It will be readily admitted that of all living writers Mr.
Alfred Russel Wallace is the one the peculiar turn of whose mind
best fits him to write on the subject of natural selection, or
the accumulation of fortunate but accidental variations through
descent and the struggle for existence. His mind in all its
more essential characteristics closely resembles that of the late
Mr. Charles Darwin himself, and it is no doubt due to this fact
that he and Mr. Darwin elaborated their famous theory at the same
time, and independently of one another. I shall have
occasion in the course of the following article to show how
misled and misleading both these distinguished men have been, in
spite of their unquestionable familiarity with the whole range of
animal and vegetable phenomena. I believe it will be more
respectful to both of them to do this in the most out-spoken
way. I believe their work to have been as mischievous as it
has been valuable, and as valuable as it has been mischievous;
and higher, whether praise or blame, I know not how to
give. Nevertheless I would in the outset, and with the
utmost sincerity, admit concerning Messrs. Wallace and Darwin
that neither can be held as the more profound and conscientious
thinker; neither can be put forward as the more ready to
acknowledge obligation to the great writers on evolution who had
preceded him, or to place his own developments in closer and more
conspicuous historical connection with earlier thought upon the
subject; neither is the more ready to welcome criticism and to
state his opponent’s case in the most pointed and telling
way in which it can be put; neither is the more quick to
encourage new truth; neither is the more genial, generous
adversary, or has the profounder horror of anything even
approaching literary or scientific want of candour; both display
the same inimitable power of putting their opinions forward in
the way that shall best ensure their acceptance; both are equally
unrivalled in the tact that tells them when silence will be
golden, and when on the other hand a whole volume of facts may be
advantageously brought forward. Less than the foregoing
tribute both to Messrs. Darwin and Wallace I will not, and more I
cannot pay.
Let us now turn to the most authoritative exponent of
latter-day evolution—I mean to Mr. Wallace, whose work,
entitled “Darwinism,” though it should have been
entitled “Wallaceism,” is still so far Darwinistic
that it develops the teaching of Mr. Darwin in the direction
given to it by Mr. Darwin himself—so far, indeed, as this
can be ascertained at all—and not in that of Lamarck.
Mr. Wallace tells us, on the first page of his preface, that he
has no intention of dealing even in outline with the vast subject
of evolution in general, and has only tried to give such an
account of the theory of natural selection as may facilitate a
clear conception of Darwin’s work. How far he has
succeeded is a point on which opinion will probably be
divided. Those who find Mr. Darwin’s works clear will
also find no difficulty in understanding Mr. Wallace; those, on
the other hand, who find Mr. Darwin puzzling are little likely to
be less puzzled by Mr. Wallace. He continues:—
“The objections now made to Darwin’s theory apply
solely to the particular means by which the change of species has
been brought about, not to the fact of that change.”
But “Darwin’s theory”—as Mr. Wallace
has elsewhere proved that he understands—has no reference
“to the fact of that change”—that is to say, to
the fact that species have been modified in course of descent
from other species. This is no more Mr. Darwin’s
theory than it is the reader’s or my own.
Darwin’s theory is concerned only with “the
particular means by which the change of species has been brought
about”; his contention being that this is mainly due to the
natural survival of those individuals that have happened by some
accident to be born most favourably adapted to their
surroundings, or, in other words, through accumulation in the
common course of nature of the more lucky variations that chance
occasionally purveys. Mr. Wallace’s words, then, in
reality amount to this, that the objections now made to
Darwin’s theory apply solely to Darwin’s theory,
which is all very well as far as it goes, but might have been
more easily apprehended if he had simply said, “There are
several objections now made to Mr. Darwin’s
theory.”
It must be remembered that the passage quoted above occurs on
the first page of a preface dated March 1889, when the writer had
completed his task, and was most fully conversant with his
subject. Nevertheless, it seems indisputable either that he
is still confusing evolution with Mr. Darwin’s theory, or
that he does not know when his sentences have point and when they
have none.
I should perhaps explain to some readers that Mr. Darwin did
not modify the main theory put forward, first by Buffon, to whom
it indisputably belongs, and adopted from him by Erasmus Darwin,
Lamarck, and many other writers in the latter half of the last
century and the earlier years of the present. The early
evolutionists maintained that all existing forms of animal and
vegetable life, including man, were derived in course of descent
with modification from forms resembling the lowest now known.
Mr. Darwin went as far as this, and farther no one can
go. The point at issue between him and his predecessors
involves neither the main fact of evolution, nor yet the
geometrical ratio of increase, and the struggle for existence
consequent thereon. Messrs. Darwin and Wallace have each
thrown invaluable light upon these last two points, but Buffon,
as early as 1756, had made them the keystone of his system.
“The movement of nature,” he then wrote, “turns
on two immovable pivots: one, the illimitable fecundity which she
has given to all species: the other, the innumerable difficulties
which reduce the results of that fecundity.” Erasmus
Darwin and Lamarck followed in the same sense. They thus
admit the survival of the fittest as fully as Mr. Darwin himself,
though they do not make use of this particular expression.
The dispute turns not upon natural selection, which is common to
all writers on evolution, but upon the nature and causes of the
variations that are supposed to be selected from and thus
accumulated. Are these mainly attributable to the inherited
effects of use and disuse, supplemented by occasional sports and
happy accidents? Or are they mainly due to sports and happy
accidents, supplemented by occasional inherited effects of use
and disuse?
The Lamarckian system has all along been maintained by Mr.
Herbert Spencer, who, in his “Principles of Biology,”
published in 1865, showed how impossible it was that accidental
variations should accumulate at all. I am not sure how far
Mr. Spencer would consent to being called a Lamarckian pure and
simple, nor yet how far it is strictly accurate to call him one;
nevertheless, I can see no important difference in the main
positions taken by him and by Lamarck.
The question at issue between the Lamarckians, supported by
Mr. Spencer and a growing band of those who have risen in
rebellion against the Charles-Darwinian system on the one hand,
and Messrs. Darwin and Wallace with the greater number of our
more prominent biologists on the other, involves the very
existence of evolution as a workable theory. For it is
plain that what Nature can be supposed able to do by way of
choice must depend on the supply of the variations from which she
is supposed to choose. She cannot take what is not offered
to her; and so again she cannot be supposed able to accumulate
unless what is gained in one direction in one generation, or
series of generations, is little likely to be lost in those that
presently succeed. Now variations ascribed mainly to use
and disuse can be supposed capable of being accumulated, for use
and disuse are fairly constant for long periods among the
individuals of the same species, and often over large areas;
moreover, conditions of existence involving changes of habit, and
thus of organisation, come for the most part gradually; so that
time is given during which the organism can endeavour to adapt
itself in the requisite respects, instead of being shocked out of
existence by too sudden change. Variations, on the other
hand, that are ascribed to mere chance cannot be supposed as
likely to be accumulated, for chance is notoriously inconstant,
and would not purvey the variations in sufficiently unbroken
succession, or in a sufficient number of individuals, modified
similarly in all the necessary correlations at the same time and
place to admit of their being accumulated. It is vital
therefore to the theory of evolution, as was early pointed out by
the late Professor Fleeming Jenkin and by Mr. Herbert Spencer,
that variations should be supposed to have a definite and
persistent principle underlying them, which shall tend to
engender similar and simultaneous modification, however small, in
the vast majority of individuals composing any species. The
existence of such a principle and its permanence is the only
thing that can be supposed capable of acting as rudder and
compass to the accumulation of variations, and of making it hold
steadily on one course for each species, till eventually many
havens, far remote from one another, are safely reached.
It is obvious that the having fatally impaired the theory of
his predecessors could not warrant Mr. Darwin in claiming, as he
most fatuously did, the theory of evolution. That he is
still generally believed to have been the originator of this
theory is due to the fact that he claimed it, and that a powerful
literary backing at once came forward to support him. It
seems at first sight improbable that those who too zealously
urged his claims were unaware that so much had been written on
the subject, but when we find even Mr. Wallace himself as
profoundly ignorant on this subject as he still either is, or
affects to be, there is no limit assignable to the ignorance or
affected ignorance of the kind of biologists who would write
reviews in leading journals thirty years ago. Mr. Wallace
writes:—
“A few great naturalists, struck by the very slight
difference between many of these species, and the numerous links
that exist between the most different forms of animals and
plants, and also observing that a great many species do vary
considerably in their forms, colours and habits, conceived the
idea that they might be all produced one from the other.
The most eminent of these writers was a great French naturalist,
Lamarck, who published an elaborate work, the Philosophie
Zoologique, in which he endeavoured to prove that all animals
whatever are descended from other species of animals. He
attributed the change of species chiefly to the effect of changes
in the conditions of life—such as climate, food, &c.;
and especially to the desires and efforts of the animals
themselves to improve their condition, leading to a modification
of form or size in certain parts, owing to the well-known
physiological law that all organs are strengthened by constant
use, while they are weakened or even completely lost by disuse .
. .
“The only other important work dealing with the question
was the celebrated ‘Vestiges of Creation,’ published
anonymously, but now acknowledged to have been written by the
late Robert Chambers.”
None are so blind as those who will not see, and it would be
waste of time to argue with the invincible ignorance of one who
thinks Lamarck and Buffon conceived that all species were
produced from one another, more especially as I have already
dealt at some length with the early evolutionists in my work,
“Evolution, Old and New,” first published ten years
ago, and not, so far as I am aware, detected in serious error or
omission. If, however, Mr. Wallace still thinks it safe to
presume so far on the ignorance of his readers as to say that the
only two important works on evolution before Mr. Darwin’s
were Lamarck’s Philosophie Zoologique and the
“Vestiges of Creation,” how fathomable is the
ignorance of the average reviewer likely to have been thirty
years ago, when the “Origin of Species” was first
published? Mr. Darwin claimed evolution as his own
theory. Of course, he would not claim it if he had no right
to it. Then by all means give him the credit of it.
This was the most natural view to take, and it was generally
taken. It was not, moreover, surprising that people failed
to appreciate all the niceties of Mr. Darwin’s
“distinctive feature” which, whether distinctive or
no, was assuredly not distinct, and was never frankly contrasted
with the older view, as it would have been by one who wished it
to be understood and judge upon its merits. It was in
consequence of this omission that people failed to note how fast
and loose Mr. Darwin played with his distinctive feature, and how
readily he dropped it on occasion.
It may be said that the question of what was thought by the
predecessors of Mr. Darwin is, after all, personal, and of no
interest to the general public, comparable to that of the main
issue—whether we are to accept evolution or not.
Granted that Buffon, Erasmus Darwin, and Lamarck bore the burden
and heat of the day before Mr. Charles Darwin was born, they did
not bring people round to their opinion, whereas Mr. Darwin and
Mr. Wallace did, and the public cannot be expected to look beyond
this broad and indisputable fact.
The answer to this is, that the theory which Messrs. Darwin
and Wallace have persuaded the public to accept is demonstrably
false, and that the opponents of evolution are certain in the end
to triumph over it. Paley, in his “Natural
Theology,” long since brought forward far too much evidence
of design in animal organisation to allow of our setting down its
marvels to the accumulations of fortunate accident, undirected by
will, effort and intelligence. Those who examine the main
facts of animal and vegetable organisation without bias will, no
doubt, ere long conclude that all animals and vegetables are
derived ultimately from unicellular organisms, but they will not
less readily perceive that the evolution of species without the
concomitance and direction of mind and effort is as inconceivable
as is the independent creation of every individual species.
