continually produced. The rule is probably without exception. No
chick, or child, is in all respects and particulars the counterpart of
its brother and sister; and in such differences we have 'variety'
incipient. No naturalist could tell how far this variation could be
carried; but the great mass of them held that never, by any amount of
internal or external change, nor by the mixture of both, could the
offspring of the same progenitor so far deviate from each other as to
constitute different species. The function of the experimental
philosopher is to combine the conditions of Nature and to produce her
results; and this was the method of Darwin. [Footnote: The first step
only towards experimental demonstration has been taken. Experiments
now begun might, a couple of centuries hence, furnish data of
incalculable value, which ought to be supplied to the science of the
future.] He made himself acquainted with what could, without any
manner of doubt, be done in the way of producing variation. He
associated himself with pigeon-fanciers--bought, begged, kept, and
observed every breed that he could obtain. Though derived from a
common stock, the diversities of these pigeons were such that 'a score
of them might be chosen which, if shown to an ornithologist, and he
were told that they were wild birds, would certainly be ranked by him
as well-defined species.' The simple principle which guides the
pigeon-fancier, as it does the cattle-breeder, is the selection of
some variety that strikes his fancy, and the propagation of this
variety by inheritance. With his eye still directed to the particular
appearance which he wishes to exaggerate, he selects it as it
reappears in successive broods, and thus adds increment to increment
until an astonishing amount of divergence from the parent type is
effected. The breeder in this case does not produce the elements of
the variation. He simply observes them, and by selection adds them
together until the required result has been obtained. 'No man,' says
Mr. Darwin, 'would ever try to make a fantail till he saw a pigeon
with a tail developed in some slight degree in an unusual manner, or a
pouter until he saw a pigeon with a crop of unusual size.' Thus nature
gives the hint, man acts upon it, and by the law of inheritance
exaggerates the deviation.
Having thus satisfied himself by indubitable facts that the
organisation of an animal or of a plant (for precisely the same
treatment applies to plants). is to some extent plastic, he passes
from variation under domestication to variation under nature. Hitherto
we have dealt with the adding together of small changes by the
conscious selection of man. Can Nature thus select? Mr. Darwin's
answer is, 'Assuredly she can.' The number of living things produced
is far in excess of the number that can be supported; hence at some
period or other of their lives there must be a struggle for existence.
And what is the infallible result? If one organism were a perfect
copy of the other in regard to strength, skill, and agility, external
conditions would decide. But this is not the case. Here we have the
fact of variety offering itself to nature, as in the former instance
it offered itself to man; and those varieties which are least
competent to cope with surrounding conditions will infallibly give way
to those that are most competent. To use a familiar proverb, the
weakest goes to the wall. But the triumphant fraction again breeds to
over-production, transmitting the qualities which secured its
maintenance, but transmitting them in different degrees. The struggle
for food again supervenes, and those to whom the favourable quality
has been transmitted in excess, will triumph as before.
It is easy to see that we have here the addition of increments
favourable to the individual, still more rigorously carried out than
in the case of domestication; for not only are unfavourable specimens
not selected by nature, but they are destroyed. This is what Mr.
Darwin calls 'Natural Selection,' which acts by the preservation and
accumulation of small inherited modifications, each profitable to the
preserved being. With this idea he interpenetrates and leavens the
vast store of facts that he and others have collected. We cannot,
without shutting our eyes through fear or prejudice, fail to see that
Darwin is here dealing, not with imaginary, but with true causes; nor
can we fail to discern what vast modifications may be produced by
natural selection in periods sufficiently long. Each individual
increment may resemble what mathematicians call a 'differential' (a
quantity indefinitely small); but definite and great changes may
obviously be produced by the integration of these infinitesimal
quantities, through practically infinite time.
