\"Permitmetotakethisopportunitytoexpressmysincereregretathavingcommittedtwograveerrorsinthelasteditionofmy’OriginofSpecies，’
inmyallusiontoyoursandProfessorCope’sviewsonaccelerationandretardationofdevelopment。IhadthoughtthatProfessorCopehadprecededyou;butInowwellrememberhavingformerlyreadwithlivelyinterest，andmarked，apaperbyyousomewhereinmylibrary，onfossilCephalapodswithremarksonthesubject。ItseemsalsothatIhavequitemisrepresentedyourjointview。Thishasvexedmemuch。IconfessthatIhaveneverbeenabletograspfullywhatyouwishtoshow，andIpresumethatthismustbeowingtosomedulnessonmypart。\"
Lastly，itmaybementionedthatthischeapeditionbeingtosomeextentintendedasapopularone，wasmadetoincludeaglossaryoftechnicalterms，\"givenbecauseseveralreadershavecomplained……thatsomeofthetermsusedwereunintelligibletothem。\"TheglossarywascompiledbyMr。
Dallas，andbeinganexcellentcollectionofclearandsufficientdefinitions，musthaveprovedusefultomanyreaders。]
CHARLESDARWINTOJ。L。A。DEQUATREFAGES。
Down，January15，1872。
MydearSir，Iammuchobligedforyourverykindletterandexertionsinmyfavour。I
hadthoughtthatthepublicationofmylastbook[’DescentofMan’]wouldhavedestroyedallyoursympathywithme，butthoughIestimatedveryhighlyyourgreatliberalityofmind，itseemsthatIunderratedit。
IamgratifiedtohearthatM。Lacaze—Duthierswillvote（HewasnotelectedasacorrespondingmemberoftheFrenchAcademyuntil1878。）forme，forIhavelonghonouredhisname。Icannothelpregrettingthatyoushouldexpendyourvaluabletimeintryingtoobtainformethehonourofelection，forIfear，judgingfromthelasttime，thatallyourlabourwillbeinvain。Whatevertheresultmaybe，Ishallalwaysretainthemostlivelyrecollectionofyoursympathyandkindness，andthiswillquiteconsolemeformyrejection。
Withmuchrespectandesteem，Iremain，dearSir，Yourstrulyobliged，CHARLESDARWIN。
P。S。——Withrespecttothegreatstresswhichyoulayonmanwalkingontwolegs，whilstthequadrumanagoonallfours，permitmetoremindyouthatnoonemuchvaluesthegreatdifferenceinthemodeoflocomotion，andconsequentlyinstructure，betweensealsandtheterrestrialcarnivora，orbetweenthealmostbipedkangaroosandothermarsupials。
CHARLESDARWINTOAUGUSTWEISMANN。（ProfessorofZoologyinFreiburg。）
Down，April5，1872。
MydearSir，Ihavenowreadyouressay（’UeberdenEinflussderIsolirungaufdieArtbildung。’Leipzig，1872。）withverygreatinterest。Yourviewofthe’Origin’oflocalracesthrough\"Amixie，\"isaltogethernewtome，andseemstothrowanimportantlightonanobscureproblem。Thereis，however，somethingstrangeabouttheperiodsorenduranceofvariability。
Iformerlyendeavouredtoinvestigatethesubject，notbylookingtopasttime，buttospeciesofthesamegenuswidelydistributed;andIfoundinmanycasesthatallthespecies，withperhapsoneortwoexceptions，werevariable。Itwouldbeaveryinterestingsubjectforaconchologisttoinvestigate，viz。，whetherthespeciesofthesamegenuswerevariableduringmanysuccessivegeologicalformations。Ibegantomakeenquiriesonthishead，butfailedinthis，asinsomanyotherthings，fromthewantoftimeandstrength。Inyourremarksoncrossing，youdonot，asitseemstome，laynearlystressenoughontheincreasedvigouroftheoffspringderivedfromparentswhichhavebeenexposedtodifferentconditions。I
haveduringthelastfiveyearsbeenmakingexperimentsonthissubjectwithplants，andhavebeenastonishedattheresults，whichhavenotyetbeenpublished。
Inthefirstpartofyouressay，Ithoughtthatyouwasted（touseanEnglishexpression）toomuchpowderandshotonM。Wagner（Prof。Wagnerhaswrittentwoessaysonthesamesubject。’DieDarwin’scheTheorieunddasMigrationsgesetz，in1868，and’UeberdenEinflussderGeographischenIsolirung，etc。，’anaddresstotheBavarianAcademyofSciencesatMunich，1870。）;butIchangedmyopinionwhenIsawhowadmirablyyoutreatedthewholecase，andhowwellyouusedthefactsaboutthePlanorbis。IwishI