The two facts, evolution and design, are equally patent to plain
people. There is no escaping from either. According
to Messrs. Darwin and Wallace, we may have evolution, but are on
no account to have it as mainly due to intelligent effort, guided
by ever higher and higher range of sensations, perceptions, and
ideas. We are to set it down to the shuffling of cards, or
the throwing of dice without the play, and this will never
stand.
According to the older men, cards did indeed count for much,
but play counted for more. They denied the teleology of the
time—that is to say, the teleology that saw all adaptation
to surroundings as part of a plan devised long ages since by a
quasi-anthropomorphic being who schemed everything out much as a
man would do, but on an infinitely vaster scale. This
conception they found repugnant alike to intelligence and
conscience, but, though they do not seem to have perceived it,
they left the door open for a design more true and more
demonstrable than that which they excluded. By making their
variations mainly due to effort and intelligence, they made
organic development run on all-fours with human progress, and
with inventions which we have watched growing up from small
beginnings. They made the development of man from the
amoeba part and parcel of the story that may be read, though on
an infinitely smaller scale, in the development of our most
powerful marine engines from the common kettle, or of our finest
microscopes from the dew-drop.
The development of the steam-engine and the microscope is due
to intelligence and design, which did indeed utilise chance
suggestions, but which improved on these, and directed each step
of their accumulation, though never foreseeing more than a step
or two ahead, and often not so much as this. The fact, as I
have elsewhere urged, that the man who made the first kettle did
not foresee the engines of the Great Eastern, or that he
who first noted the magnifying power of the dew-drop had no
conception of our present microscopes—the very limited
amount, in fact, of design and intelligence that was called into
play at any one point—this does not make us deny that the
steam-engine and microscope owe their development to
design. If each step of the road was designed, the whole
journey was designed, though the particular end was not designed
when the journey was begun. And so is it, according to the
older view of evolution, with the development of those living
organs, or machines, that are born with us, as part of the
perambulating carpenter’s chest we call our bodies.
The older view gives us our design, and gives us our evolution
too. If it refuses to see a quasi-anthropomorphic God
modelling each species from without as a potter models clay, it
gives us God as vivifying and indwelling in all His
creatures—He in them, and they in Him. If it refuses
to see God outside the universe, it equally refuses to see any
part of the universe as outside God. If it makes the
universe the body of God, it also makes God the soul of the
universe. The question at issue, then, between the
Darwinism of Erasmus Darwin and the neo-Darwinism of his
grandson, is not a personal one, nor anything like a personal
one. It not only involves the existence of evolution, but
it affects the view we take of life and things in an endless
variety of most interesting and important ways. It is
imperative, therefore, on those who take any interest in these
matters, to place side by side in the clearest contrast the views
of those who refer the evolution of species mainly to
accumulation of variations that have no other inception than
chance, and of that older school which makes design perceive and
develop still further the goods that chance provides.
But over and above this, which would be in itself sufficient,
the historical mode of studying any question is the only one
which will enable us to comprehend it effectually. The
personal element cannot be eliminated from the consideration of
works written by living persons for living persons. We want
to know who is who—whom we can depend upon to have no other
end than the making things clear to himself and his readers, and
whom we should mistrust as having an ulterior aim on which he is
more intent than on the furthering of our better
understanding. We want to know who is doing his best to
help us, and who is only trying to make us help him, or to
bolster up the system in which his interests are vested.
There is nothing that will throw more light upon these points
than the way in which a man behaves towards those who have worked
in the same field with himself, and, again, than his style.
A man’s style, as Buffon long since said, is the man
himself. By style, I do not, of course, mean grammar or
rhetoric, but that style of which Buffon again said that it is
like happiness, and vient de la douceur de
l’âme. When we find a man concealing worse
than nullity of meaning under sentences that sound plausibly
enough, we should distrust him much as we should a
fellow-traveller whom we caught trying to steal our watch.
We often cannot judge of the truth or falsehood of facts for
ourselves, but we most of us know enough of human nature to be
able to tell a good witness from a bad one.
However this may be, and whatever we may think of judging
systems by the directness or indirectness of those who advance
them, biologists, having committed themselves too rashly, would
have been more than human if they had not shown some pique
towards those who dared to say, first, that the theory of Messrs.
Darwin and Wallace was unworkable; and secondly, that even though
it were workable it would not justify either of them in claiming
evolution. When biologists show pique at all they generally
show a good deal of pique, but pique or no pique, they shunned
Mr. Spencer’s objection above referred to with a
persistency more unanimous and obstinate than I ever remember to
have seen displayed even by professional truth-seekers. I
find no rejoinder to it from Mr. Darwin himself, between 1865
when it was first put forward, and 1882 when Mr. Darwin
died. It has been similarly “ostrichised” by
all the leading apologists of Darwinism, so far at least as I
have been able to observe, and I have followed the matter closely
for many years. Mr. Spencer has repeated and amplified it
in his recent work, “The Factors of Organic
Evolution,” but it still remains without so much as an
attempt at serious answer, for the perfunctory and illusory
remarks of Mr. Wallace at the end of his “Darwinism”
cannot be counted as such. The best proof of its
irresistible weight is that Mr. Darwin, though maintaining
silence in respect to it, retreated from his original position in
the direction that would most obviate Mr. Spencer’s
objection.
Yet this objection has been repeatedly urged by the more
prominent anti-Charles-Darwinian authorities, and there is no
sign that the British public is becoming less rigorous in
requiring people either to reply to objections repeatedly urged
by men of even moderate weight, or to let judgment go by
default. As regards Mr. Darwin’s claim to the theory
of evolution generally, Darwinians are beginning now to perceive
that this cannot be admitted, and either say with some hardihood
that Mr. Darwin never claimed it, or after a few saving clauses
to the effect that this theory refers only to the particular
means by which evolution has been brought about, imply forthwith
thereafter none the less that evolution is Mr. Darwin’s
theory. Mr. Wallace has done this repeatedly in his recent
“Darwinism.” Indeed, I should be by no means
sure that on the first page of his preface, in the passage about
“Darwin’s theory,” which I have already
somewhat severely criticised, he was not intending evolution by
“Darwin’s theory,” if in his preceding
paragraph he had not so clearly shown that he knew evolution to
be a theory of greatly older date than Mr. Darwin’s.
The history of science—well exemplified by that of the
development theory—is the history of eminent men who have
fought against light and have been worsted. The tenacity
with which Darwinians stick to their accumulation of fortuitous
variations is on a par with the like tenacity shown by the
illustrious Cuvier, who did his best to crush evolution
altogether. It always has been thus, and always will be;
nor is it desirable in the interests of Truth herself that it
should be otherwise. Truth is like money—lightly
come, lightly go; and if she cannot hold her own against even
gross misrepresentation, she is herself not worth holding.
Misrepresentation in the long run makes Truth as much as it mars
her; hence our law courts do not think it desirable that pleaders
should speak their bonâ fide opinions, much less
that they should profess to do so. Rather let each side
hoodwink judge and jury as best it can, and let truth flash out
from collision of defence and accusation. When either side
will not collide, it is an axiom of controversy that it desires
to prevent the truth from being elicited.
Let us now note the courses forced upon biologists by the
difficulties of Mr. Darwin’s distinctive feature. Mr.
Darwin and Mr. Wallace, as is well known, brought the feature
forward simultaneously and independently of one another, but Mr.
Wallace always believed in it more firmly than Mr. Darwin
did. Mr. Darwin as a young man did not believe in it.
He wrote before 1889, “Nature, by making habit omnipotent
and its effects hereditary, has fitted the Fuegian for the
climate and productions of his country,” [21] a sentence than which nothing can
coincide more fully with the older view that use and disuse were
the main purveyors of variations, or conflict more fatally with
his own subsequent distinctive feature. Moreover, as I
showed in my last work on evolution, [22] in the peroration to
his “Origin of Species,” he discarded his accidental
variations altogether, and fell back on the older theory, so that
the body of the “Origin of Species” supports one
theory, and the peroration another that differs from it toto
cœlo. Finally, in his later editions, he
retreated indefinitely from his original position, edging always
more and more continually towards the theory of his grandfather
and Lamarck. These facts convince me that he was at no time
a thorough-going Darwinian, but was throughout an unconscious
Lamarckian, though ever anxious to conceal the fact alike from
himself and from his readers.
Not so with Mr. Wallace, who was both more outspoken in the
first instance, and who has persevered along the path of
Wallaceism just as Mr. Darwin with greater sagacity was ever on
the retreat from Darwinism. Mr. Wallace’s profounder
faith led him in the outset to place his theory in fuller
daylight than Mr. Darwin was inclined to do. Mr. Darwin
just waved Lamarck aside, and said as little about him as he
could, while in his earlier editions Erasmus Darwin and Buffon
were not so much as named. Mr. Wallace, on the contrary, at
once raised the Lamarckian spectre, and declared it
exorcised. He said the Lamarckian hypothesis was
“quite unnecessary.” The giraffe did not
“acquire its long neck by desiring to reach the foliage of
the more lofty shrubs, and constantly stretching its neck for
this purpose, but because any varieties which occurred among its
antitypes with a longer neck than usual at once secured a fresh
range of pasture over the same ground as their shorter-necked
companions, and on the first scarcity of food were thus enabled
to outlive them.” [23]
“Which occurred” is evidently “which
happened to occur” by some chance or accident unconnected
with use and disuse. The word “accident” is
never used, but Mr. Wallace must be credited with this instance
of a desire to give his readers a chance of perceiving that
according to his distinctive feature evolution is an affair of
luck, rather than of cunning. Whether his readers actually
did understand this as clearly as Mr. Wallace doubtless desired
that they should, and whether greater development at this point
would not have helped them to fuller apprehension, we need not
now inquire. What was gained in distinctness might have
been lost in distinctiveness, and after all he did technically
put us upon our guard.
Nevertheless he too at a pinch takes refuge in
Lamarckism. In relation to the manner in which the eyes of
soles, turbots, and other flat-fish travel round the head so as
to become in the end unsymmetrically placed, he says:—
“The eyes of these fish are curiously distorted in order
that both eyes may be upon the upper side, where alone they would
be of any use. . . . Now if we suppose this process, which in the
young is completed in a few days or weeks, to have been spread
over thousands of generations during the development of these
fish, those usually surviving whose eyes retained more and
more of the position into which the young fish tried to twist
them [italics mine], the change becomes intelligible.”
[24] When it was said by Professor Ray
Lankester—who knows as well as most people what Lamarck
taught—that this was “flat Lamarckism,” Mr.
