MydearHooker，Ihavebeendeeplyinterestedbyyourletter，andwehadagoodlaughoverHuxley’sremark，whichwassodeucedcleverthatyoucouldnotrecollectit。Icannotquitefollowyourtrainofthought，forinthelastpageyouadmitallthatIwish，havingapparentlydeniedall，orthoughtallmerewordsinthepreviouspagesofyournote;butitmaybemymuddle。IseeclearlythatanysatisfactionwhichPanmaygivewilldependontheconstitutionofeachman’smind。Ifyouhavearrivedalreadyatanysimilarconclusion，thewholewillofcourseappearstaletoyou。IheardyesterdayfromWallace，whosays（excusehorridvanity），\"IcanhardlytellyouhowmuchIadmirethechapteron’Pangenesis。’ItisaPOSITIVE
COMFORTtometohaveanyfeasibleexplanationofadifficultythathasalwaysbeenhauntingme，andIshallneverbeabletogiveituptillabetteronesuppliesitsplace，andthatIthinkhardlypossible，etc。\"Nowhisforegoing[italicised]wordsexpressmysentimentsexactlyandfully:
thoughperhapsIfeelthereliefextrastronglyfromhavingduringmanyyearsvainlyattemptedtoformsomehypothesis。WhenyouorHuxleysaythatasinglecellofaplant，orthestumpofanamputatedlimb，havethe\"potentiality\"ofreproducingthewhole——or\"diffuseaninfluence，\"thesewordsgivemenopositiveidea;——butwhenitissaidthatthecellsofaplant，orstump，includeatomsderivedfromeveryothercellofthewholeorganismandcapableofdevelopment，Igainadistinctidea。Butthisideawouldnotbewortharush，ifitappliedtoonecasealone;butitseemstometoapplytoalltheformsofreproduction——inheritance——metamorphosis——
totheabnormaltranspositionoforgans——tothedirectactionofthemaleelementonthemotherplant，etc。ThereforeIfullybelievethateachcelldoesACTUALLYthrowoffanatomorgemmuleofitscontents;——butwhetherornot，thishypothesisservesasausefulconnectinglinkforvariousgrandclassesofphysiologicalfacts，whichatpresentstandabsolutelyisolated。
Ihavetouchedonthedoubtfulpoint（alludedtobyHuxley）howfaratomsderivedfromthesamecellmaybecomedevelopedintodifferentstructureaccordinglyastheyaredifferentlynourished;Iadvancedasillustrationsgallsandpolypoidexcrescences……
Itisarealpleasuretometowritetoyouonthissubject，andIshouldbedelightedifwecanunderstandeachother;butyoumustnotletyourgoodnatureleadyouon。Remember，wealwaysfighttoothandnail。WegotoLondononTuesday，firstforaweektoQueenAnneStreet，andafterwardstoMissWedgwood’s，inRegent’sPark，andstaythewholemonth，which，asmygardenertrulysays，isa\"terriblething\"formyexperiments。
CHARLESDARWINTOW。OGLE。（Dr。WilliamOgle，nowtheSuperintendentofStatisticstotheRegistrar—General。）
Down，March6[1868]。
DearSir，Ithankyoumostsincerelyforyourletter，whichisveryinterestingtome。IwishIhadknownoftheseviewsofHippocratesbeforeIhadpublished，fortheyseemalmostidenticalwithmine——merelyachangeofterms——andanapplicationofthemtoclassesoffactsnecessarilyunknowntotheoldphilosopher。Thewholecaseisagoodillustrationofhowrarelyanythingisnew。
Hippocrateshastakenthewindoutofmysails，butIcareverylittleaboutbeingforestalled。Iadvancetheviewsmerelyasaprovisionalhypothesis，butwiththesecretexpectationthatsoonerorlatersomesuchviewwillhavetobeadmitted……Idonotexpectthereviewerswillbesolearnedasyou:otherwise，nodoubt，IshallbeaccusedofwilfullystealingPangenesisfromHippocrates，——forthisisthespiritsomereviewersdelighttoshow。
CHARLESDARWINTOVICTORCARUS。
Down，March21[1868]……IamverymuchobligedtoyouforsendingmesofranklyyouropiniononPangenesis，andIamsorryitisunfavourable，butIcannotquiteunderstandyourremarkonpangenesis，selection，andthestruggleforlifenotbeingmoremethodical。Iamnotatallsurprisedatyourunfavourableverdict;Iknowmany，probablymost，willcometothesameconclusion。OneEnglishReviewsaysitismuchtoocomplicated……Someofmyfriendsareenthusiasticonthehypothesis……SirC。Lyellsaystoeveryone，\"youmaynotbelievein’Pangenesis，’butifyouonceunderstandit，youwillnevergetitoutofyourmind。\"AndwiththiscriticismIamperfectlycontent。
