[InNovember，1880，hereceivedanaccountofafloodinBrazil，fromwhichhisfriendFritzMullerhadbarelyescapedwithhislife。MyfatherimmediatelywrotetoHermannMulleranxiouslyenquiringwhetherhisbrotherhadlostbooks，instruments，etc。，bythisaccident，andbegginginthatcase"forthesakeofscience，sothatscienceshouldnotsuffer，"tobeallowedtohelpinmakinggoodtheloss。Fortunately，however，theinjurytoFritzMuller’spossessionswasnotsogreataswasexpected，andtheincidentremainsonlyasamemento，whichItrustcannotbeotherwisethanpleasingtothesurvivor，ofthefriendshipofthetwonaturalists。
In’Nature’（November11，1880）appearedaletterfrommyfather，whichis，Ibelieve，theonlyinstanceinwhichhewrotepubliclywithanythinglikeseverity。ThelateSirWyvilleThomsonwrote，intheIntroductiontothe’Voyageofthe"Challenger"’:"Thecharacteroftheabyssalfaunarefusestogivetheleastsupporttothetheorywhichreferstheevolutionofspeciestoextremevariationguidedonlybynaturalselection。"Myfather，aftercharacterisingtheseremarksasa"standardofcriticism，notuncommonlyreachedbytheologiansandmetaphysicians，"goesontotakeexceptiontotheterm"extremevariation，"andchallengesSirWyvilletonameanyonewhohas"saidthattheevolutionofspeciesdependsonlyonnaturalselection。"ThelettercloseswithanimaginaryscenebetweenSirWyvilleandabreeder，inwhichSirWyvillecriticisesartificialselectioninasomewhatsimilarmanner。Thebreederissilent，butonthedepartureofhiscriticheissupposedtomakeuseof"emphaticbutirreverentlanguageaboutnaturalists。"Theletter，asoriginallywritten，endedwithaquotationfromSedgwickontheinvulnerabilityofthosewhowriteonwhattheydonotunderstand，butthiswasomittedontheadviceofafriend，andcuriouslyenoughafriendwhosecombativenessinthegoodcausemyfatherhadoccasionallycurbed。]
CHARLESDARWINTOG。J。ROMANES。
Down，April16，1881。
MydearRomanes，MyMS。on’Worms’hasbeensenttotheprinters，soIamgoingtoamusemyselfbyscribblingtoyouonafewpoints;butyoumustnotwasteyourtimeinansweringatanylengththisscribble。
Firstly，yourletteronintelligencewasveryusefultomeandItorupandre—wrotewhatIsenttoyou。Ihavenotattemptedtodefineintelligence;
buthavequotedyourremarksonexperience，andhaveshownhowfartheyapplytoworms。Itseemstomethattheymustbesaidtoworkwithsomeintelligence，anyhowtheyarenotguidedbyablindinstinct。
Secondly，Iwasgreatlyinterestedbytheabstractin’Nature’ofyourworkonEchinoderms（"OnthelocomotorsystemofEchinoderms，"byG。J。RomanesandJ。CossarEwart。’PhilosophicalTransactions，’1881，page829。），thecomplexitywithsimplicity，andwithsuchcuriousco—ordinationofthenervoussystemismarvellous;andyoushowedmebeforewhatsplendidgymnasticfeatstheycanperform。
Thirdly，Dr。Rouxhassentmeabookjustpublishedbyhim:’DerKampfderTheile，’etc。，1881（240pagesinlength）。
Heismanifestlyawell—readphysiologistandpathologist，andfromhispositionagoodanatomist。Itisfullofreasoning，andthisinGermanisverydifficulttome，sothatIhaveonlyskimmedthrougheachpage;hereandtherereadingwithalittlemorecare。AsfarasIcanimperfectlyjudge，itisthemostimportantbookonEvolution，whichhasappearedforsometime。IbelievethatG。H。Leweshintedatthesamefundamentalidea，viz。thatthereisastrugglegoingonwithineveryorganismbetweentheorganicmolecules，thecellsandtheorgans。Ithinkthathisbasisis，thateverycellwhichbestperformsitsfunctionis，inconsequence，atthesametimebestnourishedandbestpropagatesitskind。Thebookdoesnottouchonmentalphenomena，butthereismuchdiscussiononrudimentaryoratrophiedparts，towhichsubjectyouformerlyattended。Nowifyouwouldliketoreadthisbook，Iwouldsentit……Ifyoureadit，andarestruckwithit（butImaybeWHOLLYmistakenaboutitsvalue），youwoulddoapublicservicebyanalysingandcriticisingitin’Nature。’