Wallace rejoined that it was the survival of the modified
individuals that did it all, not the efforts of the young fish to
twist their eyes, and the transmission to descendants of the
effects of those efforts. But this, as I said in my book,
“Evolution, Old and New,” [25] is like saying that
horses are swift runners, not by reason of the causes, whatever
they were, that occasioned the direct line of their progenitors
to vary towards ever greater and greater swiftness, but because
their more slow-going uncles and aunts go away. Plain
people will prefer to say that the main cause of any accumulation
of favourable modifications consists rather in that which brings
about the initial variations, and in the fact that these can be
inherited at all, than in the fact that the unmodified
individuals were not successful. People do not become rich
because the poor in large numbers go away, but because they have
been lucky, or provident, or more commonly both. If they
would keep their wealth when they have made it they must exclude
luck thenceforth to the utmost of their power, and their children
must follow their example, or they will soon lose their
money. The fact that the weaker go to the wall does not
bring about the greater strength of the stronger; it is the
consequence of this last and not the cause—unless, indeed,
it be contended that a knowledge that the weak go to the wall
stimulates the strong to exertions which they would not otherwise
so make, and that these exertions produce inheritable
modifications. Even in this case, however, it would be the
exertions, or use and disuse, that would be the main agents in
the modification. But it is not often that Mr. Wallace thus
backslides. His present position is that acquired (as
distinguished from congenital) modifications are not inherited at
all. He does not indeed put his faith prominently forward
and pin himself to it as plainly as could be wished, but under
the heading, “The Non-Heredity of Acquired
Characters,” he writes as follows on p. 440 of his recent
work in reference to Professor Weismann’s Theory of
Heredity:—
“Certain observations on the embryology of the lower
animals are held to afford direct proof of this theory of
heredity, but they are too technical to be made clear to ordinary
readers. A logical result of the theory is the
impossibility of the transmission of acquired characters, since
the molecular structure of the germ-plasm is already determined
within the embryo; and Weismann holds that there are no facts
which really prove that acquired characters can be inherited,
although their inheritance has, by most writers, been considered
so probable as hardly to stand in need of direct proof.
“We have already seen in the earlier part of this
chapter that many instances of change, imputed to the inheritance
of acquired variations, are really cases of selection.”
And the rest of the remarks tend to convey the impression that
Mr. Wallace adopts Professor Weismann’s view, but,
curiously enough, though I have gone through Mr. Wallace’s
book with a special view to this particular point, I have not
been able to find him definitely committing himself either to the
assertion that acquired modifications never are inherited, or
that they sometimes are so. It is abundantly laid down that
Mr. Darwin laid too much stress on use and disuse, and a
residuary impression is left that Mr. Wallace is endorsing
Professor Weismann’s view, but I have found it impossible
to collect anything that enables me to define his position
confidently in this respect.
This is natural enough, for Mr. Wallace has entitled his book
“Darwinism,” and a work denying that use and disuse
produced any effect could not conceivably be called
Darwinism. Mr. Herbert Spencer has recently collected many
passages from “The Origin of Species” and from
“Animals and Plants under Domestication,” [26] which show how largely, after all, use
and disuse entered into Mr. Darwin’s system, and we know
that in his later years he attached still more importance to
them. It was out of the question, therefore, that Mr.
Wallace should categorically deny that their effects were
inheritable. On the other hand, the temptation to adopt
Professor Weismann’s view must have been overwhelming to
one who had been already inclined to minimise the effects of use
and disuse. On the whole, one does not see what Mr. Wallace
could do, other than what he has done—unless, of course, he
changed his title, or had been no longer Mr. Wallace.
Besides, thanks to the works of Mr. Spencer, Professor Mivart,
Professor Semper, and very many others, there has for some time
been a growing perception that the Darwinism of Charles Darwin
was doomed. Use and disuse must either do even more than is
officially recognised in Mr. Darwin’s later concessions, or
they must do a great deal less. If they can do as much as
Mr. Darwin himself said they did, why should they not do
more? Why stop where Mr. Darwin did? And again, where
in the name of all that is reasonable did he really stop?
He drew no line, and on what principle can we say that so much is
possible as effect of use and disuse, but so much more
impossible? If, as Mr. Darwin contended, disuse can so far
reduce an organ as to render it rudimentary, and in many cases
get rid of it altogether, why cannot use create as much as disuse
can destroy, provided it has anything, no matter how low in
structure, to begin with? Let us know where we stand.
If it is admitted that use and disuse can do a good deal, what
does a good deal mean? And what is the proportion between
the shares attributable to use and disuse and to natural
selection respectively? If we cannot be told with absolute
precision, let us at any rate have something more definite than
the statement that natural selection is “the most important
means of modification.”
Mr. Darwin gave us no help in this respect; and worse than
this, he contradicted himself so flatly as to show that he had
very little definite idea upon the subject at all. Thus in
respect to the winglessness of the Madeira beetles he
wrote:—
“In some cases we might easily put down to disuse
modifications of structure, which are wholly or mainly due to
natural selection. Mr. Wollaston has discovered the
remarkable fact that 200 beetles, out of the 550 species (but
more are now known) inhabiting Madeira, are so far deficient in
wings that they cannot fly; and that of the 29 endemic genera no
less than 23 have all their species in this condition!
Several facts,—namely, that beetles in many parts of the
world are frequently blown out to sea and perish; that the
beetles in Madeira, as observed by Mr. Wollaston, lie much
concealed until the wind lulls and the sun shines; that the
proportion of wingless beetles is larger on the exposed Desertas
than in Madeira itself; and especially the extraordinary fact, so
strongly insisted on by Mr. Wollaston, that certain large groups
of beetles, elsewhere excessively numerous, which absolutely
require the use of their wings are here almost entirely
absent;—these several considerations make me believe that
the wingless condition of so many Madeira beetles is mainly due
to the action of natural selection, combined probably with
disuse [italics mine]. For during many successive
generations each individual beetle which flew least, either from
its wings having been ever so little less perfectly developed or
from indolent habit, will have had the best chance of surviving,
from not being blown out to sea; and, on the other hand, those
beetles which most readily took to flight would oftenest have
been blown to sea, and thus destroyed.” [27]
We should like to know, first, somewhere about how much disuse
was able to do after all, and moreover why, if it can do anything
at all, it should not be able to do all. Mr. Darwin says:
“Any change in structure and function which can be effected
by small stages is within the power of natural
selection.” “And why not,” we ask,
“within the power of use and disuse?” Moreover,
on a later page we find Mr. Darwin saying:—
“It appears probable that disuse has been the main
agent in rendering organs rudimentary [italics mine].
It would at first lead by slow steps to the more and more
complete reduction of a part, until at last it has become
rudimentary—as in the case of the eyes of animals
inhabiting dark caverns, and of the wings of birds inhabiting
oceanic islands, which have seldom been forced by beasts of prey
to take flight, and have ultimately lost the power of
flying. Again, an organ, useful under certain conditions,
might become injurious under others, as with the wings of
beetles living on small and exposed islands; and in this case
natural selection will have aided in reducing the organ, until it
was rendered harmless and rudimentary [italics mine].” [28]
So that just as an undefined amount of use and disuse was
introduced on the earlier page to supplement the effects of
natural selection in respect of the wings of beetles on small and
exposed islands, we have here an undefined amount of natural
selection introduced to supplement the effects of use and disuse
in respect of the identical phenomena. In the one passage
we find that natural selection has been the main agent in
reducing the wings, though use and disuse have had an appreciable
share in the result; in the other, it is use and disuse that have
been the main agents, though an appreciable share in the result
must be ascribed to natural selection.
Besides, who has seen the uncles and aunts going away with the
uniformity that is necessary for Mr. Darwin’s
contention? We know that birds and insects do often get
blown out to sea and perish, but in order to establish Mr.
Darwin’s position we want the evidence of those who watched
the reduction of the wings during the many generations in the
course of which it was being effected, and who can testify that
all, or the overwhelming majority, of the beetles born with
fairly well-developed wings got blown out to sea, while those
alone survived whose wings were congenitally degenerate.
Who saw them go, or can point to analogous cases so conclusive as
to compel assent from any equitable thinker?
Darwinians of the stamp of Mr. Thiselton Dyer, Professor Ray
Lankester, or Mr. Romanes, insist on their pound of flesh in the
matter of irrefragable demonstration. They complain of us
for not bringing forward some one who has been able to detect the
movement of the hour-hand of a watch during a second of time, and
when we fail to do so, declare triumphantly that we have no
evidence that there is any connection between the beating of a
second and the movement of the hour-hand. When we say that
rain comes from the condensation of moisture in the atmosphere,
they demand of us a rain-drop from moisture not yet
condensed. If they stickle for proof and cavil on the ninth
part of a hair, as they do when we bring forward what we deem
excellent instances of the transmission of an acquired
characteristic, why may not we, too, demand at any rate some
evidence that the unmodified beetles actually did always, or
nearly always, get blown out to sea, during the reduction above
referred to, and that it is to this fact, and not to the masterly
inactivity of their fathers and mothers, that the Madeira beetles
owe their winglessness? If we began stickling for proof in
this way, our opponents would not be long in letting us know that
absolute proof is unattainable on any subject, that reasonable
presumption is our highest certainty, and that crying out for too
much evidence is as bad as accepting too little. Truth is
like a photographic sensitised plate, which is equally ruined by
over and by under exposure, and the just exposure for which can
never be absolutely determined.
Surely if disuse can be credited with the vast powers involved
in Mr. Darwin’s statement that it has probably “been
the main agent in rendering organs rudimentary,” no limits
are assignable to the accumulated effects of habit, provided the
effects of habit, or use and disuse, are supposed, as Mr. Darwin
supposed them, to be inheritable at all. Darwinians have at
length woke up to the dilemma in which they are placed by the
manner in which Mr. Darwin tried to sit on the two stools of use
and disuse, and natural selection of accidental variations, at
the same time. The knell of Charles-Darwinism is rung in
Mr. Wallace’s present book, and in the general perception
on the part of biologists that we must either assign to use and
disuse such a predominant share in modification as to make it the
feature most proper to be insisted on, or deny that the
modifications, whether of mind or body, acquired during a single
lifetime, are ever transmitted at all. If they can be
inherited at all, they can be accumulated. If they can be
accumulated at all, they can be so, for anything that appears to
the contrary, to the extent of the specific and generic
differences with which we are surrounded. The only thing to
do is to pluck them out root and branch: they are as a cancer
which, if the smallest fibre be left unexcised, will grow again,
and kill any system on to which it is allowed to fasten.
Mr. Wallace, therefore, may well be excused if he casts longing
eyes towards Weismannism.
And what was Mr. Darwin’s system? Who can make
head or tail of the inextricable muddle in which he left
it? The “Origin of Species” in its latest shape
is the reduction of hedging to an absurdity. How did Mr.
Darwin himself leave it in the last chapter of the last edition
of the “Origin of Species”? He
wrote:—
“I have now recapitulated the facts and considerations
which have thoroughly convinced me that species have been
modified during a long course of descent. This has been
effected chiefly through the natural selection of numerous,
successive, slight, favourable variations; aided in an important
manner by the inherited effects of the use and disuse of parts,
and in an unimportant manner—that is, in relation to
adaptive structures whether past or present—by the direct
action of external conditions, and by variations which seem to us
in our ignorance to arise spontaneously. It appears that I
formerly underrated the frequency and value of these latter forms
of variation, as leading to permanent modifications of structure
independently of natural selection.”
The “numerous, successive, slight, favourable
variations” above referred to are intended to be
fortuitous, accidental, spontaneous. It is the essence of
Mr. Darwin’s theory that this should be so. Mr.
