production of new species, on the whole, I am
inclined to believe, that largeness of area is of more importance in the
production of species capable of spreading widely.' (P. 105.)
Now,
on such a question as the origin of species, and in an express, formal,
scientific treatise on the subject, the expression of a belief, where one looks
for a demonstration, is simply provoking. We are not concerned in the author's
beliefs or inclinations to believe. Belief is a state of mind short of actual
knowledge. It is a state which may govern action, when based upon a tacit
admission of the mind's incompetency to prove a proposition, coupled with
submissive acceptance of an authoritative dogma, or worship of a favourite idol
of the mind. We readily concede, and it needs, indeed, no ghost to reveal the
fact, that the wider the area in which a species may be produced, the more
widely it will spread. But we fail to discern its import in respect of the
great question at issue.
We
have read and studied with care most of the monographs conveying the results of
close investigations of particular groups of animals, but have not found, what
Darwin asserts to be the fact, at least as regards all those investigators of
particular groups of animals and plants whose treatises he has read, viz., that
their authors 'are one and all firmly convinced that each of the well-marked
forms or species was at the first independently created.' Our experience has
been that the monographers referred to have rarely committed themselves to any
conjectural hypothesis whatever, upon the origin of the species which they have
closely studied.
Darwin
appeals from the 'experienced naturalists whose minds are stocked with a
multitude of facts' which he assumes to have been 'viewed from a point of view
opposite to his own,' to the 'few naturalists endowed with much flexibility of
mind,' for a favourable reception of his hypothesis. We must confess that the
minds to whose conclusions we incline to bow belong to that truth-loving,
truth-seeking, truth-imparting class which Robert Brown (50), Bojanus (51), Rudolphi, Cuvier
(52), Ehrenberg (53),
Herold (54), Kölliker (55),
and Siebold, worthily exemplify. The rightly and sagaciously generalising
intellect is associated with the power of endurance of continuous and laborious
research, exemplarily manifested in such monographs as we have quoted below.
Their authors are the men who trouble the intellectual world little with their
beliefs, but enrich it greatly with their proofs. If close and long-continued
research, sustained by the determination to get accurate results, blunted, as
Mr. Darwin seems to imply, the far-seeing discovering faculty, then are we
driven to this paradox, viz., that the elucidation of the higher problems, nay
the highest, in Biology, is to be sought for or expected in the lucubrations of
those naturalists whose minds are not weighted or troubled with more than a
discursive and superficial knowledge of nature.
Lasting
and fruitful conclusions have, indeed, hitherto been based only on the
possession of knowledge; now we are called upon to accept an hypothesis on the
plea of want of knowledge. The geological record, it is averred, is so
imperfect! But what human record is not? Especially must the record of past
organisms be much less perfect than of present ones. We freely admit it. But
when Mr. Darwin, in reference to the absence of the intermediate fossil forms
required by his hypothesis--and only the zootomical zoologist can
approximatively appreciate their immense numbers--the countless hosts of
transitional links which, on 'natural selection,' must certainly have existed
at one period or another of the world's history--when Mr. Darwin exclaims what
may be, or what may not be, the forms yet forthcoming out of the graveyards of
strata, we would reply, that our only ground for prophesying of what may come,
is by the analogy of what has come to light. We may expect, e.g., a
chambered-shell from a secondary rock; but not the evidence of a creature
linking on the cuttle-fish to the lump-fish.
Mr.
Darwin asks, 'How is it that varieties, which I have called incipient species,
become ultimately good and distinct species?' To which we rejoin with the
question:--Do they become good and distinct species? Is there any one instance
proved by observed facts of such transmutation? We have searched the volume in
vain for such. When we see the intervals that divide most species from their
nearest congeners, in the recent and especially the fossil series, we either
doubt the fact of progressive conversion, or, as Mr. Darwin remarks in his
letter to Dr. Asa Gray (56), one's
'imagination must fill up very wide blanks.'
