P。S。IshouldfeelextremelyobligedforyourkindofferofthesketchofHumboldt;Iveneratehim，andafterhavinghadthepleasureofconversingwithhiminLondon，Ishallstillmoreliketohaveanyportraitofhim。
[WhatfollowsisquotedfromSirJ。Hooker’snotes。\"Thenextactinthedramaofourlivesopenswithpersonalintercourse。Thisbeganwithaninvitationtobreakfastwithhimathisbrother’s（ErasmusDarwin’s）houseinParkStreet;whichwasshortlyafterwardsfollowedbyaninvitationtoDowntomeetafewbrotherNaturalists。Intheshortintervalsofgoodhealththatfollowedthelongillnesseswhichoftentimesrenderedlifeaburthentohim，between1844and1847，Ihadmanysuchinvitations，anddelightfultheywere。Amorehospitableandmoreattractivehomeundereverypointofviewcouldnotbeimagined——ofSocietythereweremostoftenDr。Falconer，EdwardForbes，ProfessorBell，andMr。Waterhouse——therewerelongwalks，rompswiththechildrenonhandsandknees，musicthathauntsmestill。Darwin’sownheartymanner，hollowlaugh，andthoroughenjoymentofhomelifewithfriends;strollswithhimalltogether，andinterviewswithusonebyoneinhisstudy，todiscussquestionsinanybranchofbiologicalorphysicalknowledgethatwehadfollowed;andwhichIatanyratealwaysleftwiththefeelingthatIhadimpartednothingandcarriedawaymorethanIcouldstaggerunder。Latterly，ashishealthbecamemoreseriouslyaffected，Iwasfordaysandweekstheonlyvisitor，bringingmyworkwithmeandenjoyinghissocietyasopportunityoffered。Itwasanestablishedrulethatheeverydaypumpedme，ashecalledit，forhalfanhourorsoafterbreakfastinhisstudy，whenhefirstbroughtoutaheapofslipswithquestionsbotanical，geographical，etc。，formetoanswer，andconcludedbytellingmeoftheprogresshehadmadeinhisownwork，askingmyopiniononvariouspoints。Isawnomoreofhimtillaboutnoon，whenIheardhismellowringingvoicecallingmynameundermywindow——thiswastojoinhiminhisdailyforenoonwalkroundthesand—walk。OnjoininghimIfoundhiminaroughgreyshooting—coatinsummer，andthickcapeoverhisshouldersinwinter，andastoutstaffinhishand;awaywetrudgedthroughthegarden，wheretherewasalwayssomeexperimenttovisit，andontothesand—walk，roundwhichafixednumberofturnsweretaken，duringwhichourconversationusuallyranonforeignlandsandseas，oldfriends，oldbooks，andthingsfarofftobothmindandeye。
\"Intheafternoontherewasanothersuchwalk，afterwhichheagainretiredtilldinnerifwellenoughtojointhefamily;ifnot，hegenerallymanagedtoappearinthedrawing—room，whereseatedinhishighchair，withhisfeetinenormouscarpetshoes，supportedonahighstool——heenjoyedthemusicorconversationofhisfamily。\"
Herefollowsaseriesoflettersillustratingthegrowthofmyfather’sviews，andthenatureofhisworkduringthisperiod。]
CHARLESDARWINTOJ。D。HOOKER。
Down[1844]……Theconclusion，whichIhavecomeatis，thatthoseareas，inwhichspeciesaremostnumerous，haveoftenestbeendividedandisolatedfromotherareas，unitedandagaindivided;aprocessimplyingantiquityandsomechangesintheexternalconditions。Thiswilljustlysoundveryhypothetical。Icannotgivemyreasonsindetail;butthemostgeneralconclusion，whichthegeographicaldistributionofallorganicbeings，appearstometoindicate，isthatisolationisthechiefconcomitantorcauseoftheappearanceofNEWforms（Iwellknowtherearesomestaringexceptions）。Secondly，fromseeinghowoftentheplantsandanimalsswarminacountry，whenintroducedintoit，andfromseeingwhatavastnumberofplantswilllive，forinstanceinEngland，ifkeptFREEFROMWEEDS，AND