If Darwin, like Bruno, rejects the notion of creative power, acting
after human fashion, it certainly is not because he is unacquainted
with the numberless exquisite adaptations, on which this notion of a
supernatural Artificer has been founded. His book is a repository of
the most startling facts of this description. Take the marvellous
observation which he cites from Dr. Krueger, where a bucket, with an
aperture serving as a spout, is formed in an orchid. Bees visit the
flower: in eager search of material for their combs, they push each
other into the bucket, the drenched ones escaping from their
involuntary bath by the spout. Here they rub their backs against the
viscid stigma of the flower and obtain glue; then against the pollen
masses, which are thus stuck to the back of the bee and carried away.
'When the bee, so provided, flies to another flower, or to the same
flower a second time, and is pushed by its comrades into the bucket,
and then crawls out by the passage, the pollen-mass upon its back
necessarily comes first into contact with the viscid stigma,' which
takes up the pollen; and this is how that orchid is fertilised. Or
take this other case of the Catasetum 'Bees visit these flowers in
order to gnaw the labellum; in doing this they inevitably touch a
long, tapering, sensitive projection. This, when touched, transmits a
sensation or vibration to a certain membrane, which is instantly
ruptured, setting free a spring, by which the pollen-mass is shot
forth like an arrow in the right direction, and adheres by its viscid
extremity to the back of the bee.' In this way the fertilising pollen
is spread abroad.
It is the mind thus stored with the choicest materials of the
teleologist that rejects teleology, seeking to refer these wonders to
natural causes. They illustrate, according to him, the method of
nature, not the 'technic' of a manlike Artificer. The beauty of
flowers is due to natural selection. Those that distinguish
themselves by vividly contrasting colours from the surrounding green
leaves are most readily seen, most frequently visited by insects, most
often fertilised, and hence most favoured by natural selection.
Coloured berries also readily attract the attention of birds and
beasts, which feed upon them, spread their manured seeds abroad, thus
giving trees and shrubs possessing such berries a greater chance in
the struggle for existence.
With profound analytic and synthetic skill, Mr. Darwin investigates
the cell-making instinct of the hive-bee. His method of dealing with
it is representative. He falls back from the more perfectly to the
less perfectly developed instinct--from the hive-bee to the humble
bee, which uses its own cocoon as a comb, and to classes of bees of
intermediate skill, endeavouring to show how the passage might be
gradually made from the lowest to the highest. The saving of wax is
the most important point in the economy of bees. Twelve to fifteen
pounds of dry sugar are said to be needed for the secretion of a
single pound of wax. The quantities of nectar necessary for the wax
must therefore be vast; and every improvement of constructive instinct
which results in the saving of wax is a direct profit to the insect's
life. The time that would otherwise be devoted to the making of wax,
is devoted to the gathering and storing of honey for winter food. Mr.
Darwin passes from the humble bee with its rude cells, through the
Melipona with its more artistic cells, to the hive-bee with its
astonishing architecture. The bees place themselves at equal
distances apart upon the wax, sweep and excavate equal spheres round
the selected points. The spheres intersect, and the planes of
intersection are built up with thin laminae. Hexagonal cells are thus
formed. This mode of treating such questions is, as I have said,
representative. The expositor habitually retires from the more
perfect and complex, to the less perfect and simple, and carries you
with him through stages of perfecting--adds increment to increment of
infinitesimal change, and in this way gradually breaks down your
reluctance to admit that the exquisite climax of the whole could be a
result of natural selection.
Mr. Darwin shirks no difficulty; and, saturated as the subject was
with his own thought, he must have known, better than his critics, the
weakness as well as the strength of his theory. This of course would
be of little avail were his object a temporary dialectic victory,
instead of the establishment of a truth which he means to be
everlasting. But he takes no pains to disguise the weakness he has
discerned; nay, he takes every pains to bring it into the strongest
light. His vast resources enable him to cope with objections started
by himself and others, so as to leave the final impression upon the
reader's mind that, if they be not completely answered, they certainly
are not fatal. Their negative force being thus destroyed, you are
free to be influenced by the vast positive mass of evidence he is able
to bring before you. This largeness of knowledge, and readiness of
resource, render Mr. Darwin the most terrible of antagonists.