The
last ichthyosaurus, by which the genus disappears in the chalk, is hardly
distinguishable specifically from the first ichthyosaurus, which abruptly
introduces that strange form of sea-lizard in the lias. The oldest Pterodactyle
is as thorough and complete a one as the latest. No contrast can be more
remarkable, nor, we believe, more instructive, than the abundance of evidence
of the various species of ichthyosaurus throughout the marine strata of the
oolite and cretaceous periods, and the utter blank in reference to any form
calculated to enlighten us as to whence the ichthyosaurus came, or what it
graduated into, before or after these periods. The Enaliosauria of the
secondary seas were superseded by the Cetacea of the tertiary ones.
Professor
Agassiz affirms:--
'Between
two successive geological periods, changes have taken place among plants and
animals. But none of those primordial forms of life which naturalists call
species, are known to have changed during any of these periods. It cannot be
denied that the species of different successive periods are supposed by some
naturalists to derive their distinguishing features from changes which have
taken place in those of preceding ages, but this is a mere supposition,
supported neither by physiological nor by geological evidence; and the
assumption that animals and plants may change in a similar manner during one
and the same manner is equally gratuitous.' (57)
Cuvier
adduced the evidence of the birds and beasts which had been preserved in the
tombs of Egypt, to prove that no change in their specific characters had taken
place during the thousands of years--two, three, or five--which had elapsed,
according to the monumental evidence, since the individuals of those species
were the subjects of the mummifier's skill.
Professor
Agassiz adduces evidence to show that there are animals of species now living
which have been for a much longer period inhabitants of our globe.
'It
has been possible' he writes, 'to trace the formation and growth of our coral
reefs, especially in Florida, with sufficient precision to ascertain that it
must take about eight thousand years for one of those coral walls to rise from
its foundation to the level of the surface of the ocean. There are around the
southernmost extremity of Florida alone, four such reefs, concentric with one
another, which can be shown to have grown up one after the other. This gives
for the beginning of the first of these reefs an age of over thirty thousand
years; and yet the corals by which they were all built up are the same
identical species in all of them. These facts, then, furnish as direct evidence
as we can obtain in any branch of physical inquiry, that some, at least, of the
species of animals now existing, have been in existence over thirty thousand
years, and have not undergone the slightest change during the whole of that
period.' (58)
To
this, of course, the transmutationists reply that a still longer period of time
might do what thirty thousand years have not done.
Professor
Baden Power, for example, affirms;--'Though each species may have possessed its
peculiarities unchanged for a lapse of time, the fact that when long periods
are considered, all those of our earlier period are replaced by new ones at a
later period, proves that species change in the end, provided a sufficiently
long time is granted.' But here lies the fallacy: it merely proves that species
are changed, it gives us no evidence as to the mode of change; transmutation,
gradual or abrupt, is in this case mere assumption. We have no objection on any
score to the change; we have the greatest desire to know how it is brought
about. Owen has long stated his belief that some pre-ordained law or secondary
cause is operative in bringing about the change; but our knowledge of such law,
if such exists, can only be acquired on the prescribed terms. We, therefore,
regard the painstaking and minute comparisons by Cuvier of the osteological and
every other character that could be tested in the mummified ibis, cat, or
crocodile, with those of the species living in his time; and the equally
philosophical investigations of the polypes operating at an interval of 30,000
years in the building up of coral reefs, by the profound palæontologist of
Neuchatel, as of far higher value in reference to the inductive determination
of the question of the origin of species that the speculations of Demaillet,
Buffon, Lamarck, 'Vestiges,' Baden Powell, or Darwin.
The
essential element in the complex idea of species, as it has been variously
framed and defined by naturalists, viz., the blood-relationship between all the
individuals of such species, is annihilated on the hypothesis of 'natural selection.'