Dr。Rouxmakes，Ithink，agiganticoversightinneverconsideringplants;
thesewouldsimplifytheproblemforhim。
Fourthly，Idonotknowwhetheryouwilldiscussinyourbookonthemindofanimalsanyofthemorecomplexandwonderfulinstincts。Itisunsatisfactorywork，astherecanbenofossilisedinstincts，andthesoleguideistheirstateinothermembersofthesameorder，andmerePROBABILITY。
Butifyoudodiscussany（anditwillperhapsbeexpectedofyou），I
shouldthinkthatyoucouldnotselectabettercasethanthatofthesandwasps，whichparalysetheirprey，asformerlydescribedbyFabre，inhiswonderfulpaperinthe’AnnalesdesSciences，’andsinceamplifiedinhisadmirable’Souvenirs。’
Whilstreadingthislatterbook，Ispeculatedalittleonthesubject。
Astonishingnonsenseisoftenspokenofthesandwasp’sknowledgeofanatomy。NowwillanyonesaythattheGauchosontheplainsofLaPlatahavesuchknowledge，yetIhaveoftenseenthempithastrugglingandlassoedcowonthegroundwithunerringskill，whichnomereanatomistcouldimitate。Thepointedknifewasinfalliblydriveninbetweenthevertebraebyasingleslightthrust。Ipresumethattheartwasfirstdiscoveredbychance，andthateachyoungGauchoseesexactlyhowtheothersdoit，andthenwithaverylittlepracticelearnstheart。NowI
supposethatthesandwaspsoriginallymerelykilledtheirpreybystingingtheminmanyplaces（seepage129ofFabre’s’Souvenirs，’andpage241）onthelowerandsoftestsideofthebody——andthattostingacertainsegmentwasfoundbyfarthemostsuccessfulmethod;andwasinheritedlikethetendencyofabulldogtopinthenoseofabull，orofaferrettobitethecerebellum。Itwouldnotbeaverygreatstepinadvancetopricktheganglionofitspreyonlyslightly，andthustogiveitslarvaefreshmeatinsteadofolddriedmeat。ThoughFabreinsistssostronglyontheunvaryingcharacterofinstinct，yetitisshownthatthereissomevariability，asatpages176，177。
IfearthatIshallhaveutterlyweariedyouwithmyscribblingandbadhandwriting。
MydearRomanes，yours，verysincerely，CH。DARWIN。
POSTSCRIPTOFALETTERTOPROFESSORA。AGASSIZ，MAY5TH，1881:——
IreadwithmuchinterestyouraddressbeforetheAmericanAssociation。
Howevertrueyourremarksonthegenealogiesoftheseveralgroupsmaybe，Ihopeandbelievethatyouhaveover—estimatedthedifficultiestobeencounteredinthefuture:——Afewdaysafterreadingyouraddress，I
interpretedtomyselfyourremarksononepoint（Ihopeinsomedegreecorrectly）inthefollowingfashion:——
Anycharacterofanancient，generalised，orintermediateformmay，andoftendoes，re—appearinitsdescendants，aftercountlessgenerations，andthisexplainstheextraordinarilycomplicatedaffinitiesofexistinggroups。Thisideaseemstometothrowafloodoflightonthelines，sometimesusedtorepresentaffinities，whichradiateinalldirections，oftentoverydistantsub—groups，——adifficultywhichhashauntedmeforhalfacentury。Astrongcasecouldbemadeoutinfavourofbelievinginsuchreversionafterimmenseintervalsoftime。Iwishtheideahadbeenputintomyheadinolddays，forIshallneveragainwriteondifficultsubjects，asIhaveseentoomanycasesofoldmenbecomingfeebleintheirminds，withoutbeingintheleastconsciousofit。IfIhaveinterpretedyourideasatallcorrectly，Ihopethatyouwillre—urge，onanyfittingoccasion，yourview。Ihavementionedittoafewpersonscapableofjudging，anditseemedquitenewtothem。Ibegyoutoforgivetheproverbialgarrulityofoldage。
C。D。
[ThefollowingletterreferstoSirJ。D。Hooker’sGeographicaladdressattheYorkMeeting（1881）oftheBritishAssociation:]
