essays on life, art and science-第37部分

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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。



THE　DEADLOCK　IN　DARWINISMPART　III



Now　let　me　return　to　the　recent　division　of　biological　opinion　into
two　main　streamsLamarckism　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　intelligencethat　is　to　say；　by　continued　increase　of　power
in　the　matter　of　knowing　our　likes　and　dislikeshas　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　identitybut　questions　may　be　raised
about　it　that　will　shortly　prove　unanswerable。　　We　cannot　so　test
every　sixpence　given　us　in　change