According to this view a genus, a family, an order, a class, a
sub-kingdom,--the individuals severally representing these grades of difference
or relationship,--now differ from individuals of the same species only in
degree: the species, like every other group, is a mere creature of the brain;
it is no longer from nature. With the present evidence from form, structure,
and procreative phenomena, of the truth of the opposite proposition, that
'classification is the task of science, but species the work of nature,' we
believe that this aphorism will endure; we are certain that it has not yet been
refuted; and we repeat in the words of Linnæus, 'Classis et Ordo est sapientiæ,
Species naturæ opus' [Class and Order are the work of human wisdom; Species is
the work of nature]
[Notes]
(1) On the Structure and Distribution of Coral Reefs, 8vo. 1842. [Back to Text]
(2) In the remarkable volume recently published by Lord Brougham,
entitled 'Tracts, mathematical and physical,' which have been produced by his
Lordship at various times from the year 1796 to the year 1858, will be found an
excellent paper on the Mathematical Structure of Bees' Cells, read before the
National Institute of France, by Lord Brougham, in the French language, in May
1858. It is a scientific and literary curiosity. [Back to text]
(3) Philosophie Zoologique, 8vo. 1809,
vol i, p. 54. [Back to text]
(4) Ib. p. 55. [Back to Text]
(5) Cuvier, Tableau Élémentaire de l'Histoire Naturelle, 8
vo. 1798, p. 9. [Back to Text]
(6) 'Les variétés de chacune ont dû être d'autant plus fortes et
plus nombreuses, que les circonstances des lieux ou de sa nature lui ont permis
de s'étendre plus loin; c'est ce qui peut faire croire que les grandes
différences que se trouvent parmi les hommes, le chiens, et les autres êtres
répandues partout le monde, ne sont que des effects des causes accidentelles,
en un mot, des variétés.' (P. 14) [The varieties of each of them must have
been that much stronger and more numerous as the circumstances of the locations
or its nature permitted it to extend itself more widely. That is what enables
us to believe that the large differences which are found among human beings,
dogs, and the other beings spread all over the world are only effects of
accident causes, in a word, varieties] [Back to Text]
(7) Philosophic Zoologique, 8vo. 1809, tom.
I, chaps. iii. vi. vii. [Back to Text]
(8) The most numerous illustrations of this
principle are to be found in Owen's palæontological works and memoirs; but he
refrains from announcing it as a general law, probably regarding the induction
as being yet incomplete. [Back to text]
(9) Palæontology, or a Systematic Summary of Extinct Animals,
and their Geological Relations, 8 vo., 1860, p. 3; and President's
Address to the British Association at Leeds, 1858, p. 3. [Back to Text]
(10) Palæontology, p. 404. [Back to Text]
(11) President's Address to the British
Association at Leeds, p. 27. [Back to Text]
(12) See the beautiful work entitled Rare and
Remarkable Animals of Scotland, 4to. vol i. 1847, by Sir J. G. Dalyell. [Back to Text]
(13) Reports of the Juries Exhibition of the
Works of All Nations, 8vo., 1852, p. 70. [Back to Text]
(14) Vestiges of Creation, 8vo., 1846, p.
231. [Back to Text]
(15) 'On the Tendency of Species to form
Varieties," &c., in Proceedings of the Linnæan Society, 1858,
p. 49. [Back to Text]
(16) Address, p. 44. [Back to Text]
(17) Archetype of the Vertebrate Skeleton,
8vo., 1840, p. 171. [Back to Text]
(18) 'The extent to which the resemblance,
expressed by the term, "Unity of Organisation," may be traced between
the higher and lower organised animals, bears an inverse ratio to their
approximation to maturity.' (Owen, Lectures on Invertebrata, p. 645). [Back to
Text]
(19) Telliamed, ou Entretiens d'un Philosophe
Indien avec un Missionaire François, Amsterdam, 8vo., 1748. [Back to
Text]
(20) Histoire Naturelle, &c., 4to.,
tom. xiv. 1766. [Back to Text]
(21) Address to the British Association at
Leeds, 1858, p. 27. [Back to Text]
(22) Proceedings of the Linnæan Society,
1858, p. 55. [Back to Text]
(23) Proceedings of the Linnæan Society (dated
from 'Ternate,' February 1858), vol. iii. p. 58. [Back to
Text]
(24) Wallace, loc. cit. p. 85. [Back to
Text]
(25) Ib., p. 58. [Back to
Text]
(26) Histoire Naturelle tom. xiv. p. 338.