CHARLESDARWINTOJ。D。HOOKER。
Down，August6，1881。
MydearHooker，ForHeaven’ssakeneverspeakofboringme，asitwouldbethegreatestpleasuretoaidyouintheslightestdegreeandyourletterhasinterestedmeexceedingly。Iwillgothroughyourpointsseriatim，butIhaveneverattendedmuchtothehistoryofanysubject，andmymemoryhasbecomeatrociouslybad。Itwillthereforebeamerechancewhetheranyofmyremarksareofanyuse。
Youridea，toshowwhattravellershavedone，seemstomeabrilliantandjustone，especiallyconsideringyouraudience。
1。IknownothingaboutTournefort’sworks。
2。IbelievethatyouarefullyrightincallingHumboldtthegreatestscientifictravellerwhoeverlived，Ihavelatelyreadtwoorthreevolumesagain。HisGeologyisfunnystuff;butthatmerelymeansthathewasnotinadvanceofhisage。Ishouldsayhewaswonderful，moreforhisnearapproachtoomnisciencethanfororiginality。Whetherornothispositionasascientificmanisaseminentaswethink，youmighttrulycallhimtheparentofagrandprogenyofscientifictravellers，who，takentogether，havedonemuchforscience。
3。ItseemstomequitejusttogiveLyell（andsecondarilyE。Forbes）averyprominentplace。
4。Danawas，Ibelieve，thefirstmanwhomaintainedthepermanenceofcontinentsandthegreatoceans……WhenIreadthe’Challenger’s’conclusionthatsedimentfromthelandisnotdepositedatgreaterdistancesthan200
or300milesfromtheland，Iwasmuchstrengthenedinmyoldbelief。
Wallaceseemstometohavearguedthecaseexcellently。Nevertheless，I
wouldspeak，ifIwereinyourplace，rathercautiously;forT。MellardReadehasarguedlatelywithsomeforceagainsttheview;butIcannotcalltomindhisarguments。Ifforcedtoexpressajudgment，IshouldabidebytheviewofapproximatepermanencesinceCambriandays。
5。TheextremeimportanceoftheArcticfossil—plants，isself—evident。
Taketheopportunityofgroaningover[our]ignoranceoftheLignitePlantsofKerguelenLand，oranyAntarcticland。Itmightdogood。
6。IcannotavoidfeelingscepticalaboutthetravellingofplantsfromtheNorthEXCEPTDURINGTHETERTIARYPERIOD。Itmayofcoursehavebeensoandprobablywassofromoneofthetwopolesattheearliestperiod，duringPre—Cambrianages;butsuchspeculationsseemtomehardlyscientificseeinghowlittleweknowoftheoldFloras。
Iwillnowjotdownwithoutanyorderafewmiscellaneousremarks。
IthinkyououghttoalludetoAlph。DeCandolle’sgreatbook，forthoughit（likealmosteverythingelse）iswashedoutofmymind，yetIremembermostdistinctlythinkingitaveryvaluablework。Anyhow，youmightalludetohisexcellentaccountofthehistoryofallcultivatedplants。
HowshallyoumanagetoalludetoyourNewZealandandTierradelFuegowork？ifyoudonotalludetothemyouwillbescandalouslyunjust。
ThemanyAngiospermplantsintheCretaceanbedsoftheUnitedStates（andasfarasIcanjudgetheageofthesebedshasbeenfairlywellmadeout）
seemstomeafactofverygreatimportance，soistheirrelationtotheexistingfloraoftheUnitedStatesunderanEvolutionarypointofview。
HavenotsomeAustralianextinctformsbeenlatelyfoundinAustralia？orhaveIdreamedit？
Again，therecentdiscoveryofplantsratherlowdowninourSilurianbedsisveryimportant。
NothingismoreextraordinaryinthehistoryoftheVegetableKingdom，asitseemstome，thantheAPPARENTLYverysuddenorabruptdevelopmentofthehigherplants。Ihavesometimesspeculatedwhethertheredidnotexistsomewhereduringlongagesanextremelyisolatedcontinent，perhapsneartheSouthPole。
HenceIwasgreatlyinterestedbyaviewwhichSaportapropoundedtome，afewyearsago，atgreatlengthinMS。andwhichIfancyhehassincepublished，asIurgedhimtodo——viz。，thatassoonasflower—frequentinginsectsweredeveloped，duringthelatterpartofthesecondaryperiod，anenormousimpulsewasgiventothedevelopmentofthehigherplantsbycross—fertilizationbeingthussuddenlyformed。