hadstudiedthislattercasemorecarefully。Themannerinwhich，asyoushow，thedifferentvarietiesblendtogetherandmakeaconstantwhole，agreesperfectlywithmyhypotheticalillustrations。
ManyyearsagothelateE。Forbesdescribedthreecloselyconsecutivebedsinasecondaryformation，eachwithrepresentativeformsofthesamefresh—
watershells:thecaseisevidentlyanalogouswiththatofHilgendorf（\"UeberPlanorbismultiformisimSteinheimerSusswasser—kalk。\"
MonatsberichtoftheBerlinAcademy，1866。），buttheinterestingconnectingvarietiesorlinkswerehereabsent。IrejoicetothinkthatIformerlysaidasemphaticallyasIcould，thatneitherisolationnortimebythemselvesdoanythingforthemodificationofspecies。Hardlyanythinginyouressayhaspleasedmesomuchpersonally，astofindthatyoubelievetoacertainextentinsexualselection。AsfarasIcanjudge，veryfewnaturalistsbelieveinthis。Imayhaveerredonmanypoints，andextendedthedoctrinetoofar，butIfeelastrongconvictionthatsexualselectionwillhereafterbeadmittedtobeapowerfulagency。Icannotagreewithwhatyousayaboutthetasteforbeautyinanimalsnoteasilyvarying。Itmaybesuspectedthateventhehabitofviewingdifferentlycolouredsurroundingobjectswouldinfluencetheirtaste，andFritzMullerevengoessofarastobelievethatthesightofgaudybutterfliesmightinfluencethetasteofdistinctspecies。Therearemanyremarksandstatementsinyouressaywhichhaveinterestedmegreatly，andIthankyouforthepleasurewhichIhavereceivedfromreadingit。
Withsincererespect，Iremain，MydearSir，yoursveryfaithfully，CHARLESDARWIN。
P。S。——Ifyoushouldeverbeinducedtoconsiderthewholedoctrineofsexualselection，Ithinkthatyouwillbeledtotheconclusion，thatcharactersthusgainedbyonesexareverycommonlytransferredinagreaterorlessdegreetotheothersex。
[WithregardtoMoritzWagner’sfirstEssay，myfatherwrotetothatnaturalist，apparentlyin1868:]
DearandrespectedSir，Ithankyousincerelyforsendingmeyour’Migrationsgesetz，etc。，’andfortheverykindandmosthonourablenoticewhichyouhavetakenofmyworks。
Thatanaturalistwhohastravelledintosomanyandsuchdistantregions，andwhohasstudiedanimalsofsomanyclasses，should，toaconsiderableextent，agreewithme，is，Icanassureyou，thehighestgratificationofwhichIamcapable……AlthoughIsawtheeffectsofisolationinthecaseofislandsandmountain—ranges，andknewofafewinstancesofrivers，yetthegreaternumberofyourfactswerequiteunknowntome。InowseethatfromthewantofknowledgeIdidnotmakenearlysufficientuseoftheviewswhichyouadvocate;andIalmostwishIcouldbelieveinitsimportancetothesameextentwithyou;foryouwellshow，inamannerwhichneveroccurredtome，thatitremovesmanydifficultiesandobjections。ButI
muststillbelievethatinmanylargeareasalltheindividualsofthesamespecieshavebeenslowlymodified，inthesamemanner，forinstance，astheEnglishrace—horsehasbeenimproved，thatisbythecontinuedselectionofthefleetestindividuals，withoutanyseparation。ButIadmitthatbythisprocesstwoormorenewspeciescouldhardlybefoundwithinthesamelimitedarea;somedegreeofseparation，ifnotindispensable，wouldbehighlyadvantageous;andhereyourfactsandviewswillbeofgreatvalue……
[Thefollowingletterbearsonthesamesubject。ItreferstoProfessorM。
Wagner’sEssay，publishedin\"DasAusland\"，May31，1875:]
CHARLESDARWINTOMORITZWAGNER。
Down，October13，1876。
DearSir，Ihavenowfinishedreadingyouressays，whichhaveinterestedmeinaveryhighdegree，notwithstandingthatIdiffermuchfromyouonvariouspoints。