NATIVEPLANTS，Ihavebeenledtoconsiderthatthespreadingandnumberoftheorganicbeingsofanycountrydependlessonitsexternalfeatures，thanonthenumberofforms，whichhavebeenthereoriginallycreatedorproduced。Imuchdoubtwhetheryouwillfinditpossibletoexplainthenumberofformsbyproportionaldifferencesofexposure;andIcannotdoubtifhalfthespeciesinanycountryweredestroyedorhadnotbeencreated，yetthatcountrywouldappeartousfullypeopled。Withrespecttooriginalcreationorproductionofnewforms，Ihavesaidthatisolationappearsthechiefelement。Hence，withrespecttoterrestrialproductions，atractofcountry，whichhadoftenestwithinthelategeologicalperiodssubsidedandbeenconvertedintoislands，andreunited，Ishouldexpecttocontainmostforms。
Butsuchspeculationsareamusingonlytooneself，andinthiscaseuseless，astheydonotshowanydirectlineofobservation:ifIhadseenhowhypothetical[is]thelittle，whichIhaveunclearlywritten，Iwouldnothavetroubledyouwiththereadingofit。Believeme，——atlastnothypothetically，Yoursverysincerely，C。DARWIN。
CHARLESDARWINTOJ。D。HOOKER。
Down，1844……Iforgetmylastletter，butitmusthavebeenaverysillyone，asitseemsIgavemynotionofthenumberofspeciesbeingingreatdegreegovernedbythedegreetowhichtheareahadbeenoftenisolatedanddivided;Imusthavebeencrackedtohavewrittenit，forIhavenoevidence，withoutapersonbewillingtoadmitallmyviews，andthenitdoesfollow;butinmymostsanguinemoments，allIexpect，isthatIshallbeabletoshoweventosoundNaturalists，thattherearetwosidestothequestionoftheimmutabilityofspecies;——thatfactscanbeviewedandgroupedunderthenotionofalliedspecieshavingdescendedfromcommonstocks。Withrespecttobooksonthissubject，Idonotknowofanysystematicalones，exceptLamarck’s，whichisveritablerubbish;butthereareplenty，asLyell，Pritchard，etc。，ontheviewoftheimmutability。
Agassizlatelyhasbroughtthestrongestargumentinfavourofimmutability。IsidoreG。St。HilairehaswrittensomegoodEssays，tendingtowardsthemutability—side，inthe’SuitesaBuffon，’entitled\"Zoolog。
Generale。\"Isitnotstrangethattheauthor，ofsuchabookasthe’AnimauxsansVertebres，’shouldhavewrittenthatinsects，whichneverseetheireggs，shouldWILL（andplants，theirseeds）tobeofparticularforms，soastobecomeattachedtoparticularobjects。Theother，common（speciallyGermanic）notionishardlylessabsurd，viz。thatclimate，food，etc。，shouldmakeaPediculusformedtoclimbhair，orwood—pecker，toclimbtrees。Ibelievealltheseabsurdviewsarise，fromnoonehaving，asfarasIknow，approachedthesubjectonthesideofvariationunderdomestication，andhavingstudiedallthatisknownaboutdomestication。I
wasverygladtohearyourcriticismonisland—florasandonnon—diffusionofplants:thesubjectistoolongforaletter:Icoulddefendmyselftosomeconsiderableextent，butIdoubtwhethersuccessfullyinyoureyes，orindeedinmyown……
CHARLESDARWINTOJ。D。HOOKER。
Down[July，1844]……Iamnowreadingawonderfulbookforfactsonvariation——Bronn，’GeschichtederNatur。’ItisstiffGerman:itforestallsme，sometimesI
thinkdelightfully，andsometimescruelly。YouwillbetentimeshereaftermorehorrifiedatmethanatH。Watson。Ihateargumentsfromresults，butonmyviewsofdescent，reallyNaturalHistorybecomesasublimelygrandresult—givingsubject（nowyoumayquizmeforsofoolishanescapeofmouth）……Imustleavethislettertillto—morrow，forIamtired;butIsoenjoywritingtoyou，thatImustinflictalittlemoreonyou。
