REVIEW OF THE POSITION
The modern story of the theory of organic evolution shows certain
important dates--1859, 1880, 1894, 1895, 1899 and 1909. These begin
with the _Origin of Species_ and end with the publication of a volume
in commemoration of its jubilee, when most of the leading students of
evolution united to render homage to Darwin. The year 1859 has been so
often and so worthily treated that it is enough here to say that the
fifty years between the issue of the work of Darwin and Wallace and
1909 saw a greater revolution in biology, speculative and practical,
than any period so relatively brief had ever seen.
In the year 1880 the “coming of age” of the _Origin of Species_ was
celebrated. On the 9th of April at the Royal Institution an address
was given by the powerful friend, champion and candid critic of
Darwin, and before the scientific and educated world Huxley was able
to say with his own force and directness: “Evolution is no longer an
hypothesis, but an historical fact.” It may be noted in passing that
Darwin’s theory of natural selection is not referred to in the address.
Challenges and opposition from various quarters met this confident
claim of the formidable speaker, as doubtless he desired, but the work
of the succeeding half-century has done little or nothing that does
not establish that claim. It is hardly to be doubted that if in the
jubilee-year, 1909, Huxley had been alive on this earth, instead of
elsewhere, his eloquent voice would have been heard to declare with
emphasis equal to that of 1880: “Selection is no longer an hypothesis,
but an historical fact.” Some such statement, with the _imprimatur_ of
a great name would have removed from the jubilee-volume that slight
aspect as of a Dutch chorus[3] which is apparent in it. A remark of
Kelvin’s when he was conferring a medal of the Royal Society on Huxley
may illustrate what has been said above. He said that they must all be
thankful to have still among them that champion of Evolution who once
bore down its enemies, but was now possibly needed to save it from its
friends. It may be regretted that it was not so in 1909.
[3] The above remark as to the jubilee-volume needs to be explained
and justified. In it there is an important essay on each of the great
provinces of Weismann, Mendel and de Vries, and in each of these the
highest living exponent speaks, Professors Weismann, Bateson and de
Vries. Bateson expresses admiration for Weismann’s destructive work,
but shows plainly that he holds it to have failed in its fundamental
purpose. Nevertheless, by a neat _tour d’addresse_ he adopts
Weismann’s uncompromising attitude on the inheritance of acquired
characters, which happens to agree exceedingly well with his own
scheme. He has but one insignificant reference to de Vries on p. 95
where he finds help for his doctrine.
Weismann makes no reference to Mendel or de Vries. De Vries makes
none to Weismann or Mendel, but without stating it in his essay he
is known to be in opposition to Weismann’s dogma on the inheritance
of acquired characters. These three eminent biologists would
thus seem to have worked on diverging lines. The two first agree
heartily, Weismann explicitly and Bateson by implication, as to the
forbidden doctrine, “on the ground that it closes the way to deeper
insight”--in other words their mutually destructive theories. So it
stands thus in the book--Weismann throws over Lamarck, Mendel and de
Vries; Bateson throws over Weismann (as again in 1914) and de Vries;
de Vries ignores Weismann and Mendel.
Dr. Lock in his book on Variation, Heredity and Evolution, 1906,
says that Weismann practically ignores the evidence of Mendelism in
heredity, and adds, p. 261, “But at the next step the Mendelian parts
company with Weismann.”
One cannot avoid noticing, incidentally, that the vast mass of work
of the biometricians led by Galton, Weldon and Professor Karl Pearson
is conspicuously absent from the book. Prof. J. Arthur Thomson says
that there should be no opposition between Mendelian and Galtonian
formulæ, “they are correlated, and ultimately they will be seen in
complete harmony as different aspects of the same phenomena. But it
is simply muddleheadedness which can find any opposition between a
statistical formula applicable to averages of successive generations
breeding freely, and a physiological formula applicable to particular
sets of cases where parents with contrasted dominant and recessive
characters are crossed and their hybrid offspring are inbred.”(a)
concerning which see the Preface to Bateson’s _Mendel’s Principles of
Heredity_, 1902, with remarks on some of the Galtonians.