Darwin’s solemn statement, therefore, of his theory, after
he had done his best or his worst with it, is, when stripped of
surplusage, as follows:—
“The modification of species has been mainly effected by
accumulation of spontaneous variations; it has been aided in an
important manner by accumulation of variations due to use and
disuse, and in an unimportant manner by spontaneous variations; I
do not even now think that spontaneous variations have been very
important, but I used once to think them less important than I do
now.”
It is a discouraging symptom of the age that such a system
should have been so long belauded, and it is a sign of returning
intelligence that even he who has been more especially the
alter ego of Mr. Darwin should have felt constrained to
close the chapter of Charles-Darwinism as a living theory, and
relegate it to the important but not very creditable place in
history which it must henceforth occupy. It is astonishing,
however, that Mr. Wallace should have quoted the extract from the
“Origin of Species” just given, as he has done on p.
412 of his “Darwinism,” without betraying any sign
that he has caught its driftlessness—for drift, other than
a desire to hedge, it assuredly has not got. The battle now
turns on the question whether modifications of either structure
or instinct due to use or disuse are ever inherited, or whether
they are not. Can the effects of habit be transmitted to
progeny at all? We know that more usually they are not
transmitted to any perceptible extent, but we believe also that
occasionally, and indeed not infrequently, they are inherited and
even intensified. What are our grounds for this
opinion? It will be my object to put these forward in the
following number of the Universal Review.
At the close of my article in last month’s number of the
Universal Review, I said I would in this month’s
issue show why the opponents of Charles-Darwinism believe the
effects of habits acquired during the lifetime of a parent to
produce an effect on their subsequent offspring, in spite of the
fact that we can rarely find the effect in any one generation, or
even in several, sufficiently marked to arrest our attention.
I will now show that offspring can be, and not very
infrequently is, affected by occurrences that have produced a
deep impression on the parent organism—the effect produced
on the offspring being such as leaves no doubt that it is to be
connected with the impression produced on the parent.
Having thus established the general proposition, I will proceed
to the more particular one—that habits, involving use and
disuse of special organs, with the modifications of structure
thereby engendered, produce also an effect upon offspring, which,
though seldom perceptible as regards structure in a single, or
even in several generations, is nevertheless capable of being
accumulated in successive generations till it amounts to specific
and generic difference. I have found the first point as
much as I can treat within the limits of this present article,
and will avail myself of the hospitality of the Universal
Review next month to deal with the second.
The proposition which I have to defend is one which no one
till recently would have questioned, and even now, those who look
most askance at it do not venture to dispute it unreservedly;
they every now and then admit it as conceivable, and even in some
cases probable; nevertheless they seek to minimise it, and to
make out that there is little or no connection between the great
mass of the cells of which the body is composed, and those cells
that are alone capable of reproducing the entire organism.
The tendency is to assign to these last a life of their own,
apart from, and unconnected with that of the other cells of the
body, and to cheapen all evidence that tends to prove any
response on their part to the past history of the individual, and
hence ultimately of the race.
Professor Weismann is the foremost exponent of those who take
this line. He has naturally been welcomed by English
Charles-Darwinians; for if his view can be sustained, then it can
be contended that use and disuse produce no transmissible effect,
and the ground is cut from under Lamarck’s feet; if, on the
other hand, his view is unfounded, the Lamarckian reaction,
already strong, will gain still further strength. The
issue, therefore, is important, and is being fiercely contested
by those who have invested their all of reputation for
discernment in Charles-Darwinian securities.
Professor Weismann’s theory is, that at every new birth
a part of the substance which proceeds from parents and which
goes to form the new embryo is not used up in forming the new
animal, but remains apart to generate the germ-cells—or
perhaps I should say “germ-plasm”—which the new
animal itself will in due course issue.
Contrasting the generally received view with his own,
Professor Weismann says that according to the first of these
“the organism produces germ-cells afresh again and again,
and that it produces them entirely from its own
substance.” While by the second “the germ-cells
are no longer looked upon as the product of the parent’s
body, at least as far as their essential part—the specific
germ-plasm—is concerned; they are rather considered as
something which is to be placed in contrast with the tout
ensemble of the cells which make up the parent’s body,
and the germ-cells of succeeding generations stand in a similar
relation to one another as a series of generations of unicellular
organisms arising by a continued process of cell-division.”
[30]
On another page he writes:—
“I believe that heredity depends upon the fact that a
small portion of the effective substance of the germ, the
germ-plasm, remains unchanged during the development of the ovum
into an organism, and that this part of the germ-plasm serves as
a foundation from which the germ-cells of the new organism are
produced. There is, therefore, continuity of the germ-plasm
from one generation to another. One might represent the
germ-plasm by the metaphor of a long creeping root-stock from
which plants arise at intervals, these latter representing the
individuals of successive generations.” [31]
Mr. Wallace, who does not appear to have read Professor
Weismann’s essays themselves, but whose remarks are, no
doubt, ultimately derived from the sequel to the passage just
quoted from page 266 of Professor Weismann’s book, contends
that the impossibility of the transmission of acquired characters
follows as a logical result from Professor Weismann’s
theory, inasmuch as the molecular structure of the germ-plasm
that will go to form any succeeding generation is already
predetermined within the still unformed embryo of its
predecessor; “and Weismann,” continues Mr. Wallace,
“holds that there are no facts which really prove that
acquired characters can be inherited, although their inheritance
has, by most writers, been considered so probable as hardly to
stand in need of direct proof.” [32]
Professor Weismann, in passages too numerous to quote, shows
that he recognises this necessity, and acknowledges that the
non-transmission of acquired characters “forms the
foundation of the views” set forth in his book, p. 291.
Professor Ray Lankester does not commit himself absolutely to
this view, but lends it support by saying (Nature,
December 12, 1889): “It is hardly necessary to say that it
has never yet been shown experimentally that anything
acquired by one generation is transmitted to the next (putting
aside diseases).”
Mr. Romanes, writing in Nature, March 18, 1890, and
opposing certain details of Professor Weismann’s theory, so
far supports it as to say that “there is the gravest
possible doubt lying against the supposition that any really
inherited decrease is due to the inherited effects of
disuse.” The “gravest possible doubt”
should mean that Mr. Romanes regards it as a moral certainty that
disuse has no transmitted effect in reducing an organ, and it
should follow that he holds use to have no transmitted effect in
its development. The sequel, however, makes me uncertain
how far Mr. Romanes intends this, and I would refer the reader to
the article which Mr. Romanes has just published on Weismann in
the Contemporary Review for this current month.
The burden of Mr. Thiselton Dyer’s controversy with the
Duke of Argyll (see Nature, January 16, 1890, et
seq.) was that there was no evidence in support of the
transmission of any acquired modification. The orthodoxy of
science, therefore, must be held as giving at any rate a
provisional support to Professor Weismann, but all of them,
including even Professor Weismann himself, shrink from committing
themselves to the opinion that the germ-cells of any organisms
remain in all cases unaffected by the events that occur to the
other cells of the same organism, and until they do this they
have knocked the bottom out of their case.
From among the passages in which Professor Weismann himself
shows a desire to hedge I may take the following from page 170 of
his book:—
“I am also far from asserting that the germ-plasm which,
as I hold, is transmitted as the basis of heredity from one
generation to another, is absolutely unchangeable or totally
uninfluenced by forces residing in the organism within which it
is transformed into germ-cells. I am also compelled to
admit it as conceivable that organisms may exert a modifying
influence upon their germ-cells, and even that such a process is
to a certain extent inevitable. The nutrition and growth of
the individual must exercise some influence upon its germ-cells .
. . ”
Professor Weismann does indeed go on to say that this
influence must be extremely slight, but we do not care how slight
the changes produced may be provided they exist and can be
transmitted. On an earlier page (p. 101) he said in regard
to variations generally that we should not expect to find them
conspicuous; their frequency would be enough, if they could be
accumulated. The same applies here, if stirring events that
occur to the somatic cells can produce any effect at all on
offspring. A very small effect, provided it can be repeated
and accumulated in successive generations, is all that even the
most exacting Lamarckian will ask for.
Having now made the reader acquainted with the position taken
by the leading Charles-Darwinian authorities, I will return to
Professor Weismann himself, who declares that the transmission of
acquired characters “at first sight certainly seems
necessary,” and that “it appears rash to attempt to
dispense with its aid.” He continues:—
“Many phenomena only appear to be intelligible if we
assume the hereditary transmission of such acquired characters as
the changes which we ascribe to the use or disuse of particular
organs, or to the direct influence of climate. Furthermore,
how can we explain instinct as hereditary habit, unless it has
gradually arisen by the accumulation, through heredity, of habits
which were practised in succeeding generations?” [33]
I may say in passing that Professor Weismann appears to
suppose that the view of instinct just given is part of the
Charles-Darwinian system, for on page 889 of his book he says
“that many observers had followed Darwin in explaining them
[instincts] as inherited habits.” This was not Mr.
Darwin’s own view of the matter. He wrote:—
“If we suppose any habitual action to become
inherited—and I think it can be shown that this does
sometimes happen—then the resemblance between what
originally was a habit and an instinct becomes so close as not to
be distinguished. . . But it would be the most serious error to
suppose that the greater number of instincts have been acquired
by habit in one generation, and then transmitted by inheritance
to succeeding generations. It can be clearly shown that the
most wonderful instincts with which we are acquainted, namely,
those of the hive-bee and of many ants, could not possibly have
been thus acquired.”—[“Origin of
Species,” ed., 1859, p. 209.]
Again we read: “Domestic instincts are sometimes spoken
of as actions which have become inherited solely from
long-continued and compulsory habit, but this, I think, is not
true.”—Ibid., p. 214.
Again: “I am surprised that no one has advanced this
demonstrative case of neuter insects, against the well-known
doctrine of inherited habit, as advanced by
Lamarck.”—[“Origin of Species,” ed. 1872,
p. 283.]
I am not aware that Lamarck advanced the doctrine that
instinct is inherited habit, but he may have done so in some work
that I have not seen.
It is true, as I have more than once pointed out, that in the
later editions of the “Origin of Species” it is no
longer “the most serious” error to refer
instincts generally to inherited habit, but it still remains
“a serious error,” and this slight relaxation of
severity does not warrant Professor Weismann in ascribing to Mr.
Darwin an opinion which he emphatically condemned. His
tone, however, is so offhand, that those who have little
acquaintance with the literature of evolution would hardly guess
that he is not much better informed on this subject than
themselves.
Returning to the inheritance of acquired characters, Professor
Weismann says that this has never been proved either by means of
direct observation or by experiment. “It must be
admitted,” he writes, “that there are in existence
numerous descriptions of cases which tend to prove that such
mutilations as the loss of fingers, the scars of wounds, &c.,
are inherited by the offspring, but in these descriptions the
previous history is invariably obscure, and hence the evidence
loses all scientific value.”
The experiments of M. Brown-Séquard throw so much
light upon the question at issue that I will quote at some length
from the summary given by Mr. Darwin in his “Variation of
Animals and Plants under Domestication.” [34] Mr. Darwin writes:—
“With respect to the inheritance of structures mutilated
by injuries or altered by disease, it was until lately difficult
to come to any definite conclusion.” [Then follow
several cases in which mutilations practised for many generations
are not found to be transmitted.]