AfewyearsagoIwasmuchstruckwithAxelBlytt’sEssayshowingfromobservation，onthepeatbedsinScandinavia，thattherehadapparentlybeenlongperiodswithmorerainandotherwithlessrain（perhapsconnectedwithCroll’srecurrentastronomicalperiods），andthattheseperiodshadlargelydeterminedthepresentdistributionoftheplantsofNorwayandSweden。Thisseemedtome，averyimportantessay。
IhavejustreadovermyremarksandIfearthattheywillnotbeoftheslightestusetoyou。
Icannotbutthinkthatyouhavegotthroughthehardest，oratleastthemostdifficult，partofyourworkinhavingmadesogoodandstrikingasketchofwhatyouintendtosay;butIcanquiteunderstandhowyoumustgroanoverthegreatnecessarylabour。
ImostheartilysympathisewithyouonthesuccessesofB。andR。:asyearsadvancewhathappenstooneselfbecomesofverylittleconsequence，incomparisonwiththecareersofourchildren。
Keepyourspiritsup，forIamconvincedthatyouwillmakeanexcellentaddress。
Everyours，affectionately，CHARLESDARWIN。
[InSeptemberhewrote:——
"Ihavethisminutefinishedreadingyoursplendidbuttooshortaddress。
IcannotdoubtthatitwillhavebeenfullyappreciatedbytheGeographersofYork;ifnot，theyareassesandfools。"]
CHARLESDARWINTOJOHNLUBBOCK。
Sundayevening[1881]。
MydearL。，Youraddress（PresidentialAddressattheYorkmeetingoftheBritishAssociation。）hasmademethinkoverwhathavebeenthegreatstepsinGeologyduringthelastfiftyyears，andtherecanbenoharmintellingyoumyimpression。ButitisveryoddthatIcannotrememberwhatyouhavesaidonGeology。IsupposethattheclassificationoftheSilurianandCambrianformationsmustbeconsideredthegreatestormostimportantstep;
forIwellrememberwhenalltheseolderrockswerecalledgrau—wacke，andnobodydreamedofclassingthem;andnowwehavethreeazoicformationsprettywellmadeoutbeneaththeCambrian！ButthemoststrikingstephasbeenthediscoveryoftheGlacialperiod:youaretooyoungtoremembertheprodigiouseffectthisproducedabouttheyear1840（？）onallourminds。EliedeBeaumontneverbelievedinittothedayofhisdeath！thestudyoftheglacialdepositsledtothestudyofthesuperficialdrift，whichwasformerlyNEVERSTUDIEDandcalledDiluvium，asIwellremember。
Thestudyunderthemicroscopeofrock—sectionsisanothernotinconsiderablestep。Soagainthemakingoutofcleavageandthefoliationofthemetamorphicrocks。ButIwillnotrunon，havingnoweasedmymind。
Praydonotwasteevenoneminuteinacknowledgingmyhorridscrawls。
Everyours，CH。DARWIN。
[ThefollowingextractsreferringtothelateFrancisMaitlandBalfour（ProfessorofAnimalMorphologyatCambridge。Hewasbornin1851，andwaskilled，withhisguide，ontheAiguilleBlanche，nearCourmayeur，inJuly，1882。），showmyfather’sestimateofhisworkandintellectualqualities，buttheygivemerelyanindicationofhisstrongappreciationofBalfour’smostlovablepersonalcharacter:——
FromalettertoFritzMuller，January5，1882:——
"YourappreciationofBalfour’sbook[’ComparativeEmbryology’]haspleasedmeexcessively，forthoughIcouldnotproperlyjudgeofit，yetitseemedtomeoneofthemostremarkablebookswhichhavebeenpublishedforsomeconsiderabletime。Heisquiteayoungman，andifhekeepshishealth，willdosplendidwork……Hehasafairfortuneofhisown，sothathecangiveuphiswholetimetoBiology。Heisverymodest，andverypleasant，andoftenvisitshereandwelikehimverymuch。"
FromalettertoDr。Dohrn，February13，1882:——
"Ihavegotoneverybadpieceofnewstotellyou，thatF。BalfourisveryillatCambridgewithtyphoidfever……Ihopethatheisnotinaverydangerousstate;butthefeverissevere。GoodHeavens，whatalosshewouldbetoScience，andtohismanylovingfriends！"]