Haveyouanygoodevidenceforabsenceofinsectsinsmallislands？I
foundthirteenspeciesinKeelingAtoll。Fliesaregoodfertilizers，andI
haveseenamicroscopicThripsandaCecidomyatakeflightfromaflowerinthedirectionofanotherwithpollenadheringtothem。InArcticcountriesabeeseemstogoasfarN。asanyflower……
CHARLESDARWINTOJ。D。HOOKER。
Shrewsbury[September，1845]。
MydearHooker，IwritealinetosaythatCosmos（AtranslationofHumboldt’s’Kosmos。’）
arrivedquitesafely[N。B。OnesheetcamelooseinPartI。}，andtothankyouforyournicenote。Ihavejustbeguntheintroduction，andgroanoverthestyle，whichinsuchpartsisfullhalfthebattle。Howtruemanyoftheremarksare（i。e。asfarasIcanunderstandthewretchedEnglish）onthescenery;itisanexactexpressionofone’sownthoughts。
IwishIeverhadanybookstolendyouinreturnforthemanyyouhavelentme……
Allofwhatyoukindlysayaboutmyspeciesworkdoesnotalteroneiotamylongself—acknowledgedpresumptioninaccumulatingfactsandspeculatingonthesubjectofvariation，withouthavingworkedoutmydueshareofspecies。Butnowfornineyearsithasbeenanyhowthegreatestamusementtome。
Farewell，mydearHooker，Igrievemorethanyoucanwellbelieve，overourprospectofsoseldommeeting。
Ihaveneverperceivedbutonefaultinyou，andthatyouhavegrievously，viz。modesty;youformanexceptiontoSydneySmith’saphorism，thatmeritandmodestyhavenootherconnection，exceptintheirfirstletter。
Farewell，C。DARWIN。
CHARLESDARWINTOL。JENYNS（BLOMEFIELD）。
Down，October12th，[1845]。
MydearJenyns，Thanksforyournote。IamsorrytosayIhavenoteventhetail—endofafactinEnglishZoologytocommunicate。Ihavefoundthateventriflingobservationsrequire，inmycase，someleisureandenergy，bothofwhichingredientsIhavehadnonetospare，aswritingmyGeologythoroughlyexpendsboth。IhadalwaysthoughtthatIwouldkeepajournalandrecordeverything，butinthewayInowliveIfindIobservenothingtorecord。
Lookingaftermygardenandtrees，andoccasionallyaverylittlewalkinanidleframeofmind，fillsupeveryafternooninthesamemanner。Iamsurprisedthatwithallyourparishaffairs，youhavehadtimetodoallthatwhichyouhavedone。Ishallbeverygladtoseeyourlittlework（Mr。Jenyns’’ObservationsinNaturalHistory。’ItisprefacedbyanIntroductionon\"HabitsofobservingasconnectedwiththestudyofNaturalHistory，\"andfollowedbya\"CalendarofPeriodicPhenomenainNaturalHistory，\"with\"RemarksontheimportanceofsuchRegisters。\"MyfatherseemstobealludingtothisRegisterintheP。S。totheletterdatedOctober17，1846。）（andproudshouldIhavebeenifIcouldhaveaddedasinglefacttoit）。Myworkonthespeciesquestionhasimpressedmeveryforciblywiththeimportanceofallsuchworksasyourintendedone，containingwhatpeoplearepleasedgenerallytocalltriflingfacts。Thesearethefactswhichmakeoneunderstandtheworkingoreconomyofnature。
Thereisonesubject，onwhichIamverycurious，andwhichperhapsyoumaythrowsomelighton，ifyouhaveeverthoughtonit;namely，whatarethechecksandwhattheperiodsoflife，——bywhichtheincreaseofanygivenspeciesislimited。Justcalculatetheincreaseofanybird，ifyouassumethatonlyhalftheyoungarereared，andthesebreed:withintheNATURAL
（i。e。，iffreefromaccidents）lifeoftheparentsthenumberofindividualswillbecomeenormous，andIhavebeenmuchsurprisedtothinkhowgreatdestructionMUSTannuallyoroccasionallybefallingoneveryspecies，yetthemeansandperiodofsuchdestructionisscarcelyperceivedbyus。
Ihavecontinuedsteadilyreadingandcollectingfactsonvariationofdomesticanimalsandplants，andonthequestionofwhatarespecies。I