[Back to Text]
(27) 'Quelques espèces isolées, qui, comme celle
de l'homme, fassent en même temps espèce et genre.' (Tom. Cit., p. 335.)
[Certain isolated species which, like that of the human being, are
simultaneously species and genus] [Back to Text]
(28) Ib., p. 360. [Back to
the Text]
(29) Philosophie Zoologique, vol. ii. p.
463. [Back to Text]
(30) Ib., p. 463. [Back to Text]
(31) Vestiges of Creation, p. 231. [Back to
text]
(32) Op. Cit., p. 484. [Back to
Text]
(33) Ib. [Back to
Text]
(34) On the Nature of Limbs, p. 86. [Back to
Text]
(35) On the Nature of the Limbs, p. 482.
[Back to Text]
(36) Owen's Palæontology, p. 4. [Back to
Text]
(37) Pouchet, Hétérogénie, ou Traité de la
Génération spontanée, basé sur des nouvelles Expériences, 8vo., 1859. [Back to
Text]
(38) Owen's Palæontology, p. 18. [Back to
Text]
(39) By Darwin and Wallace, Proceedings of
the Linnæan Society, August 1858, p. 45. [Back to Text]
(40) Darwin, p. 184. (1st edition.) [Back to Text]
(41) Darwin, p. 1. (1st edition). [Back to
Text]
(42) Telliamed, ou Entretiens d'un Philosophe
Indien avec un Missionaire François, sur la Diminution de la Mer, &c.,
8vo. Amsterdam, 1768. (An edition in two volumes of this original and
suggestive work, was printed, with the life of the author (Demaillet), at the
Hague, in 1755. The passage quoted will be found at p. 166, tom. ii. of this
edition) [Back to Text]
(43) 'Individual males have had, in successive
generations, some slight advantage over other males in their weapons, and have
transmitted these advantages to their male offspring.' (Darwin, p. 89.) [Back to
Text]
(44) Darwin, p. 22. [Back to
Text]
(45) Professor Huxley's Lecture 'On Species and
Races and their Origin,' Friday, February 10th, 1860, Journal of the Royal
Institution of Great Britain. [Back to Text]
(46) Darwin, p. 26. [Back to Text]
(47) 'Characters of the skull of the male Pithecus
morio, with remarks on the varieties of Pithecus satyrus,' by
Professor Owen. Zoological Transactions, vol. iv. p. 163. 1856. [Back to
Text]
(48) Edinb. Review, January, 1860, p.
179. [Back to Text]
(49) Ib., pp. 167-9. [Back to Text]
(50) Prodromus Floræ Novæ Hollandiæ. [Back to Text]
(51) Anatome Testudinis Europææ. [Back to Text]
(52) Mémoires pour servir à l'Anatomie des
Mollusques. [Back to
Text]
(53) Die Infusionsthierchen, als vollkommene
Organismen. [Back to
Text]
(54) Disquisitiones de Aminalium vertebris
carentium, &c. [Back
to Text]
(55) Entwickelungsgeschichte des Cephalopoden.
[Back to Text]
(56) Proceedings of the Linnæan Society,
1858, p. 61. [Back to
Text]
(57) Contributions to Natural History: Essay
on Classification, p. 51. [Back to Text]
(58) Ibid., p. 53. [Back to
Text]
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