Allcasesofinheritanceandreversionanddevelopmentnowappeartomeunderanewlight……
[AnextractfromalettertoFritzMuller，thoughoflaterdate（June），maybegivenhere:——
\"YourletterofApril22hasmuchinterestedme。Iamdelightedthatyouapproveofmybook，forIvalueyouropinionmorethanthatofalmostanyone。IhaveyethopesthatyouwillthinkwellofPangenesis。Ifeelsurethatourmindsaresomewhatalike，andIfinditagreatrelieftohavesomedefinite，thoughhypotheticalview，whenIreflectonthewonderfultransformationsofanimals，——there—growthofparts，——andespeciallythedirectactionofpollenonthemother—form，etc。Itoftenappearstomealmostcertainthatthecharactersoftheparentsare\"photographed\"onthechild，onlybymeansofmaterialatomsderivedfromeachcellinbothparents，anddevelopedinthechild。\"]
CHARLESDARWINTOASAGRAY。
Down，May8[1868]。
MydearGray，Ihavebeenamostungratefulandungraciousmannottohavewrittentoyouanimmensetimeagotothankyouheartilyforthe\"Nation\"，andforallyourmostkindaidinregardtotheAmericanedition[of’AnimalsandPlants’]。ButIhavebeenoflateoverwhelmedwithletters，whichIwasforcedtoanswer，andsoputoffwritingtoyou。ThismorningIreceivedtheAmericanedition（whichlookscapital），withyournicepreface，forwhichheartythanks。Ihopetoheaventhatthebookwillsucceedwellenoughtopreventyourepentingofyouraid。Thisarrivalhasputthefinishingstroketomyconscience，whichwillendureitswrongsnolonger……Yourarticleinthe\"Nation\"[March19]seemstomeverygood，andyougiveanexcellentideaofPangenesis——aninfantcherishedbyfewasyet，excepthistenderparent，butwhichwilllivealonglife。Thereisparentalpresumptionforyou！Yougiveagoodslapatmyconcludingmetaphor（AshortabstractoftheprecipicemetaphorisgiveninVolumeI。
Dr。Gray’scriticismonthispointisasfollows:\"ButinMr。Darwin’sparallel，tomeetthecaseofnatureaccordingtohisownviewofit，notonlythefragmentsofrock（answeringtovariation）shouldfall，buttheedifice（answeringtonaturalselection）shouldrise，irrespectiveofwillorchoice！\"Butmyfather’sparalleldemandsthatnaturalselectionshallbethearchitect，nottheedifice——thequestionofdesignonlycomesinwithregardtotheformofthebuildingmaterials。）:undoubtedlyIoughttohavebroughtinandcontrastednaturalandartificialselection;butitseemssoobvioustomethatnaturalselectiondependedoncontingenciesevenmorecomplexthanthosewhichmusthavedeterminedtheshapeofeachfragmentatthebaseofmyprecipice。WhatIwantedtoshowwasthatinreferencetopre—ordainmentwhateverholdsgoodintheformationofapouterpigeonholdsgoodintheformationofanaturalspeciesofpigeon。
Icannotseethatthisisfalse。Iftherightvariationsoccurred，andnoothers，naturalselectionwouldbesuperfluous。AreviewerinanEdinburghpaper，whotreatsmewithprofoundcontempt，saysonthissubjectthatProfessorAsaGraycouldwiththegreatesteasesmashmeintolittlepieces。（The\"DailyReview\"，April27，1868。Myfatherhasgivenratherahighlycolouredversionofthereviewer’sremarks:\"WedoubtnotthatProfessorAsaGray……couldshowthatnaturalselection……issimplyaninstrumentinthehandsofanomnipotentandomniscientcreator。\"Thereviewergoesontosaythatthepassageinquestionisa\"verymelancholyone，\"andthatthetheoryisthe\"apotheosisofmaterialism。\"）
Believeme，mydearGray，Yourungratefulbutsincerefriend，CHARLESDARWIN。
CHARLESDARWINTOG。BENTHAM。
Down，June23，1868。