(a) _Heredity_, p. 374.
Considering the mole-like and persistent work of the biometricians,
some who are at present keeping well-ordered lawns may find some
day a few disturbing heaps of facts. I am reminded here of an
historic duel, Oxford _v._ Cambridge, which took place soon after
the introduction of Mendel’s discoveries into England at the London
Zoological Society, when Prof. Bateson expounded them with enthusiasm
and when Weldon repelled them with cogent and incisive arguments.
The duel lasted nearly two hours and that was not too long for the
audience, but one has the impression that some of what Professor
Thomson calls muddleheadedness must have been somewhere existing.
However, the duel was fought when Mendelism was young.
Three Blows to Darwin.
But other historic events are more relevant to my immediate purpose
than these.
Three blows were delivered against Darwinism in the years 1894, 1895
and 1899 by Prof. Bateson, Weismann, and again Prof. Bateson, under
which it seemed to reel, but from which it is more than likely it has
derived but greater strength.
BATESON.
In 1894 Prof. Bateson published his large and important work,
_Materials for the Study of Variation_. As a distinguished student
and teacher of biology he found the received doctrine of evolution
in straits as regards the factor of natural selection in producing
specific differences, as indeed happened to another equally eminent man
during the next year. He was profoundly discontented as to the origin
of specific differences on the theory of direct utility of variations,
and he said “on our present knowledge the matter is talked out.”[4]
He threw over the study of adaptation “as a means of directly solving
the problem of species.” He came to the conclusion “Variation is
Evolution,” and affirmed that the readiest way of solving the problem
of evolution is to study the facts of variation. Hence arose this
notable book, and hence one of his trenchant statements to the effect
“that the existence of new forms having from their beginning more or
less of the kind of perfection that we associate with normality, is a
fact that once and for all disposes of the attempt to interpret all
perfection and definiteness of form as the work of selection,”[5]
and “Inquiry into the causes of variation is as yet, in my judgment,
premature.”[6] It will hardly be denied that a work which contained
such statements as these from such a source seemed momentous in its
influence on the fate of Darwin’s theory. Prof. Bateson yielded to
none in his loyalty to Darwin, as far as he knew himself, and here he
is as candid as Huxley, and he declares that in his treatment of the
phenomena of variation is found nothing which is in any way opposed
to Darwin’s theory. The shade of Darwin might nevertheless have
looked with some misgiving at this man over against him with a drawn
sword in his hand, and have asked gently, “Art thou for us or for our
adversaries?” Prof. Bateson’s work chiefly requires to be considered
here because to any reader of it there must come the conviction on
the one hand of Prof. Bateson’s merits and power, and on the other of
his limitation as a student of organic evolution. In 1894 is evident
already an exclusive attention to structure rather than function,
to anatomy than physiology; the anatomical leaven in doctrine has
leavened the whole lump. For him physiology of animals and plants does
not exist, or at the best is the outcome of structures which arise
through variation and selection. This, if I may say so, is as much his
strength as his weakness. There have been other great biologists, such
as Geoffrey Saint-Hilaire and Richard Owen, of whom this is true. If
that were all one would not wish the reader to be troubled with any
criticism of one’s betters, indeed such remarks as are here made do not
amount to criticism at all, but just plain text-book statements. It is
also evident that the outlook of Prof. Bateson was being prepared for
a revelation which had not yet come, in which he took a prominent, if
not dominant part, I mean the great rediscovery of Mendel’s work by
de Vries, Correns and Tschermak and himself in England. His keen and
close attention to anatomical structures was preparing his mind for the
germinal conceptions of unit-characters, dominance and segregation.