Forinstance，severalconsiderationsmakemedoubtwhetherspeciesaremuchmorevariableatoneperiodthanatanother，exceptthroughtheagencyofchangedconditions。Iwish，however，thatIcouldbelieveinthisdoctrine，asitremovesmanydifficulties。Butmystrongestobjectiontoyourtheoryisthatitdoesnotexplainthemanifoldadaptationsinstructureineveryorganicbeing——forinstanceinaPicusforclimbingtreesandcatchinginsects——orinaStrixforcatchinganimalsatnight，andsoonadinfinitum。Notheoryisintheleastsatisfactorytomeunlessitclearlyexplainssuchadaptations。Ithinkthatyoumisunderstandmyviewsonisolation。Ibelievethatalltheindividualsofaspeciescanbeslowlymodifiedwithinthesamedistrict，innearlythesamemannerasmaneffectsbywhatIhavecalledtheprocessofunconsciousselection……Idonotbelievethatonespecieswillgivebirthtotwoormorenewspeciesaslongastheyaremingledtogetherwithinthesamedistrict。NeverthelessIcannotdoubtthatmanynewspecieshavebeensimultaneouslydevelopedwithinthesamelargecontinentalarea;andinmy’OriginofSpecies’Iendeavouredtoexplainhowtwonewspeciesmightbedeveloped，althoughtheymetandintermingledontheBORDERSoftheirrange。ItwouldhavebeenastrangefactifIhadoverlookedtheimportanceofisolation，seeingthatitwassuchcasesasthatoftheGalapagosArchipelago，whichchieflyledmetostudytheoriginofspecies。
InmyopinionthegreatesterrorwhichIhavecommitted，hasbeennotallowingsufficientweighttothedirectactionoftheenvironment，i。e。
food，climate，etc。，independentlyofnaturalselection。Modificationsthuscaused，whichareneitherofadvantagenordisadvantagetothemodifiedorganism，wouldbeespeciallyfavoured，asIcannowseechieflythroughyourobservations，byisolationinasmallarea，whereonlyafewindividualslivedundernearlyuniformconditions。
WhenIwrotethe’Origin，’andforsomeyearsafterwards，Icouldfindlittlegoodevidenceofthedirectactionoftheenvironment;nowthereisalargebodyofevidence，andyourcaseoftheSaturniaisoneofthemostremarkableofwhichIhaveheard。Althoughwediffersogreatly，Ihopethatyouwillpermitmetoexpressmyrespectforyourlong—continuedandsuccessfullaboursinthegoodcauseofnaturalscience。
Iremain，dearSir，yoursveryfaithfully，CHARLESDARWIN。
[Thetwofollowinglettersarealsoofinterestasbearingonmyfather’sviewsontheactionofisolationasregardstheoriginofnewspecies:]
CHARLESDARWINTOK。SEMPER。
Down，November26，1878。
MydearProfessorSemper，WhenIpublishedthesixtheditionofthe’Origin，’Ithoughtagooddealonthesubjecttowhichyourefer，andtheopinionthereinexpressedwasmydeliberateconviction。IwentasfarasIcould，perhapstoofarinagreementwithWagner;sincethattimeIhaveseennoreasontochangemymind，butthenImustaddthatmyattentionhasbeenabsorbedonothersubjects。Therearetwodifferentclassesofcases，asitappearstome，viz。thoseinwhichaspeciesbecomesslowlymodifiedinthesamecountry（ofwhichIcannotdoubtthereareinnumerableinstances）andthosecasesinwhichaspeciessplitsintotwoorthreeormorenewspecies，andinthelattercase，Ishouldthinknearlyperfectseparationwouldgreatlyaidintheir\"specification，\"tocoinanewword。
Iamverygladthatyouaretakingupthissubject，foryouwillbesuretothrowmuchlightonit。Irememberwell，longago，oscillatingmuch;whenIthoughtoftheFaunaandFloraoftheGalapagosIslandsIwasallforisolation，whenIthoughtofS。AmericaIdoubtedmuch。Praybelieveme，Yoursverysincerely，CH。DARWIN。
P。S。——Ihopethatthisletterwillnotbequiteillegible，butIhavenoamanuensisatpresent。
CHARLESDARWINTOK。SEMPER。
Down，November30，1878。
