SPECIFIC GENESIS.
Review of the statements and arguments of preceding
chapters.--Cumulative argument against predominant action of "Natural
Selection."--Whether anything positive as well as negative can be
enunciated.--Constancy of laws of nature does not necessarily imply
constancy of specific evolution.--Possible exceptional stability of
existing epoch.--Probability that an internal cause of change
exists.--Innate powers must be conceived as existing somewhere or
other.--Symbolism of molecular action under vibrating
impulses.--Professor Owen's statement.--Statement of the Author's
view.--It avoids the difficulties which oppose "Natural Selection."--It
harmonizes apparently conflicting conceptions.--Summary and conclusion.
Having now severally reviewed the principal biological facts which bear
upon specific manifestation, it remains to sum up the results, and to
endeavour to ascertain what, if anything, can be said _positively_, as well
as negatively, on this deeply interesting question.
In the preceding chapters it has been contended, in the first place, that
no mere survival of the fittest accidental and minute variations can
account for the incipient stages of useful structures, such as, _e.g._, the
heads of flat-fishes, the baleen of whales, vertebrate limbs, the laryngeal
structures of the newborn kangaroo, the pedicellariæ of Echinoderms, or for
many of the facts of mimicry, and especially those last touches of mimetic
perfection, where an insect not only mimics a leaf, but one worm-eaten and
attacked by fungi. [Page 221]
Also, that structures like the hood of the cobra and the rattle of the
rattlesnake seem to require another explanation.
Again, it has been contended that instances of colour, as in some apes; of
beauty, as in some shell-fish; and of utility, as in many orchids, are
examples of conditions which are quite beyond the power of Natural
Selection to originate and develop.
Next, the peculiar mode of origin of the eye (by the simultaneous and
concurrent modification of distinct parts), with the wonderful refinement
of the human ear and voice, have been insisted on; as also, that the
importance of all these facts is intensified through the necessity
(admitted by Mr. Darwin) that many individuals should be similarly and
simultaneously modified in order that slightly favourable variations may
hold their own in the struggle for life, against the overwhelming force and
influence of mere number.
Again, we have considered, in the third chapter, the great improbability
that from minute variations in all directions alone and unaided, save by
the survival of the fittest, closely similar structures should
independently arise; though, on a non-Darwinian evolutionary hypothesis,
their development might be expected _a priori_. We have seen, however, that
there are many instances of wonderfully close similarity which are not due
to genetic affinity; the most notable instance, perhaps, being that brought
forward by Mr. Murphy, namely, the appearance of the same eye-structure in
the vertebrate and molluscous sub-kingdoms. A curious resemblance, though
less in degree, has also been seen to exist between the auditory organs of
fishes and of Cephalopods. Remarkable similarities between certain
placental and implacental mammals, between the bird's-head processes of
Polyzoa and the pedicellariæ of Echinoderms, between Ichthyosauria and
Cetacea, with very many other similar coincidences, have also been pointed
out.
Evidence has also been brought forward to show that similarity is sometimes
directly induced by very obscure conditions, at present quite {222}
inexplicable, _e.g._ by causes immediately connected with geographical
distribution; as in the loss of the tail in certain forms of Lepidoptera
and in simultaneous modifications of colour in others, and in the direct
modification of young English oysters, when transported to the shore of the
Mediterranean.
Again, it has been asserted that certain groups of organic forms seem to
have an innate tendency to remarkable developments of some particular kind,
as beauty and singularity of plumage in the group of birds of paradise.
It has also been contended that there is something to be said in favour of
sudden, as opposed to exceedingly minute and gradual, modifications, even
if the latter are not fortuitous. Cases were brought forward, in Chapter
IV., such as the bivalve just mentioned, twenty-seven kinds of American
trees simultaneously and similarly modified, also the independent
production of pony breeds, and the case of the English greyhounds in
Mexico, the offspring of which produced directly acclimated progeny.
Besides these, the case of the Normandy pigs, of _Datura tatula_, and also
of the black-shouldered peacock, have been spoken of. The teeth of the
labyrinthodon, the hand of the potto, the whalebone of whales, the wings of
birds, the climbing tendrils of some plants, &c. have also been adduced as
instances of structures, the origin and production of which are probably
due rather to considerable modifications than to minute increments.