Accomplished naturalists have levelled heavy and sustained criticisms
against him--not always with the view of fairly weighing his theory,
but with the express intention of exposing its weak points only. This
does not irritate him. He treats every objection with a soberness and
thoroughness which even Bishop Butler might be proud to imitate,
surrounding each fact with its appropriate detail, placing it in its
proper relations, and usually giving it a significance which, as long
as it was kept isolated, failed to appear. This is done without a
trace of ill-temper. He moves over the subject with the passionless
strength of a glacier; and the grinding of the rocks is not always
without a counterpart in the logical pulverisation of the objector.
But though in handling this mighty theme all passion has been stilled,
there is an emotion of the intellect, incident to the discernment of
new truth, which often colours and warms the pages of Mr. Darwin.
His success has been great; and this implies not only the solidity of
his work, but the preparedness of the public mind for such a
revelation. On this head, a remark of Agassiz impressed me more than
anything else. Sprung from a race of theologians, this celebrated man
combated to the last the theory of natural selection. One of the many
times I had the pleasure of meeting him in the United States was at
Mr. Winthrop's beautiful residence at Brookline, near Boston. Rising
from luncheon, we all halted as if by common consent, in front of a
window, and continued there a discussion which had been started at
table. The maple was in its autumn glory, and the exquisite beauty of
the scene outside seemed, in my case, to interpenetrate without
disturbance the intellectual action. Earnestly, almost sadly, Agassiz
turned, and said to the gentlemen standing round, 'I confess that I
was not prepared to see this theory received as it has been by the
best intellects of our time. Its success is greater than I could have
thought possible.'
7.
In our day grand generalisations have been reached. The theory of the
origin of species is but one of them. Another, of still wider grasp
and more radical significance, is the doctrine of the Conservation of
Energy, the ultimate philosophical issues of which are as yet but
dimly seen--that doctrine which 'binds nature fast in fate,' to an
extent not hitherto recognised, exacting from every antecedent its
equivalent consequent, from every consequent its equivalent
antecedent, and bringing vital as well as physical phenomena under the
dominion of that law of causal connection which, so far as the human
understanding has yet pierced, asserts itself everywhere in nature.
Long in advance of all definite experiment upon the subject, the
constancy and indestructibility of matter had been affirmed; and all
subsequent experience justified the affirmation. Mayer extended the
attribute of indestructibility to energy, applying it in the first
instance to inorganic, and afterwards with profound insight to organic
nature. [Footnote: Dr. Berthold has shown that Leibnitz had sound views
regarding the conservation of energy in inorganic nature.] The
vegetable world, though drawing all its nutriment from invisible
sources, was proved incompetent to generate anew either matter or
force. Its matter is for the most part transmuted gas; its force
transformed solar force. The animal world was proved to be equally
uncreative, all its motive energies being referred to the combustion
of its food. The activity of each animal, as a whole, was proved to
be the transferred activity of its molecules. The muscles were shown
to be stores of mechanical energy, potential until unlocked by the
nerves, and then resulting in muscular contractions. The speed at
which messages fly to and fro along the nerves was determined by
Helmholtz, and found to be, not, as had been previously supposed,
equal to that of light or electricity, but less than the speed of
sound--less even than that of an eagle.
This was the work of the physicist: then came the conquests of the
comparative anatomist and physiologist, revealing the structure of
every animal, and the function of every organ in the whole biological
series, from the lowest zoophyte up to man. The nervous system had
been made the object of profound and continued study, the wonderful
and, at bottom, entirely mysterious controlling power which it
exercises over the whole organism, physical and mental, being
recognised more and more. Thought could not be kept back from a
subject so profoundly suggestive. Besides the physical life dealt
with by Mr. Darwin, there is a psychical life presenting similar
gradations, and asking equally for a solution. How are the different
grades and orders of Mind to be accounted for? What is the principle
of growth of that mysterious power which on our planet culminates in
Reason? These are questions which, though not thrusting themselves so
forcibly upon the attention of the general public, had not only
occupied many reflecting minds, but had been formally broached by one
of them before the 'Origin of Species' appeared.