The intensive cultivation of the fertile field of genetics proceeded
apace, and Prof. Bateson in his contribution to the jubilee-volume of
1909 betrayed the trend of his devotion to a system of _distribution_
rather than formation of the qualities of an organism. The organism as
an historical functioning, striving being, had receded once for all
from his vision. He hazarded the suggestion in _Heredity and Variation
in Modern Lights_ that “variation consists largely in the unpacking
and repacking of an original complexity,” and that “it is not so
certain as we might like to think that the order of these events is not
predetermined.” Incidentally one may remark that, _malgré lui_, Prof.
Bateson stands forth as a modern Paley as does Weismann in his great
rival and opposing scheme. It is true that he says “I see no ground
whatever for holding such a view, but in fairness the possibility
should not be forgotten and in the light of modern research it scarcely
looks so absurdly improbable as before.” Having drawn the sword he
threw away the scabbard in 1914 when he occupied the presidential chair
of the British Association of Science at Melbourne and Sydney. He had
said in 1894 in his book on variation as stated before, “Inquiry into
the causes of variation is as yet, in my opinion, premature,” and
then in 1914 at Melbourne, after twenty more years of study of the
subject in the Mendelian direction, “It is likely that the occurrence
of these variations is wholly irregular, and as to their causation _we
are absolutely without surmise or even plausible speculation_.” (my
italics).[7] So, on this fundamental point, he stands where he did when
he began the study of variation, but apart from this point he again
threw out his suggestion of 1909 as to the unpacking and repacking of
an original complexity. At Melbourne he said, “Lotsy has lately with
great courage suggested to us that all variation may be due to such
crossing. I do not disguise my sympathy with this effort.”[8] _All
variation!_ He said later, “In spite of seeming perversity, therefore,
we have to admit that there is no evolutionary change which in the
present state of our knowledge we can positively declare _not due to
loss_.”[9] (Italics mine.) These two statements of 1914 are enough to
show that the biologist of 1894, 1899, 1909 and 1914 has evolved in
a definite line, and it is to his honour that he has remembered “to
thine ownself be true.” But he is not so true to himself in his scorn
of those who propound theories. For myself I would give little for
the biologist who did not hold or propound some theory. What was the
penultimate and stirring message of the gifted G. B. Howes? “We live
by ideas, we advance by a knowledge of the facts.” The self-denying
ordinance affirmed and reaffirmed by Prof. Bateson is not observed
even in the Melbourne and Sydney addresses. In the former, he says
“at first it may seem rank absurdity to suppose that the primordial
form or forms of protoplasm could have contained complexity enough to
produce the divers types of life,” and asks us to open our minds to
this possibility. Again “I have confidence that the artistic gifts of
mankind will prove to be due not to something added to the makeup of an
ordinary man, but to the absence of factors which in the normal person
inhibit the development of these gifts.” And at Sydney, “Ages before
written history began, in some unknown place, plants, or more likely a
plant of wheat lost the dominant factor to which this brittleness is
due, and the recessive thrashable wheat resulted. Some man noticed this
wonderful novelty, and it has been disseminated over the earth. The
original variation may well have occurred once only in a single germ,”
and “so must it have been with man.”[10]
[4] _Materials for the Study of Variation_, p. 5.
[5] _Op, cit._, p. 568.
[6] _Op. cit._, p. 78.
[7] _Nature_, 1914.
[8] _Op. cit._, Aug. 20th and Aug. 27th, 1914.
[9] _Nature_, 1914.
[10] _Op. cit._, 1914.
These are three stupendous stretches of imagination and theory in one
address, which would have been the poorer if they had not overcome
the accomplished speaker’s dislike of the theories--of others. If
they are not ideal constructions of a high order I do not know the
meaning of that term. They are worthy of Weismann the Prince of ideal
constructionists. Prof. Bateson might indeed be another Newton with his
_Hypotheses non fingo_.
Turning to another important biological doctrine one can see what it
may be legitimate to call a bi-phyletic parallelism in the biological
make-up of Prof. Bateson. Again is seen consistency of view and loyalty
to his first love. Two references from these addresses will be enough
to introduce the point.