DearProfessorSemper，SincewritingIhaverecalledsomeofthethoughtsandconclusionswhichhavepassedthroughmymindoflateyears。InNorthAmerica，ingoingfromnorthtosouthorfromeasttowest，itisclearthatthechangedconditionsoflifehavemodifiedtheorganismsinthedifferentregions，sothattheynowformdistinctracesorevenspecies。Itisfurtherclearthatinisolateddistricts，howeversmall，theinhabitantsalmostalwaysgetslightlymodified，andhowfarthisisduetothenatureoftheslightlydifferentconditionstowhichtheyareexposed，andhowfartomereinterbreeding，inthemannerexplainedbyWeismann，Icanformnoopinion。Thesamedifficultyoccurredtome（asshowninmy’VariationofAnimalsandPlantsunderDomestication’）withrespecttotheaboriginalbreedsofcattle，sheep，etc。，intheseparateddistrictsofGreatBritain，andindeedthroughoutEurope。Asourknowledgeadvances，veryslightdifferences，consideredbysystematistsasofnoimportanceinstructure，arecontinuallyfoundtobefunctionallyimportant;andIhavebeenespeciallystruckwiththisfactinthecaseofplantstowhichmyobservationshaveoflateyearsbeenconfined。Thereforeitseemstomeratherrashtoconsidertheslightdifferencesbetweenrepresentativespecies，forinstancethoseinhabitingthedifferentislandsofthesamearchipelago，asofnofunctionalimportance，andasnotinanywayduetonaturalselection。Withrespecttoalladaptedstructures，andtheseareinnumerable，IcannotseehowM。Wagner’sviewthrowsanylight，norindeeddoIseeatallmoreclearlythanIdidbefore，fromthenumerouscaseswhichhehasbroughtforward，howandwhyitisthatalongisolatedformshouldalmostalwaysbecomeslightlymodified。Idonotknowwhetheryouwillcareabouthearingmyfurtheropiniononthepointinquestion，forasbeforeremarkedIhavenotattendedmuchoflateyearstosuchquestions，thinkingitprudent，nowthatIamgrowingold，toworkateasiersubjects。
Believeme，yoursverysincerely，CH。DARWIN。
Ihopeandtrustthatyouwillthrowlightonthesepoints。
P。S。——IwilladdanotherremarkwhichIrememberoccurredtomewhenI
firstreadM。Wagner。Whenaspeciesfirstarrivesonasmallisland，itwillprobablyincreaserapidly，andunlessalltheindividualschangeinstantaneously（whichisimprobableinthehighestdegree），theslowly，moreorless，modifyingoffspringmustintercrossonewithanother，andwiththeirunmodifiedparents，andanyoffspringnotasyetmodified。Thecasewillthenbelikethatofdomesticatedanimalswhichhaveslowlybecomemodified，eitherbytheactionoftheexternalconditionsorbytheprocesswhichIhavecalledtheUNCONSCIOUSSELECTIONbyman——i。e。，incontrastwithmethodicalselection。
[Theletterscontinuethehistoryoftheyear1872，whichhasbeeninterruptedbyadigressiononIsolation。]
CHARLESDARWINTOTHEMARQUISDESAPORTA。
Down，April8，1872。
DearSir，IthankyouverysincerelyandfeelmuchhonouredbythetroublewhichyouhavetakeningivingmeyourreflectionsontheoriginofMan。Itgratifiesmeextremelythatsomepartsofmyworkhaveinterestedyou，andthatweagreeonthemainconclusionofthederivationofmanfromsomelowerform。
Iwillreflectonwhatyouhavesaid，butIcannotatpresentgiveupmybeliefinthecloserelationshipofMantothehigherSimiae。Idonotputmuchtrustinanysinglecharacter，eventhatofdentition;butIputthegreatestfaithinresemblancesinmanypartsofthewholeorganisation，forIcannotbelievethatsuchresemblancescanbeduetoanycauseexceptclosebloodrelationship。ThatmaniscloselyalliedtothehigherSimiaeisshownbytheclassificationofLinnaeus，whowassogoodajudgeofaffinity。ThemanwhoinEnglandknowsmostaboutthestructureoftheSimiae，namely，Mr。Mivart，andwhoisbitterlyopposedtomydoctrinesaboutthederivationofthementalpowers，yethaspubliclyadmittedthatI
havenotputmantooclosetothehigherSimiae，asfarasbodilystructureisconcerned。Idonotthinktheabsenceofreversionsofstructureinmanisofmuchweight;C。Vogt，indeed，arguesthat[theexistenceof]Micro—
cephalousidiotsisacaseofreversion。NoonewhobelievesinEvolutionwilldoubtthatthePhocaearedescendedfromsometerrestrialCarnivore。