It has also been shown that certain forms which were once supposed to be
especially transitional and intermediate (as, _e.g._, the aye-aye) are
really by no means so; while the general rule, that the progress of forms
has been "from the more general to the more special," has been shown to
present remarkable exceptions, as, _e.g._, Macrauchenia, the Glyptodon, and
the sabre-toothed tiger (Machairodus).
Next, as to specific stability, it has been seen that there may be a {223}
certain limit to normal variability, and that if changes take place they
may be expected _a priori_ to be marked and considerable ones, from the
facts of the inorganic world, and perhaps also of the lowest forms of the
organic world. It has also been seen that with regard to minute spontaneous
variations in races, there is a rapidly increasing difficulty in
intensifying them, in any one direction, by ever such careful breeding.
Moreover, it has appeared that different species show a tendency to
variability in special directions, and probably in different degrees, and
that at any rate Mr. Darwin himself concedes the existence of an internal
barrier to change when he credits the goose with "a singularly inflexible
organization;" also, that he admits the presence of an _internal_
proclivity to change when he speaks of "a whole organization seeming to
have become plastic, and tending to depart from the parental type."
We have seen also that a marked tendency to reversion does exist, inasmuch
as it sometimes takes place in a striking manner, as exemplified in the
white silk fowl in England, _in spite of_ careful selection in breeding.
Again, we have seen that a tendency exists in nature to eliminate hybrid
races, by whatever means that elimination is effected, while no similar
tendency bars the way to an indefinite blending of varieties. This has also
been enforced by statements as to the prepotency of certain pollen of
identical species, but of distinct races.
To all the preceding considerations have been added others derived from the
relations of species to past time. It has been contended that we have as
yet no evidence of minutely intermediate forms connecting uninterruptedly
together undoubtedly distinct species. That while even "horse ancestry"
fails to supply such a desideratum, in very strongly marked and exceptional
kinds (such as the Ichthyosauria, Chelonia, and Anoura), the absence of
links is very important and significant. For if every species, without{224}
exception, has arisen by minute modifications, it seems incredible that a
small percentage of such transitional forms should not have been preserved.
This, of course, is especially the case as regards the marine Ichthyosauria
and Plesiosauria, of which such numbers of remains have been discovered.
Sir William Thomson's great authority has been seen to oppose itself to
"Natural Selection," by limiting, on astronomical and physical grounds, the
duration of life on this planet to about one hundred million years. This
period, it has been contended, is not nearly enough on the one hand for the
evolution of all organic forms by the exclusive action of mere minute,
fortuitous variations; on the other hand, for the deposition of all the
strata which must have been deposited, if minute fortuitous variation was
the manner of successive specific manifestation.
Again, the geographical distribution of existing animals has been seen to
present difficulties which, though not themselves insurmountable, yet have
a certain weight when taken in conjunction with all the other objections.
The facts of homology, serial, bilateral and vertical, have also been
passed in review. Such facts, it has been contended, are not explicable
without admitting the action of what may most conveniently be spoken of as
an _internal_ power, the existence of which is supported by facts not only
of comparative anatomy but of teratology and pathology also. "Natural
Selection" also has been shown to be impotent to explain these phenomena,
while the existence of such an internal power of homologous evolution
diminishes the _a priori_ improbability of an analogous law of specific
origination.
All these various considerations have been supplemented by an endeavour to
show the utter inadequacy of Mr. Darwin's theory with regard to the higher
psychical phenomena of man (especially the evolution of moral conceptions),
and with regard to the evolution of individual organisms by the action{225}
of Pangenesis. And it was implied that if Mr. Darwin's latter hypothesis
can be shown to be untenable, an antecedent doubt is thus thrown upon his
other conception, namely, the theory of "Natural Selection."
A cumulative argument thus arises against the prevalent action of "Natural
Selection," which, to the mind of the Author, is conclusive. As before
observed, he was not originally disposed to reject Mr. Darwin's fascinating
theory. Reiterate endeavours to solve its difficulties have, however, had
the effect of convincing him that that theory as the one or as the leading
explanation of the successive evolution and manifestation of specific
forms, is untenable. At the same time he admits fully that "Natural
Selection" acts and must act, and that it plays in the organic world a
certain though a secondary and subordinate part.
