JustatthetimewhenthisthoughtwastakingforminGoethe’sbrain，thesameideawasgerminatinginthemindofanotherphilosopher，anEnglishmanofinternationalfame，Dr。ErasmusDarwin，who，whilehelived，enjoyedthewidestpopularityasapoet，therhymedcoupletsofhisBotanicGardenbeingquotedeverywherewithadmiration。Andposterityrepudiatingtheversewhichmakesthebodyofthebook，yetgrantspermanentvaluetothebookitself，because，forsooth，itscopiousexplanatoryfoot-notesfurnishanoutlineofthestatusofalmosteverydepartmentofscienceofthetime。
　　Buteventhoughhelackedthehighestartoftheversifier，Darwinhad，beyondperadventure，theimaginationofapoetcoupledwithprofoundscientificknowledge；anditwashispoeticinsight，correlatingorganismsseeminglydiverseinstructureandimbuingthelowliestflowerwithavitalpersonality，whichledhimtosuspectthattherearenolinesofdemarcationinnature。
　　"Canitbe，"hequeries，"thatoneformoforganismhasdevelopedfromanother；thatdifferentspeciesarereallybutmodifieddescendantsofoneparentstock？"Thealluringthoughtnestledinhismindandwasnurturedthere，andgrewinafixedbelief，whichwasgivenfullerexpressioninhisZoonomiaandintheposthumousTempleofNature。
　　HereishisrenderingoftheideaasversifiedintheTempleofNature:
　　"OrganiclifebeneaththeshorelesswavesWasborn，andnursedinOcean’spearlycaves；
　　Firstformsminute，unseenbysphericglass，Moveonthemud，orpiercethewaterymass；
　　These，assuccessivegenerationsbloom，Newpowersacquireandlargerlimbsassume；
　　Whencecountlessgroupsofvegetationspring，Andbreathingrealmsoffin，andfeet，andwing。
　　"ThusthetallOak，thegiantofthewood，WhichbearsBritannia’sthundersontheflood；
　　TheWhale，unmeasuredmonsterofthemain；
　　Thelordlylion，monarchoftheplain；
　　Theeagle，soaringintherealmsofair，Whoseeye，undazzled，drinksthesolarglare；
　　Imperiousman，whorulesthebestialcrowd，Oflanguage，reason，andreflectionproud，Withbrowerect，whoscornsthisearthysod，AndstyleshimselftheimageofhisGod——
　　Arosefromrudimentsofformandsense，Anembryonpointormicroscopicens！"[2]
　　Here，clearlyenough，istheideaofevolution。Butinthatdaytherewaslittleproofforthcomingofitsvaliditythatcouldsatisfyanyonebutapoet，andwhenErasmusDarwindied，in1802，theideaoftransmutationofspecieswasstillbutanunsubstantiateddream。
　　Itwasadream，however，whichwasnotconfinedtoGoetheandDarwin。Evenearliertheideahadcomemoreorlessvaguelytoanothergreatdreamer——andworker——ofGermany，ImmanuelKant，andtoseveralgreatFrenchmen，includingDeMaillet，Maupertuis，Robinet，andthefamousnaturalistBuffon——amanwhohadtheimaginationofapoet，thoughhismessagewascouchedinmostartisticprose。NotlongafterthemiddleoftheeighteenthcenturyBuffonhadputforwardtheideaoftransmutationofspecies，andhereiterateditfromtimetotimefromthenontillhisdeathin1788。Butthetimewasnotyetripefortheideaoftransmutationofspeciestoburstitsbonds。
　　Andyetthisidea，inamodifiedorundevelopedform，hadtakenstrangeholduponthegenerationthatwasuponthesceneatthecloseoftheeighteenthcentury。Vastnumbersofhithertounknownspeciesofanimalshadbeenrecentlydiscoveredinpreviouslyunexploredregionsoftheglobe，andthewisemenweresorelypuzzledtoaccountforthedisposalofalloftheseatthetimeofthedeluge。Itsimplifiedmattersgreatlytosupposethatmanyexistingspecieshadbeendevelopedsincetheepisodeofthearkbymodificationoftheoriginalpairs。Theremoterbearingsofsuchatheorywereoverlookedforthetime，andtheideathatAmericananimalsandbirds，forexample，weremodifieddescendantsofOld-Worldforms——thejaguaroftheleopard，thepumaofthelion，andsoon——becameacurrentbeliefwiththatclassofhumanitywhoacceptalmostanystatementastruethatharmonizeswiththeirprejudiceswithoutrealizingitsimplications。
　　ThusitisrecordedwitheclatthatthediscoveryofthecloseproximityofAmericaatthenorthwestwithAsiaremovesalldifficultiesastotheoriginoftheOccidentalfaunasandfloras，sinceOrientalspeciesmighteasilyhavefoundtheirwaytoAmericaontheice，andhavebeenmodifiedaswefindthemby"thewell-knowninfluenceofclimate。"Andthepersonswhogaveexpressiontothisideaneverdreamedofitsrealsignificance。
　　Intruth，herewasthedoctrineofevolutioninanutshell，and，becauseitsultimatebearingswerenotclear，itseemedthemostnaturalofdoctrines。Butmostofthepersonswhoadvanceditwouldhaveturnedfromitaghastcouldtheyhaverealizeditsimport。Asitwas，however，onlyhereandthereamanlikeBuffonreasonedfarenoughtoinquirewhatmightbethelimitsofsuchassumedtransmutation；andonlyhereandthereaDarwinoraGoethereachedtheconvictionthattherearenolimits。
　　LAMARCKVERSUSCUVIER
　　AndevenGoetheandDarwinhadscarcelypassedbeyondthattentativestageofconvictioninwhichtheyheldthethoughtoftransmutationofspeciesasanancillarybeliefnotreadyforfullexposition。Therewasoneoftheircontemporaries，however，who，holdingthesameconception，wasmovedtogiveitfullexplication。ThiswasthefriendanddiscipleofBuffon，JeanBaptistedeLamarck。Possessedofthespiritofapoetandphilosopher，thisgreatFrenchmanhadalsothewidestrangeoftechnicalknowledge，coveringtheentirefieldofanimatenature。
　　Thefirsthalfofhislonglifewasdevotedchieflytobotany，inwhichheattainedhighdistinction。Then，justatthebeginningofthenineteenthcentury，heturnedtozoology，inparticulartothelowerformsofanimallife。Studyingtheselowlyorganisms，existingandfossil，hewasmoreandmoreimpressedwiththegradationsofformeverywheretobeseen；thelinkingofdiversefamiliesthroughintermediateones；andinparticularwiththepredominanceoflowtypesoflifeintheearliergeologicalstrata。Calleduponconstantlytoclassifythevariousformsoflifeinthecourseofhissystematicwritings，hefounditmoreandmoredifficulttodrawsharplinesofdemarcation，andatlastthesuspicionlongharboredgrewintoasettledconvictionthatthereisreallynosuchthingasaspeciesoforganisminnature；that"species"isafigmentofthehumanimagination，whereasinnaturethereareonlyindividuals。
　　Thatcertainsetsofindividualsaremorelikeoneanotherthanlikeothersetsisofcoursepatent，butthisonlymeans，saidLamarck，thatthesesimilargroupshavehadcomparativelyrecentcommonancestors，whiledissimilarsetsofbeingsaremoreremotelyrelatedinconsanguinity。Buttracebackthelinesofdescentfarenough，andallwillculminateinoneoriginalstock。
　　Allformsoflifewhatsoeveraremodifieddescendantsofanoriginalorganism。Fromlowesttohighest，then，thereisbutonerace，onespecies，justasallthemultitudinousbranchesandtwigsfromonerootarebutonetree。Forpurposesofconvenienceofdescription，wemaydivideorganismsintoorders，families，genera，species，justaswedivideatreeintoroot，trunk，branches，twigs，leaves；butintheonecase，asintheother，thedivisionisarbitraryandartificial。