“Notwithstanding,” continues Mr. Darwin, “the
above several negative cases, we now possess conclusive evidence
that the effects of operations are sometimes inherited. Dr.
Brown-Séquard gives the following summary of his
observations on guinea-pigs, and this summary is so important
that I will quote the whole:—
“‘1st. Appearance of epilepsy in animals
born of parents having been rendered epileptic by an injury to
the spinal cord.
“‘2nd. Appearance of epilepsy also in
animals born of parents having been rendered epileptic by the
section of the sciatic nerve.
“‘3rd. A change in the shape of the ear in
animals born of parents in which such a change was the effect of
a division of the cervical sympathetic nerve.
“‘4th. Partial closure of the eyelids in
animals born of parents in which that state of the eyelids had
been caused either by the section of the cervical sympathetic
nerve or the removal of the superior cervical ganglion.
“‘5th. Exophthalmia in animals born of
parents in which an injury to the restiform body had produced
that protrusion of the eyeball. This interesting fact I
have witnessed a good many times, and I have seen the
transmission of the morbid state of the eye continue through four
generations. In these animals modified by heredity, the two
eyes generally protruded, although in the parents usually only
one showed exophthalmia, the lesion having been made in most
cases only on one of the corpora restiformia.
“‘6th. Hæmatoma and dry gangrene of
the ears in animals born of parents in which these
ear-alterations had been caused by an injury to the restiform
body near the nib of the calamus.
“‘7th. Absence of two toes out of the three
of the hind leg, and sometimes of the three, in animals whose
parents had eaten up their hind-leg toes which had become
anæsthetic from a section of the sciatic nerve alone, or of
that nerve and also of the crural. Sometimes, instead of
complete absence of the toes, only a part of one or two or three
was missing in the young, although in the parent not only the
toes but the whole foot was absent (partly eaten off, partly
destroyed by inflammation, ulceration, or gangrene).
“‘8th. Appearance of various morbid states
of the skin and hair of the neck and face in animals born of
parents having had similar alterations in the same parts, as
effects of an injury to the sciatic nerve.’
“It should be especially observed that
Brown-Séquard has bred during thirty years many thousand
guinea-pigs from animals which had not been operated upon, and
not one of these manifested the epileptic tendency. Nor has
he ever seen a guinea-pig born without toes, which was not the
offspring of parents which had gnawed off their own toes owing to
the sciatic nerve having been divided. Of this latter fact
thirteen instances were carefully recorded, and a greater number
were seen; yet Brown-Séquard speaks of such cases as one
of the rarer forms of inheritance. It is a still more
interesting fact, ‘that the sciatic nerve in the
congenitally toeless animal has inherited the power of passing
through all the different morbid states which have occurred in
one of its parents from the time of the division till after its
reunion with the peripheric end. It is not, therefore,
simply the power of performing an action which is inherited, but
the power of performing a whole series of actions, in a certain
order.’
“In most of the cases of inheritance recorded by
Brown-Séquard only one of the two parents had been
operated upon and was affected. He concludes by expressing
his belief that ‘what is transmitted is the morbid state of
the nervous system,’ due to the operation performed on the
parents.”
Mr. Darwin proceeds to give other instances of inherited
effects of mutilations:—
“With the horse there seems hardly a doubt that
exostoses on the legs, caused by too much travelling on hard
roads, are inherited. Blumenbach records the case of a man
who had his little finger on the right hand almost cut off, and
which in consequence grew crooked, and his sons had the same
finger on the same hand similarly crooked. A soldier,
fifteen years before his marriage, lost his left eye from
purulent ophthalmia, and his two sons were microphthalmic on the
same side.”
The late Professor Rolleston, whose competence as an observer
no one is likely to dispute, gave Mr. Darwin two cases as having
fallen under his own notice, one of a man whose knee had been
severely wounded, and whose child was born with the same spot
marked or scarred, and the other of one who was severely cut upon
the cheek, and whose child was born scarred in the same
place. Mr. Darwin’s conclusion was that “the
effects of injuries, especially when followed by disease, or
perhaps exclusively when thus followed, are occasionally
inherited.”
Let us now see what Professor Weismann has to say against
this. He writes:—
“The only cases worthy of discussion are the well-known
experiments upon guinea-pigs conducted by the French
physiologist, Brown-Séquard. But the explanation of
his results is, in my opinion, open to discussion. In these
cases we have to do with the apparent transmission of
artificially produced malformations . . . All these effects were
said to be transmitted to descendants as far as the fifth or
sixth generation.
“But we must inquire whether these cases are really due
to heredity, and not to simple infection. In the case of
epilepsy, at any rate, it is easy to imagine that the passage of
some specific organism through the reproductive cells may take
place, as in the case of syphilis. We are, however,
entirely ignorant of the nature of the former disease. This
suggested explanation may not perhaps apply to the other cases;
but we must remember that animals which have been subjected to
such severe operations upon the nervous system have sustained a
great shock, and if they are capable of breeding, it is only
probable that they will produce weak descendants, and such as are
easily affected by disease. Such a result does not,
however, explain why the offspring should suffer from the same
disease as that which was artificially induced in the
parents. But this does not appear to have been by any means
invariably the case. Brown-Séquard himself says:
‘The changes in the eye of the offspring were of a very
variable nature, and were only occasionally exactly similar to
those observed in the parents.’
“There is no doubt, however, that these experiments
demand careful consideration, but before they can claim
scientific recognition, they must be subjected to rigid criticism
as to the precautions taken, the nature and number of the control
experiments, &c.
“Up to the present time such necessary conditions have
not been sufficiently observed. The recent experiments
themselves are only described in short preliminary notices,
which, as regards their accuracy, the possibility of mistake, the
precautions taken, and the exact succession of individuals
affected, afford no data on which a scientific opinion can be
founded” (pp. 81, 82).
The line Professor Weismann takes, therefore, is to discredit
the facts; yet on a later page we find that the experiments have
since been repeated by Obersteiner, “who has described them
in a very exact and unprejudiced manner,” and that
“the fact”—(I imagine that Professor Weismann
intends “the facts”)—“cannot be
doubted.”
On a still later page, however, we read:—
“If, for instance, it could be shown that artificial
mutilation spontaneously reappears in the offspring with
sufficient frequency to exclude all possibilities of chance, then
such proof [i.e., that acquired characters can be
transmitted] would be forthcoming. The transmission of
mutilations has been frequently asserted, and has been even
recently again brought forward, but all the supposed instances
have broken down when carefully examined” (p. 390).
Here, then, we are told that proof of the occasional
transmission of mutilations would be sufficient to establish the
fact, but on p. 267 we find that no single fact is known which
really proves that acquired characters can be transmitted,
“for the ascertained facts which seem to point to the
transmission of artificially produced diseases cannot be
considered as proof” [Italics mine.] Perhaps; but
it was mutilation in many cases that Professor Weismann
practically admitted to have been transmitted when he declared
that Obersteiner had verified Brown-Séquard’s
experiments.
That Professor Weismann recognises the vital importance to his
own theory of the question whether or no mutilations can be
transmitted under any circumstances, is evident from a passage on
p. 425 of his work, on which he says: “It can hardly be
doubted that mutilations are acquired characters; they do not
arise from any tendency contained in the germ, but are merely the
reaction of the body under certain external influences.
They are, as I have recently expressed it, purely somatogenic
characters—viz., characters which emanate from the body
(soma) only, as opposed to the germ-cells; they are,
therefore, characters that do not arise from the germ itself.
“If mutilations must necessarily be transmitted”
[which no one that I know of has maintained], “or even if
they might occasionally be transmitted” [which cannot, I
imagine, be reasonably questioned], “a powerful support
would be given to the Lamarckian principle, and the transmission
of functional hypertrophy or atrophy would thus become highly
probable.”
I have not found any further attempt in Professor
Weismann’s book to deal with the evidence adduced by Mr.
Darwin to show that mutilations, if followed by diseases, are
sometimes inherited; and I must leave it to the reader to
determine how far Professor Weismann has shown reason for
rejecting Mr. Darwin’s conclusion. I do not, however,
dwell upon these facts now as evidence of a transmitted change of
bodily form, or of instinct due to use and disuse or habit; what
they prove is that the germ-cells within the parent’s body
do not stand apart from the other cells of the body so completely
as Professor Weismann would have us believe, but that, as
Professor Hering, of Prague, has aptly said, they echo with more
or less frequency and force to the profounder impressions made
upon other cells.
I may say that Professor Weismann does not more cavalierly
wave aside the mass of evidence collected by Mr. Darwin and a
host of other writers, to the effect that mutilations are
sometimes inherited, than does Mr. Wallace, who says that,
“as regards mutilations, it is generally admitted that they
are not inherited, and there is ample evidence on this
point.” It is indeed generally admitted that
mutilations, when not followed by disease, are very rarely, if
ever, inherited; and Mr. Wallace’s appeal to the
“ample evidence” which he alleges to exist on this
head, is much as though he should say that there is ample
evidence to show that the days are longer in summer than in
winter. “Nevertheless,” he continues, “a
few cases of apparent inheritance of mutilations have been
recorded, and these, if trustworthy, are difficulties in the way
of the theory.” . . . “The often-quoted case of a
disease induced by mutilation being inherited
(Brown-Séquard’s epileptic guinea-pigs) has been
discussed by Professor Weismann and shown to be not
conclusive. The mutilation itself—a section of
certain nerves—was never inherited, but the resulting
epilepsy, or a general state of weakness, deformity, or sores,
was sometimes inherited. It is, however, possible that the
mere injury introduced and encouraged the growth of certain
microbes, which, spreading through the organism, sometimes
reached the germ-cells, and thus transmitted a diseased condition
to the offspring.” [35]
I suppose a microbe which made guinea-pigs eat their toes off
was communicated to the germ-cells of an unfortunate guinea-pig
which had been already microbed by it, and made the offspring
bite its toes off too. The microbe has a good deal to
answer for.
On the case of the deterioration of horses in the Falkland
Islands after a few generations, Professor Weismann
says:—
“In such a case we have only to assume that the climate
which is unfavourable, and the nutriment which is insufficient
for horses, affect not only the animal as a whole but also its
germ-cells. This would result in the diminution in size of
the germ-cells, the effects upon the offspring being still
further intensified by the insufficient nourishment supplied
during growth. But such results would not depend upon the
transmission by the germ-cells of certain peculiarities due to
the unfavourable climate, which only appear in the full-grown
horse.”
But Professor Weismann does not like such cases, and admits
that he cannot explain the facts in connection with the climatic
varieties of certain butterflies, except “by supposing the
passive acquisition of characters produced by the direct
influence of climate.”
Nevertheless in his next paragraph but one he calls such cases
“doubtful,” and proposes that for the moment they
should be left aside. He accordingly leaves them, but I
have not yet found what other moment he considered auspicious for
returning to them. He tells us that “new experiments
will be necessary, and that he has himself already begun to
undertake them.” Perhaps he will give us the results
of these experiments in some future book—for that they will
prove satisfactory to him can hardly, I think, be doubted.