The one _modus operandi_ yet suggested having been found insufficient, the
question arises, Can another be substituted in its place? If not, can
anything that is positive, and if anything, what, be said as to the
question of specific origination?
Now, in the first place, it is of course axiomatic that the laws which
conditioned the evolution of extinct and of existing species are of as much
efficacy at this moment as at any preceding period, that they _tend_ to the
manifestation of new forms as much now as ever before. It by no means
necessarily follows, however, that this tendency is actually being carried
into effect, and that new species of the higher animals and plants are
actually now produced. They may be so or they may not, according as
existing circumstances favour, or conflict with, the action of those laws.
It is possible that lowly organized creatures may be continually evolved at
the present day, the requisite conditions being more or less easily
supplied. There is, however, no similar evidence at present as to higher
forms; while, as we have seen in Chapter VII., there are _a priori_
considerations which militate against their being similarly evolved. {226}
The presence of wild varieties and the difficulty which often exists in the
determination of species are sometimes adduced as arguments that high forms
are now in process of evolution. These facts, however, do not necessarily
prove more than that some species possess a greater variability than
others, and (what is indeed unquestionable) that species have often been
unduly multiplied by geologists and botanists. It may be, for example, that
Wagner was right, and that all the American monkeys of the genus cebus may
be reduced to a single species or to two.
With regard to the lower organisms, and supposing views recently advanced
to become fully established, there is no reason to think that the forms
said to be evolved were new species, but rather reappearances of definite
kinds which had appeared before and will appear again under the same
conditions. In the same way, with higher forms similar conditions must
educe similar results, but here practically similar conditions can rarely
obtain because of the large part which "descent" and "inheritance" always
play in such highly organized forms.
Still it is conceivable that different combinations at different times may
have occasionally the same outcome just as the multiplications of different
numbers may have severally the same result.
There are reasons, however, for thinking it possible that the human race is
a witness of an exceptionally unchanging and stable condition of things, if
the calculations of Mr. Croll are valid as to how far variations in the
eccentricity in the earth's orbit together with the precession of the
equinoxes have produced changes in climate. Mr. Wallace has pointed
out[229] that the last 60,000 years having been exceptionally unchanging as
regards these conditions, specific evolution may have been {227}
exceptionally rare. It becomes then possible to suppose that for a similar
period stimuli to change in the manifestation of animal forms may have been
exceptionally few and feeble,--that is, if the conditions of the earth's
orbit have been as exceptional as stated. However, even if new species are
actually now being evolved as actively as ever, or if they have been so
quite recently, no conflict thence necessarily arises with the view here
advocated. For it by no means follows that if some examples of new species
have recently been suddenly produced from individuals of antecedent
species, we ought to be able to put our fingers on such cases; as Mr.
Murphy well observes[230] in a passage before quoted, "If a species were to
come suddenly into being in the wild state, as the Ancon sheep did under
domestication, how could we ascertain the fact? If the first of a
newly-born species were found, the fact of its discovery would tell nothing
about its origin. Naturalists would register it as a very rare species,
having been only once met with, but they would have no means of knowing
whether it were the first or the last of its race."
But are there any grounds for thinking that in the genesis of species an
_internal_ force or tendency interferes, co-operates with and controls the
action of external conditions?
It is here contended that there are such grounds, and that though
inheritance, reversion, atavism, Natural Selection, &c., play a part not
unimportant, yet that such an internal power is a great, perhaps the main,
determining agent.
It will, however, be replied that such an entity is no _vera causa_; that
if the conception is accepted, it is no real explanation; and that it is
merely a roundabout way of saying that the facts are as they are, while the
cause remains unknown. To this it may be rejoined that for all who believe
in the existence of the abstraction "force" at all, other than will, {228}
this conception of an internal force must be accepted and located
somewhere--cannot be eliminated altogether; and that therefore it may as
reasonably be accepted in this mode as in any other.
It was urged at the end of the third chapter that it is congruous to credit
mineral species with an internal power or force. By such a power it may be
conceived that crystals not only assume their external symmetry, but even
repair it when injured. Ultimate chemical elements must also be conceived
as possessing an innate tendency to form certain unions, and to cohere in
stable aggregations. This was considered towards the end of Chapter VIII.
Turning to the organic world, even on the hypothesis of Mr. Herbert Spencer
or that of Mr. Darwin, it is impossible to escape the conception of innate
internal forces. With regard to the physiological units of the former, Mr.