CHARLESDARWINTOT。H。HUXLEY。
Down，January12，1882。
MydearHuxley，Verymanythanksfor’ScienceandCulture，’andIamsurethatIshallreadmostoftheessayswithmuchinterest。WithrespecttoAutomatism（"Onthehypothesisthatanimalsareautomataanditshistory，"anAddressgivenattheBelfastmeetingoftheBritishAssociation，1874，andpublishedinthe’FortnightlyReview，’1874，andin’ScienceandCulture。’），Iwishthatyoucouldreviewyourselfintheold，andofcourseforgotten，trenchantstyle，andthenyouwouldhereansweryourselfwithequalincisiveness;andthus，byJove，youmightgoonadinfinitum，tothejoyandinstructionoftheworld。
Everyoursverysincerely，CHARLESDARWIN。
[ThefollowingletterreferstoDr。Ogle’stranslationofAristotle，’OnthePartsofAnimals’（1882）:]
CHARLESDARWINTOW。OGLE。
Down，February22，1882。
MydearDr。Ogle，YoumustletmethankyouforthepleasurewhichtheintroductiontotheAristotlebookhasgivenme。Ihaverarelyreadanythingwhichhasinterestedmemore，thoughIhavenotreadasyetmorethanaquarterofthebookproper。
FromquotationswhichIhadseen，IhadahighnotionofAristotle’smerits，butIhadnotthemostremotenotionwhatawonderfulmanhewas。
LinnaeusandCuvierhavebeenmytwogods，thoughinverydifferentways，buttheyweremereschoolboystooldAristotle。Howverycurious，also，hisignoranceonsomepoints，asonmusclesasthemeansofmovement。Iamgladthatyouhaveexplainedinsoprobableamannersomeofthegrossestmistakesattributedtohim。Ineverrealized，beforereadingyourbook，towhatanenormoussummationoflabourweoweevenourcommonknowledge。I
wisholdAristotlecouldknowwhatagrandDefenderoftheFaithhehadfoundinyou。Believeme，mydearDr。Ogle，Yoursverysincerely，CH。DARWIN。
[InFebruary，hereceivedaletterandaspecimenfromaMr。W。D。Crick，whichillustratedacuriousmodeofdispersalofbivalveshells，namely，byclosureoftheirvalvessoastoholdontothelegofawater—beetle。
Thisclassoffacthadaspecialcharmforhim，andhewroteto’Nature，’
describingthecase。（’Nature，’April6，1882。）
InAprilhereceivedaletterfromDr。W。VanDyck，LecturerinZoologyattheProtestantCollegeofBeyrout。ThelettershowedthatthestreetdogsofBeyrouthadbeenrapidlymongrelisedbyintroducedEuropeandogs，andthefactshaveaninterestingbearingonmyfather’stheoryofSexualSelection。]
CHARLESDARWINTOW。T。VANDYCK。
Down，April3，1882。
DearSir，Aftermuchdeliberation，IhavethoughtitbesttosendyourveryinterestingpapertotheZoologicalSociety，inhopesthatitwillbepublishedintheirJournal。Thisjournalgoestoeveryscientificinstitutionintheworld，andthecontentsareabstractedinallyear—booksonZoology。ThereforeIhavepreferreditto’Nature，’thoughthelatterhasawidercirculation，butisephemeral。
Ihaveprefacedyouressaybyafewgeneralremarks，towhichIhopethatyouwillnotobject。
OfcourseIdonotknowthattheZoologicalSociety，whichismuchaddictedtomeresystematicwork，willpublishyouressay。Ifitdoes，Iwillsendyoucopiesofyouressay，butthesewillnotbereadyforsomemonths。IfnotpublishedbytheZoologicalSociety，Iwillendeavourtoget’Nature’
topublishit。Iamveryanxiousthatitshouldbepublishedandpreserved。
DearSir，Yoursfaithfully，CH。DARWIN。
[ThepaperwasreadatameetingoftheZoologicalSocietyonApril18th——
thedaybeforemyfather’sdeath。
ThepreliminaryremarkswithwhichDr。VanDyck’spaperisprefacedarethusthelatestofmyfather’swritings。]……
Wemustnowreturntoanearlyperiodofhislife，andgiveaconnectedaccountofhisbotanicalwork，whichhashithertobeenomitted。
CHAPTER2。X。
FERTILISATIONOFFLOWERS。