　　InPhilosophieZoologique1809，Lamarckfirstexplicitlyformulatedhisideasastothetransmutationofspecies，thoughhehadoutlinedthemasearlyas1801。Inthismemorablepublicationnotonlydidhestatehisbeliefmoreexplicitlyandinfullerdetailthantheideahadbeenexpressedbyanypredecessor，buthetookanotherlongforwardstep，carryinghimfarbeyondallhisforerunnersexceptDarwin，inthathemadeanattempttoexplainthewayinwhichthetransmutationofspecieshadbeenbroughtabout。Thechangeshavebeenwrought，hesaid，throughtheunceasingeffortsofeachorganismtomeettheneedsimposeduponitbyitsenvironment。Constantstrivingmeanstheconstantuseofcertainorgans。Thusabirdrunningbytheseashoreisconstantlytemptedtowadedeeperanddeeperinpursuitoffood；itsincessanteffortstendtodevelopitslegs，inaccordancewiththeobservedprinciplethattheuseofanyorgantendstostrengthenanddevelopit。Butsuchslightlyincreaseddevelopmentofthelegsistransmittedtotheoffspringofthebird，whichinturndevelopsitsalreadyimprovedlegsbyitsindividualefforts，andtransmitstheimprovedtendency。Generationaftergenerationthisisrepeated，untilthesumoftheinfinitesimalvariations，allinthesamedirection，resultsintheproductionofthelong-leggedwading-bird。Inasimilarway，throughindividualeffortandtransmittedtendency，allthediversifiedorgansofallcreatureshavebeendeveloped——thefinofthefish，thewingofthebird，thehandofman；nay，more，thefishitself，thebird，theman，even。
　　Collectivelytheorgansmakeuptheentireorganism；andwhatistrueoftheindividualorgansmustbetruealsooftheirensemble，thelivingbeing。
　　WhatevermightbethoughtofLamarck’sexplanationofthecauseoftransmutation——whichreallywasthatalreadysuggestedbyErasmusDarwin——theideaoftheevolutionforwhichhecontendedwasbutthelogicalextensionoftheconceptionthatAmericananimalsarethemodifiedanddegenerateddescendantsofEuropeananimals。Butpeopleasarulearelittlepronetofollowideastotheirlogicalconclusions，andinthiscasetheconclusionsweresoutterlyopposedtotheproximalbearingsoftheideathatthewholethinkingworldrepudiatedthemwithacclaim。TheverypersonswhohadmosteagerlyacceptedtheideaoftransmutationofEuropeanspeciesintoAmericanspecies，andsimilarlimitedvariationsthroughchangedenvironment，becauseofthereliefthusgiventheotherwiseovercrowdedark，werenowforemostindenouncingsuchanextensionofthedoctrineoftransmutationasLamarckproposed。
　　And，forthatmatter，theleadersofthescientificworldwereequallyantagonistictotheLamarckianhypothesis。Cuvierinparticular，oncethepupilofLamarck，butnowhiscolleague，andinauthoritymorethanhispeer，stoodoutagainstthetransmutationdoctrinewithallhisforce。Hearguedfortheabsolutefixityofspecies，bringingtobeartheresourcesofamindwhich，asamererepositoryoffacts，perhapsneverwasexcelled。Asafinalandtangibleproofofhisposition，hebroughtforwardthebodiesofibisesthathadbeenembalmedbytheancientEgyptians，andshowedbycomparisonthatthesedonotdifferintheslightestparticularfromtheibisesthatvisittheNileto-day。
　　Cuvier’sreasoninghassuchgreathistoricalinterest——beingtheargumentofthegreatestopponentofevolutionofthatday——thatwequoteitatsomelength。
　　"Thefollowingobjections，"hesays，"havealreadybeenstartedagainstmyconclusions。Whymaynotthepresentlyexistingracesofmammiferouslandquadrupedsbemeremodificationsorvarietiesofthoseancientraceswhichwenowfindinthefossilstate，whichmodificationsmayhavebeenproducedbychangeofclimateandotherlocalcircumstances，andsinceraisedtothepresentexcessivedifferencebytheoperationsofsimilarcausesduringalongperiodofages？
　　"Thisobjectionmayappearstrongtothosewhobelieveintheindefinitepossibilityofchangeofforminorganizedbodies，andthinkthat，duringasuccessionofagesandbyalterationsofhabitudes，allthespeciesmaychangeintooneanother，oroneofthemgivebirthtoalltherest。Yettothesepersonsthefollowinganswermaybegivenfromtheirownsystem:Ifthespecieshavechangedbydegrees，astheyassume，weoughttofindtracesofthisgradualmodification。Thus，betweenthepalaeotheriumandthespeciesofourownday，weshouldbeabletodiscoversomeintermediateforms；andyetnosuchdiscoveryhaseverbeenmade。Sincethebowelsoftheearthhavenotpreservedmonumentsofthisstrangegenealogy，wehavenorighttoconcludethattheancientandnowextinctspecieswereaspermanentintheirformsandcharactersasthosewhichexistatpresent；or，atleast，thatthecatastrophewhichdestroyedthemdidnotleavesufficienttimefortheproductionsofthechangesthatareallegedtohavetakenplace。
　　"Inordertoreplytothosenaturalistswhoacknowledgethatthevarietiesofanimalsarerestrainedbynaturewithincertainlimits，itwouldbenecessarytoexaminehowfartheselimitsextend。Thisisaverycuriousinquiry，andinitselfexceedinglyinterestingunderavarietyofrelations，buthasbeenhithertoverylittleattendedto……
　　Wildanimalswhichsubsistuponherbagefeeltheinfluenceofclimatealittlemoreextensively，becausethereisaddedtoittheinfluenceoffood，bothinregardtoitsabundanceanditsquality。Thustheelephantsofoneforestarelargerthanthoseofanother；theirtusksalsogrowsomewhatlongerinplaceswheretheirfoodmayhappentobemorefavorablefortheproductionofthesubstanceofivory。Thesamemaytakeplaceinregardtothehornsofstagsandreindeer。Butletusexaminetwoelephants，themostdissimilarthatcanbeconceived，weshallnotdiscoverthesmallestdifferenceinthenumberandarticulationsofthebones，thestructureoftheteeth，etc……
　　"Natureappearsalsotohaveguardedagainstthealterationsofspecieswhichmightproceedfrommixtureofbreedsbyinfluencingthevariousspeciesofanimalswithmutualaversionfromoneanother。Henceallthecunningandalltheforcethatmanisabletoexertisnecessarytoaccomplishsuchunions，evenbetweenspeciesthathavethenearestresemblances。Andwhenthemulebreedsthatarethusproducedbytheseforcedconjunctionshappentobefruitful，whichisseldomthecase，thisfecunditynevercontinuesbeyondafewgenerations，andwouldnotprobablyproceedsofarwithoutacontinuanceofthesamecareswhichexciteditatfirst。Thusweneverseeinawildstateintermediateproductionsbetweenthehareandtherabbit，betweenthestagandthedoe，orbetweenthemartenandtheweasel。Butthepowerofmanchangesthisestablishedorder，andcontinuestoproducealltheseintermixturesofwhichthevariousspeciesaresusceptible，butwhichtheywouldneverproduceiflefttothemselves。
　　"Thedegreesofthesevariationsareproportionaltotheintensityofthecausesthatproducedthem——namely，theslaveryorsubjectionunderwhichthoseanimalsaretoman。Theydonotproceedfarinhalf-domesticatedspecies。Inthecat，forexample，asofterorharsherfur，morebrilliantormorevariedcolors，greaterorlesssize——theseformthewholeextentofvarietyinthespecies；theskeletonofthecatofAngoradiffersinnoregularandconstantcircumstancesfromthewild-catofEurope……
　　Themostremarkableeffectsoftheinfluenceofmanareproduceduponthatanimalwhichhehasreducedmostcompletelyundersubjection。Dogshavebeentransportedbymankindintoeverypartoftheworldandhavesubmittedtheiractiontohisentiredirection。Regulatedintheirunionsbythepleasureorcapriceoftheirmasters，thealmostendlessvarietiesofdogsdifferfromoneanotherincolor，inlength，andabundanceofhair，whichissometimesentirelywanting；intheirnaturalinstincts；
　　insize，whichvariesinmeasureasonetofive，mountinginsomeinstancestomorethanahundredfoldinbulk；intheformoftheirears，noses，andtails；intherelativelengthoftheirlegs；intheprogressivedevelopmentofthebrain，inseveralofthedomesticatedvarietiesoccasioningalterationsevenintheformofthehead，someofthemhavinglong，slendermuzzleswithaflatforehead，othershavingshortmuzzleswithaforeheadconvex，etc。，insomuchthattheapparentdifferencebetweenamastiffandawater-spanielandbetweenagreyhoundandapugdogareevenmorestrikingthanbetweenalmostanyofthewildspeciesofagenus……
　　Itfollowsfromtheseobservationsthatanimalshavecertainfixedandnaturalcharacterswhichresisttheeffectsofeverykindofinfluence，whetherproceedingfromnaturalcausesorhumaninterference；andwehavenotthesmallestreasontosuspectthattimehasanymoreeffectonthemthanclimate。