haveagrandbodyoffacts，andIthinkIcandrawsomesoundconclusions。
ThegeneralconclusionsatwhichIhaveslowlybeendrivenfromadirectlyoppositeconviction，isthatspeciesaremutable，andthatalliedspeciesareco—descendantsfromcommonstocks。IknowhowmuchIopenmyselftoreproachforsuchaconclusion，butIhaveatleasthonestlyanddeliberatelycometoit。Ishallnotpublishonthissubjectforseveralyears。AtpresentIamontheGeologyofSouthAmerica。Ihopetopickupfromyourbooksomefactsonslightvariationsinstructureorinstinctsintheanimalsofyouracquaintance。
Believeme，everyours，C。DARWIN。
CHARLESDARWINTOL。JENYNS（REV。L。BLOMEFIELD）。
Down，[1845？]。
MydearJenyns，Iamverymuchobligedtoyouforthetroubleyouhavetakeninhavingwrittenmesolonganote。Thequestionofwhere，when，andhowthechecktotheincreaseofagivenspeciesfallsappearstomeparticularlyinteresting，andourdifficultyinansweringitshowshowreallyignorantweareofthelivesandhabitsofourmostfamiliarspecies。Iwasawareofthebarefactofoldbirdsdrivingawaytheiryoung，buthadneverthoughtoftheeffectyousoclearlypointout，oflocalgapsinnumberbeingthusimmediatelyfilledup。Buttheoriginaldifficultyremains;forifyourfarmershadnotkilledyoursparrowsandrooks，whatwouldhavebecomeofthosewhichnowimmigrateintoyourparish？inthemiddleofEnglandoneistoofardistantfromthenaturallimitsoftherookandsparrowtosupposethattheyoungarethusfarexpelledfromCambridgeshire。Thecheckmustfallheavilyatsometimeofeachspecies’
life;for，ifonecalculatesthatonlyhalftheprogenyarerearedandbred，howenormousistheincrease！Onehas，however，nobusinesstofeelsomuchsurpriseatone’signorance，whenoneknowshowimpossibleitiswithoutstatisticstoconjecturethedurationoflifeandpercentageofdeathstobirthsinmankind。IfitcouldbeshownthatapparentlythebirdsofpassageWHICHBREEDHEREandincrease，returninthesucceedingyearsinaboutthesamenumber，whereasthosethatcomeherefortheirwinterandnon—breedingseasonannually，comeherewiththesamenumbers，butreturnwithgreatlydecreasednumbers，onewouldknow（asindeedseemsprobable）thatthecheckfellchieflyonfull—grownbirdsinthewinterseason，andnotontheeggsandveryyoungbirds，whichhasappearedtomeoftenthemostprobableperiod。Ifatanytimeanyremarksonthissubjectshouldoccurtoyou，Ishouldbemostgratefulforthebenefitofthem。
Withrespecttomyfardistantworkonspecies，ImusthaveexpressedmyselfwithsingularinaccuracyifIledyoutosupposethatImeanttosaythatmyconclusionswereinevitable。Theyhavebecomeso，afteryearsofweighingpuzzles，tomyselfALONE;butinmywildestday—dream，Ineverexpectmorethantobeabletoshowthattherearetwosidestothequestionoftheimmutabilityofspecies，i。e。whetherspeciesareDIRECTLY
createdorbyintermediatelaws（aswiththelifeanddeathofindividuals）。Ididnotapproachthesubjectonthesideofthedifficultyindeterminingwhatarespeciesandwhatarevarieties，but（though，whyI
shouldgiveyousuchahistoryofmydoingsitwouldbehardtosay）fromsuchfactsastherelationshipbetweenthelivingandextinctmammifersinSouthAmerica，andbetweenthoselivingontheContinentandonadjoiningislands，suchastheGalapagos。Itoccuredtomethatacollectionofallsuchanalogousfactswouldthrowlighteitherfororagainsttheviewofrelatedspeciesbeingco—descendantsfromacommonstock。Alongsearchingamongstagriculturalandhorticulturalbooksandpeoplemakesmebelieve（I