[InthelettersalreadygivenwehavehadoccasiontonoticethegeneralbearingofanumberofbotanicalproblemsonthewiderquestionofEvolution。ThedetailedworkinbotanywhichmyfatheraccomplishedbytheguidanceofthelightcastonthestudyofnaturalhistorybyhisownworkonEvolutionremainstobenoticed。InalettertoMr。Murray，September24th，1861，speakingofhisbookonthe’FertilisationofOrchids，’hesays:"ItwillperhapsservetoillustratehowNaturalHistorymaybeworkedunderthebeliefofthemodificationofspecies。"Thisremarkgivesasuggestionastothevalueandinterestofhisbotanicalwork，anditmightbeexpressedinfarmoreemphaticlanguagewithoutdangerofexaggeration。
InthesamelettertoMr。Murray，hesays:"Ithinkthislittlevolumewilldogoodtothe’Origin，’asitwillshowthatIhaveworkedhardatdetails。"ItistruethathisbotanicalworkaddedamassofcorroborativedetailtothecaseforEvolution，butthechiefsupporttohisdoctrinesgivenbytheseresearcheswasofanotherkind。Theysuppliedanargumentagainstthosecriticswhohavesofreelydogmatisedastotheuselessnessofparticularstructures，andastotheconsequentimpossibilityoftheirhavingbeendevelopedbymeansofnaturalselection。HisobservationsonOrchidsenabledhimtosay:"Icanshowthemeaningofsomeoftheapparentlymeaninglessridges，horns，whowillnowventuretosaythatthisorthatstructureisuseless？"AkindredpointisexpressedinalettertoSirJ。D。Hooker（May14th，1862:）——
"Whenmanypartsofstructure，asinthewoodpecker，showdistinctadaptationtoexternalbodies，itispreposteroustoattributethemtotheeffectsofclimate，etc。，butwhenasinglepointalone，asahookedseed，itisconceivableitmaythushavearisen。IhavefoundthestudyofOrchidseminentlyusefulinshowingmehownearlyallpartsoftheflowerareco—adaptedforfertilizationbyinsects，andthereforetheresultsofnaturalselection——eventhemosttriflingdetailsofstructure。"
OneofthegreatestservicesrenderedbymyfathertothestudyofNaturalHistoryistherevivalofTeleology。TheevolutioniststudiesthepurposeormeaningoforganswiththezealoftheolderTeleology，butwithfarwiderandmorecoherentpurpose。Hehastheinvigoratingknowledgethatheisgainingnotisolatedconceptionsoftheeconomyofthepresent，butacoherentviewofbothpastandpresent。Andevenwherehefailstodiscovertheuseofanypart，hemay，byaknowledgeofitsstructure，unravelthehistoryofthepastvicissitudesinthelifeofthespecies。
Inthiswayavigourandunityisgiventothestudyoftheformsoforganisedbeings，whichbeforeitlacked。ThispointhasalreadybeendiscussedinMr。Huxley’schapteronthe’Receptionofthe"OriginofSpecies"，’andneednotbehereconsidered。Itdoes，however，concernustorecognizethatthis"greatservicetonaturalscience，"asDr。Graydescribesit，waseffectedalmostasmuchbyhisspecialbotanicalworkasbythe’OriginofSpecies。’
Forastatementofthescopeandinfluenceofmyfather’sbotanicalwork，I
mayrefertoMr。ThiseltonDyer’sarticlein’CharlesDarwin，’oneofthe"NatureSeries"。Mr。Dyer’swideknowledge，hisfriendshipwithmyfather，andespeciallyhispowerofsympathisingwiththeworkofothers，combinetogivethisessayapermanentvalue。Thefollowingpassage（page43）
givesatruepicture:——
"Notwithstandingtheextentandvarietyofhisbotanicalwork，Mr。Darwinalwaysdisclaimedanyrighttoberegardedasaprofessedbotanist。Heturnedhisattentiontoplants，doubtlessbecausetheywereconvenientobjectsforstudyingorganicphenomenaintheirleastcomplicatedforms;