　　"Iamawarethatsomenaturalistslayprodigiousstressuponthethousandswhichtheycancallintoactionbyadashoftheirpens。Insuchmatters，however，ouronlywayofjudgingastotheeffectswhichmaybeproducedbyalongperiodoftimeisbymultiplying，asitwere，suchasareproducedbyashortertime。
　　WiththisviewIhaveendeavoredtocollectalltheancientdocumentsrespectingtheformsofanimals；andtherearenoneequaltothosefurnishedbytheEgyptians，bothinregardtotheirantiquityandabundance。Theyhavenotonlyleftusrepresentativesofanimals，buteventheiridenticalbodiesembalmedandpreservedinthecatacombs。
　　"Ihaveexamined，withthegreatestattention，theengravedfiguresofquadrupedsandbirdsbroughtfromEgypttoancientRome，andallthesefigures，onewithanother，haveaperfectresemblancetotheirintendedobjects，suchastheystillareto-day。
　　"Fromalltheseestablishedfacts，theredoesnotseemtobethesmallestfoundationforsupposingthatthenewgenerawhichI
　　havediscoveredorestablishedamongextraneousfossils，suchasthepaleoetherium，anoplotherium，megalonyx，mastodon，pterodactylis，etc。，haveeverbeenthesourcesofanyofourpresentanimals，whichonlydiffersofarastheyareinfluencedbytimeorclimate。Evenifitshouldprovetrue，whichIamfarfrombelievingtobethecase，thatthefossilelephants，rhinoceroses，elks，andbearsdonotdifferfurtherfromtheexistingspeciesofthesamegenerathanthepresentracesofdogsdifferamongthemselves，thiswouldbynomeansbeasufficientreasontoconcludethattheywereofthesamespecies；
　　sincetheracesorvarietiesofdogshavebeeninfluencedbythetrammelsofdomesticity，whichthoseotheranimalsneverdid，andindeednevercould，experience。"[3]
　　ToCuvier’sargumentfromthefixityofEgyptianmummifiedbirdsandanimals，asabovestated，LamarckrepliedthatthisprovednothingexceptthattheibishadbecomeperfectlyadaptedtoitsEgyptiansurroundingsinanearlyday，historicallyspeaking，andthattheclimaticandotherconditionsoftheNileValleyhadnotsincethenchanged。Histheory，healleged，providedforthestabilityofspeciesunderfixedconditionsquiteaswellasfortransmutationundervaryingconditions。
　　But，needlesstosay，thepopularverdictlaywithCuvier；talentwonforthetimeagainstgenius，andLamarckwaslookeduponasanimpiousvisionary。Hisfaithneverwavered，however。Hebelievedthathehadgainedatrueinsightintotheprocessesofanimatenature，andhereiteratedhishypothesesoverandover，particularlyintheintroductiontohisHistoireNaturelledesAnimauxsansVertebres，in1815，andinhisSystemedesConnaissancesPositivesdel’Homme，in1820。Helivedontill1829，respectedasanaturalist，butalmostunrecognizedasaprophet。
　　TENTATIVEADVANCES
　　WhilethenamesofDarwinandGoethe，andinparticularthatofLamarck，mustalwaysstandoutinhighreliefinthisgenerationastheexponentsoftheideaoftransmutationofspecies，thereareafewotherswhichmustnotbealtogetheroverlookedinthisconnection。OfthesethemostconspicuousisthatofGottfriedReinholdTreviranus，aGermannaturalistphysician，professorofmathematicsinthelyceumatBremen。
　　ItwasaninterestingcoincidencethatTreviranusshouldhavepublishedthefirstvolumeofhisBiologie，oderPhilosophiederlebendenNatur，inwhichhisviewsonthetransmutationofspecieswereexpounded，in1802，thesametwelvemonthinwhichLamarck’sfirstexpositionofthesamedoctrineappearedinhisRecherchessurl’OrganisationdesCorpsVivants。Itissingular，too，thatLamarck，inhisHydrogelogieofthesamedate，shouldindependentlyhavesuggested"biology"asanappropriatewordtoexpressthegeneralscienceoflivingthings。Itissignificantofthetendencyofthoughtofthetimethattheneedofsuchaunifyingwordshouldhavepresenteditselfsimultaneouslytoindependentthinkersindifferentcountries。
　　Thatsamememorableyear，LorenzOken，anotherphilosophicalnaturalist，professorintheUniversityofZurich，publishedthepreliminaryoutlinesofhisPhilosophiederNatur，which，asdevelopedthroughlaterpublications，outlinedatheoryofspontaneousgenerationandofevolutionofspecies。Thusitappearsthatthisideawasgerminatinginthemindsofseveraloftheablestmenofthetimeduringthefirstdecadeofourcentury。Butthesingularresultoftheirvariousexplicationswastogivesuddenchecktothatundercurrentofthoughtwhichforsometimehadbeensettingtowardsthisconception。Assoonasitwasmadeclearwhithertheconcessionthatanimalsmaybechangedbytheirenvironmentmustlogicallytrend，therecoilfromtheideawasinstantaneousandfervid。ThenforagenerationCuvierwasalmostabsolutelydominant，andhisverdictwasgenerallyconsideredfinal。
　　Therewas，indeed，onenaturalistofauthorityinFrancewhohadthehardihoodtostandoutagainstCuvierandhisschool，andwhowasinapositiontogainahearing，thoughbynomeanstodividethefollowing。ThiswasEtienneGeoffroySaint-Hilaire，thefamousauthorofthePhilosophieAnatomique，andformanyyearsthecolleagueofLamarckattheJardindesPlantes。LikeGoethe，Geoffroywaspre-eminentlyananatomist，and，likethegreatGerman，hehadearlybeenimpressedwiththeresemblancesbetweentheanalogousorgansofdifferentclassesofbeings。Heconceivedtheideathatanabsoluteunityoftypeprevailsthroughoutorganicnatureasregardseachsetoforgans。Outofthisideagrewhisgraduallyformedbeliefthatsimilarityofstructuremightimplyidentityoforigin——that，inshort，onespeciesofanimalmighthavedevelopedfromanother。
　　Geoffroy’sgraspofthisideaoftransmutationwasbynomeanssocompleteasthatofLamarck，andheseemsnevertohavefullydeterminedinhisownmindjustwhatmightbethelimitsofsuchdevelopmentofspecies。Certainlyhenowhereincludesallorganiccreaturesinonelineofdescent，asLamarckhaddone；
　　nevertheless，heheldtenaciouslytothetruthashesawit，inopenoppositiontoCuvier，withwhomheheldamemorabledebateattheAcademyofSciencesin1830——thedebatewhichsoarousedtheinterestandenthusiasmofGoethe，butwhich，intheopinionofnearlyeveryoneelse，resultedincrushingdefeatforGeoffrey，andbrilliant，seeminglyfinal，victoryfortheadvocateofspecialcreationandthefixityofspecies。
　　Withthatallardentcontroversyoverthesubjectseemedtoend，andforjustaquarterofacenturytocometherewaspublishedbutasingleargumentfortransmutationofspecieswhichattractedanygeneralattentionwhatever。ThisoasisinadesertgenerationwasalittlebookcalledVestigesoftheNaturalHistoryofCreation，whichappearedanonymouslyinEnglandin1844，andwhichpassedthroughnumerouseditions，andwasthesubjectofnoendofabusiveandderisivecomment。Thisbook，theauthorshipofwhichremainedforfortyyearsasecret，isnowconcededtohavebeentheworkofRobertChambers，thewell-knownEnglishauthorandpublisher。Thebookitselfisremarkableasbeinganavowedandunequivocalexpositionofageneraldoctrineofevolution，itsviewbeingasradicalandcomprehensiveasthatofLamarckhimself。Butitwasaresumeofearliereffortsratherthananewdeparture，tosaynothingofitstechnicalshortcomings，whichmaybestbeillustratedbyaquotation。