Yetnoonewouldexpecttomeetwithanysuchreversioninthem。ThelesserdivergenceofcharacterintheracesofmanincomparisonwiththespeciesofSimiadaemayperhapsbeaccountedforbymanhavingspreadovertheworldatamuchlaterperiodthandidtheSimiadae。Iamfullypreparedtoadmitthehighantiquityofman;butthenwehaveevidence，intheDryopithecus，ofthehighantiquityoftheAnthropomorphousSimiae。
Iamgladtohearthatyouareatworkonyourfossilplants，whichoflateyearshaveaffordedsorichafieldfordiscovery。Withmybestthanksforyourgreatkindness，andwithmuchrespect，Iremain，DearSir，yoursveryfaithfully，CHARLESDARWIN。
[InApril，1872，hewaselectedtotheRoyalSocietyofHolland，andwrotetoProfessorDonders:——
\"Verymanythanksforyourletter。ThehonourofbeingelectedaforeignmemberofyourRoyalSocietyhaspleasedmemuch。Thesympathyofhisfellowworkershasalwaysappearedtomebyfarthehighestrewardtowhichanyscientificmancanlook。Mygratificationhasbeennotalittleincreasedbyfirsthearingofthehonourfromyou。\"]
CHARLESDARWINTOCHAUNCEYWRIGHT。
Down，June3，1872。
MydearSir，Manythanksforyourarticle（Theproof—sheetsofanarticlewhichappearedintheJulynumberofthe’NorthAmericanReview。’ItwasarejoindertoMr。Mivart’sreply（’NorthAmericanReview，’April1872）toMr。ChaunceyWright’spamphlet。ChaunceyWrightsaysofit（’Letters，’page238）:——\"Itisnotproperlyarejoinderbutanewarticle，repeatingandexpoundingsomeofthepointsofmypamphlet，andansweringsomeofMr。Mivart’srepliesincidentally。\"）inthe’NorthAmericanReview，’whichIhavereadwithgreatinterest。Nothingcanbeclearerthanthewayinwhichyoudiscussthepermanenceorfixityofspecies。ItneveroccurredtometosupposethatanyonelookedatthecaseasitseemsMr。Mivartdoes。HadI
readhisanswertoyou，perhapsIshouldhaveperceivedthis;butIhaveresolvedtowastenomoretimeinreadingreviewsofmyworksoronEvolution，exceptingwhenIhearthattheyaregoodandcontainnewmatter……ItisprettyclearthatMr。Mivarthascometotheendofhistetheronthissubject。
Asyourmindissoclear，andasyouconsidersocarefullythemeaningofwords，Iwishyouwouldtakesomeincidentaloccasiontoconsiderwhenathingmayproperlybesaidtobeeffectedbythewillofman。IhavebeenledtothewishbyreadinganarticlebyyourProfessorWhitneyversusSchleicher。Heargues，becauseeachstepofchangeinlanguageismadebythewillofman，thewholelanguagesochanges;butIdonotthinkthatthisisso，asmanhasnointentionorwishtochangethelanguage。ItisaparallelcasewithwhatIhavecalled\"unconsciousselection，\"whichdependsonmenconsciouslypreservingthebestindividuals，andthusunconsciouslyalteringthebreed。
MydearSir，yourssincerely，CHARLESDARWIN。
[Notlongafterwards（September）Mr。ChaunceyWrightpaidavisittoDown（Mr。andMrs。C。L。Brace，whohadgivenmuchoftheirlivestophilanthropicworkinNewYork，alsopaidavisitatDowninthissummer。
SomeoftheirworkisrecordedinMr。Brace’s’TheDangerousClassesofNewYork，’andofthisbookmyfatherwrotetotheauthor:——
\"Sinceyouwereheremywifehasreadaloudtomemorethanhalfofyourwork，andithasinterestedusbothinthehighestdegree，andweshallreadeverywordoftheremainder。Thefactsseemtomeverywelltold，andtheinferencesverystriking。Butafterallthisisbutaweakpartoftheimpressionleftonourmindsbywhatwehaveread;forwearebothfilledwithearnestadmirationattheheroiclaboursofyourselfandothers。\"），whichhedescribedinaletter（’Letters，page246—248。）toMissS。
Sedgwick（nowMrs。WilliamDarwin）:\"Ifyoucanimaginemeenthusiastic——
absolutelyandunqualifiedlyso，withoutaBUTorcriticism，thenthinkofmylastevening’sandthismorning’stalkswithMr。Darwin……Iwasneversoworkedupinmylife，anddidnotsleepmanyhoursunderthehospitableroof……Itwouldbequiteimpossibletogivebywayofreportanyideaofthesetalksbeforeandatandafterdinner，atbreakfast，andatleave—