At Melbourne, “We thus reach the essential principle that an organism
cannot pass on to offspring a factor which it did not itself receive in
fertilization.”[11]
[11] _Op. cit._, 1914.
At Sydney, “The factors which the individual receives from his
parents, and no others, are those which he can transmit to his
offspring”[12]--in other words the doctrine of the inheritance of
acquired characters is estopped. As to this he speaks in 1909 more
doubtfully on p. 90 and on p. 95 almost dogmatically.[13] There is just
a convenient haziness of meaning in the term “factor” with which some
play might be made, but, taking it to mean what the context indicates,
an acquirement made by the individual during its personal life, we have
pretty clear evidence that Prof. Bateson will have nothing to do with
the inheritance of acquired characters as that doctrine is understood
by the unsophisticated biologist. This opposition should be counted
unto him for righteousness rather than the reverse, for it falls into
line with his life’s work to which he has given of his best.--_Vestigia
nulla retrorsum._ The point reached here which concerns my purpose is
that the orthodox Mendelian still knows nothing of the cause or origin
of variation, and will have none of Lamarck.
[12] _Nature_, 1914.
[13] _Darwin and Modern Science._
This consideration of Prof. Bateson’s work of a quarter of a century
has been necessary for showing how the work of Weismann and himself
diverge gravely and yet meet at one point, and the year 1899, being
linked with 1894, has been taken out of its chronological order.
It may be permitted perhaps to say respectfully to the Mendelians in
the words of the dying father in the fable, “Dig, my sons, dig in the
vineyard.” If they follow still the course of the sons they may find
more gold than they have found already and perchance that which is
better than gold. But they will produce from it nothing that is not
there.
Two Parables.
Here gentle reader (I seem to remember this style of address in
the stories of our youth) pause with me in a little oasis of the
desert-stage of our journey, and brush off some of the dust, while I
briefly narrate two incidents, but I pray you also not to leave me in
the midst of them so that you may escape the next short stage.
A traveller, small and insignificant, armed only with an oak cudgel,
was passing alone through a South American forest. As he trudged
forward he noticed at a certain point in the path (shall we call it
1894–1899?) that a jaguar was watching him and was about to break his
truce with man. He turned off to the right and there he saw a puma
and this too seemed to meditate evil. He hastened forward just in
time as his two enemies sprang at him, and these two near relatives
were locked in mortal grip--and so he passed on safe!
The reader, naturalist or layman, can point the moral for himself.
At the battle of Trafalgar, while fighting was in full progress on
one of the ships, some sailors were occupied in throwing overboard
the bodies of those who had been killed. A poor Scotchman badly
wounded and hardly conscious was taken up by two seamen, an
Englishman and an Irishman, and as they were about to throw him
overboard his feeble voice was heard to say “I’m no deed yet.”
“What’s that?” said the Irishman. “I’m no deed yet”; “Arrah, the
doctor said he was dead, over wid him,” said the Irishman.
Weismann.
During the period 1894–1899 there was a dramatic proclamation on the
part of one of the greatest living biologists, which was, in the cosmos
of biology, what the Proclamation of the Empress-Queen of India was in
1876, and it is not out of place to remind the reader that the fates
of the two Imperial utterances have been somewhat different. In 1895
Weismann issued his official statement of doctrine which was to crown
the work of his life, an essay on Germinal Selection. From Freyburg
in November, 1895, he wrote a preface to his address delivered on
September 16th in that year to the International Congress of Zoologists
at Leyden. This formed an epoch in biological thought and there lived
none so well qualified as Weismann to stand forth as its interpreter.