　　"Thewholequestion，"saysChambers，"standsthus:Forthetheoryofuniversalorder——thatis，orderaspresidinginboththeoriginandadministrationoftheworld——wehavethetestimonyofavastnumberoffactsinnature，andthisoneinaddition——thatwhateverisleftfromthedomainofignorance，andmadeundoubtedmatterofscience，formsanewsupporttothesamedoctrine。Theoppositeview，oncepredominant，hasbeenshrinkingforagesintolesserspace，andnowmaintainsafootingonlyinafewdepartmentsofnaturewhichhappentobelessliablethanotherstoaclearinvestigation。Thechiefofthese，ifnotalmosttheonlyone，istheoriginoftheorganickingdoms。Solongasthisremainsobscure，thesupernaturalwillhaveacertainholduponenlightenedpersons。Shoulditeverbeclearedupinawaythatleavesnodoubtofanaturaloriginofplantsandanimals，theremustbeacompleterevolutionintheviewwhichisgenerallytakenoftherelationoftheFatherofourbeing。
　　"Thispreparesthewayforafewremarksonthepresentstateofopinionwithregardtotheoriginoforganicnature。Thegreatdifficultyhereistheapparentdeterminatenessofspecies。Theseformsoflifebeingapparentlyunchangeable，oratleastalwaysshowingatendencytoreturntothecharacterfromwhichtheyhavediverged，theideaarisesthattherecanhavebeennoprogressionfromonetoanother；eachmusthavetakenitsspecialform，independentlyofotherforms，directlyfromtheappointmentoftheCreator。TheEdinburghReviewwritersays，’theywerecreatedbythehandofGodandadaptedtotheconditionsoftheperiod。’Nowitis，inthefirstplace，notcertainthatspeciesconstantlymaintainafixedcharacter，forwehaveseenthatwhatwerelongconsideredasdeterminatespecieshavebeentransmutedintoothers。Passing，however，fromthisfact，asitisnotgenerallyreceivedamongmenofscience，thereremainsomegreatdifficultiesinconnectionwiththeideaofspecialcreation。
　　Firstweshouldhavetosuppose，aspointedoutinmyformervolume，amoststartlingdiversityofplaninthedivineworkings，agreatgeneralplanorsystemoflawintheleadingeventsofworld-making，andaplanofminute，niceoperation，andspecialattentioninsomeofthemeredetailsoftheprocess。Thediscrepancybetweenthetwoconceptionsissurelyoverpowering，whenweallowourselvestoseethewholematterinasteadyandrationallight。Thereis，also，thestrikingfactofanascertainedhistoricalprogressofplantsandanimalsintheorderoftheirorganization；marineandcellularplantsandinvertebratedanimalsfirst，afterwardshigherexamplesofboth。
　　Inanarbitrarysystemwehadsurelynoreasontoexpectmammalsafterreptiles；yetinthisordertheycame。ThewriterintheEdinburghReviewspeaksofanimalsascominginadaptationtoconditions，butthisisonlytrueinalimitedsense。Thegroveswhichformedthecoal-bedsmighthavebeenafittinghabitationforreptiles，birds，andmammals，assuchgrovesareatthepresentday；yetweseenoneofthelastoftheseclassesandhardlyanytracesofthetwofirstatthatperiodoftheearth。
　　Wheretheiguanodonlivedtheelephantmighthavelived，buttherewasnoelephantatthattime。TheseaoftheLowerSilurianerawascapableofsupportingfish，butnofishexisted。Ithenceforciblyappearsthattheatresoflifemusthaveremainedunserviceable，orinthepossessionofatenantryinferiortowhatmighthaveenjoyedthem，formanyages:theresurelywouldhavebeennosuchwasteallowedinasystemwhereOmnipotencewasworkingupontheplanofminuteattentiontospecialities。Thefactseemstodenotethattheactualprocedureofthepeoplingoftheearthwasoneofanaturalkind，requiringalongspaceoftimeforitsevolution。Inthissuppositionthelongexistenceoflandwithoutlandanimals，andmoreparticularlywithoutthenoblestclassesandorders，isonlyanalogoustothefact，notnearlyenoughpresenttothemindsofacivilizedpeople，thattothisdaythebulkoftheearthisawasteasfarasmanisconcerned。
　　"Anotherstartlingobjectionisintheinfinitelocalvariationoforganicforms。Didthevegetableandanimalkingdomsconsistofadefinitenumberofspeciesadaptedtopeculiaritiesofsoilandclimate，anduniversallydistributed，thefactwouldbeinharmonywiththeideaofspecialexertion。Butthetruthisthatvariousregionsexhibitvariationsaltogetherwithoutapparentendorpurpose。ProfessorHenslowenumeratesforty-fivedistinctflowersorsetsofplantsuponthesurfaceoftheearth，notwithstandingthatmanyofthesewouldbeequallysuitableelsewhere。Theanimalsofdifferentcontinentsareequallyvarious，fewspeciesbeingthesameinanytwo，thoughthegeneralcharactermayconform。Theinferenceatpresentdrawnfromthisfactisthattheremusthavebeen，tousethelanguageoftheRev。Dr。PyeSmith，’separateandoriginalcreations，perhapsatdifferentandrespectivelydistinctepochs。’Itseemshardlyconceivablethatrationalmenshouldgiveanadherencetosuchadoctrinewhenwethinkofwhatitinvolves。InthesinglefactthatitnecessitatesaspecialfiatoftheinconceivableAuthorofthissand-cloudofworldstoproducethefloraofSt。
　　Helena，wereaditsmorethansufficientcondemnation。Itsurelyharmonizesfarbetterwithourgeneralideasofnaturetosupposethat，justasallelseinthisfar-spreadsciencewasformedonthelawsimpresseduponitatfirstbyitsAuthor，soalsowasthis。Anexceptionpresentedtousinsuchalightappearsadmissibleonlywhenwesucceedinforbiddingourmindstofollowoutthosereasoningprocessestowhich，byanotherlawoftheAlmighty，theytend，andforwhichtheyareadapted。"[4]
　　Suchreasoningasthisnaturallyarousedbitteranimadversions，andcannothavebeenwithouteffectincreatinganundercurrentofthoughtinoppositiontothemaintrendofopinionofthetime。Butthebookcanhardlybesaidtohavedonemorethanthat。Indeed，somecriticshavedeniediteventhismerit。Afteritspublication，asbefore，theconceptionoftransmutationofspeciesremainedinthepopularestimation，bothlayandscientific，analmostforgotten"heresy。"
　　Itistruethathereandthereascientistofgreaterorlessrepute——asVonBuch，Meckel，andVonBaerinGermany，BorySaint-VincentinFrance，Wells，Grant，andMatthewinEngland，andLeidyinAmerica——hadexpressedmoreorlesstentativedissentfromthedoctrineofspecialcreationandimmutabilityofspecies，buttheirunaggressivesuggestions，usuallyputforwardinobscurepublications，andincidentally，wereutterlyoverlookedandignored。Andso，despitethescientificadvancesalongmanylinesatthemiddleofthecentury，theideaofthetransmutabilityoforganicraceshadnosuchprominence，eitherinscientificorunscientificcircles，asithadacquiredfiftyyearsbefore。Specialcreationheldtheday，seeminglyunopposed。
　　DARWINANDTHEORIGINOFSPECIES
　　Butevenatthistimethefanciedsecurityofthespecial-creationhypothesiswasbynomeansreal。Thoughitseemedsoinvincible，itsrealpositionwasthatofanapparentlyimpregnablefortressbeneathwhich，allunbeknowntothegarrison，apowder-minehasbeendugandliesreadyforexplosion。Foralreadythereexistedinthesecludedwork-roomofanEnglishnaturalist，amanuscriptvolumeandaportfolioofnoteswhichmighthavesufficed，ifgivenpublicity，toshattertheentirestructureofthespecial-creationhypothesis。Thenaturalistwho，bydintoflongandpatienteffort，hadconstructedthispowder-mineoffactswasCharlesRobertDarwin，grandsonoftheauthorofZoonomia。
　　AslongagoasJuly1，1837，youngDarwin，thentwenty-eightyearsofage，hadopenedaprivatejournal，inwhichhepurposedtorecordallfactsthatcametohimwhichseemedtohaveanybearingonthemootpointofthedoctrineoftransmutationofspecies。Fourorfiveyearsearlier，duringthecourseofthatfamoustriparoundtheworldwithAdmiralFitzroy，asnaturalisttotheBeagle，Darwinhadmadethepersonalobservationswhichfirsttendedtoshakehisbeliefofthefixityofspecies。InSouthAmerica，inthePampeanformation，hehaddiscovered"greatfossilanimalscoveredwitharmorlikethatontheexistingarmadillos，"andhadbeenstruckwiththissimilarityoftypebetweenancientandexistingfaunasofthesameregion。Hewasalsogreatlyimpressedbythemannerinwhichcloselyrelatedspeciesofanimalswereobservedtoreplaceoneanotherasheproceededsouthwardoverthecontinent；and"bytheSouth-AmericancharacterofmostoftheproductionsoftheGalapagosArchipelago，andmoreespeciallybythemannerinwhichtheydifferslightlyoneachislandofthegroup，noneoftheislandsappearingtobeveryancientinageologicalsense。"