He writes:—
“Leaving on one side, for the moment, these doubtful and
insufficiently investigated cases, we may still maintain that the
assumption that changes induced by external conditions in the
organism as a whole are communicated to the germ-cells after the
manner indicated in Darwin’s hypothesis of pangenesis, is
wholly unnecessary for the explanation of these phenomena.
Still we cannot exclude the possibility of such a transmission
occasionally occurring, for even if the greater part of the
effects must be attributable to natural selection, there might be
a smaller part in certain cases which depends on this exceptional
factor.”
I repeatedly tried to understand Mr. Darwin’s theory of
pangenesis, and so often failed that I long since gave the matter
up in despair. I did so with the less unwillingness because
I saw that no one else appeared to understand the theory, and
that even Mr. Darwin’s warmest adherents regarded it with
disfavour. If Mr. Darwin means that every cell of the body
throws off minute particles that find their way to the
germ-cells, and hence into the new embryo, this is indeed
difficult of comprehension and belief. If he means that the
rhythms or vibrations that go on ceaselessly in every cell of the
body communicate themselves with greater or less accuracy or
perturbation, as the case may be, to the cells that go to form
offspring, and that since the characteristics of matter are
determined by vibrations, in communicating vibrations they in
effect communicate matter, according to the view put forward in
the last chapter of my book “Luck or Cunning,” [36] then we can better understand it.
I have nothing, however, to do with Mr. Darwin’s theory of
pangenesis beyond avoiding the pretence that I understand either
the theory itself or what Professor Weismann says about it; all I
am concerned with is Professor Weismann’s admission, made
immediately afterwards, that the somatic cells may, and perhaps
sometimes do, impart characteristics to the germ-cells.
“A complete and satisfactory refutation of such an
opinion,” he continues, “cannot be brought forward at
present”; so I suppose we must wait a little longer, but in
the meantime we may again remark that, if we admit even
occasional communication of changes in the somatic cells to the
germ-cells, we have let in the thin end of the wedge, as Mr.
Darwin did when he said that use and disuse did a good deal
towards modification. Buffon, in his first volume on the
lower animals, [37] dwells on the impossibility of stopping
the breach once made by admission of variation at all.
“If the point,” he writes, “were once gained,
that among animals and vegetables there had been, I do not say
several species, but even a single one, which had been produced
in the course of direct descent from another species; if, for
example, it could be once shown that the ass was but a
degeneration from the horse—then there is no farther limit
to be set to the power of Nature, and we should not be wrong in
supposing that with sufficient time she could have evolved all
other organised forms from one primordial type.” So
with use and disuse and transmission of acquired characteristics
generally—once show that a single structure or instinct is
due to habit in preceding generations, and we can impose no limit
on the results achievable by accumulation in this respect, nor
shall we be wrong in conceiving it as possible that all
specialisation, whether of structure or instinct, may be due
ultimately to habit.
How far this can be shown to be probable is, of course,
another matter, but I am not immediately concerned with this; all
I am concerned with now is to show that the germ-cells not
unfrequently become permanently affected by events that have made
a profound impression upon the somatic cells, in so far that they
transmit an obvious reminiscence of the impression to the embryos
which they go subsequently towards forming. This is all
that is necessary for my case, and I do not find that Professor
Weismann, after all, disputes it.
But here, again, comes the difficulty of saying what Professor
Weismann does, and what he does not, dispute. One moment he
gives all that is wanted for the Lamarckian contention, the next
he denies common-sense the bare necessaries of life. For a
more exhaustive and detailed criticism of Professor
Weismann’s position, I would refer the reader to an
admirably clear article by Mr. Sidney H. Vines, which appeared in
Nature, October 24, 1889. I can only say that while
reading Professor Weismann’s book, I feel as I do when I
read those of Mr. Darwin, and of a good many other writers on
biology whom I need not name. I become like a fly in a
window-pane. I see the sunshine and freedom beyond, and
buzz up and down their pages, ever hopeful to get through them to
the fresh air without, but ever kept back by a mysterious
something, which I feel but cannot either grasp or see. It
was not thus when I read Buffon, Erasmus Darwin, and Lamarck; it
is not thus when I read such articles as Mr. Vines’s just
referred to. Love of self-display, and the want of
singleness of mind that it inevitably engenders—these, I
suppose, are the sins that glaze the casements of most
men’s minds; and from these, no matter how hard he tries to
free himself, nor how much he despises them, who is altogether
exempt?
Finally, then, when we consider the immense mass of evidence
referred to briefly, but sufficiently, by Mr. Charles Darwin, and
referred to without other, for the most part, than off-hand
dismissal by Professor Weismann in the last of the essays that
have been recently translated, I do not see how any one who
brings an unbiased mind to the question can hesitate as to the
side on which the weight of testimony inclines. Professor
Weismann declares that “the transmission of mutilations may
be dismissed into the domain of fable.” [38] If so, then, whom can we
trust? What is the use of science at all if the conclusions
of a man as competent as I readily admit Mr. Darwin to have been,
on the evidence laid before him from countless sources, is to be
set aside lightly and without giving the clearest and most cogent
explanation of the why and wherefore? When we see a person
“ostrichising” the evidence which he has to meet, as
clearly as I believe Professor Weismann to be doing, we shall in
nine cases out of ten be right in supposing that he knows the
evidence to be too strong for him.
Now let me return to the recent division of biological opinion
into two main streams—Lamarckism and Weismannism Both
Lamarckians and Weismannists, not to mention mankind in general,
admit that the better adapted to its surroundings a living form
may be, the more likely it is to outbreed its compeers. The
world at large, again, needs not to be told that the normal
course is not unfrequently deflected through the fortunes of war;
nevertheless, according to Lamarckians and Erasmus-Darwinians,
habitual effort, guided by ever-growing intelligence—that
is to say, by continued increase of power in the matter of
knowing our likes and dislikes—has been so much the main
factor throughout the course of organic development, that the
rest, though not lost sight of, may be allowed to go without
saying. According, on the other hand, to extreme
Charles-Darwinians and Weismannists, habit, effort and
intelligence acquired during the experience of any one life goes
for nothing. Not even a little fraction of it endures to
the benefit of offspring. It dies with him in whom it is
acquired, and the heirs of a man’s body take no interest
therein. To state this doctrine is to arouse instinctive
loathing; it is my fortunate task to maintain that such a
nightmare of waste and death is as baseless as it is
repulsive.
The split in biological opinion occasioned by the deadlock to
which Charles-Darwinism has been reduced, though comparatively
recent, widens rapidly. Ten years ago Lamarck’s name
was mentioned only as a byword for extravagance; now, we cannot
take up a number of Nature without seeing how hot the
contention is between his followers and those of Weismann.
This must be referred, as I implied earlier, to growing
perception that Mr. Darwin should either have gone farther
towards Lamarckism or not so far. In admitting use and
disuse as freely as he did, he gave Lamarckians leverage for the
overthrow of a system based ostensibly on the accumulation of
fortunate accidents. In assigning the lion’s share of
development to the accumulation of fortunate accidents, he
tempted fortuitists to try to cut the ground from under
Lamarck’s feet by denying that the effects of use and
disuse can be inherited at all. When the public had once
got to understand what Lamarck had intended, and wherein Mr.
Charles Darwin had differed from him, it became impossible for
Charles-Darwinians to remain where they were, nor is it easy to
see what course was open to them except to cast about for a
theory by which they could get rid of use and disuse
altogether. Weismannism, therefore, is the inevitable
outcome of the straits to which Charles-Darwinians were reduced
through the way in which their leader had halted between two
opinions.
This is why Charles-Darwinians, from Professor Huxley
downwards, have kept the difference between Lamarck’s
opinions and those of Mr. Darwin so much in the background.
Unwillingness to make this understood is nowhere manifested more
clearly than in Dr. Francis Darwin’s life of his
father. In this work Lamarck is sneered at once or twice,
and told to go away, but there is no attempt to state the two
cases side by side; from which, as from not a little else, I
conclude that Dr. Francis Darwin has descended from his father
with singularly little modification.
Proceeding to the evidence for the transmissions of acquired
habits, I will quote two recently adduced examples from among the
many that have been credibly attested. The first was
contributed to Nature (March 14, 1889) by Professor Marcus
M. Hartog, who wrote:—
“A. B. is moderately myopic and very astigmatic in the
left eye; extremely myopic in the right. As the left eye
gave such bad images for near objects, he was compelled in
childhood to mask it, and acquired the habit of leaning his head
on his left arm for writing, so as to blind that eye, or of
resting the left temple and eye on the hand, with the elbow on
the table. At the age of fifteen the eyes were equalised by
the use of suitable spectacles, and he soon lost the habit
completely and permanently. He is now the father of two
children, a boy and a girl, whose vision (tested repeatedly and
fully) is emmetropic in both eyes, so that they have not
inherited the congenital optical defect of their father.
All the same, they have both of them inherited his early acquired
habit, and need constant watchfulness to prevent their hiding the
left eye when writing, by resting the head on the left forearm or
hand. Imitation is here quite out of the question.
“Considering that every habit involves changes in the
proportional development of the muscular and osseous systems, and
hence probably of the nervous system also, the importance of
inherited habits, natural or acquired, cannot be overlooked in
the general theory of inheritance. I am fully aware that I
shall be accused of flat Lamarckism, but a nickname is not an
argument.”
To this Professor Ray Lankester rejoined (Nature, March
21, 1889):—
“It is not unusual for children to rest the head on the
left forearm or hand when writing, and I doubt whether much value
can be attached to the case described by Professor Hartog.
The kind of observation which his letter suggests is, however,
likely to lead to results either for or against the transmission
of acquired characters. An old friend of mine lost his
right arm when a schoolboy, and has ever since written with his
left. He has a large family and grandchildren, but I have
not heard of any of them showing a disposition to
left-handedness.”
From Nature (March 21, 1889) I take the second instance
communicated by Mr. J. Jenner-Weir, who wrote as
follows:—
“Mr. Marcus M. Hartog’s letter of March 6th,
inserted in last week’s number (p. 462), is a very valuable
contribution to the growing evidence that acquired characters may
be inherited. I have long held the view that such is often
the case, and I have myself observed several instances of the, at
least I may say, apparent fact.
“Many years ago there was a very fine male of the
Capra megaceros in the gardens of the Zoological
Society. To restrain this animal from jumping over the
fence of the enclosure in which he was confined, a long, and
heavy chain was attached to the collar round his neck. He
was constantly in the habit of taking this chain up by his horns
and moving it from one side to another over his back; in doing
this he threw his head very much back, his horns being placed in
a line with the back. The habit had become quite chronic
with him, and was very tiresome to look at. I was very much
astonished to observe that his offspring inherited the habit, and
although it was not necessary to attach a chain to their necks, I
have often seen a young male throwing his horns over his back and
shifting from side to side an imaginary chain. The action
was exactly the same as that of his ancestor. The case of
the kid of this goat appears to me to be parallel to that of
child and parent given by Mr. Hartog. I think at the time I
made this observation I informed Mr. Darwin of the fact by
letter, and he did not accuse me of ‘flat
Lamarckism.’”