Spencer himself, as we have seen, distinctly attributes to them "an
_innate_ tendency" to evolve the parent form from which they sprang. With
regard to the gemmules of Mr. Darwin, we have seen, in Chapter X., with how
many innate powers, tendencies, and capabilities they must each be
severally endowed, to reproduce their kind, to evolve complex organisms or
cells, to exercise germinative affinity, &c.
If then (as was before said at the end of Chapter VIII.) such innate powers
must be attributed to chemical atoms, to mineral species, to gemmules, and
to physiological units, it is only reasonable to attribute such to each
individual organism.
The conception of such internal and latent capabilities is somewhat like
that of Mr. Galton, before mentioned, according to which the organic world
consists of entities, each of which is, as it were, a spheroid with many
facets on its surface, upon one of which it reposes in stable equilibrium.
When by the accumulated action of incident forces this equilibrium is {229}
disturbed, the spheroid is supposed to turn over until it settles on an
adjacent facet once more in stable equilibrium.
The internal tendency of an organism to certain considerable and definite
changes would correspond to the facets on the surface of the spheroid.
It may be objected that we have no knowledge as to how terrestrial,
cosmical and other forces can affect organisms so as to stimulate and
evolve these latent, merely potential forms. But we have had evidence that
such mysterious agencies _do_ affect organisms in ways as yet inexplicable,
in the very remarkable effects of geographical conditions which were
detailed in the third chapter.
It is quite conceivable that the material organic world may be so
constituted that the simultaneous action upon it of all known forces,
mechanical, physical, chemical, magnetic, terrestrial, and cosmical,
together with other as yet unknown forces which probably exist, may result
in changes which are harmonious and symmetrical, just as the internal
nature of vibrating plates causes particles of sand scattered over them to
assume definite and symmetrical figures when made to oscillate in different
ways by the bow of a violin being drawn along their edges. The results of
these combined internal powers and external influences might be represented
under the symbol of complex series of vibrations (analogous to those of
sound or light) forming a most complex harmony or a display of most varied
colours. In such a way the reparation of local injuries might be symbolized
as a filling up and completion of an interrupted rhythm. Thus also
monstrous aberrations from typical structure might correspond to a discord,
and sterility from crossing be compared with the darkness resulting from
the interference of waves of light.
Such symbolism will harmonize with the peculiar reproduction, before
mentioned, of heads in the body of certain annelids, with the facts of
serial homology, as well as those of bilateral and vertical symmetry. {230}
Also, as the atoms of a resonant body may be made to give out sound by the
juxtaposition of a vibrating tuning-fork, so it is conceivable that the
physiological units of a living organism may be so influenced by
surrounding conditions (organic and other) that the accumulation of these
conditions may upset the previous rhythm of such units, producing
modifications in them--a fresh chord in the harmony of nature--a new
species!
But it may be again objected that to say that species arise by the help of
an innate power possessed by organisms is no explanation, but is a
reproduction of the absurdity, _l'opium endormit parcequ'il a une vertu
soporifique_. It is contended, however, that this objection does not apply,
even if it be conceded that there is that force in Molière's ridicule which
is generally attributed to it.[231] Much, however, might be said in
opposition to more than one of that brilliant dramatist's smart
philosophical epigrams, just as to the theological ones of Voltaire, or to
the biological one of that other Frenchman who for a time discredited a
cranial skeletal theory by the phrase "Vertèbre pensante."[232]
In fact, however, it is a real explanation of how a man lives to say that
he lives independently, on his own income, instead of being supported by
his relatives and friends. In the same way, there is fully as real a
distinction between the production of new specific manifestations entirely
_ab externo_, and by the production of the same through an innate force and
tendency, the determination of which into action is occasioned by {231}
external circumstances.
To say that organisms possess this innate power, and that by it new species
are from time to time produced, is by no means a mere assertion that they
_are_ produced, and in an unknown mode. It is the negation of that view
which deems external forces alone sufficient, and at the same time the
assertion of something positive, to be arrived at by the process of
_reductio ad absurdum_.
All physical explanations result ultimately in such conceptions of innate
power, or else in that of will force. The far-famed explanation of the
celestial motions ends in the conception that every particle of matter has
the innate power of attracting every other particle directly as the mass,
and inversely as the square of the distance.