　　Atfirstthefullforceoftheseobservationsdidnotstrikehim；
　　for，underswayofLyell’sgeologicalconceptions，hetentativelyexplainedtherelativeabsenceoflifeononeoftheGalapagosIslandsbysuggestingthatperhapsnospecieshadbeencreatedsincethatislandarose。Butgraduallyitdawneduponhimthatsuchfactsashehadobserved"couldonlybeexplainedonthesuppositionthatspeciesgraduallybecomemodified。"Fromthenon，asheafterwardsasserted，thesubjecthauntedhim；hencethejournalof1837。
　　ItwillthusbeseenthattheideaofthevariabilityofspeciescametoCharlesDarwinasaninferencefrompersonalobservationsinthefield，notasathoughtborrowedfrombooks。Hehad，ofcourse，readtheworksofhisgrandfathermuchearlierinlife，buttheargumentsofZoonomiaandTheTempleofNaturehadnotservedintheleasttoweakenhisacceptanceofthecurrentbeliefinfixityofspecies。NorhadhebeenmoreimpressedwiththedoctrineofLamarck，socloselysimilartothatofhisgrandfather。Indeed，evenafterhisSouth-Americanexperiencehadarousedhimtoanewpointofviewhewasstillunabletoseeanythingofvalueintheseearlierattemptsatanexplanationofthevariationofspecies。Inopeninghisjournal，therefore，hehadnopreconceivednotionofupholdingtheviewsoftheseoranyothermakersofhypotheses，noratthetimehadheformulatedanyhypothesisofhisown。Hismindwasopenandreceptive；hewaseageronlyforfactswhichmightleadhimtoanunderstandingofaproblemwhichseemedutterlyobscure。Itwassomethingtofeelsurethatspecieshavevaried；buthowhavesuchvariationsbeenbroughtabout？
　　ItwasnotlongbeforeDarwinfoundaclewwhichhethoughtmightleadtotheanswerhesought。Incastingaboutforfactshehadsoondiscoveredthatthemostavailablefieldforobservationlayamongdomesticatedanimals，whosenumerousvariationswithinspecificlinesarefamiliartoeveryone。Thusunderdomesticationcreaturessotangiblydifferentasamastiffandaterrierhavesprungfromacommonstock。SohavetheShetlandpony，thethoroughbred，andthedraught-horse。Inshort，thereisnodomesticatedanimalthathasnotdevelopedvarietiesdeviatingmoreorlesswidelyfromtheparentstock。Now，howhasthisbeenaccomplished？Why，clearly，bythepreservation，throughselectivebreeding，ofseeminglyaccidentalvariations。Thusonehorseman，byconstantlyselectinganimalsthat"chance"tohavetherightbuildandstamina，finallydevelopsaraceofrunning-horses；whileanotherhorseman，byselectingadifferentseriesofprogenitors，hasdevelopedaraceofslow，heavydraughtanimals。
　　Sofar，sogood；thepreservationof"accidental"variationsthroughselectivebreedingisplainlyameansbywhichracesmaybedevelopedthatareverydifferentfromtheiroriginalparentform。Butthisisunderman’ssupervisionanddirection。Bywhatprocesscouldsuchselectionbebroughtaboutamongcreaturesinastateofnature？Heresurelywasapuzzle，andonethatmustbesolvedbeforeanotherstepcouldbetakeninthisdirection。
　　ThekeytothesolutionofthispuzzlecameintoDarwin’smindthroughachancereadingofthefamousessayon"Population"
　　whichThomasRobertMalthushadpublishedalmosthalfacenturybefore。Thisessay，expositingideasbynomeansexclusivelyoriginalwithMalthus，emphasizesthefactthatorganismstendtoincreaseatageometricalratiothroughsuccessivegenerations，andhencewouldoverpopulatetheearthifnotsomehowkeptincheck。Cogitatingthisthought，Darwingainedanewinsightintotheprocessesofnature。Hesawthatinvirtueofthistendencyofeachraceofbeingstooverpopulatetheearth，theentireorganicworld，animalandvegetable，mustbeinastateofperpetualcarnageandstrife，individualagainstindividual，fightingforsustenanceandlife。
　　Thatideafullyimagined，itbecomesplainthataselectiveinfluenceisallthetimeatworkinnature，sinceonlyafewindividuals，relatively，ofeachgenerationcancometomaturity，andthesefewmust，naturally，bethosebestfittedtobattlewiththeparticularcircumstancesinthemidstofwhichtheyareplaced。Inotherwords，theindividualsbestadaptedtotheirsurroundingswill，ontheaverage，bethosethatgrowtomaturityandproduceoffspring。Totheseoffspringwillbetransmittedthefavorablepeculiarities。Thusthesepeculiaritieswillbecomepermanent，andnaturewillhaveaccomplishedpreciselywhatthehumanbreederisseentoaccomplish。Grantthatorganismsinastateofnaturevary，howeverslightly，onefromanotherwhichisindubitable，andthatsuchvariationswillbetransmittedbyaparenttoitsoffspringwhichnoonethendoubted；grant，further，thatthereisincessantstrifeamongthevariousorganisms，sothatonlyasmallproportioncancometomaturity——grantthesethings，saidDarwin，andwehaveanexplanationofthepreservationofvariationswhichleadsontothetransmutationofspeciesthemselves。
　　ThiswonderfulcoignofvantageDarwinhadreachedby1839。Herewasthefulloutlineofhistheory；hereweretheideaswhichafterwardscametobeembalmedinfamiliarspeechinthephrases"spontaneousvariation，"andthe"survivalofthefittest，"
　　through"naturalselection。"Aftersuchadiscoveryanyordinarymanwouldatoncehaverunthroughthestreetsofscience，sotospeak，screaming"Eureka！"NotsoDarwin。Heplacedthemanuscriptoutlineofhistheoryinhisportfolio，andwentongatheringfactsbearingonhisdiscovery。In1844hemadeanabstractinamanuscriptbookofthemassoffactsbythattimeaccumulated。HeshowedittohisfriendHooker，madecarefulprovisionforitspublicationintheeventofhissuddendeath，thenstoreditawayinhisdeskandwentaheadwiththegatheringofmoredata。Thiswastheunexplodedpowder-minetowhichIhavejustreferred。
　　Twelveyearsmoreelapsed——yearsduringwhichthesilentworkergatheredaprodigiousmassoffacts，answeredamultitudeofobjectionsthataroseinhisownmind，vastlyfortifiedhistheory。Allthistimethetoilerwasaninvalid，neverknowingadayfreefromillnessanddiscomfort，obligedtohusbandhisstrength，neverabletoworkmorethananhourandahalfatastretch；yetheaccomplishedwhatwouldhavebeenvastachievementsforhalfadozenmenofrobusthealth。Twofriendsamongtheeminentscientistsofthedayknewofhislabors——SirJosephHooker，thebotanist，andSirCharlesLyell，thegeologist。GraduallyHookerhadcometobemorethanhalfaconverttoDarwin’sviews。Lyellwasstillsceptical，yetheurgedDarwintopublishhistheorywithoutfurtherdelaylesthebeforestalled。Atlastthepatientworkerdecidedtocomplywiththisadvice，andin1856hesettoworktomakeanotherandfullerabstractofthemassofdatahehadgathered。
　　Andthenastrangethinghappened。AfterDarwinhadbeenatworkonhis"abstract"abouttwoyears，butbeforehehadpublishedalineofit，therecametohimonedayapaperinmanuscript，sentforhisapprovalbyanaturalistfriendnamedAlfredRusselWallace，whohadbeenforsometimeatworkintheEastIndiaArchipelago。Hereadthepaper，and，tohisamazement，foundthatitcontainedanoutlineofthesametheoryof"naturalselection"whichhehimselfhadoriginatedandfortwentyyearshadworkedupon。Workingindependently，onoppositesidesoftheglobe，DarwinandWallacehadhituponthesameexplanationofthecauseoftransmutationofspecies。"WereWallace’spaperanabstractofmyunpublishedmanuscriptof1844，"saidDarwin，"itcouldnotbetterexpressmyideas。"