To this letter there was no rejoinder. It may be said,
of course, that the action of the offspring in each of these
cases was due to accidental coincidence only. Anything can
be said, but the question turns not on what an advocate can say,
but on what a reasonably intelligent and disinterested jury will
believe; granted they might be mistaken in accepting the
foregoing stories, but the world of science, like that of
commerce, is based on the faith or confidence, which both creates
and sustains them. Indeed the universe itself is but the
creature of faith, for assuredly we know of no other
foundation. There is nothing so generally and reasonably
accepted—not even our own continued identity—but
questions may be raised about it that will shortly prove
unanswerable. We cannot so test every sixpence given us in
change as to be sure that we never take a bad one, and had better
sometimes be cheated than reduce caution to an absurdity.
Moreover, we have seen from the evidence given in my preceding
article that the germ-cells issuing from a parent’s body
can, and do, respond to profound impressions made on the
somatic-cells. This being so, what impressions are more
profound, what needs engage more assiduous attention than those
connected with self-protection, the procuring of food, and the
continuation of the species? If the mere anxiety connected
with an ill-healing wound inflicted on but one generation is
sometimes found to have so impressed the germ-cells that they
hand down its scars to offspring, how much more shall not
anxieties that have directed action of all kinds from birth till
death, not in one generation only but in a longer series of
generations than the mind can realise to itself, modify, and
indeed control, the organisation of every species?
I see Professor S. H. Vines, in the article on
Weismann’s theory referred to in my preceding article, says
Mr. Darwin “held that it was not the sudden variations due
to altered external conditions which become permanent, but those
slowly produced by what he termed ‘the accumulative action
of changed conditions of life.’” Nothing can be
more soundly Lamarckian, and nothing should more conclusively
show that, whatever else Mr. Darwin was, he was not a
Charles-Darwinian; but what evidence other than inferential can
from the nature of the case be adduced in support of this, as I
believe, perfectly correct judgment? None know better than
they who clamour for direct evidence that their master was right
in taking the position assigned to him by Professor Vines, that
they cannot reasonably look for it. With us, as with
themselves, modification proceeds very gradually, and it violates
our principles as much as their own to expect visible permanent
progress, in any single generation, or indeed in any number of
generations of wild species which we have yet had time to
observe. Occasionally we can find such cases, as in that of
Branchipus stagnalis, quoted by Mr. Wallace, or in that of
the New Zealand Kea whose skin, I was assured by the late Sir
Julius von Haast, has already been modified as a consequence of
its change of food. Here we can show that in even a few
generations structure is modified under changed conditions of
existence, but as we believe these cases to occur comparatively
rarely, so it is still more rarely that they occur when and where
we can watch them. Nature is eminently conservative, and
fixity of type, even under considerable change of conditions, is
surely more important for the well-being of any species than an
over-ready power of adaptation to, it may be, passing
changes. There could be no steady progress if each
generation were not mainly bound by the traditions of those that
have gone before it. It is evolution and not incessant
revolution that both parties are upholding; and this being so,
rapid visible modification must be the exception, not the
rule. I have quoted direct evidence adduced by competent
observers, which is, I believe, sufficient to establish the fact
that offspring can be and is sometimes modified by the acquired
habits of a progenitor. I will now proceed to the still
more, as it appears to me, cogent proof afforded by general
considerations.
What, let me ask, are the principal phenomena of
heredity? There must be physical continuity between parent,
or parents, and offspring, so that the offspring is, as Erasmus
Darwin well said, a kind of elongation of the life of the
parent.
Erasmus Darwin put the matter so well that I may as well give
his words in full; he wrote:—
“Owing to the imperfection of language the offspring is
termed a new animal, but is in truth a branch or elongation of
the parent, since a part of the embryon animal is, or was, a part
of the parent, and therefore, in strict language, cannot be said
to be entirely new at the time of its production; and therefore
it may retain some of the habits of the parent system.
“At the earliest period of its existence the embryon
would seem to consist of a living filament with certain
capabilities of irritation, sensation, volition, and association,
and also with some acquired habits or propensities peculiar to
the parent; the former of these are in common with other animals;
the latter seem to distinguish or produce the kind of animal,
whether man or quadruped, with the similarity of feature or form
to the parent.” [39]
Those who accept evolution insist on unbroken physical
continuity between the earliest known life and ourselves, so that
we both are and are not personally identical with the unicellular
organism from which we have descended in the course of many
millions of years, exactly in the same way as an octogenarian
both is and is not personally identical with the microscopic
impregnate ovum from which he grew up. Everything both is
and is not. There is no such thing as strict identity
between any two things in any two consecutive seconds. In
strictness they are identical and yet not identical, so that in
strictness they violate a fundamental rule of
strictness—namely, that a thing shall never be itself and
not itself at one and the same time; we must choose between logic
and dealing in a practical spirit with time and space; it is not
surprising, therefore, that logic, in spite of the show of
respect outwardly paid to her, is told to stand aside when people
come to practice. In practice identity is generally held to
exist where continuity is only broken slowly and piecemeal,
nevertheless, that occasional periods of even rapid change are
not held to bar identity, appears from the fact that no one
denies this to hold between the microscopically small impregnate
ovum and the born child that springs from it, nor yet, therefore,
between the impregnate ovum and the octogenarian into which the
child grows; for both ovum and octogenarian are held personally
identical with the newborn baby, and things that are identical
with the same are identical with one another.
The first, then, and most important element of heredity is
that there should be unbroken continuity, and hence sameness of
personality, between parents and offspring, in neither more nor
less than the same sense as that in which any other two
personalities are said to be the same. The repetition,
therefore, of its developmental stages by any offspring must be
regarded as something which the embryo repeating them has already
done once, in the person of one or other parent; and if once,
then, as many times as there have been generations between any
given embryo now repeating it, and the point in life from which
we started—say, for example, the amoeba. In the case
of asexually and sexually produced organisms alike, the offspring
must be held to continue the personality of the parent or
parents, and hence on the occasion of every fresh development, to
be repeating something which in the person of its parent or
parents it has done once, and if once, then any number of times,
already.
It is obvious, therefore, that the germ-plasm (or whatever the
fancy word for it may be) of any one generation is as physically
identical with the germ-plasm of its predecessor as any two
things can be. The difference between Professor Weismann
and, we will say, Heringians consists in the fact that the first
maintains the new germ-plasm when on the point of repeating its
developmental processes to take practically no cognisance of
anything that has happened to it since the last occasion on which
it developed itself; while the latter maintain that offspring
takes much the same kind of account of what has happened to it in
the persons of its parents since the last occasion on which it
developed itself, as people in ordinary life take of things that
happen to them. In daily life people let fairly normal
circumstances come and go without much heed as matters of
course. If they have been lucky they make a note of it and
try to repeat their success. If they have been unfortunate
but have recovered rapidly they soon forget it; if they have
suffered long and deeply they grizzle over it and are scared and
scarred by it for a long time. The question is one of
cognisance or non-cognisance on the part of the new germs, of the
more profound impressions made on them while they were one with
their parents, between the occasion of their last preceding
development, and the new course on which they are about to
enter. Those who accept the theory put forward
independently by Professor Hering of Prague (whose work on this
subject is translated in my book, “Unconscious
Memory”) [40] and by myself in “Life and
Habit,” [41] believe in cognizance, as do
Lamarckians generally. Weismannites, and with them the
orthodoxy of English science, find non-cognisance more
acceptable.
If the Heringian view is accepted, that heredity is only a
mode of memory, and an extension of memory from one generation to
another, then the repetition of its development by any embryo
thus becomes only the repetition of a lesson learned by rote;
and, as I have elsewhere said, our view of life is simplified by
finding that it is no longer an equation of, say, a hundred
unknown quantities, but of ninety-nine only, inasmuch as two of
the unknown quantities prove to be substantially identical.
In this case the inheritance of acquired characteristics cannot
be disputed, for it is postulated in the theory that each embryo
takes note of, remembers and is guided by the profounder
impressions made upon it while in the persons of its parents,
between its present and last preceding development. To
maintain this is to maintain use and disuse to be the main
factors throughout organic development; to deny it is to deny
that use and disuse can have any conceivable effect. For
the detailed reasons which led me to my own conclusions I must
refer the reader to my books, “Life and Habit” [42] and “Unconscious Memory,”
the conclusions of which have been
often adopted, but never, that I have seen, disputed. A
brief résumé of the leading points in the
argument is all that space will here allow me to give.
We have seen that it is a first requirement of heredity that
there shall be physical continuity between parents and
offspring. This holds good with memory. There must be
continued identity between the person remembering and the person
to whom the thing that is remembered happened. We cannot
remember things that happened to some one else, and in our
absence. We can only remember having heard of them.
We have seen, however, that there is as much
bonâ-fide sameness of personality between parents
and offspring up to the time at which the offspring quits the
parent’s body, as there is between the different states of
the parent himself at any two consecutive moments; the offspring
therefore, being one and the same person with its progenitors
until it quits them, can be held to remember what happened to
them within, of course, the limitations to which all memory is
subject, as much as the progenitors can remember what happened
earlier to themselves. Whether it does so remember can only
be settled by observing whether it acts as living beings commonly
do when they are acting under guidance of memory. I will
endeavour to show that, though heredity and habit based on memory
go about in different dresses, yet if we catch them
separately—for they are never seen together—and strip
them there is not a mole nor strawberry-mark, nor trick nor leer
of the one, but we find it in the other also.
What are the moles and strawberry-marks of habitual action, or
actions remembered and thus repeated? First, the more often
we repeat them the more easily and unconsciously we do
them. Look at reading, writing, walking, talking, playing
the piano, &c.; the longer we have practised any one of these
acquired habits, the more easily, automatically and
unconsciously, we perform it. Look, on the other hand,
broadly, at the three points to which I called attention in
“Life and Habit”:—
I. That we are most conscious of and have most control
over such habits as speech, the upright position, the arts and
sciences—which are acquisitions peculiar to the human race,
always acquired after birth, and not common to ourselves and any
ancestor who had not become entirely human.
II. That we are less conscious of and have less control
over eating and drinking [provided the food be normal],
swallowing, breathing, seeing, and hearing—which were
acquisitions of our prehuman ancestry, and for which we had
provided ourselves with all the necessary apparatus before we saw
light, but which are still, geologically speaking, recent.
III. That we are most unconscious of and have least
control over our digestion and circulation—powers possessed
even by our invertebrate ancestry, and, geologically speaking, of
extreme antiquity.
I have put the foregoing very broadly, but enough is given to
show the reader the gist of the argument. Let it be noted
that disturbance and departure, to any serious extent, from
normal practice tends to induce resumption of consciousness even
in the case of such old habits as breathing, seeing, and hearing,
digestion and the circulation of the blood. So it is with
habitual actions in general. Let a player be never so
proficient on any instrument, he will be put out if the normal
conditions under which he plays are too widely departed from, and
will then do consciously, if indeed he can do it at all, what he
had hitherto been doing unconsciously. It is an axiom as
regards actions acquired after birth, that we never do them
automatically save as the result of long practice; the stages in
the case of any acquired facility, the inception of which we have
been able to watch, have invariably been from a nothingness of
ignorant impotence to a little somethingness of highly
self-conscious, arduous performance, and thence to the
unselfconsciousness of easy mastery. I saw one year a poor
blind lad of about eighteen sitting on a wall by the wayside at
Varese, playing the concertina with his whole body, and snorting
like a child. The next year the boy no longer snorted, and
he played with his fingers only; the year after that he seemed
hardly to know whether he was playing or not, it came so easily
to him. I know no exception to this rule. Where is
the intricate and at one time difficult art in which perfect
automatic ease has been reached except as the result of long
practice? If, then, wherever we can trace the development
of automatism we find it to have taken this course, is it not
most reasonable to infer that it has taken the same even when it
has risen in regions that are beyond our ken? Ought we not,
whenever we see a difficult action performed, automatically to
suspect antecedent practice? Granted that without the
considerations in regard to identity presented above it would not
have been easy to see where a baby of a day old could have had
the practice which enables it to do as much as it does
unconsciously, but even without these considerations it would
have been more easy to suppose that the necessary opportunities
had not been wanting, than that the easy performance could have
been gained without practice and memory.