MydearMr。Bentham，Asyouraddress（PresidentialAddresstotheLinneanSociety。）issomewhatofthenatureofaverdictfromajudge，Idonotknowwhetheritisproperformetodoso，butImustandwillthankyouforthepleasurewhichyouhavegivenme。Iamdelightedatwhatyousayaboutmybook。Igotsotiredofit，thatformonthstogetherIthoughtmyselfaperfectfoolforhavinggivenupsomuchtimeincollectingandobservinglittlefacts，butnowIdonotcareifascoreofcommoncriticsspeakascontemptuouslyofthebookasdidthe\"Athenaeum\"。Ifeeljustifiedinthis，forIhavesocompletearelianceonyourjudgmentthatIfeelcertainthatIshouldhavebowedtoyourjudgmenthaditbeenasunfavourableasitisthecontrary。
WhatyousayaboutPangenesisquitesatisfiesme，andisasmuchperhapsasanyoneisjustifiedinsaying。IhavereadyourwholeAddresswiththegreatestinterest。Itmusthavecostyouavastamountoftrouble。Withcordialthanks，praybelieveme，Yoursverysincerely，CH。DARWIN。
P。S。——IfearthatitisnotlikelythatyouhaveasuperfluouscopyofyourAddress;ifyouhave，IshouldmuchliketosendonetoFritzMullerintheinteriorofBrazil。BythewayletmeaddthatIdiscussedbud—variationchieflyfromabeliefwhichiscommontoseveralpersons，thatallvariabilityisrelatedtosexualgeneration;Iwishedtoshowclearlythatthiswasanerror。
[Theaboveseriesoflettersmayservetoshowtosomeextentthereceptionwhichthenewbookreceived。Beforepassingon（inthenextchapter）tothe’DescentofMan，’IgivealetterreferringtothetranslationofFritzMuller’sbook，’FurDarwin，’itwasoriginallypublishedin1864，buttheEnglishtranslation，byMr。Dallas，whichborethetitlesuggestedbySirC。Lyell，of’FactsandArgumentsforDarwin，’didnotappearuntil1869:]
CHARLESDARWINTOF。MULLER。
Down，March16[1868]。
MydearSir，Yourbrother，asyouwillhaveheardfromhim，feltsoconvincedthatyouwouldnotobjecttoatranslationof’FurDarwin’（InalettertoFritzMuller，myfatherwrote:——\"Iamvexedtoseethatonthetitlemynameismoreconspicuousthanyours，whichIespeciallyobjectedto，andI
cautionedtheprintersafterseeingoneproof。\"），thatIhaveventuredtoarrangeforatranslation。Engelmannhasveryliberallyofferedmeclichesofthewoodcutsfor22thalers;Mr。Murrayhasagreedtobringoutatranslation（andheisourbestpublisher）oncommission，forhewouldnotundertaketheworkonhisownrisk;andIhaveagreedwithMr。W。S。Dallas（whohastranslatedVonSieboldonParthenogenesis，andmanyGermanworks，andwhowritesverygoodEnglish）totranslatethebook。Hethinks（andheisagoodjudge）thatitisimportanttohavesomefewcorrectionsoradditions，inordertoaccountforatranslationappearingsolately[i。e。
atsuchalongintervaloftime]aftertheoriginal;sothatIhopeyouwillbeabletosendsome……
[TwolettersmaybeplacedhereasbearingonthespreadofEvolutionaryideasinFranceandGermany:]
CHARLESDARWINTOA。GAUDRY。
Down，January21[1868]。
DearSir，IthankyouforyourinterestingessayontheinfluenceoftheGeologicalfeaturesofthecountryonthemindandhabitsoftheAncientAthenians（ThisappearstorefertoM。Gaudry’spapertranslatedinthe’Geol。Mag。，’
1868，page372。），andforyourveryobligingletter。Iamdelightedtohearthatyouintendtoconsidertherelationsoffossilanimalsinconnectionwiththeirgenealogy;itwillaffordyouafinefieldfortheexerciseofyourextensiveknowledgeandpowersofreasoning。YourbeliefwillIsuppose，atpresent，loweryouintheestimationofyourcountrymen;
butjudgingfromtherapidspreadinallpartsofEurope，exceptingFrance，ofthebeliefinthecommondescentofalliedspecies，Imustthinkthatthisbeliefwillbeforelongbecomeuniversal。HowstrangeitisthatthecountrywhichgavebirthtoBuffon，theelderGeoffroy，andespeciallytoLamarck，shouldnowclingsopertinaciouslytothebeliefthatspeciesareimmutablecreations。