　　Herewasadilemma。TopublishthispaperwithnowordfromDarwinwouldgiveWallacepriority，andwrestfromDarwinthecreditofadiscoverywhichhehadmadeyearsbeforehiscodiscovererenteredthefield。Yet，ontheotherhand，couldDarwinhonorablydootherwisethanpublishhisfriend’spaperandhimselfremainsilent？Itwasacomplicationwellcalculatedtotryaman’ssoul。Darwin’swasequaltothetest。Keenlyalivetothedelicacyoftheposition，heplacedthewholematterbeforehisfriendsHookerandLyell，andleftthedecisionastoacourseofactionabsolutelytothem。Needlesstosay，thesegreatmendidtheonethingwhichinsuredfulljusticetoallconcerned。Theycounselledajointpublication，toincludeontheonehandWallace’spaper，andontheotheranabstractofDarwin’sideas，intheexactforminwhichithadbeenoutlinedbytheauthorinalettertoAsaGrayinthepreviousyear——anabstractwhichwasinGray’shandsbeforeWallace’spaperwasinexistence。Thisjointproduction，togetherwithafullstatementofthefactsofthecase，waspresentedtotheLinnaeanSocietyofLondonbyHookerandLyellontheeveningofJuly1，1858，thisbeing，byanoddcoincidence，thetwenty-firstanniversaryofthedayonwhichDarwinhadopenedhisjournaltocollectfactsbearingonthe"speciesquestion。"Notoftenbeforeinthehistoryofsciencehasithappenedthatagreattheoryhasbeennurturedinitsauthor’sbrainthroughinfancyandadolescencetoitsfulllegalmajoritybeforebeingsentoutintotheworld。
　　Thusthefusethatledtothegreatpowder-minehadbeenlighted。
　　Theexplosionitselfcamemorethanayearlater，inNovember，1859，whenDarwin，afterthirteenmonthsoffurthereffort，completedtheoutlineofhistheory，whichwasatfirstbegunasanabstractfortheLinnaeanSociety，butwhichgrewtothesizeofanindependentvolumedespitehiseffortsatcondensation，andwhichwasgiventhatever-to-be-famoustitle，TheOriginofSpeciesbyMeansofNaturalSelection，orthePreservationofFavoredRacesintheStruggleforLife。Andwhatanexplosionitwas！Thejointpaperof1858hadmadeamomentaryflare，causingthehearers，asHookersaid，to"speakofitwithbatedbreath，"
　　butbeyondthatitmadenosensation。WhattheresultwaswhentheOriginitselfappearednooneofourgenerationneedbetold。
　　Therumbleandroarthatitmadeintheintellectualworldhavenotyetaltogetherceasedtoechoaftermorethanfortyyearsofreverberation。
　　NEWCHAMPIONS
　　TotheOriginofSpecies，then，andtoitsauthor，CharlesDarwin，mustalwaysbeascribedchiefcreditforthatvastrevolutioninthefundamentalbeliefsofourracewhichhascomeaboutsince1859，andwhichmadethesecondhalfofthecenturymemorable。Butitmustnotbeoverlookedthatnosuchsuddenmetamorphosiscouldhavebeeneffectedhaditnotbeenfortheaidofafewnotablelieutenants，whoralliedtothestandardsoftheleaderimmediatelyafterthepublicationoftheOrigin。
　　Darwinhadallalongfelttheutmostconfidenceintheultimatetriumphofhisideas。"Ourposterity，"hedeclared，inalettertoHooker，"willmarvelasmuchaboutthecurrentbelief[inspecialcreation]aswedoaboutfossilshellshavingbeenthoughttobecreatedaswenowseethem。"Buthefullyrealizedthatforthepresentsuccessofhistheoryoftransmutationthechampionshipofafewleadersofsciencewasall-essential。HefeltthatifhecouldmakeconvertsofHookerandLyellandofThomasHenryHuxleyatonce，allwouldbewell。
　　Hissuccessinthisregard，asinothers，exceededhisexpectations。Hookerwasanardentdisciplefromreadingtheproof-sheetsbeforethebookwaspublished；Lyellrenouncedhisformerbeliefsandfellintolineafewmonthslater；whileHuxley，sosoonashehadmasteredthecentralideaofnaturalselection，marvelledthatsosimpleyetall-potentathoughthadescapedhimsolong，andthenrushedeagerlyintothefray，wieldingthekeenestdialecticbladethatwasdrawnduringtheentirecontroversy。Then，too，unexpectedrecruitswerefoundinSirJohnLubbockandJohnTyndall，whocarriedthewareagerlyintotheirrespectiveterritories；whileHerbertSpencer，whohadadvocatedadoctrineoftransmutationonphilosophicgroundssomeyearsbeforeDarwinpublishedthekeytothemystery——andwhohimselfhadbarelyescapedindependentdiscoveryofthatkey——lenthismasterfulinfluencetothecause。InAmericathefamousbotanistAsaGray，whohadlongbeenacorrespondentofDarwin’sbutwhoseadvocacyofthenewtheoryhadnotbeenanticipated，becameanardentpropagandist；whileinGermanyErnstHeinrichHaeckel，theyouthfulbutalreadynotedzoologist，tookupthefightwithequalenthusiasm。
　　Againstthesefewdoughtychampions——withhereandthereanotheroflessgeneralrenown——wasarrayed，attheoutset，practicallyallChristendom。Theinterestofthequestioncamehometoeverypersonofintelligence，whateverhiscalling，andthemoredeeplyasitbecamemoreandmoreclearhowfar-reachingaretherealbearingsofthedoctrineofnaturalselection。Soonitwasseenthatshouldthedoctrineofthesurvivalofthefavoredracesthroughthestruggleforexistencewin，theremustcomewithitasradicalachangeinman’sestimateofhisownpositionashadcomeinthedaywhen，throughtheeffortsofCopernicusandGalileo，theworldwasdethronedfromitssupposedcentralpositionintheuniverse。Thewholeconservativemajorityofmankindrecoiledfromthisnecessitywithhorror。Andthisconservativemajorityincludednotlaymenmerely，butavastpreponderanceoftheleadersofsciencealso。
　　Withtheopen-mindedminority，ontheotherhand，thetheoryofnaturalselectionmadeitswaybyleapsandbounds。Itsdelightfulsimplicity——whichatfirstsightmadeitseemneithernewnorimportant——coupledwiththemarvellouscomprehensivenessofitsimplications，gaveitaholdontheimagination，andsecureditahearingwhereothertheoriesoftransmutationofspecieshadbeenutterlyscorned。MenwhohadfoundLamarck’sconceptionofchangethroughvoluntaryeffortridiculous，andthevaporingsoftheVestigesaltogetherdespicable，menwhosescientificcautionsheldthembackfromSpencer’sdeductiveargument，tookeagerholdofthattangible，ever-presentprincipleofnaturalselection，andwereledonandontoitsgoal。Hourbyhourtheattitudeofthethinkingworldtowardsthisnewprinciplechanged；neverbeforewassogreatarevolutionwroughtsosuddenly。
　　Norwasthismerelybecause"thetimeswereripe"or"men’smindspreparedforevolution。"Darwinhimselfbearswitnessthatthiswasnotaltogetherso。Allthroughtheyearsinwhichhebroodedthistheoryhesoundedhisscientificfriends，andcouldfindamongthemnotonewhoacknowledgedadoctrineoftransmutation。
　　Thereactionfromthestand-pointofLamarckandErasmusDarwinandGoethehadbeencomplete，andwhenCharlesDarwinavowedhisownconvictionheexpectedalwaystohaveitmetwithridiculeorcontempt。In1857therewasbutonemanspeakingwithanylargedegreeofauthorityintheworldwhoopenlyavowedabeliefintransmutationofspecies——thatmanbeingHerbertSpencer。ButtheOriginofSpeciescame，asHuxleyhassaid，likeaflashinthedarkness，enablingthebenightedvoyagertoseetheway。Thescoreofyearsduringwhichitsauthorhadwaitedandworkedhadbeenyearswellspent。Darwinhadbecome，ashehimselfsays，averitableCroesus，"overwhelmedwithhisrichesinfacts"——factsofzoology，ofselectiveartificialbreeding，ofgeographicaldistributionofanimals，ofembryology，ofpaleontology。Hehadmassedhisfactsabouthistheory，condensedthemandrecondensed，untilhisvolumeoffivehundredpageswasanencyclopaediainscope。Duringthoselongyearsofmusinghehadthoughtoutalmosteveryconceivableobjectiontohistheory，andinhisbookeverysuchobjectionwasstatedwithfullestforceandcandor，togetherwithsuchreplyasthefactsatcommandmightdictate。Itwastheforceofthosetwentyyearsofeffortofamaster-mindthatmadethesuddenbreachinthebreaswtork{sic}ofcurrentthought。