taking;andyetIdisliketheegotismof’testifying’likeotherreligiousenthusiasts，withoutanyverification，orhintofsimilarexperience。\"]
CHARLESDARWINTOHERBERTSPENCER。
Bassett，Southampton，June10，[1872]。
DearSpencer，Idaresayyouwillthinkmeafoolishfellow，butIcannotresistthewishtoexpressmyunboundedadmirationofyourarticle（’Mr。MartineauonEvolution，’byHerbertSpencer，’ContemporaryReview，’July1872。）inanswertoMr。Martineau。Itis，indeed，admirable，andhardlylesssoyoursecondarticleonSociology（which，however，Ihavenotyetfinished）:I
neverbelievedinthereigninginfluenceofgreatmenontheworld’sprogress;butifaskedwhyIdidnotbelieve，Ishouldhavebeensorelyperplexedtohavegivenagoodanswer。Everyonewitheyestoseeandearstohear（thenumber，Ifear，arenotmany）oughttobowtheirkneetoyou，andIforonedo。
Believeme，yoursmostsincerely，C。DARWIN。
CHARLESDARWINTOJ。D。HOOKER。
Down，July12[1872]。
MydearHooker，Imustexhaleandexpressmyjoyatthewayinwhichthenewspapershavetakenupyourcase。Ihaveseenthe\"Times\"，the\"DailyNews\"，andthe\"PallMall\"，andhearthatothershavetakenupthecase。
TheMemorialhasdonegreatgoodthisway，whatevermaybetheresultintheactionofourwretchedGovernment。Onmysoul，itisenoughtomakeoneturnintoanoldhonestTory……
Ifyouanswerthis，IshallbesorrythatIhaverelievedmyfeelingsbywriting。
Yoursaffectionately，C。DARWIN。
[ThememorialherereferredtowasaddressedtoMr。Gladstone，andwassignedbyanumberofdistinguishedmen，includingSirCharlesLyell，Mr。
Bentham，Mr。Huxley，andSirJamesPaget。ItgivesacompleteaccountofthearbitraryandunjusttreatmentreceivedbySirJ。D。Hookeratthehandsofhisofficialchief，theFirstCommissionerofWorks。Thedocumentispublishedinfullin’Nature’（July11，1872），andiswellworthstudyingasanexampleofthetreatmentwhichitispossibleforsciencetoreceivefromofficialism。As’Nature’observes，itisapaperwhichmustbereadwiththegreatestindignationbyscientificmenineverypartoftheworld，andwithshamebyallEnglishmen。ThesignatoriesofthememorialconcludebyprotestingagainsttheexpectedconsequencesofSirJosephHooker’spersecution——namelyhisresignation，andthelossof\"amanhonouredforhisintegrity，belovedforhiscourtesyandkindlinessofheart;andwhohasspentinthepublicservicenotonlyastainlessbutanillustriouslife。\"
Happilythismisfortunewasaverted，andSirJosephwasfreedfromfurthermolestation。]
CHARLESDARWINTOA。R。WALLACE。
Down，August3[1872]。
MydearWallace，Ihatecontroversy，chieflyperhapsbecauseIdoitbadly;butasDr。Breeaccusesyou（Mr。WallacehadreviewedDr。Bree’sbook，’AnExpositionofFallaciesintheHypothesisofMr。Darwin，’in’Nature，’July25，1872。）of\"blundering，\"Ihavethoughtmyselfboundtosendtheenclosedletter（Theletterisasfollows:——\"BreeonDarwinism。\"’Nature，’August8，1872。
Permitmetostate——thoughthestatementisalmostsuperfluous——thatMr。
Wallace，inhisreviewofDr。Bree’swork，giveswithperfectcorrectnesswhatIintendedtoexpress，andwhatIbelievewasexpressedclearly，withrespecttotheprobablepositionofmanintheearlypartofhispedigree。
AsIhavenotseenDr。Bree’srecentwork，andashisletterisunintelligibletome，Icannotevenconjecturehowhehassocompletelymistakenmymeaning:but，perhaps，noonewhohasreadMr。Wallace’sarticle，orwhohasreadaworkformerlypublishedbyDr。Breeonthesamesubjectashisrecentone，willbesurprisedatanyamountofmisunderstandingonhispart。——CharlesDarwin。August3。）to’Nature，’