andthispointofview，which，ifonemayusetheexpressionwithoutdisrespect，hadsomethingoftheamateuraboutit，wasinitselfofthegreatestimportance。For，fromnotbeing，tillhetookupanypoint，familiarwiththeliteraturebearingonit，hismindwasabsolutelyfreefromanyprepossession。Hewasneverafraidofhisfacts，orofframinganyhypothesis，howeverstartling，whichseemedtoexplainthem……Inanyoneelsesuchanattitudewouldhaveproducedmuchworkthatwascrudeandrash。ButMr。Darwin——ifonemayventureonlanguagewhichwillstrikenoonewhohadconversedwithhimasover—strained——seemedbygentlepersuasiontohavepenetratedthatreserveofnaturewhichbafflessmallermen。Inotherwords，hislongexperiencehadgivenhimakindofinstinctiveinsightintothemethodofattackofanybiologicalproblem，howeverunfamiliartohim，whileherigidlycontrolledthefertilityofhismindinhypotheticalexplanationsbythenolessfertilityofingeniouslydevisedexperiment。"
Toformanyjustideaofthegreatnessoftherevolutionworkedbymyfather’sresearchesinthestudyofthefertilisationofflowers，itisnecessarytoknowfromwhataconditionthisbranchofknowledgehasemerged。Itshouldberememberedthatitwasonlyduringtheearlyyearsofthepresentcenturythattheideaofsex，asappliedtoplants，becameatallfirmlyestablished。Sachs，inhis’HistoryofBotany’（1875），hasgivensomestrikingillustrationsoftheremarkableslownesswithwhichitsacceptancegainedground。HeremarksthatwhenweconsidertheexperimentalproofsgivenbyCamerarius（1694），andbyKolreuter（1761—66），itappearsincrediblethatdoubtsshouldafterwardshavebeenraisedastothesexualityofplants。Yetheshowsthatsuchdoubtsdidactuallyrepeatedlycropup。Theseadversecriticismsrestedforthemostpartoncarelessexperiments，butinmanycasesonaprioriarguments。Evenaslateas1820，abookofthiskind，whichwouldnowrankwithcirclesquaring，orflat—earthphilosophy，wasseriouslynoticedinabotanicaljournal。
Adistinctconceptionofsexasappliedtoplants，hadnotlongemergedfromthemistsofprofitlessdiscussionandfeebleexperiment，atthetimewhenmyfatherbeganbotanybyattendingHenslow’slecturesatCambridge。
Whenthebeliefinthesexualityofplantshadbecomeestablishedasanincontrovertiblepieceofknowledge，aweightofmisconceptionremained，weighingdownanyrationalviewofthesubject。Camerarius（Sachs，’Geschichte，’page419。）believed（naturallyenoughinhisday）thathermaphroditeflowersarenecessarilyself—fertilised。Hehadthewittobeastonishedatthis，adegreeofintelligencewhich，asSachspointsout，themajorityofhissuccessorsdidnotattainto。
Thefollowingextractsfromanote—bookshowthatthispointoccurredtomyfatherasearlyas1837:——
"Donotplantswhichhavemaleandfemaleorganstogether[i。e。inthesameflower]yetreceiveinfluencefromotherplants？DoesnotLyellgivesomeargumentaboutvarietiesbeingdifficulttokeep[true]onaccountofpollenfromotherplants？Becausethismaybeappliedtoshowallplantsdoreceiveintermixture。"
Sprengel（ChristianConradSprengel，1750—1816。），indeed，understoodthatthehermaphroditestructureofflowersbynomeansnecessarilyleadstoself—fertilisation。ButalthoughhediscoveredthatinmanycasespollenisofnecessitycarriedtothestigmaofanotherFLOWER，hedidnotunderstandthatintheadvantagegainedbytheintercrossingofdistinctPLANTSliesthekeytothewholequestion。HermannMullerhaswellremarkedthatthis"omissionwasforseveralgenerationsfataltoSprengel’swork……Forbothatthetimeandsubsequently，botanistsfeltabovealltheweaknessofhistheory，andtheysetaside，alongwithhisdefectiveideas，hisrichstoreofpatientandacuteobservationsandhiscomprehensiveandaccurateinterpretations。"ItremainedformyfathertoconvincetheworldthatthemeaninghiddeninthestructureofflowerswastobefoundbyseekinglightinthesamedirectioninwhichSprengel，seventyyearsbefore，hadlaboured。RobertBrownwastheconnectinglinkbetweenthem，foritwasathisrecommendationthatmyfatherin1841readSprengel’snowcelebrated’SecretofNatureDisplayed。’（’DasentdeckteGeheimnissderNaturimBaueundinderBefruchtungderBlumen。’Berlin，1793。）Thebookimpressedhimasbeing"fulloftruth，"although"withsomelittlenonsense。"Itnotonlyencouragedhiminkindredspeculation，butguidedhiminhiswork，forin1844hespeaksofverifyingSprengel’sobservations。ItmaybedoubtedwhetherRobertBrowneverplantedamorebeautifulseedthaninputtingsuchabookintosuchhands。