　　Oncethisbreachwaseffectedtheworkofconquestwentrapidlyon。Daybydaysquadsoftheenemycapitulatedandstrucktheirarms。Bythetimeanotherscoreofyearshadpassedthedoctrineofevolutionhadbecometheworkinghypothesisofthescientificworld。Therevolutionhadbeeneffected。
　　AndfromamidthewreckageofopinionandbeliefstandsforththefigureofCharlesDarwin，calm，imperturbable，serene；scathelesstoridicule，contumely，abuse；unspoiledbyultimatesuccess；
　　unsulliedalikebythestrifeandthevictory——takehimforallinall，forcharacter，forintellect，forwhathewasandwhathedid，perhapsthemostSocraticfigureofthecentury。When，in1882，hedied，friendandfoealikeconcededthatoneofthegreatestsonsofmenhadrestedfromhislabors，andalltheworldfeltitfittingthattheremainsofCharlesDarwinshouldbeentombedinWestminsterAbbeyclosebesidethehonoredgraveofIsaacNewton。NorweretheremanywhowoulddisputethejusticeofHuxley’sestimateofhisaccomplishment:"Hefoundagreattruthtroddenunderfoot。Reviledbybigots，andridiculedbyalltheworld，helivedlongenoughtoseeit，chieflybyhisownefforts，irrefragablyestablishedinscience，inseparablyincorporatedwiththecommonthoughtsofmen，andonlyhatedandfearedbythosewhowouldrevilebutdarenot。"
　　THEORIGINOFTHEFITTEST
　　WideasaretheimplicationsofthegreattruthwhichDarwinandhisco-workersestablished，however，itleavesquiteuntouchedtheproblemoftheoriginofthose"favoredvariations"uponwhichitoperates。ThatsuchvariationsareduetofixedanddeterminatecausesnooneunderstoodbetterthanDarwin；butinhisoriginalexpositionofhisdoctrinehemadenoassumptionastowhatthesecausesare。Heacceptedtheobservedfactofvariation——asconstantlywitnessed，forexample，inthedifferencesbetweenparentsandoffspring——andwentaheadfromthisassumption。
　　Butassoonasthevalidityoftheprincipleofnaturalselectioncametobeacknowledgedspeculatorsbegantosearchfortheexplanationofthosevariationswhich，forpurposesofargument，hadbeenprovisionallycalled"spontaneous。"HerbertSpencerhadallalongdweltonthisphaseofthesubject，expoundingtheLamarckianconceptionsofthedirectinfluenceoftheenvironmentanideawhichhadespeciallyappealedtoBuffonandtoGeoffroySaint-Hilaire，andofeffortinresponsetoenvironmentandstimulusasmodifyingtheindividualorganism，andthussupplyingthebasisfortheoperationofnaturalselection。Haeckelalsobecameanadvocateofthisidea，andpresentlytherearoseaso-calledschoolofneo-Lamarckians，whichdevelopedparticularstrengthandprominenceinAmericaundertheleadershipofProfessorsA。HyattandE。D。Cope。
　　Butjustasthetideofopinionwasturningstronglyinthisdirection，anutterlyunexpectedobstacleappearedintheformofthetheoryofProfessorAugustWeismann，putforwardin1883，whichantagonizedtheLamarckianconceptionthoughnottouchingtheDarwinian，ofwhichWeismannisafirmupholderbydenyingthatindividualvariations，howeveracquiredbythematureorganism，aretransmissible。Theflurrywhichthisdenialcreatedhasnotyetaltogethersubsided，butsubsequentobservationsseemtoshowthatitwasquitedisproportionatetotherealmeritsofthecase。NotwithstandingProfessorWeismann’sobjections，thebalanceofevidenceappearstofavortheviewthattheLamarckianfactorofacquiredvariationsstandsasthecomplementoftheDarwinianfactorofnaturalselectionineffectingthetransmutationofspecies。
　　EventhoughthispartialexplanationofwhatProfessorCopecallsthe"originofthefittest"beaccepted，therestillremainsonegreatlifeproblemwhichthedoctrineofevolutiondoesnottouch。Theoriginofspecies，genera，orders，andclassesofbeingsthroughendlesstransmutationsisinasenseexplained；
　　butwhatofthefirsttermofthislongseries？Whencecamethatprimordialorganismwhosetransmuteddescendantsmakeuptheexistingfaunasandflorasoftheglobe？
　　Therewasatime，soonafterthedoctrineofevolutiongainedahearing，whentheanswertothatquestionseemedtosomescientistsofauthoritytohavebeengivenbyexperiment。
　　Recurringtoaformerbelief，andrepeatingsomeearlierexperiments，thedirectoroftheMuseumofNaturalHistoryatRouen，M。F。A。Pouchet，reachedtheconclusionthatorganicbeingsarespontaneouslygeneratedaboutusconstantly，inthefamiliarprocessesofputrefaction，whichwereknowntobeduetotheagencyofmicroscopicbacteria。Butin1862LouisPasteurprovedthatthisseemingspontaneousgenerationisinrealityduetotheexistenceofgermsintheair。Notwithstandingtheconclusivenessoftheseexperiments，theclaimsofPouchetwererevivedinEnglandtenyearslaterbyProfessorBastian；butthentheexperimentsofJohnTyndall，fullycorroboratingtheresultsofPasteur，gaveafinalquietustotheclaimof"spontaneousgeneration"ashithertoformulated。
　　Thereforthemomentthematterrests。Buttheendisnotyet。
　　Faunaandfloraarehere，and，thankstoLamarckandWallaceandDarwin，theirdevelopment，throughtheoperationofthose"secondarycauses"whichwecalllawsofnature，hasbeenproximallyexplained。Thelowestformsoflifehavebeenlinkedwiththehighestinunbrokenchainsofdescent。Meantime，throughtheeffortsofchemistsandbiologists，thegapbetweentheinorganicandtheorganicworlds，whichonceseemedalmostinfinite，hasbeenconstantlynarrowed。Alreadyphilosophycanthrowabridgeacrossthatgap。Butinductivescience，whichbuildsitsownbridges，hasnotyetspannedthechasm，smallthoughitappear。Untilitshallhavedoneso，thebridgeoforganicevolutionisnotquitecomplete；yetevenasitstandsto-dayitisperhapsthemoststupendousscientificstructureofthenineteenthcentury。
　　VII。EIGHTEENTH-CENTURYMEDICINE
　　THESYSTEMOFBOERHAAVE
　　AtleasttwopupilsofWilliamHarveydistinguishedthemselvesinmedicine，GiorgioBaglivi1669-1707，whohasbeencalledthe"ItalianSydenham，"andHermannBoerhaave1668-1738。TheworkofBagliviwashardlybegunbeforehisearlydeathremovedoneofthemostpromisingoftheearlyeighteenth-centuryphysicians。
　　LikeBoerhaave，herepresentsatypeofskilled，practicalclinitianratherthantheabstractscientist。Oneofhiscontributionstomedicalliteratureisthefirstaccuratedescriptionoftyphoid，or，ashecallsit，mesentericfever。
　　Iffornothingelse，BoerhaavemustalwaysberememberedastheteacherofVonHaller，butinhisowndayhewasthewidestknownandthemostpopularteacherinthemedicalworld。HewastheidolofhispupilsatLeyden，whoflockedtohislecturesinsuchnumbersthatitbecamenecessaryto"teardownthewallsofLeydentoaccommodatethem。"HisfameextendednotonlyalloverEuropebuttoAsia，NorthAmerica，andevenintoSouthAmerica。
　　AlettersenthimfromChinawasaddressedto"BoerhaaveinEurope。"Histeachingsrepresentthebestmedicalknowledgeofhisday，ahighstandardofmorality，andakeenappreciationofthevalueofobservation；anditwasthroughsuchteachingsimpartedtohispupilsandadvancedbythem，ratherthantoanynewdiscoveries，thathisnameisimportantinmedicalhistory。
　　Hisarrangementandclassificationofthedifferentbranchesofmedicineareinterestingasrepresentingtheattitudeofthemedicalprofessiontowardsthesevariousbranchesatthattime。
　　"InthefirstplaceweconsiderLife；thenHealth，afterwardsDiseases；andlastlytheirseveralRemedies。
　　"HealththefirstgeneralbranchofPhysicinourInstitutionsistermedPhysiology，ortheAnimalOeconomy；demonstratingtheseveralPartsofthehumanBody，withtheirMechanismandActions。
　　"ThesecondbranchofPhysiciscalledPathology，treatingofDiseases，theirDifferences，CausesandEffects，orSymptoms；bywhichthehumanBodyisknowntovaryfromitshealthystate。
