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　mannerthat　is；
  in　relation　to　adaptive　structures　whether　past　or　presentby　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　driftlessnessfor　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。
  THE　DEADLOCK　IN　DARWINISMPART　II　｛29｝
  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　organismthe　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　onethat　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…cellsor　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　partthe　specific　germ…
  plasmis　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　organi