MyworkonVariation，etc。，underdomestication，willappearinaFrenchtranslationinafewmonths’time，andIwilldomyselfthepleasureandhonourofdirectingthepublishertosendacopytoyoutothesameaddressasthisletter。
Withsincererespect，Iremain，dearsir，Yoursveryfaithfully，CHARLESDARWIN。
[Thenextletterisofespecialinterest，asshowinghowhighavaluemyfatherplacedonthesupportoftheyoungerGermannaturalists:]
CHARLESDARWINTOW。PREYER。（NowProfessorofPhysiologyatJena。）
March31，1868……IamdelightedtohearthatyouupholdthedoctrineoftheModificationofSpecies，anddefendmyviews。ThesupportwhichIreceivefromGermanyismychiefgroundforhopingthatourviewswillultimatelyprevail。TothepresentdayIamcontinuallyabusedortreatedwithcontemptbywritersofmyowncountry;buttheyoungernaturalistsarealmostallonmyside，andsoonerorlaterthepublicmustfollowthosewhomakethesubjecttheirspecialstudy。Theabuseandcontemptofignorantwritershurtsmeverylittle……
CHAPTER2。VI。
WORKON’MAN。’
1864—1870。
[IntheautobiographicalchapterinVolumeI。，myfathergivesthecircumstanceswhichledtohiswritingthe’DescentofMan。’Hestatesthathiscollectionoffacts，begunin1837or1838，wascontinuedformanyyearswithoutanydefiniteideaofpublishingonthesubject。ThefollowinglettertoMr。Wallaceshowsthatintheperiodofill—healthanddepressionabout1864hedespairedofeverbeingabletodoso:]
CHARLESDARWINTOA。R。WALLACE。
Down，[May？]28[1864]。
DearWallace，IamsomuchbetterthatIhavejustfinishedapaperforLinneanSociety（Onthethreeforms，etc。，ofLythrum。）;butIamnotyetatallstrong，I
feltmuchdisinclinationtowrite，andthereforeyoumustforgivemefornothavingsoonerthankedyouforyourpaperon’Man’（’AnthropologicalReview，’March1864。），receivedonthe11th。ButfirstletmesaythatI
havehardlyeverinmylifebeenmorestruckbyanypaperthanthaton’Variation，’etc。etc。，inthe\"Reader\"。（’\"Reader\"，April16，1864。\"OnthePhenomenaofVariation，\"etc。AbstractofapaperreadbeforetheLinneanSociety，March17，1864。）IfeelsurethatsuchpaperswilldomoreforthespreadingofourviewsonthemodificationofspeciesthananyseparateTreatisesonthesimplesubjectitself。Itisreallyadmirable;
butyououghtnotintheManpapertospeakofthetheoryasmine;itisjustasmuchyoursasmine。Onecorrespondenthasalreadynoticedtomeyour\"high—minded\"conductonthishead。ButnowforyourManpaper，aboutwhichIshouldliketowritemorethanIcan。Thegreatleadingideaisquitenewtome，viz。thatduringlateages，themindwillhavebeenmodifiedmorethanthebody;yetIhadgotasfarastoseewithyouthatthestrugglebetweentheracesofmandependedentirelyonintellectualandMORALqualities。ThelatterpartofthepaperIcandesignateonlyasgrandandmosteloquentlydone。Ihaveshownyourpapertotwoorthreepersonswhohavebeenhere，andtheyhavebeenequallystruckwithit。I
amnotsurethatIgowithyouonallminorpoints:whenreadingSirG。
Grey’saccountoftheconstantbattlesofAustraliansavages，Irememberthinkingthatnaturalselectionwouldcomein，andlikewisewiththeEsquimaux，withwhomtheartoffishingandmanagingcanoesissaidtobehereditary。Iratherdifferontherank，underaclassificatorypointofview，whichyouassigntoman;Idonotthinkanycharactersimplyinexcessoughtevertobeusedforthehigherdivisions。Antswouldnotbeseparatedfromotherhymenopterousinsects，howeverhightheinstinctoftheone，andhoweverlowtheinstinctsoftheother。Withrespecttothedifferencesofrace，aconjecturehasoccurredtomethatmuchmaybeduetothecorrelationofcomplexion（andconsequentlyhair）withconstitution。
Assumethataduskyindividualbestescapedmiasma，andyouwillreadilyseewhatImean。IpersuadedtheDirector—GeneraloftheMedicalDepartmentoftheArmytosendprintedformstothesurgeonsofallregimentsintropicalcountriestoascertainthispoint，butIdaresayI