　　"ThethirdpartofPhysicistermedSemiotica，whichshowstheSignsdistinguishingbetweensicknessandHealth，DiseasesandtheirCausesinthehumanBody；italsoimportstheStateandDegreesofHealthandDiseases，andpresagestheirfutureEvents。
　　"ThefourthgeneralbranchofPhysicistermedHygiene，orProphylaxis。
　　"ThefifthandlastpartofPhysiciscalledTherapeutica；whichinstructsusintheNature，PreparationandusesoftheMateriaMedica；andthemethodsofapplyingthesame，inordertocureDiseasesandrestorelostHealth。"[1]
　　Fromthiswemaygatherthathisgeneralviewofmedicinewasnotunlikethattakenatthepresenttime。
　　Boerhaave’sdoctrineswerearrangedintoa"system"byFriedrichHoffmann，ofHalle1660-1742，thissystemhavingthemeritofbeingsimpleandmoreeasilycomprehendedthanmanyothers。Inthissystemforceswereconsideredinherentinmatter，beingexpressedasmechanicalmovements，anddeterminedbymass，number，andweight。Similarly，forcesexpressthemselvesinthebodybymovement，contraction，andrelaxation，etc。，andlifeitselfismovement，"particularlymovementoftheheart。"Lifeanddeathare，therefore，mechanicalphenomena，healthisdeterminedbyregularlyrecurringmovements，anddiseasebyirregularityofthem。Thebodyissimplyalargehydraulicmachine，controlledby"theaether"or"sensitivesoul，"andthechiefcentreofthissoulliesinthemedulla。
　　InthepracticalapplicationofmedicinestodiseasesHoffmanusedsimpleremedies，frequentlywithhappyresults，forwhateverthemedicalman’stheorymaybeheseldomhasthetemeritytofollowitoutlogically，andusetheremediesindicatedbyhistheorytotheexclusionoflong-established，althoughperhapspurelyempirical，remedies。Consequently，manyvaguetheoristshavebeenexcellentpractitioners，andHoffmanwasoneofthese。
　　Someoftheremediesheintroducedarestillinuse，notablythespiritsofether，or"Hoffman’sanodyne。"
　　ANIMISTS，VITALISTS，ANDORGANICISTS
　　BesidesHoffman’ssystemofmedicine，therewerenumerousothersduringtheeighteenthcentury，mostofwhichareofnoimportancewhatever；butthree，atleast，thatcameintoexistenceanddisappearedduringthecenturyareworthyoffullernotice。Oneofthese，theAnimists，hadforitschiefexponentGeorgErnstStahlof"phlogiston"fame；another，theVitalists，waschampionedbyPaulJosephBarthez1734-1806；andthethirdwastheOrganicists。Thislast，whileagreeingwiththeothertwothatvitalactivitycannotbeexplainedbythelawsofphysicsandchemistry，differedinnotbelievingthatlife"wasduetosomespiritualentity，"butrathertothestructureofthebodyitself。
　　TheAnimiststaughtthatthesoulperformedfunctionsofordinarylifeinman，whilethelifeofloweranimalswascontrolledbyordinarymechanicalprinciples。Stahlsupportedthistheoryardently，sometimesviolently，attimesdeclaringthattherewere"nolongeranydoctors，onlymechanicsandchemists。"Hedeniedthatchemistryhadanythingtodowithmedicine，and，inthemain，discardedanatomyasuselesstothemedicalman。Thesoul，hethought，wasthesourceofallvitalmovement；andtheimmediatecauseofdeathwasnotdiseasebutthedirectactionofthesoul。Whenthroughsomelesion，orbecausethemachineryofthebodyhasbecomeunworkable，asinoldage，thesoulleavesthebodyanddeathisproduced。Thesoulordinarilyselectsthechannelsofthecirculation，andthecontractileparts，astherouteforinfluencingthebody。Henceinfeverthepulseisquickened，duetotheincreasedactivityofthesoul，andconvulsionsandspasmodicmovementsindiseasearedue，tothe，samecause。Stagnationofthe，bloodwassupposedtobeafertilecauseofdiseases，andsuchdiseasesweresupposedtoarisemostlyfrom"plethora"——anall-importantelementinStahl’stherapeutics。BymanythistheoryisregardedasanattemptonthepartofthepiousStahltoreconcilemedicineandtheologyinawaysatisfactorytobothphysiciansandtheologians，but，likemanyconciliatoryattempts，itwasviolentlyopposedbybothdoctorsandministers。
　　Abeliefinsuchatheorywouldleadnaturallytosimplicityintherapeutics，andinthisrespectatleastStahlwasconsistent。
　　Sincethesoulknewmoreaboutthebodythananyphysiciancouldknow，Stahlconceivedthatitwouldbeahinderanceratherthanahelpforthephysiciantointerferewithcomplicateddosesofmedicine。Asheadvancedinagethisviewoftheadministrationofdrugsgrewuponhim，untilafterrejectingquinine，andfinallyopium，heatlastusedonlysaltandwaterintreatinghispatients。Fromthislastwemayjudgethathis"system，"ifnotdoingmuchgood，wasatleastdoinglittleharm。
　　ThetheoryoftheVitalistswascloselyalliedtothatoftheAnimists，anditsmostimportantrepresentative，PaulJosephBarthez，wasaculturedandeagerscientist。Afteraneventfulandvariedcareerasphysician，soldier，editor，lawyer，andphilosopherinturn，hefinallyreturnedtothefieldofmedicine，wasmadeconsultingphysicianbyNapoleonin1802，anddiedinParisfouryearslater。
　　Thetheorythathechampionedwasbasedontheassumptionthattherewasa"vitalprinciple，"thenatureofwhichwasunknown，butwhichdifferedfromthethinkingmind，andwasthecauseofthephenomenaoflife。This"vitalprinciple"differedfromthesoul，andwasnotexhibitedinhumanbeingsalone，buteveninanimalsandplants。Thisforce，orwhateveritmightbecalled，wassupposedtobepresenteverywhereinthebody，andalldiseasesweretheresultsofit。
　　ThetheoryoftheOrganicists，likethatoftheAnimistsandVitalists，agreedwiththeothertwothatvitalactivitycouldnotbeexplainedbythelawsofphysicsandchemistry，but，unlikethem，itheldthatitwasapartofthestructureofthebodyitself。Naturallythepracticalphysiciansweremoreattractedbythistangibledoctrinethanbyvaguetheories"whichconverteddiseasesintounknownderangementsofsomeequallyunknown’principle。’"
　　Itisperhapsstrainingapointtoincludethisbriefdescriptionofthesethreeschoolsofmedicineinthehistoryoftheprogressofthescience。But，onthewhole，theywerenegativelyatleastprominentfactorsindirectingtrueprogressalongitsproperchannel，showingwhatcourseswerenottobepursued。Someonehassaidthatscienceusuallystumblesintotherightcourseonlyafterstumblingintoallthewrongones；andifthisbeonlypartiallytrue，thewrongonesstillplayaprominentifnotaverycreditablepart。ThusthemedicalsystemsofWilliamCullen1710-1790，andJohnBrown1735-1788，whiledoinglittletowardstheactualadvancementofscientificmedicine，playedsoconspicuousapartinsowideafieldthatthe"Brunoniansystem"
　　atleastmustbegivensomelittleattention。
　　AccordingtoBrown’stheory，life，diseases，andmethodsofcureareexplainedbythepropertyof"excitability。"Allexcitingpowersweresupposedtobestimulating，theapparentdebilitatingeffectsofsomebeingduetoadeficiencyintheamountofstimulus。Thus"thewholephenomenaoflife，health，aswellasdisease，weresupposedtoconsistofstimulusandnothingelse。"
　　Thistheorycreatedagreatstirinthemedicalworld，andpartisansandopponentssprangupeverywhere。InItalyitwasenthusiasticallysupported；inEnglanditwasstronglyopposed；
　　whileinScotlandriotstookplacebetweentheopposingfactions。
　　Justwhythissystemshouldhavecreatedanystir，eitherfororagainstit，isnotnowapparent。
　　Likesomanyoftheother"theorists"ofhiscentury，Brown’spracticalconclusionsdeducedfromhistheoryorperhapsinspiteofitweregenerallybeneficialtomedicine，andsomeofthemextremelyvaluableinthetreatmentofdiseases。Hefirstadvocatedthemodernstimulant，or"feedingtreatment"offevers，andfirstrecognizedtheusefulnessofanimalsoupsandbeef-teaincertaindiseases。