The well-translated, forcible language, and lucid thought leave the
reader in no manner of doubt as to his meaning. It took a wider form
in his final book on the Evolution Theory, but the germinal and
essential thoughts of the latter were contained in the former. From
1895 onwards the praise of Weismann was in all the churches. Probably
no modern worker in the fields of heredity and evolution has done so
much as Weismann towards raising great issues and removing some ancient
misconceptions; but it is one thing to raise great issues and another
to solve them. In this he has signally failed, nevertheless biological
theory would be the poorer if he had not made the attempt. Reflection,
the work of other biologists, and the remorseless hand of time have
shaken the edifices then raised. I will here only bring forward a few
of the most illuminating passages of the 1895 essay, and then refer to
the handling of Weismann’s work by Romanes.
This trenchant essay contains fifty-seven pages, of which reasoning
forms the greater part. As to the facts it might well pass for an
essay from Professor Poulton’s pen, for Weismann’s special province
of insects occupies nearly all the evidence from facts. Outside this
highly specialised group there are exactly fifty-three lines, or one
and a half pages, which deal with other animal groups, and there are
four casual allusions to plants occupying twelve lines in all! In the
essay of 1909 on the Selection Theory this treatment of animated life
in the world is improved upon and thirteen out of its forty-seven pages
refer to animals outside his favourite group of insects. Such exclusive
dealing with these little things does not commend the reasoning, at any
rate to a neo-Lamarckian; such a circle is too select for him.
Weismann’s Twelve Points.
The most striking remarks from the 1895 essay on germinal selection
are:--
1. “The real aim of the present essay is to rehabilitate the principle
of selection. If I should succeed in reinstating this principle in its
imperilled rights, it would be a source of extreme satisfaction to
me.”[14]
[14] Preface to _Germinal Selection_, 1895, p. xii.
2. Speaking of the whole theory of selection he claimed to have
found a position “which is necessary to protect it against the many
doubts which gathered around it on all sides like so many lowering
thunder-clouds.”[15] And he speaks on page 26 of “the flood of
objections against the theory of selection touching its inability to
modify many parts at once.”
[15] p. 38.
Thus Weismann stood forth to defend the crumbling edifice of Darwinism
and threw his shining sword into the scales, a scientific Athanasius
“contending for our all.” Again is seen a friend of Darwin from another
camp than that of Mendel, whose support needs to be received with some
caution. _Toujours en vedette_ is a useful rule.
3. Speaking of adaptedness in animated nature he says, “We know of
only one natural principle of explanation for this fact--that of
selection.”[16]
[16] p. 43.
4. “Germinal selection is the last consequence of the application of
the principle of Malthus to living nature.”[17]
[17] p. 43.
5. “Without doubt the theory (Germinal Selection) requires that the
initial steps of a variation should also have selective value.”[18]
[18] p. 38.
6. “Something is still wanting in the theory of Darwin and Wallace
which it is obligatory on us to discover if we possibly can. We must
seek to discover why it happens that useful variations are always
present.”[19]
[19] p. 15.
7. “It is impossible to do without the assumption that the useful
variations are always present, or that _they always exist in
a sufficiently large number of individuals for the selective
process_.”[20]
[20] p. 14.
8. “_Some profound connexions must exist between the utility of a
variation and its actual appearance, or the direction of the variation
of a part must be determined by utility._”[21]
[21] p. 18.
9. That “germinal selection performs the same services for the
understanding of observed transformations ... that a heredity of
acquired characters would perform without rendering necessary so
_violent an assumption_!”[22] (Italics mine.)
[22] p. 40.
10. Weismann speaks warmly of Professor Lloyd Morgan for his caution
and calmness of judgment but complains of him that he “has not been
able to abandon completely the heredity of acquired characters.”[23]
[23] p. 56.
11. As to passive effects of environment, etc., he says “the Lamarckian
principle is here excluded _ab initio_.”[24]
[24] p. 11.
12. “It seems to me that a hypothesis of this kind (Lamarckism) has
performed its services and must be discarded the moment it is found to
be at hopeless variance with the facts.”[25]
[25] p. 17.
I have only to add here that several years ago I wrote to Weismann
drawing his attention to some facts I had observed which seemed to me
to be instances of use-inheritance, and I received a reply in polite
but brief and Prussian terms to the effect that the facts referred to
must be capable of some other interpretation, for _the machinery for
their transmission did not exist_.