We are logically driven to this positive conception if we do not accept the
view that there is no force but volition, and that all phenomena whatever
are the immediate results of the action of intelligent and self-conscious
will.
We have seen that the notion of sudden changes--saltatory actions in
nature--has received countenance from Professor Huxley.[233] We must
conceive that these jumps are orderly, and according to law, inasmuch as
the whole cosmos is such. Such orderly evolution harmonizes with a
teleology derived, not indeed from external nature directly, but from the
mind of man. On this point, however, more will be said in the next chapter.
But, once more, if new species are not manifested by the action of external
conditions upon minute indefinite individual differences, in what precise
way may we conceive that manifestation to have taken place?
Are new species now evolving, as they have been from time to time evolved?
If so, in what way and by what conceivable means?
{232}
In the first place, they must be produced by natural action in pre-existing
material, or by supernatural action.
For reasons to be given in the next chapter, the second hypothesis need not
be considered.
If, then, new species are and have been evolved from pre-existing material,
must that material have been organic or inorganic?
As before said, additional arguments have lately been brought forward to
show that individual organisms _do_ arise from a basis of _in_-organic
material only. As, however, this at the most appears to be the case, if at
all, only with the lowest and most minute organisms exclusively, the
process cannot be observed, though it may perhaps be fairly inferred.
We may therefore, if for no other reason, dismiss the notion that highly
organized animals and plants can be suddenly or gradually built up by any
combination of physical forces and natural powers acting externally and
internally upon and in merely inorganic material as a base.
But the question is, how have the highest kinds of animals and plants
arisen? It seems impossible that they can have appeared otherwise than by
the agency of antecedent organisms not greatly different from them.
A multitude of facts, ever increasing in number and importance, all point
to such a mode of specific manifestation.
One very good example has been adduced by Professor Flower in the
introductory lecture of his first Hunterian Course.[234] It is the
reduction in size, to a greater or less degree, of the second and third
digits of the foot in Australian marsupials, and this, in spite of the very
different form and function of the foot in different groups of those
animals.
A similarly significant evidence of relationship is afforded by processes
of the zygomatic region of the skull in certain edentates existing and
extinct.
{233}
Again, the relation between existing and recent faunas of the different
regions of the world, and the predominating (though by no means exclusive)
march of organization, from the more general to the more special, point in
the same direction.
Almost all the facts brought forward by the patient industry of Mr. Darwin
in support of his theory of "Natural Selection," are of course available as
evidence in favour of the agency of pre-existing and similar animals in
specific evolution.
Now the new forms must be produced by changes taking place in organisms in,
after or before their birth, either in their embryonic, or towards or in
their adult, condition.
Examples of strange births are sufficiently common, and they may arise
either from direct embryonic modifications or apparently from some obscure
change in the parental action. To the former category belong the hosts of
instances of malformation through arrest of development, and perhaps
generally monstrosities of some sort are the result of such affections of
the embryo. To the second category belong all cases of hybridism, of cross
breed, and in all probability the new varieties and forms, such as the
memorable one of the black-shouldered peacock. In all these cases we do not
have abortions or monstrosities, but more or less harmonious forms often of
great functional activity, endowed with marked viability and generative
prepotency, except in the case of hybrids, when we often find even a more
marked generative impotency.
It seems probable therefore that new species may arise from some
constitutional affection of parental forms--an affection mainly, if not
exclusively, of their generative system. Mr. Darwin has carefully
collected[235] numerous instances to show how excessively sensitive to
various influences this system is. He says:[236] "Sterility is independent
of general health, and is often accompanied by excess of size, or {234}
great luxuriance," and, "No one can tell, till he tries; whether any
particular animal will breed under confinement, or any exotic plant seed
freely under culture." Again, "When a new character arises, whatever its
nature may be, it generally tends to be inherited, at least in a temporary
and sometimes in a most persistent manner."[237] Yet the obscure action of
conditions will alter characters long inherited, as the grandchildren of
Aylesbury ducks, removed to a distant part of England, completely lost
their early habit of incubation, and hatched their eggs at the same time
with the common ducks of the same place.[238]
Mr. Darwin quotes Mr. Bartlett as saying: "It is remarkable that lions
breed more freely in travelling collections than in the zoological gardens;
probably the constant excitement and irritation produced by moving from
place to place, or change of air, may have considerable influence in the
matter."[239]
Mr. Darwin also says: "There is reason to believe that insects are affected
by confinement like the higher animals," and he gives examples.[240]
Again, he gives examples of change of plumage in the linnet, bunting,
oriole, and other birds, and of the temporary modification of the horns of
a male deer during a voyage.[241]
Finally, he adds that these changes cannot be attributed to loss of health
or vigour, "when we reflect how healthy, long-lived, and vigorous many
animals are under captivity, such as parrots, and hawks when used for
hawking, chetahs when used for hunting, and elephants. The reproductive
organs themselves are not diseased; and the diseases from which animals in
menageries usually perish, are not those which in any way affect their
fertility. No domestic animal is more subject to disease than the sheep,
yet it is remarkably prolific.... It would appear that any change in {235}
the habits of life, whatever these habits may be, if great enough, tends to
affect in an inexplicable manner the powers of reproduction."