shallnevergetanyreturns。Secondly，Isuspectthatasortofsexualselectionhasbeenthemostpowerfulmeansofchangingtheracesofman。I
canshowthatthedifferentraceshaveawidelydifferentstandardofbeauty。Amongsavagesthemostpowerfulmenwillhavethepickofthewomen，andtheywillgenerallyleavethemostdescendants。Ihavecollectedafewnotesonman，butIdonotsupposethatIshalleverusethem。Doyouintendtofollowoutyourviews，andifso，wouldyoulikeatsomefuturetimetohavemyfewreferencesandnotes？IamsureIhardlyknowwhethertheyareofanyvalue，andtheyareatpresentinastateofchaos。
ThereismuchmorethatIshouldliketowrite，butIhavenotstrength。
Believeme，dearWallace，yoursverysincerely，CH。DARWIN。
P。S。——Ouraristocracyishandsomer（morehideousaccordingtoaChineseorNegro）thanthemiddleclasses，from（havingthe）pickofthewomen;butoh，whataschemeisprimogeniturefordestroyingnaturalselection！I
fearmyletterwillbebarelyintelligibletoyou。
[InFebruary1867，whenthemanuscriptof’AnimalsandPlants’hadbeensenttoMessrs。Clowestobeprinted，andbeforetheproofsbegantocomein，hehadanintervalofsparetime，andbegana\"chapteronMan，\"buthesoonfounditgrowingunderhishands，anddeterminedtopublishitseparatelyasa\"verysmallvolume。\"
Theworkwasinterruptedbythenecessityofcorrectingtheproofsof’AnimalsandPlants，’andbysomebotanicalwork，butwasresumedinthefollowingyear，1868，themomenthecouldgivehimselfuptoit。
Herecognizedwithregretthegradualchangeinhismindthatrenderedcontinuousworkmoreandmorenecessarytohimashegrewolder。ThisisexpressedinalettertoSirJ。D。Hooker，June17，1868，whichrepeatstosomeextentwhatisexpressedintheAutobiography:——
\"Iamgladyouwereatthe’Messiah，’itistheonethingthatIshouldliketohearagain，butIdaresayIshouldfindmysoultoodrieduptoappreciateitasinolddays;andthenIshouldfeelveryflat，foritisahorridboretofeelasIconstantlydo，thatIamawitheredleafforeverysubjectexceptScience。ItsometimesmakesmehateScience，thoughGodknowsIoughttobethankfulforsuchaperennialinterest，whichmakesmeforgetforsomehourseverydaymyaccursedstomach。\"
TheworkonManwasinterruptedbyillnessintheearlysummerof1868，andhelefthomeonJuly16thforFreshwater，intheIsleofWight，whereheremainedwithhisfamilyuntilAugust21st。HerehemadetheacquaintanceofMrs。Cameron。Shereceivedthewholefamilywithopen—heartedkindnessandhospitality，andmyfatheralwaysretainedawarmfeelingoffriendshipforher。Shemadeanexcellentphotographofhim，whichwaspublishedwiththeinscriptionwrittenbyhim:\"Ilikethisphotographverymuchbetterthananyotherwhichhasbeentakenofme。\"Furtherinterruptionoccurredintheautumnsothatcontinuousworkonthe’DescentofMan’didnotbeginuntil1869。Thefollowinglettersgivesomeideaoftheearlierworkin1867:]
CHARLESDARWINTOA。R。WALLACE。
Down，February22，[1867？]。
MydearWallace，Iamhardatworkonsexualselection，andamdrivenhalfmadbythenumberofcollateralpointswhichrequireinvestigation，suchastherelativenumberofthetwosexes，andespeciallyonpolygamy。Canyouaidmewithrespecttobirdswhichhavestronglymarkedsecondarysexualcharacters，suchasbirdsofparadise，humming—birds，theRupicola，oranyothersuchcases？Manygallinaceousbirdscertainlyarepolygamous。Isupposethatbirdsmaybeknownnottobepolygamousiftheyareseenduringthewholebreedingseasontoassociateinpairs，orifthemaleincubatesoraidsinfeedingtheyoung。Willyouhavethekindnesstoturnthisinyourmind？
Butitisashametotroubleyounowthat，asIamHEARTILYgladtohear，youareatworkonyourMalayantravels。Iamfearfullypuzzledhowfartoextendyourprotectiveviewswithrespecttothefemalesinvariousclasses。ThemoreIworkthemoreimportantsexualselectionapparentlycomesout。