Each of these twelve quotations from Weismann’s essay is important from
the present point of view, and shows how far neo-Darwinians are likely
to promote the greater glory of Darwin, and though more than a quarter
of a century elapsed between this essay and his death Weismann was not
the man to have repudiated any of these strong statements.
Lighthouse Value.
I hope at this point a small digression is not out of place in order
to introduce an aspect of Weismann’s work which is not usually
appreciated. A child is aware of the great and lesser lights that
rule the day and night, but for modern man these are not sufficient.
Accordingly he has invented from immemorial times his oil lamps,
rushlights, tallow and wax candles, gas and electric light for the
illumination of his streets and houses. Prehistoric man did not seem to
need them, as he thought. These useful examples of applied knowledge
were obviously brought into use for showing man better where he was
going and where to go, what he was doing and what he wished to see. I
hope this trite remark may be pardoned, for there is another form of
light which suits my purpose of illustrating the aspect of Weismannism
referred to above, that is the light of a lighthouse. The ancients in
their crude way saw the need for this and as far back as the days of
Ptolemy II. a tower to give light was erected on the island of Pharus,
off the Egyptian coast, and it was called a _pharos_. Man found it
necessary, as navigation and seafaring advanced, to use this principle
more and more, and on headland, sandbank and rugged coast has built
noble structures to aid the sailor in his dangerous course. The oldest
and finest of these in Great Britain is the Eddystone lighthouse, built
first in 1695 by Winstanley and finally by Smeaton in 1756–9. For what
reason is a lighthouse built and placed where it is? For the precisely
opposite reason to that of the domestic candle. While this shows you
where to go and how better to do your immediate business, a lighthouse
is for the main purpose of showing a mariner where he should _not go_.
It has no relation to adornment or pleasure. It does not invite you to
come in your vessel and admire it. It tells you to go away and avoid
the sunken rock or treacherous sands.
I submit here the suggestion with all deference, that the final work
of Weismann has lighthouse value of a high order, as to the _modus
operandi_ of evolution. His greatness as a biologist, his candour and
skill in dialectics, have built up a veritable lighthouse which may
usefully warn the seeker after the path of evolution that he must turn
elsewhere if he would not founder upon a reef of facts.
The two great contributions to evolutionary thought that Weismann has
made should be considered separately, the theory of germ-plasm and that
of evolution, though the latter seems to be the necessary outcome of
the former. But the truth of Weismann’s view of heredity does not of
necessity require the error of his theory of evolution.
Romanes on Weismann.
For this study the examination of Weismannism by Romanes published in
1893 is of great value. I need only refer here to the main conclusions
of that lucid and learned examination.
Weismann’s work on the germ-plasm in pursuance of a theory of heredity
is pronounced by Romanes to have remained up to 1893 substantially
unaltered, though largely added to in matters of detail, and at the
present time as far as I gather from a study of the more recent
literature this theory holds the field or at least a commanding
position in it.[26] Originally he held that the germ-plasm possessed
_perpetual_ continuity since the first origin of life, and _absolute_
stability since the first origin of sexual propagation, but he has
shown himself willing to surrender the first postulate, and has himself
altered the second. As it stands now it must be admitted that the
continuity of the germ-plasm is an interrupted continuity with the
appearance of every inherited change; the continuity is theoretical,
not actual, and the stability of the germ-plasm is not absolute but of
a high degree. We can thus see in the story of this original theory of
heredity the lighthouse value of the _pharos_ of Ptolemy II.
[26] Romanes, _Examination of Weismannism_, p. 115.