Such, then, is the singular sensitiveness of the generative system.
As to the means by which that system is affected, we see that a variety of
conditions affect it; but as to the modes in which they act upon it, we
have as yet little if any clue.
We have also seen the singular effects (in tailed Lepidoptera, &c.) of
causes connected with geographical distribution, the mode of action of
which is as yet quite inexplicable; and we have also seen the innate
tendency which there appears to be in certain groups (birds of paradise,
&c.) to develop peculiarities of a special kind.
It is, to say the least, probable that other influences exist, terrestrial
and cosmical, as yet un-noted. The gradually accumulating or diversely
combining actions of all these on highly sensitive structures, which are
themselves possessed of internal responsive powers and tendencies, may well
result in occasional repeated productions of forms harmonious and vigorous,
and differing from the parental forms in proportion to the result of the
combining or conflicting action of all external and internal influences.
If, in the past history of this planet, more causes ever intervened, or
intervened more energetically than at present, we might _a priori_ expect a
richer and more various evolution of forms more radically differing than
any which could be produced under conditions of more perfect equilibrium.
At the same time, if it be true that the last few thousand years have been
a period of remarkable and exceptional uniformity as regards this planet's
astronomical relations, there are then some grounds for thinking that
organic evolution may have been exceptionally depressed during the same
epoch.
Now, as to the fact that sudden changes and sudden developments have {236}
occurred, and as to the probability that such changes are likely to occur,
evidence was given in Chapter IV.
In Chapter V. we also saw that minerals become modified suddenly and
considerably by the action of incident forces--as, _e.g._, the production
of hexagonal tabular crystals of carbonate of copper by sulphuric acid, and
of long rectangular prisms by ammonia, &c.
We have thus a certain antecedent probability that if changes are produced
in specific manifestation through incident forces, these changes will be
sensible and considerable, not minute and infinitesimal.
Consequently, it is probable that new species have appeared from time to
time with comparative suddenness, and that they still continue so to arise
if all the conditions necessary for specific evolution now obtain.
This probability will be increased if the observations of Dr. Bastian are
confirmed by future investigation. According to his report, when the
requisite conditions were supplied, the transformations which appeared to
take place (from very low to higher organisms) were sudden, definite, and
complete.
Therefore, if this is so, there must probably exist in higher forms a
similar tendency to such change. That tendency may indeed be long
suppressed, and ultimately modified by the action of heredity--an action
which would increase in force with the increase in the perfection and
complexity of the organism affected. Still we might expect that such
changes as do take place would be also sudden, definite, and complete.
Moreover, as the same causes produce the same effects, several individual
parent forms must often have been similarly and simultaneously affected.
That they should be so affected--at least that several similarly modified
individuals should simultaneously arise--has been seen to be a generally
necessary circumstance for the permanent duration of such new
modifications.
It is also conceivable that such new forms may be endowed with {237}
excessive constitutional strength and viability, and with generative
prepotency, as was the case with the black-shouldered peacock in Sir J.
Trevelyan's flock. This flock was entirely composed of the common kind, and
yet the new form rapidly developed itself "_to the extinction of the
previously existing breed_."[242]
Indeed, the notion accepted by both Mr. Darwin and Mr. Herbert Spencer, and
which is plainly the fact (namely, that changes of conditions and incident
forces, within limits, augment the viability and fertility of individuals),
harmonizes well with the suggested possibility as to an augmented viability
and prepotency in new organic forms evolved by peculiar consentaneous
actions of conditions and forces, both external and internal.