Canbutterfliesbepolygamous！i。e。willonemaleimpregnatemorethanonefemale？Forgivemetroublingyou，andIdaresayIshallhavetoaskforgivenessagain……
CHARLESDARWINTOA。R。WALLACE。
Down，February23[1867]。
DearWallace，ImuchregrettedthatIwasunabletocallonyou，butafterMondayIwasunableeventoleavethehouse。OnMondayeveningIcalledonBates，andputadifficultybeforehim，whichhecouldnotanswer，and，asonsomeformersimilaroccasion，hisfirstsuggestionwas，\"YouhadbetteraskWallace。\"Mydifficultyis，whyarecaterpillarssometimessobeautifullyandartisticallycoloured？Seeingthatmanyarecolouredtoescapedanger，Icanhardlyattributetheirbrightcolourinothercasestomerephysicalconditions。BatessaysthemostgaudycaterpillarheeversawinAmazonia（ofasphinx）wasconspicuousatthedistanceofyards，fromitsblackandredcolours，whilstfeedingonlargegreenleaves。Ifanyoneobjectedtomalebutterflieshavingbeenmadebeautifulbysexualselection，andaskedwhyshouldtheynothavebeenmadebeautifulaswellastheircaterpillars，whatwouldyouanswer？Icouldnotanswer，butshouldmaintainmyground。
Willyouthinkoverthis，andsometime，eitherbyletterorwhenwemeet，tellmewhatyouthink？AlsoIwanttoknowwhetheryourFEMALEmimeticbutterflyismorebeautifulandbrighterthanthemale。WhennextinLondonImustgetyoutoshowmeyourkingfishers。Myhealthisadreadfulevil;IfailedinhalfmyengagementsduringthislastvisittoLondon。
Believeme，yoursverysincerely，C。DARWIN。
CHARLESDARWINTOA。R。WALLACE。
Down，February26[1867]。
MydearWallace，Bateswasquiteright;youarethemantoapplytoinadifficulty。I
neverheardanythingmoreingeniousthanyoursuggestion（Thesuggestionthatconspicuouscaterpillarsorperfectinsects（e。g。whitebutterflies），whicharedistastefultobirds，areprotectedbybeingeasilyrecognisedandavoided。SeeMr。Wallace’s’NaturalSelection，’2ndedition，page117。），andIhopeyoumaybeabletoproveittrue。Thatisasplendidfactaboutthewhitemoths;itwarmsone’sverybloodtoseeatheorythusalmostprovedtobetrue。（Mr。JennerWeir’sobservationspublishedintheTransactionsoftheEntomolog。Soc。（1869and1870）givestrongsupporttothetheoryinquestion。）Withrespecttothebeautyofmalebutterflies，I
mustasyetthinkitisduetosexualselection。Thereissomeevidencethatdragon—fliesareattractedbybrightcolours;butwhatleadsmetotheabovebeliefis，somanymaleOrthopteraandCicadashavingmusicalinstruments。Thisbeingthecase，theanalogyofbirdsmakesmebelieveinsexualselectionwithrespecttocolourininsects。IwishIhadstrengthandtimetomakesomeoftheexperimentssuggestedbyyou，butIthoughtbutterflieswouldnotpairinconfinement。IamsureIhaveheardofsomesuchdifficulty。ManyyearsagoIhadadragon—flypaintedwithgorgeouscolours，butIneverhadanopportunityoffairlytryingit。
Thereasonofmybeingsomuchinterestedjustatpresentaboutsexualselectionis，thatIhavealmostresolvedtopublishalittleessayontheoriginofMankind，andIstillstronglythink（thoughIfailedtoconvinceyou，andthis，tome，istheheaviestblowpossible）thatsexualselectionhasbeenthemainagentinformingtheracesofman。
Bytheway，thereisanothersubjectwhichIshallintroduceinmyessay，namely，expressionofcountenance。Now，doyouhappentoknowbyanyoddchanceaverygood—naturedandacuteobserverintheMalayArchipelago，whoyouthinkwouldmakeafeweasyobservationsformeontheexpressionoftheMalayswhenexcitedbyvariousemotions？ForinthiscaseIwouldsendtosuchpersonalistofqueries。Ithankyouforyourmostinterestingletter，andremain，Yoursverysincerely，CH。DARWIN。
CHARLESDARWINTOA。R。WALLACE。
Down，March[1867]。
MydearWallace，Ithankyoumuchforyourtwonotes。ThecaseofJuliaPastrana（Abeardedwomanhavinganirregulardoublesetofteeth。’AnimalsandPlants，’