“It is doubtful if anything better as to Weismann’s theory of
heredity can be said to-day than Romanes said in 1893, and inasmuch
as these two latter or distinctive postulates are not needed for
Weismann’s theory of heredity, while they are both essential to his
theory of evolution, I cannot but regret that he should have thus
crippled the former by burdening it with the latter. Hence my object
throughout has been to display, as sharply as possible, the contrast
that is presented between the brass (“iron” preferably) and the clay
in the colossal figure which Weismann has constructed. Hence also
my emphatic dissent from his theory of evolution does not prevent
me from sincerely appreciating the great value which attaches to
his theory of heredity. And although I have not hesitated to say
that this theory is, in my opinion, incomplete; that it presents not
a few manifest inconsistencies, and even logical contradictions;
that the facts on which it is founded have always been facts of
general knowledge; that in all its main features it was present to
the mind of Darwin, and distinctly formulated by Galton; that in so
far as it has been constituted the basis of a more general theory
of organic evolution it has proved a failure; such considerations
in no way diminish my cordial recognition of the services which its
distinguished author has rendered to science by his speculations
upon these topics. For not only has he been successful in drawing
renewed and much more general attention to the important questions
touching the transmissibility of acquired characters, the causes of
variation, and so on; but even those parts of his system which have
proved untenable are not without such value as temporary scaffoldings
present in relation to permanent buildings. Therefore, if I have
appeared to play the _role_ of a hostile critic, this has been only
an expression of my desire to separate what seems to me the grain of
good science from the chaff of bad speculation.”
It is far otherwise with Weismann’s theory of evolution. Romanes shows
that with the removal of its essential postulate the absolute stability
of germ-plasm, Weismann’s theory of evolution falls to the ground. He
has indeed surrendered much in his later building, his second temple
of Solomon, and prominent among these was the claim that the only
causes of individual variation and of the origin of species in the
uni-cellular organisms are the Lamarckian factors, just as in the
multicellular _the only cause of these is natural selection_. Thus we
see standing at the critical date, 1892, the first Eddystone lighthouse
of Winstanley, a greater and more important structure than the old
pharos.
Germinal Selection.
It can hardly be doubted that one of the “thunderclouds” threatening
Darwinism, of which Weismann spoke in 1895, was this examination of
Weismannism by Romanes. As the case stood then some fresh strategy
was needed if victory for Darwin was to be won, at least so the great
leader said. It must be remembered that it was the _personal_ selection
of Darwin which was held to be in danger. Accordingly germinal
selection was brought forth and remained the basis of Weismann’s later
_Evolution Theory_ of 1904 and 1909. Romanes did not live to see or
assist in the disproof of this ambitious piece of work so that his
“examination” is so far incomplete.
The position of germinal selection is defined in Weismann’s statement
that “it is the adaptive requirement itself that produces the useful
direction of variation by means of selectional processes within the
germ.” Here it is in a nutshell. The theory itself is consistent,
and clearness has been added to the earlier evolution theory by the
claim that a struggle for nutriment occurs within the fertilised ovum
between the innumerable determinants of the different parts, so that
maintenance or victory over weaker determinants takes place. Thus we
have a survival of the fittest _in petto_ in the germ analogous to
that of the individual organisms as we see them. There is of course
a resemblance here to the cellular or histonal selection of Roux,
but his doctrines are not weighted with the intolerable dogma of the
non-inheritance of acquired characters. But ultimately this conception
of germinal selection has to come down and bow to the tribunal of
facts, and the remark of Weismann on Lamarckism which has been
already quoted, “It seems to me that an hypothesis of this kind has
performed its service and must be discarded the moment it is found
to be at hopeless variance with the facts,” confronts the consistent
Weismannian. And I venture to say here that germinal selection is
represented by the Eddystone lighthouse of 1756–9 erected by Smeaton.
The grounds for this statement are afforded by numerous facts and
experiments, to which in the later chapters I propose to add a few
fresh ones, and by a growing body of opinion and authority in favour of
Lamarckian factors in evolution.
Three “lighthouses” of this metaphorical sort have thus been afforded
by the work of Weismann, represented by the Pharos of old, Winstanley’s
Eddystone lighthouse and that of Smeaton.
Authority.
