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　doneunless；　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　rudimentaryas　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　pro