When I wrote “Life and Habit” (originally
published in 1877) I said in slightly different words:—
“Shall we say that a baby of a day old sucks (which
involves the whole principle of the pump and hence a profound
practical knowledge of the laws of pneumatics and hydrostatics),
digests, oxygenises its blood—millions of years before any
one had discovered oxygen—sees and hears, operations that
involve an unconscious knowledge of the facts concerning optics
and acoustics compared with which the conscious discoveries of
Newton are insignificant—shall we say that a baby can do
all these things at once, doing them so well and so regularly
without being even able to give them attention, and yet without
mistake, and shall we also say at the same time that it has not
learnt to do them, and never did them before?
“Such an assertion would contradict the whole experience
of mankind.”
I have met with nothing during the thirteen years since the
foregoing was published that has given me any qualms about its
soundness. From the point of view of the law courts and
everyday life it is, of course, nonsense; but in the kingdom of
thought, as in that of heaven, there are many mansions, and what
would be extravagance in the cottage or farmhouse, as it were, of
daily practice, is but common decency in the palace of high
philosophy, wherein dwells evolution. If we leave evolution
alone, we may stick to common practice and the law courts; touch
evolution and we are in another world; not higher, not lower, but
different as harmony from counterpoint. As, however, in the
most absolute counterpoint there is still harmony, and in the
most absolute harmony still counterpoint, so high philosophy
should be still in touch with common sense, and common sense with
high philosophy.
The common-sense view of the matter to people who are not
over-curious and to whom time is money, will be that a baby is
not a baby until it is born, and that when born it should be born
in wedlock. Nevertheless, as a sop to high philosophy,
every baby is allowed to be the offspring of its father and
mother.
The high-philosophy view of the matter is that every human
being is still but a fresh edition of the primordial cell with
the latest additions and corrections; there has been no leap nor
break in continuity anywhere; the man of to-day is the primordial
cell of millions of years ago as truly as he is the himself of
yesterday; he can only be denied to be the one on grounds that
will prove him not to be the other. Every one is both
himself and all his direct ancestors and descendants as well;
therefore, if we would be logical, he is one also with all his
cousins, no matter how distant, for he and they are alike
identical with the primordial cell, and we have already noted it
as an axiom that things which are identical with the same are
identical with one another. This is practically making him
one with all living things, whether animal or vegetable, that
ever have existed or ever will—something of all which may
have been in the mind of Sophocles when he wrote:—
“Nor seest thou yet the gathering hosts of
ill
That shall en-one thee both with thine own self
And with thine offspring.”
And all this has come of admitting that a man may be the same
person for two days running! As for sopping common sense it
will be enough to say that these remarks are to be taken in a
strictly scientific sense, and have no appreciable importance as
regards life and conduct. True they deal with the
foundations on which all life and conduct are based, but like
other foundations they are hidden out of sight, and the sounder
they are, the less we trouble ourselves about them.
What other main common features between heredity and memory
may we note besides the fact that neither can exist without that
kind of physical continuity which we call personal
identity? First, the development of the embryo proceeds in
an established order; so must all habitual actions based on
memory. Disturb the normal order and the performance is
arrested. The better we know “God save the
Queen,” the less easily can we play or sing it
backwards. The return of memory again depends on the return
of ideas associated with the particular thing that is
remembered—we remember nothing but for the presence of
these, and when enough of these are presented to us we remember
everything. So, if the development of an embryo is due to
memory, we should suppose the memory of the impregnate ovum to
revert not to yesterday, when it was in the persons of its
parents, but to the last occasion on which it was an impregnate
ovum. The return of the old environment and the presence of
old associations would at once involve recollection of the course
that should be next taken, and the same should happen throughout
the whole course of development. The actual course of
development presents precisely the phenomena agreeable with
this. For fuller treatment of this point I must refer the
reader to the chapter on the abeyance of memory in my book
“Life and Habit,” already referred to.
Secondly, we remember best our last few performances of any
given kind, so our present performance will probably resemble
some one or other of these; we remember our earlier performances
by way of residuum only, but every now and then we revert to an
earlier habit. This feature of memory is manifested in
heredity by the way in which offspring commonly resembles most
its nearer ancestors, but sometimes reverts to earlier
ones. Brothers and sisters, each as it were giving their
own version of the same story, but in different words, should
generally resemble each other more closely than more distant
relations. And this is what actually we find.
Thirdly, the introduction of slightly new elements into a
method already established varies it beneficially; the new is
soon fused with the old, and the monotony ceases to be
oppressive. But if the new be too foreign, we cannot fuse
the old and the new—nature seeming to hate equally too wide
a deviation from ordinary practice and none at all. This
fact reappears in heredity as the beneficial effects of
occasional crossing on the one hand, and on the other, in the
generally observed sterility of hybrids. If heredity be an
affair of memory, how can an embryo, say of a mule, be expected
to build up a mule on the strength of but two
mule-memories? Hybridism causes a fault in the chain of
memory, and it is to this cause that the usual sterility of
hybrids must be referred.
Fourthly, it requires many repeated impressions to fix a
method firmly, but when it has been engrained into us we cease to
have much recollection of the manner in which it came to be so,
or indeed of any individual repetition, but sometimes a single
impression, if prolonged as well as profound, produces a lasting
impression and is liable to return with sudden force, and then to
go on returning to us at intervals. As a general rule,
however, abnormal impressions cannot long hold their own against
the overwhelming preponderance of normal authority. This
appears in heredity as the normal non-inheritance of mutilations
on the one hand, and on the other as their occasional inheritance
in the case of injuries followed by disease.
Fifthly, if heredity and memory are essentially the same, we
should expect that no animal would develop new structures of
importance after the age at which its species begins ordinarily
to continue its race; for we cannot suppose offspring to remember
anything that happens to the parent subsequently to the
parent’s ceasing to contain the offspring within
itself. From the average age, therefore, of reproduction,
offspring should cease to have any farther steady, continuous
memory to fall back upon; what memory there is should be full of
faults, and as such unreliable. An organism ought to
develop as long as it is backed by memory—that is to say,
until the average age at which reproduction begins; it should
then continue to go for a time on the impetus already received,
and should eventually decay through failure of any memory to
support it, and tell it what to do. This corresponds
absolutely with what we observe in organisms generally, and
explains, on the one hand, why the age of puberty marks the
beginning of completed development—a riddle hitherto not
only unexplained but, so far as I have seen, unasked; it
explains, on the other hand, the phenomena of old
age—hitherto without even attempt at explanation.
Sixthly, those organisms that are the longest in reaching
maturity should on the average be the longest-lived, for they
will have received the most momentous impulse from the weight of
memory behind them. This harmonises with the latest opinion
as to the facts. In his article on Weismann in the
Contemporary Review for May 1890, Mr. Romanes writes:
“Professor Weismann has shown that there is throughout the
metazoa a general correlation between the natural lifetime of
individuals composing any given species, and the age at which
they reach maturity or first become capable of
procreation.” This, I believe, has been the
conclusion generally arrived at by biologists for some years
past.
Lateness, then, in the average age of reproduction appears to
be the principle underlying longevity. There does not
appear at first sight to be much connection between such distinct
and apparently disconnected phenomena as 1, the orderly normal
progress of development; 2, atavism and the resumption of feral
characteristics; 3, the more ordinary resemblance inter se
of nearer relatives; 4, the benefit of an occasional cross, and
the usual sterility of hybrids; 5, the unconsciousness with which
alike bodily development and ordinary physiological functions
proceed, so long as they are normal; 6, the ordinary
non-inheritance, but occasional inheritance of mutilations; 7,
the fact that puberty indicates the approach of maturity; 8, the
phenomena of middle life and old age; 9, the principle underlying
longevity. These phenomena have no conceivable bearing on
one another until heredity and memory are regarded as part of the
same story. Identify these two things, and I know no
phenomenon of heredity that does not immediately become
infinitely more intelligible. Is it conceivable that a
theory which harmonises so many facts hitherto regarded as
without either connection or explanation should not deserve at
any rate consideration from those who profess to take an interest
in biology?
It is not as though the theory were unknown, or had been
condemned by our leading men of science. Professor Ray
Lankester introduced it to English readers in an appreciative
notice of Professor Hering’s address, which appeared in
Nature, July 18, 1876. He wrote to the
Athenæum, March 24, 1884, and claimed credit for
having done so, but I do not believe he has ever said more in
public about it than what I have here referred to. Mr.
Romanes did indeed try to crush it in Nature, January 27,
1881, but in 1883, in his “Mental Evolution in
Animals,” he adopted its main conclusion without
acknowledgment. The Athenæum, to my unbounded
surprise, called him to task for this (March 1, 1884), and since
that time he has given the Heringian theory a sufficiently wide
berth. Mr. Wallace showed himself favourably enough
disposed towards the view that heredity and memory are part of
the same story when he reviewed my book “Life and
Habit” in Nature, March 27, 1879, but he has never
since betrayed any sign of being aware that such a theory
existed. Mr. Herbert Spencer wrote to the
Athenæum (April 5, 1884), and claimed the theory for
himself, but, in spite of his doing this, he has never, that I
have seen, referred to the matter again. I have dealt
sufficiently with his claim in my book, “Luck or
Cunning.” [43] Lastly, Professor Hering himself
has never that I know of touched his own theory since the single
short address read in 1870, and translated by me in 1881.
Every one, even its originator, except myself, seems afraid to
open his mouth about it. Of course the inference suggests
itself that other people have more sense than I have. I
readily admit it; but why have so many of our leaders shown such
a strong hankering after the theory, if there is nothing in
it?
The deadlock that I have pointed out as existing in Darwinism
will, I doubt not, lead ere long to a consideration of Professor
Hering’s theory. English biologists are little likely
to find Weismann satisfactory for long, and if he breaks down
there is nothing left for them but Lamarck, supplemented by the
important and elucidatory corollary on his theory proposed by
Professor Hering. When the time arrives for this to obtain
a hearing it will be confirmed, doubtless, by arguments clearer
and more forcible than any I have been able to adduce; I shall
then be delighted to resign the championship which till then I
shall continue, as for some years past, to have much pleasure in
sustaining. Heretofore my satisfaction has mainly lain in
the fact that more of our prominent men of science have seemed
anxious to claim the theory than to refute it; in the confidence
thus engendered I leave it to any fuller consideration which the
outline I have above given may incline the reader to bestow upon
it.