thatisifyouintheleastdesireit。Inthiscasepleasepostit。IfyoudonotATALLwishit，Ishouldratherprefernotsendingit，andinthiscasepleasetotearitup。AndIbegyoutodothesame，ifyouintendansweringDr。Breeyourself，asyouwilldoitincomparablybetterthanIshould。Alsopleasetearitupifyoudon’tliketheletter。
MydearWallace，yoursverysincerely，CH。DARWIN。
CHARLESDARWINTOA。R。WALLACE。
Down，August28，1872。
MydearWallace，IhaveatlastfinishedthegiganticjobofreadingDr。Bastian’sbook（’TheBeginningsofLife。’H。C。Bastian，1872。）andhavebeendeeplyinterestedbyit。Youwishedtohearmyimpression，butitisnotworthsending。
Heseemstomeanextremelyableman，as，indeed，IthoughtwhenIreadhisfirstessay。HisgeneralargumentinfavourofArchebiosis（Thatistosay，SpontaneousGeneration。ForthedistinctionbetweenArchebiosisandHeterogenesis，seeBastian，chaptervi。）iswonderfullystrong，thoughI
cannotthinkmuchofsomefewofhisarguments。TheresultisthatIambewilderedandastonishedbyhisstatements，butamnotconvinced，though，onthewhole，itseemstomeprobablethatArchebiosisistrue。Iamnotconvinced，partlyIthinkowingtothedeductivecastofmuchofhisreasoning;andIknownotwhy，butIneverfeelconvincedbydeduction，eveninthecaseofH。Spencer’swritings。IfDr。Bastian’sbookhadbeenturnedupsidedown，andhehadbegunwiththevariouscasesofHeterogenesis，andthengoneontoorganic，andafterwardstosalinesolutions，andhadthengivenhisgeneralarguments，Ishouldhavebeen，I
believe，muchmoreinfluenced。Isuspect，however，thatmychiefdifficultyistheeffectofoldconvictionsbeingstereotypedonmybrain。
Imusthavemoreevidencethatgerms，ortheminutestfragmentsofthelowestforms，arealwayskilledby212degreesofFahr。PerhapsthemerereiterationofthestatementsgivenbyDr。Bastian[by]othermen，whosejudgmentIrespect，andwhohaveworkedlongonthelowerorganisms，wouldsufficetoconvinceme。Hereisafineconfessionofintellectualweakness;butwhataninexplicableframeofmindisthatofbelief！
AsforRotifersandTardigradesbeingspontaneouslygenerated，mymindcannomoredigestsuchstatements，whethertrueorfalse，thanmystomachcandigestalumpoflead。Dr。BastianisalwayscomparingArchebiosis，aswellasgrowth，tocrystallisation;but，onthisview，aRotiferorTardigradeisadaptedtoitshumbleconditionsoflifebyahappyaccident，andthisIcannotbelieve……Hemusthaveworkedwithveryimpurematerialsinsomecases，asplentyoforganismsappearedinasalinesolutionnotcontaininganatomofnitrogen。
IwhollydisagreewithDr。Bastianaboutmanypointsinhislatterchapters。Thusthefrequencyofgeneralisedformsintheolderstrataseemstomeclearlytoindicatethecommondescentwithdivergenceofmorerecentforms。Notwithstandingallhissneers，IdonotstrikemycoloursasyetaboutPangenesis。IshouldliketolivetoseeArchebiosisprovedtrue，foritwouldbeadiscoveryoftranscendentimportance;or，iffalse，Ishouldliketoseeitdisproved，andthefactsotherwiseexplained;butI
shallnotlivetoseeallthis。Ifeverproved，Dr。Bastianwillhavetakenaprominentpartinthework。Howgrandistheonwardrushofscience;itisenoughtoconsoleusforthemanyerrorswhichwehavecommitted，andforoureffortsbeingoverlaidandforgotteninthemassofnewfactsandnewviewswhicharedailyturningup。
ThisisallIhavetosayaboutDr。Bastian’sbook，anditcertainlyhasnotbeenworthsaying……
CHARLESDARWINTOA。DECANDOLLE。
Down，December11，1872。
MydearSir，Ibeganreadingyournewbook（’HistoiredesSciencesetdesSavants。’
1873。）soonerthanIintended，andwhenIoncebegan，Icouldnotstop;andnowyoumustallowmetothankyoufortheverygreatpleasurewhichithasgivenme。Ihavehardlyeverreadanythingmoreoriginalandinterestingthanyourtreatmentofthecauseswhichfavourthedevelopmentofscientificmen。Thewholewasquitenewtome，andmostcurious。WhenI