Apassageinthe’Autobiography’（volumei。）showshowitwasthatmyfatherwasattractedtothesubjectoffertilisation:"Duringthesummerof1839，andIbelieveduringtheprevioussummer，Iwasledtoattendtothecross—fertilisationofflowersbytheaidofinsects，fromhavingcometotheconclusioninmyspeculationsontheoriginofspecies，thatcrossingplayedanimportantpartinkeepingspecificformsconstant。"
Theoriginalconnectionbetweenthestudyofflowersandtheproblemofevolutioniscurious，andcouldhardlyhavebeenpredicted。Moreover，itwasnotapermanentbond。Assoonastheideaarosethattheoffspringofcross—fertilisationis，inthestruggleforlife，likelytoconquertheseedlingsofself—fertilisedparentage，afarmorevigorousbeliefinthepotencyofnaturalselectioninmouldingthestructureofflowersisattained。Acentralideaisgainedtowardswhichexperimentandobservationmaybedirected。
Dr。Grayhaswellremarkedwithregardtothiscentralidea（’Nature，’June4，1874）:——"Theaphorism，’Natureabhorsavacuum，’isacharacteristicspecimenofthescienceofthemiddleages。Theaphorism，Natureabhorsclosefertilisation，’andthedemonstrationoftheprinciple，belongtoourageandtoMr。Darwin。Tohaveoriginatedthis，andalsotheprincipleofNaturalSelection……andtohaveappliedtheseprinciplestothesystemofnature，insuchamannerastomake，withinadozenyears，adeeperimpressionuponnaturalhistorythanhasbeenmadesinceLinnaeus，isampletitleforoneman’sfame。"
TheflowersofthePapilionaceaeattractedhisattentionearly，andwerethesubjectofhisfirstpaperonfertilisation。（"Gardeners’Chronicle"，1857，page725。Itappearsthatthispaperwasapieceof"over—time"
work。Hewrotetoafriend，"thatconfoundedleguminouspaperwasdoneintheafternoon，andtheconsequencewasIhadtogotoMoorParkforaweek。"）ThefollowingextractfromanundatedlettertoDr。AsaGrayseemstohavebeenwrittenbeforethepublicationofthispaper，probablyin1856
or1857:——
"……WhatyousayonPapilionaceousflowersisverytrue;andIhavenofactstoshowthatvarietiesarecrossed;butyet（andthesameremarkisapplicableinabeautifulwaytoFumariaandDielytra，asInoticedmanyyearsago），Imustbelievethattheflowersareconstructedpartlyindirectrelationtothevisitsofinsects;andhowinsectscanavoidbringingpollenfromotherindividualsIcannotunderstand。ItisreallyprettytowatchtheactionofaHumble—beeonthescarletkidneybean，andinthisgenus（andinLathyrusgrandiflorus）thehoneyissoplacedthatthebeeinvariablyalightsonthatONEsideoftheflowertowardswhichthespiralpistilisprotruded（bringingoutwithitpollen），andbythedepressionofthewing—petalisforcedagainstthebee’ssidealldustedwithpollen。（Ifyouwilllookatabedofscarletkidneybeansyouwillfindthatthewing—petalsontheLEFTsidealoneareallscratchedbythetarsiofthebees。[NoteintheoriginalletterbyC。Darwin。]）Inthebroomthepistilisrubbedonthecentreofthebackofthebee。IsuspectthereissomethingtobemadeoutabouttheLeguminosae，whichwillbringthecasewithinOURtheory;thoughIhavefailedtodoso。Ourtheorywillexplainwhyinthevegetableandanimalkingdomtheactoffertilisationeveninhermaphroditesusuallytakesplacesub—jove，thoughthusexposedtoGREATinjuryfromdampandrain。Inanimalswhichcannotbe[fertilised]