With the mass of materials furnished by the physicist and physiologist
in his hands, Mr. Herbert Spencer, twenty years ago, sought to graft
upon this basis a system of psychology; and two years ago a second and
greatly amplified edition of his work appeared. Those who have
occupied themselves with the beautiful experiments of Plateau will
remember that when two spherules of olive-oil suspended in a mixture
of alcohol and water of the same density as the oil, are brought
together, they do not immediately unite. Something like a pellicle
appears to be formed around the drops, the rupture of which is
immediately followed by the coalescence of the globules into one.
There are organisms whose vital actions are almost as purely physical
as the coalescence of such drops of oil. They come into contact and
fuse themselves thus together. From such organisms to others a shade
higher, from these to others a shade higher still, and on through an
ever-ascending series, Mr. Spencer conducts his argument. There are
two obvious factors to be here taken into account--the creature and
the medium in which it lives, or, as it is often expressed, the
organism and its environment. Mr. Spencer's fundamental principle is,
that between these two factors there is incessant interaction. The
organism is played upon by the environment, and is modified to meet
the requirements of the environment. Life he defines to be 'a
continuous adjustment of internal relations to external relations.
In the lowest organisms we have a kind of tactual sense diffused over
the entire body; then, through impressions from without and their
corresponding adjustments, special portions of the surface become more
responsive to stimuli than others. The senses are nascent, the basis
of all of them being that simple tactual sense which the sage
Democritus recognised 2,300 years ago as their common progenitor. The
action of light, in the first instance, appears to be a mere
disturbance of the chemical processes in the animal organism, similar
to that which occurs in the leaves of plants. By degrees the action
becomes localised in a few pigment-cells, more sensitive to light than
the surrounding tissue. The eye is incipient. At first it is merely
capable of revealing differences of light and shade produced by bodies
close at hand. Followed, as the interception of the light commonly
is, by the contact of the closely adjacent opaque body, sight in this
condition becomes a kind of 'anticipatory touch.' The adjustment
continues; a slight bulging out of the epidermis over the
pigment-granules supervenes. A lens is incipient, and, through the
operation of infinite adjustments, at length reaches the perfection
that it displays in the hawk and eagle. So of the other senses; they
are special differentiations of a tissue which was originally vaguely
sensitive all over.
With the development of the senses, the adjustments between the
organism and its environment gradually extend in space, a
multiplication of experiences and a corresponding modification of
conduct being the result.
The adjustments also extend in time, covering continually greater
intervals. Along with this extension in space and time the
adjustments also increase in speciality and complexity, passing
through the various grades of brute life, and prolonging themselves
into the domain of reason. Very striking are Mr. Spencer's remarks
regarding the influence of the sense of touch upon the development of
intelligence. This is, so to say, the mother-tongue of all the
senses, into which they must be translated to be of service to the
organism. Hence its importance. The parrot is the most intelligent
of birds, and its tactual power is also greatest. From this sense it
gets knowledge, unattainable by birds which cannot employ their feet
as hands. The elephant is the most sagacious of quadrupeds--its
tactual range and skill, and the consequent multiplication of
experiences, which it owes to its wonderfully adaptable trunk, being
the basis of its sagacity. Feline animals, for a similar cause, are
more sagacious than hoofed animals,--atonement being to some extent
made in the case of the horse, by the possession of sensitive
prehensile lips. In the Primates the evolution of intellect and the
evolution of tactual appendages go hand in hand. In the most
intelligent anthropoid apes we find the tactual range and delicacy
greatly augmented, new avenues of knowledge being thus opened to the
animal. Alan crowns the edifice here, not only in virtue of his own
manipulatory power, but through the enormous extension of his range of
experience, by the invention of instruments of precision, which serve
as supplemental senses and supplemental limbs. The reciprocal action
of these is finely described and illustrated That chastened
intellectual emotion to which I have referred in connection with Mr.