The remarkable series of changes noted by Dr. Bastian were certainly not
produced by external incident forces _only_, but by these acting on a
peculiar _materia_, having special properties and powers. Therefore, the
changes were induced by the consentaneous action of internal and external
forces.[243] In the same way then, we may expect changes in higher forms to
be evolved by similar united action of internal and external forces.
One other point may here be alluded to. When the remarkable way in which
structure and function simultaneously change, is borne in mind; when those
numerous instances in which nature has supplied similar wants by similar
means, as detailed in Chapter III., are remembered; when also all the
wonderful contrivances of orchids, of mimicry, and the strange complexity
of certain instinctive actions are considered: then the conviction forces
itself on many minds that the organic world is the expression of an
intelligence of some kind. This view has been well advocated by Mr. Joseph
John Murphy, in his recent work so often here referred to.
{238}
This intelligence, however, is evidently not altogether such as ours, or
else has other ends in view than those most obvious to us. For the end is
often attained in singularly roundabout ways, or with a prodigality of
means which seems out of all proportion with the result: not with the
simple action directed to one end which generally marks human activity.
Organic nature then speaks clearly to many minds of the action of an
intelligence resulting, on the whole and in the main, in order, harmony,
and beauty, yet of an intelligence the ways of which are not such as ours.
This view of evolution harmonizes well with Theistic conceptions; not, of
course, that this harmony is brought forward as an argument in its favour
generally, but it will have weight with those who are convinced that Theism
reposes upon solid grounds of reason as _the_ rational view of the
universe. To such it may be observed that, thus conceived, the Divine
action has that slight amount of resemblance to, and that wide amount of
divergence from what human action would be, which might be expected _a
priori_--might be expected, that is, from a Being whose nature and aims are
utterly beyond our power to imagine, however faintly, but whose truth and
goodness are the fountain and source of our own perceptions of such
qualities.
The view of evolution maintained in this work, though arrived at in
complete independence, yet seems to agree in many respects with the views
advocated by Professor Owen in the last volume of his "Anatomy of
Vertebrates," under the term "derivation." He says:[244] "Derivation holds
that every species changes in time, by virtue of inherent tendencies
thereto. 'Natural Selection' holds that no such change can take place
without the influence of altered external circumstances.[245] {239}
'Derivation' sees among the effects of the innate tendency to change
irrespective of altered circumstances, a manifestation of creative power in
the variety and beauty of the results; and, in the ultimate forthcoming of
a being susceptible of appreciating such beauty, evidence of the
pre-ordaining of such relation of power to the appreciation. 'Natural
Selection' acknowledges that if ornament or beauty, in itself, should be a
purpose in creation, it would be absolutely fatal to it as a hypothesis."
"'Natural Selection' sees grandeur in the view of life, with its several
powers, having been originally breathed by the Creator into a few forms or
into one. 'Derivation' sees therein a narrow invocation of a special
miracle and an unworthy limitation of creative power, the grandeur of which
is manifested daily, hourly, in calling into life many forms, by conversion
of physical and chemical into vital modes of force, under as many
diversified conditions of the requisite elements to be so combined."
The view propounded in this work allows, however, a greater and more
important part to the share of external influences, it being believed by
the Author, however, that these external influences equally with the
internal ones are the results of one harmonious action underlying the whole
of nature, organic and inorganic, cosmical, physical, chemical,
terrestrial, vital, and social.
According to this view, an internal law presides over the actions of every
part of every individual, and of every organism as a unit, and of the
entire organic world as a whole. It is believed that this conception of an
internal innate force will ever remain necessary, however much its
subordinate processes and actions may become explicable:
That by such a force, from time to time, new species are manifested by
ordinary generation just as _Pavo nigripennis_ appeared suddenly, these new
forms not being monstrosities but harmonious self-consistent wholes. That
thus, as specific distinctness is manifested by obscure sexual {240}
conditions, so in obscure sexual modifications specific distinctions arise.
That these "jumps" are considerable in comparison with the minute
variations of "Natural Selection"--are in fact sensible steps, such as
discriminate species from species.