volumeii。page328。）isasplendidadditiontomyothercasesofcorrelatedteethandhair，andIwilladditincorrectingthepressofmypresentvolume。Prayletmehearinthecourseofthesummerifyougetanyevidenceaboutthegaudycaterpillars。Ishouldmuchliketogive（orquoteifpublished）thisideaofyours，ifinanywaysupported，assuggestedbyyou。Itwill，however，bealongtimehence，forIcanseethatsexualselectionisgrowingintoquitealargesubject，whichIshallintroduceintomyessayonMan，supposingthatIeverpublishit。Ihadintendedgivingachapteronman，inasmuchasmanycallhim（notQUITE
truly）aneminentlydomesticatedanimal，butIfoundthesubjecttoolargeforachapter。NorshallIbecapableoftreatingthesubjectwell，andmysolereasonfortakingitupis，thatIamprettywellconvincedthatsexualselectionhasplayedanimportantpartintheformationofraces，andsexualselectionhasalwaysbeenasubjectwhichhasinterestedmemuch。IhavebeenverygladtoseeyourimpressionfrommemoryontheexpressionofMalays。Ifullyagreewithyouthatthesubjectisinnowayanimportantone;itissimplya\"hobby—horse\"withme，abouttwenty—sevenyearsold;andAFTERthinkingthatIwouldwriteanessayonman，itflashedonmethatIcouldworkinsome\"supplementalremarksonexpression。\"Afterthehorrid，tedious，dullworkofmypresenthuge，andIfearunreadable，book[’TheVariationofAnimalsandPlants’]，IthoughtIwouldamusemyselfwithmyhobby—horse。Thesubjectis，Ithink，morecuriousandmoreamenabletoscientifictreatmentthanyouseemwillingtoallow。Iwant，anyhow，toupsetSirC。Bell’sview，giveninhismostinterestingwork，’TheAnatomyofExpression，’thatcertainmuscleshavebeengiventomansolelythathemayrevealtoothermenhisfeelings。I
wanttotryandshowhowexpressionshavearisen。Thatisagoodsuggestionaboutnewspapers，butmyexperiencetellsmethatprivateapplicationsaregenerallymostfruitful。Iwill，however，seeifIcangetthequeriesinsertedinsomeIndianpaper。Idonotknowthenamesoraddressesofanyotherpapers……Mytwofemaleamanuensesarebusywithfriends，andIfearthisscrawlwillgiveyoumuchtroubletoread。Withmanythanks，Yoursverysincerely，CH。DARWIN。
[Thefollowinglettermaybeworthgiving，asanexampleofhissourcesofinformation，andasshowingwhatwerethethoughtsatthistimeoccupyinghim:]
CHARLESDARWINTOF。MULLER。
Down，February22[1867]……ManythanksforallthecuriousfactsabouttheunequalnumberofthesexesinCrustacea，butthemoreIinvestigatethissubjectthedeeperI
sinkindoubtanddifficulty。ThanksalsofortheconfirmationoftherivalryofCicadae。Ihaveoftenreflectedwithsurpriseonthediversityofthemeansforproducingmusicwithinsects，andstillmorewithbirds。
Wethusgetahighideaoftheimportanceofsongintheanimalkingdom。
PleasetotellmewhereIcanfindanyaccountoftheauditoryorgansintheOrthoptera。Yourfactsarequitenewtome。ScudderhasdescribedaninsectintheDevonianstrata，furnishedwithastridulatingapparatus。I
believeheistobetrusted，and，ifso，theapparatusisofastonishingantiquity。AfterreadingLandois’spaperIhavebeenworkingatthestridulatingorganintheLamellicornbeetles，inexpectationoffindingitsexual;butIhaveonlyfounditasyetintwocases，andintheseitwasequallydevelopedinbothsexes。Iwishyouwouldlookatanyofyourcommonlamellicorns，andtakeholdofbothmalesandfemales，andobservewhethertheymakethesqueakingorgratingnoiseequally。Iftheydonot，youcould，perhaps，sendmeamaleandfemaleinalightlittlebox。Howcuriousitisthatthereshouldbeaspecialorganforanobjectapparentlysounimportantassqueaking。Hereisanotherpoint;haveyouanytoucans？