Darwin, is not absent in Mr. Spencer. His illustrations possess at
times exceeding vividness and force; and from his style on such
occasions it is to be inferred, that the ganglia of this Apostle of
the Understanding are sometimes the seat of a nascent poetic thrill.
It is a fact of supreme importance that actions, the performance of
which at first requires even painful effort and deliberation, may, by
habit, be rendered automatic. Witness the slow learning of its
letters by a child, and the subsequent facility of reading in a man,
when each group of letters which forms a word is instantly, and
without effort, fused to a single perception. Instance the
billiard-player, whose muscles of hand and eye, when he reaches the
perfection of his art, are unconsciously co-ordinated. Instance the
musician, who, by practice, is enabled to fuse a multitude of
arrangements, auditory, tactual, and muscular, into a process of
automatic manipulation. Combining such facts with the doctrine of
hereditary transmission, we reach a theory of Instinct. A chick,
after coming out of the egg, balances itself correctly, runs about,
picks up food, thus snowing that it possesses a power of directing its
movements to definite ends. How did the chick learn this very complex
co-ordination of eyes, muscles, and beak? It has not been
individually taught; its personal experience is nit; but it has the
benefit of ancestral experience. In its inherited organisation are
registered the powers which it displays at birth. So also as regards
the instinct of the hive-bee, already referred to. The distance at
which the insects stand apart when they sweep their hemispheres and
build their cells is 'organically remembered.' Man also carries with
him the physical texture of his ancestry, as well as the inherited
intellect bound up with it. The defects of intelligence during
infancy and youth are probably less due to a lack of individual
experience, than to the fact that in early life the cerebral
organisation is still incomplete. The period necessary for completion
varies with the race, and with the individual. As a round shot
outstrips the rifled bolt on quitting the muzzle of the gun, so the
lower race, in childhood, may outstrip the higher. But the higher
eventually overtakes the lower, and surpasses it in range. As regards
individuals, we do not always find the precocity of youth prolonged to
mental power in maturity; while the dulness of boyhood is sometimes
strikingly contrasted with the intellectual energy of after years.
Newton, when a boy, was weakly, and he showed no particular aptitude
at school; but in his eighteenth year he went to Cambridge, and soon
afterwards astonished his teachers by his power of dealing with
geometrical problems. During his quiet youth his brain was slowly
preparing itself to be the organ of those energies which he
subsequently displayed.
By myriad blows (to use a Lucretian phrase) the image and
superscription of the external world are stamped as states of
consciousness upon the organism, the depth of the impression depending
on the number of the blows. When two or more phenomena occur in the
environment invariably together, they are stamped to the same depth or
to the same relief, and indissolubly connected. And here we come to
the threshold of a great question. Seeing that he could in no way rid
himself of the consciousness of Space and Time, Kant assumed them to
be necessary 'forms of intuition,' the moulds and shapes into which
our intuitions are thrown, belonging to ourselves, and without
objective existence. With unexpected power and success, Mr. Spencer
brings the hereditary experience theory, as he holds it, to bear upon
this question. 'If there exist certain external relations which are
experienced by all organisms at all instants of their waking
lives--relations which are absolutely constant and universal--there
will be established answering internal relations, that are absolutely
constant and universal. Such relations we have in those of Space and
Time. As the substratum of all other relations of the Non-Ego, they
must be responded to by conceptions that are the substrata of all
other relations in the Ego. Being the constant and infinitely
repeated elements of thought, they must become the automatic elements
of thought--the elements of thought which it is impossible to get rid
of--the "forms of intuition."'