That the latent tendency which exists to these sudden evolutions is
determined to action by the stimulus of external conditions.
That "Natural Selection" rigorously destroys monstrosities, and abortive
and feeble attempts at the performance of the evolutionary process.
That "Natural Selection" removes the antecedent species rapidly when the
new one evolved is more in harmony with surrounding conditions.
That "Natural Selection" favours and develops useful variations, though it
is impotent to originate them or to erect the physiological barrier which
seems to exist between species.
By some such conception as this, the difficulties here enumerated, which
beset the theory of "Natural Selection" pure and simple, are to be got
over.
Thus, for example, the difficulties discussed in the first chapter--namely,
those as to the origins and first beginnings of certain structures--are
completely evaded.
Again, as to the independent origin of closely similar structures, such as
the eyes of the Vertebrata and cuttle-fishes, the difficulty is removed if
we may adopt the conception of an innate force similarly directed in each
case, and assisted by favourable external conditions.
Specific stability, limitation to variability, and the facts of reversion,
all harmonize with the view here put forward. The same may be said with
regard to the significant facts of homology, and of organic symmetry; and
our consideration of the hypothesis of Pangenesis in Chapter X., has seemed
to result in a view as to innate powers which accords well with what is
here advocated. [Page 241]
The evolutionary hypothesis here advocated also serves to explain all those
remarkable facts which were stated in the first chapter to be explicable by
the theory of Natural Selection, namely, the relation of existing to recent
faunas and floras; the phenomena of homology and of rudimentary structures;
also the processes gone through in development; and lastly, the wonderful
facts of mimicry.
Finally, the view adopted is the synthesis of many distinct and, at first
sight, conflicting conceptions, each of which contains elements of truth,
and all of which it appears to be able more or less to harmonize.
Thus it has been seen that "Natural Selection" is accepted. It acts and
must act, though alone it does not appear capable of fulfilling the task
assigned to it by Mr. Darwin.
Pangenesis has probably also much truth in it, and has certainly afforded
valuable and pregnant suggestions, but unaided and alone it seems
inadequate to explain the evolution of the individual organism.
Those three conceptions of the organic world which may be spoken of as the
teleological, the typical, and the transmutationist, have often been
regarded as mutually antagonistic and conflicting.
The genesis of species as here conceived, however, accepts, locates, and
harmonizes all the three.
Teleology concerns the ends for which organisms were designed. The
recognition, therefore, that their formation took place by an evolution not
fortuitous, in no way invalidates the acknowledgment of their final causes
if on other grounds there are reasons for believing that such final causes
exist.
Conformity to type, or the creation of species according to certain "divine
ideas," is in no way interfered with by such a process of evolution as is
here advocated. Such "divine ideas" must be accepted or declined upon quite
other grounds than the mode of their realization, and of their
manifestation in the world of sensible phenomena. [Page 242]
Transmutationism (an old name for the evolutionary hypothesis), which was
conceived at one time to be the very antithesis to the two preceding
conceptions, harmonizes well with them if the evolution be conceived to be
orderly and designed. It will in the next chapter be shown to be completely
in harmony with conceptions, upon the acceptance of which "final causes"
and "divine ideal archetypes" alike depend.
Thus then, if the cumulative argument put forward in this book is valid, we
must admit the insufficiency of Natural Selection both on account of the
residuary phenomena it fails to explain, and on account of certain other
phenomena which seem actually to conflict with that theory. We have seen
that though the laws of nature are constant, yet some of the conditions
which determine specific change may be exceptionally absent at the present
epoch of the world's history; also that it is not only possible, but highly
probable, that an internal power or tendency is an important if not the
main agent in evoking the manifestation of new species on the scene of
realized existence, and that in any case, from the facts of homology,
innate internal powers to the full as mysterious must anyhow be accepted,
whether they act in specific origination or not. Besides all this, we have
seen that it is probable that the action of this innate power is
stimulated, evoked, and determined by external conditions, and also that
the same external conditions, in the shape of "Natural Selection," play an
important part in the evolutionary process: and finally, it has been
affirmed that the view here advocated, while it is supported by the facts
on which Darwinism rests, is not open to the objections and difficulties
which oppose themselves to the reception of "Natural Selection," as the
exclusive or even as the main agent in the successive and orderly evolution
of organic forms in the _genesis of species_. [Page 243]
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