ifso，askanytrustworthyhunterwhetherthebeaksofthemales，orofbothsexes，aremorebrightlycolouredduringthebreedingseasonthanatothertimesoftheyear……HeavenknowswhetherIshalleverlivetomakeuseofhalfthevaluablefactswhichyouhavecommunicatedtome！YourpaperonBalanusarmatus，translatedbyMr。Dallas，hasjustappearedinour’AnnalsandMagazineofNaturalHistory，’andIhavereaditwiththegreatestinterest。IneverthoughtthatIshouldlivetohearofahybridBalanus！Iamverygladthatyouhaveseenthecementtubes;theyappeartomeextremelycurious，and，asfarasIknow，youarethefirstmanwhohasverifiedmyobservationsonthispoint。
Withmostcordialthanksforallyourkindness，mydearSir，Yoursverysincerely，C。DARWIN。
CHARLESDARWINTOA。DECANDOLLE。
Down，July6，1868。
MydearSir，IreturnyoumySINCEREthanksforyourlongletter，whichIconsideragreatcompliment，andwhichisquitefullofmostinterestingfactsandviews。Yourreferencesandremarkswillbeofgreatuseshouldaneweditionofmybook（’VariationofAnimalsandPlants。’）bedemanded，butthisishardlyprobable，forthewholeeditionwassoldwithinthefirstweek，andanotherlargeeditionimmediatelyreprinted，whichIshouldthinkwouldsupplythedemandforever。YouaskmewhenIshallpublishonthe’VariationofSpeciesinaStateofNature。’IhavehadtheMS。foranothervolumealmostreadyduringseveralyears，butIwassomuchfatiguedbymylastbookthatIdeterminedtoamusemyselfbypublishingashortessayonthe’DescentofMan。’IwaspartlyledtodothisbyhavingbeentauntedthatIconcealedmyviews，butchieflyfromtheinterestwhichIhadlongtakeninthesubject。Nowthisessayhasbranchedoutintosomecollateralsubjects，andIsupposewilltakememorethanayeartocomplete。Ishallthenbeginon’Species，’butmyhealthmakesmeaveryslowworkman。Ihopethatyouwillexcusethesedetails，whichIhavegiventoshowthatyouwillhaveplentyoftimetopublishyourviewsfirst，whichwillbeagreatadvantagetome。Ofallthecuriousfactswhichyoumentioninyourletter，Ithinkthatofthestronginheritanceofthescalp—muscleshasinterestedmemost。Ipresumethatyouwouldnotobjecttomygivingthisverycuriouscaseonyourauthority。AsIbelieveallanatomistslookatthescalp—musclesasaremnantofthePanniculuscarnosuswhichiscommontoallthelowerquadrupeds，Ishouldlookattheunusualdevelopmentandinheritanceofthesemusclesasprobablyacaseofreversion。Yourobservationonsomanyremarkablemeninnoblefamilieshavingbeenillegitimateisextremelycurious;andshouldIevermeetanyonecapableofwritinganessayonthissubject，Iwillmentionyourremarksasagoodsuggestion。Dr。Hookerhasseveraltimesremarkedtomethatmoralsandpoliticswouldbeveryinterestingifdiscussedlikeanybranchofnaturalhistory，andthisisnearlytothesameeffectwithyourremarks……
CHARLESDARWINTOL。AGASSIZ。
Down，August19，1868。
DearSir，Ithankyoucordiallyforyourverykindletter。Icertainlythoughtthatyouhadformedsolowanopinionofmyscientificworkthatitmighthaveappearedindelicateinmetohaveaskedforinformationfromyou，butitneveroccurredtomethatmyletterwouldhavebeenshowntoyou。Ihaveneverforamomentdoubtedyourkindnessandgenerosity，andIhopeyouwillnotthinkitpresumptioninmetosay，thatwhenwemet，manyyearsago，attheBritishAssociationatSouthampton，Ifeltforyouthewarmestadmiration。
YourinformationontheAmazonianfisheshasinterestedmeEXTREMELY，andtellsmeexactlywhatIwantedtoknow。Iwasaware，throughnotesgivenmebyDr。Gunther，thatmanyfishesdifferedsexuallyincolourandothercharacters，butIwasparticularlyanxioustolearnhowfarthiswasthecasewiththosefishesinwhichthemale，differentlyfromwhatoccurswithmostbirds，takesthelargestshareinthecareoftheovaandyoung。Yourletterhasnotonlyinterestedmemuch，buthasgreatlygratifiedmeinotherrespects，andIreturnyoumysincerethanksforyourkindness。Praybelieveme，mydearSir，Yoursveryfaithfully，CHARLESDARWIN。