第 31 节
作者:无组织      更新:2022-04-21 11:08      字数:9322
  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 sciencewell exemplified by that of the development
  theoryis 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 moneylightly 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 bona 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
  caelo。  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
  Lankesterwho 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 causeunless; 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 with