We have then Weismann and Professor Bateson definitely ranged against
the position taken in this volume as to a cause or origin or variation
and the inheritance of acquired characters. To these we must add the
great weight of Sir E. Ray Lankester’s opinion lately given in a reply
to Professor Adami that “it is very widely admitted (more correctly
“claimed”) that no case of the transmission of what are called acquired
characters from parent to offspring has been demonstrated in so far as
those higher animals and plants which multiply by means of specialised
egg-cells and sperm-cells are concerned.”
It is not necessary to mention more than these “three mighties” of the
biological world.
Many others such as Prof. J. Arthur Thomson and Prof. W. K. Brooks,
of Johns Hopkins University, are still unconvinced as to Lamarckian
factors and ask for more evidence, and they have many to support them
in their opinion and claim. There is often a tone of weariness, as well
as wariness in their remarks on the matter.
In favour of the neo-Lamarckian position, with which stands or falls
the suggested cause of variation, there is a growing body of opinion,
with the mention of which I conclude this review.
1. The accomplished writer of _Form and Function_, Mr. E. S. Russell,
says the theory of Lamarck “although it had little influence upon
biological thought during and for a long time after the lifetime of
its author, _is still at the present day a living and developing
doctrine_.”[27]
[27] p. 215.
2. Sir Francis Darwin from the Presidential Chair of the British
Association of Science in Dublin in 1908 proclaimed his adherence to
the mnemonic theory of heredity, foreshadowed by Samuel Butler and
inaugurated by Semon, a condition of which is that acquired characters
are inherited. This caused much stir in the camp of “our friends the
enemy.”
3. Observations and experiments at variance with germinal selection and
its negative presupposition have been rapidly accumulated from the work
of botanists and zoologists who were prepared to appeal to the tribunal
of natural processes; though Weismann and some of his followers, with
some reason, look upon the evidence from plants as a weak link in
the chain of evidence. Many of the observations and experiments are
well-known and only a mere mention of them need be made here, they are
such as Mr. J. T. Cunningham’s observations on the effect of light on
the under surface of flounders, Kammerer’s on the changes in the colour
of salamanders to surrounding objects, and others by him on certain
amphibia and reptiles especially _alytes_ held by Professor McBride
to be convincing, though the latter are to be repeated at the London
Zoological Society’s gardens and are therefore _sub judice_--others
on brine-shrimps, on the effects of change of food on bee-grubs and
tadpoles, and of the change of level of environments of certain
cereals--others by Henslow on plants which have never been refuted, and
many by the late Prince Kropotkin. The latter have appeared at length
in certain issues of the Nineteenth Century in September 1901, March
1912, October 1914, and the last in January 1919, and they deal both
with plants and animals, and are too numerous to be mentioned here
individually.
Again, Professor Dendy as President of the Zoological Section of
the British Association of Science in September, 1914, devoted most
of his address to the subject of Lamarckism and firmly claimed as a
necessary factor of evolution “the direct response of the organism to
environmental stimuli at all stages of development, whereby individual
adaptation is secured, and this individual adaptation must arise
again and again in each succeeding generation.” He also maintains
this position in several passages in his important work _Outlines of
Evolutionary Biology_ published in 1912.
A statement by Professor Bower, President of the Botanical section
of the British Association of Science in 1914 should also be noted:
“I share it (the doctrine in question) in whole or in part with many
botanists, with men who have lived their lives in the atmosphere of
observation and experiment found in large botanical gardens and not
least with a former President of the British Association, viz., Sir
Francis Darwin.”
Professor Adami, in 1917, published an original work called _Medical
Contributions to the Study of Evolution_ in which from his extensive
knowledge of the subject he deals with evidence of inheritance of
acquired characters in lowly organisms as well as higher animals from
the point of view of pathology.
Enough has been stated here to show that the dogma of Weismann or
Lamarckian factors in organic evolution, _quâ_ authority, has been in
poor case during recent years, and it remains for me now to add my
small quota of the authority of facts.