beganyouressayIwasafraidthatyouweregoingtoattacktheprincipleofinheritanceinrelationtomind，butIsoonfoundmyselffullycontenttofollowyouandacceptyourlimitations。Ihavefelt，ofcourse，specialinterestinthelatterpartofyourwork，buttherewasherelessnoveltytome。Inmanypartsyoudomemuchhonour，andeverywheremorethanjustice。Authorsgenerallyliketohearwhatpointsmoststrikedifferentreaders，soIwillmentionthatofyourshorteressays，thatonthefutureprevalenceoflanguages，andonvaccinationinterestedmethemost，as，indeed，didthatonstatistics，andfreewill。Greatliabilitytocertaindiseases，beingprobablyliabletoatavism，isquiteanewideatome。Atpage322yousuggestthatayoungswallowoughttobeseparated，andthenletlooseinordertotestthepowerofinstinct;butnatureannuallyperformsthisexperiment，asoldcuckoosmigrateinEnglandsomeweeksbeforetheyoungbirdsofthesameyear。Bytheway，Ihavejustusedtheforbiddenword\"nature，\"which，afterreadingyouressay，Ialmostdeterminednevertouseagain。ThereareveryfewremarksinyourbooktowhichIdemur，butwhenyoubackupAsaGrayinsayingthatallinstinctsarecongenitalhabits，Imustprotest。
Finally，willyoupermitmetoaskyouaquestion:haveyouyourself，orsomeonewhocanbequitetrusted，observed（page322）thatthebutterfliesontheAlpsaretamerthanthoseonthelowlands？Dotheybelongtothesamespecies？Hasthisfactbeenobservedwithmorethanonespecies？Aretheybrightlycolouredkinds？Iamespeciallycuriousabouttheiralightingonthebrightlycolouredpartsofladies’dresses，moreespeciallybecauseIhavebeenmorethanonceassuredthatbutterflieslikebrightcolours，forinstance，inIndiathescarletleavesofPoinsettia。
Onceagainallowmetothankyouforhavingsentmeyourwork，andfortheveryunusualamountofpleasurewhichIhavereceivedinreadingit。
Withmuchrespect，Iremain，mydearSir，Yoursverysincerely，CHARLESDARWIN。
[Thelastreviseofthe’ExpressionoftheEmotions’wasfinishedonAugust22nd，1872，andhewroteinhisDiary:——\"Hastakenmeabouttwelvemonths。\"
Asusualhehadnobeliefinthepossibilityofthebookbeinggenerallysuccessful。ThefollowingpassageinalettertoHaeckelgivestheimpressionthathehadfeltthewritingofthisbookasasomewhatseverestrain:——
\"Ihavefinishedmylittlebookon’Expression，’andwhenitispublishedinNovemberIwillofcoursesendyouacopy，incaseyouwouldliketoreaditforamusement。Ihaveresumedsomeoldbotanicalwork，andperhapsIshallneveragainattempttodiscusstheoreticalviews。
\"Iamgrowingoldandweak，andnomancantellwhenhisintellectualpowersbegintofail。Longlifeandhappinesstoyouforyourownsakeandforthatofscience。\"
Itwaspublishedintheautumn。Theeditionconsistedof7000，andofthese5267copiesweresoldatMr。Murray’ssaleinNovember。Twothousandwereprintedattheendoftheyear，andthisprovedamisfortune，astheydidnotafterwardssellsorapidly，andthusamassofnotescollectedbytheauthorwasneveremployedforasecondeditionduringhislifetime。
Amongthereviewsofthe’ExpressionoftheEmotions’maybementionedtheunfavourablenoticesinthe\"Athenaeum\"，November9，1872，andthe\"Times\"，December13，1872。AgoodreviewbyMr。Wallaceappearedinthe’QuarterlyJournalofScience，’January1873。Mr。Wallacetrulyremarksthatthebookexhibitscertain\"characteristicsoftheauthor’smindinaneminentdegree，\"namely，\"theinsatiablelongingtodiscoverthecausesofthevariedandcomplexphenomenapresentedbylivingthings。\"Headdsthatinthecaseoftheauthor\"therestlesscuriosityofthechildtoknowthe’whatfor？’the’why？’andthe’how？’ofeverything\"seems\"nevertohaveabateditsforce。\"
Awriterinoneofthetheologicalreviewsdescribesthebookasthemost\"powerfulandinsidious\"ofalltheauthor’sworks。
ProfessorAlexanderBaincriticisedthebookinapostscripttothe’SensesandtheIntellect;’tothisessaythefollowingletterrefers:]