wellknowhowabsurdlypresumptuousthismustappear）thatIseethewayinwhichnewvarietiesbecomeexquisitelyadaptedtotheexternalconditionsoflifeandtoothersurroundingbeings。Iamaboldmantolaymyselfopentobeingthoughtacompletefool，andamostdeliberateone。Fromthenatureofthegroundswhichmakemebelievethatspeciesaremutableinform，thesegroundscannotberestrictedtotheclosest—alliedspecies;buthowfartheyextendIcannottell，asmyreasonsfallawaybydegrees，whenappliedtospeciesmoreandmoreremotefromeachother。PraydonotthinkthatIamsoblindasnottoseethattherearenumerousimmensedifficultiesinmynotions，buttheyappeartomelessthanonthecommonview。Ihavedrawnupasketchandhaditcopied（in200pages）ofmyconclusions;andifIthoughtatsomefuturetimethatyouwouldthinkitworthreading，Ishould，ofcourse，bemostthankfultohavethecriticismofsocompetentacritic。Excusethisverylongandegotisticalandill—
writtenletter，whichbyyourremarksyouhadledmeinto，andbelieveme，Yoursverytruly，C。DARWIN。
CHARLESDARWINTOL。JENYNS（BLOMEFIELD）。
Down，October17th，1846。
DearJenyns，Ihavetakenamostungratefullengthoftimeinthankingyouforyourverykindpresentofyour’Observations。’ButIhappenedtohavehadinhandseveralotherbooks，andhavefinishedyoursonlyafewdaysago。Ifounditverypleasantreading，andmanyofyourfactsinterestedmemuch。I
thinkIwasmoreinterested，whichisodd，withyournotesonsomeoftheloweranimalsthanonthehigherones。Theintroductionstruckmeasverygood;butthisiswhatIexpected，forIwellrememberbeingquitedelightedwithapreliminaryessaytothefirstnumberofthe’AnnalsofNaturalHistory。’Imissedonediscussion，andthinkmyselfill—used，forIrememberyoursayingyouwouldmakesomeremarksontheweatherandbarometer，asaguidefortheignorantinprediction。Ihadalsohopedtohaveperhapsmetwithsomeremarksontheamountofvariationinourcommonspecies。AndrewSmithoncedeclaredhewouldgetsomehundredsofspecimensoflarksandsparrowsfromallpartsofGreatBritain，andseewhether，withfinestmeasurements，hecoulddetectanyproportionalvariationsinbeaksorlimbs，etc。ThispointinterestsmefromhavinglatelybeenskimmingovertheabsurdlyoppositeconclusionsofGlogerandBrehm;theonemakinghalf—a—dozenspeciesoutofeverycommonbird，andtheotherturningsomanyreputedspeciesintoone。Haveyoueverdoneanythingofthiskind，orhaveyoueverstudiedGloger’sorBrehm’sworks？
Iwasinterestedinyouraccountofthemartins，forIhadjustbeforebeenutterlyperplexedbynoticingjustsuchaproceedingasyoudescribe:I
countedseven，onedaylately，visitingasinglenestandstickingdirtontheadjoiningwall。ImaymentionthatIoncesawsomesquirrelseagerlysplittingthoselittlesemi—transparentsphericalgallsonthebackofoak—
leavesforthemaggotwithin;sothattheyareinsectivorous。ACychrusrostratusoncesquirtedintomyeyesandgavemeextremepain;andImusttellyouwhathappenedtomeonthebanksoftheCam，inmyearlyentomologicaldays:underapieceofbarkIfoundtwoCarabi（Iforgetwhich），andcaughtoneineachhand，whenloandbeholdIsawasacredPanagaeuscruxmajor！IcouldnotbeartogiveupeitherofmyCarabi，andtolosePanagaeuswasoutofthequestion;sothatindespairIgentlyseizedoneoftheCarabibetweenmyteeth，whentomyunspeakabledisgustandpainthelittleinconsideratebeastsquirtedhisaciddownmythroat，andIlostbothCarabiandPanagaeus！IwasquiteastonishedtohearofaterrestrialPlanaria;foraboutayearortwoagoIdescribedinthe’AnnalsofNaturalHistory’severalbeautifullycolouredterrestrialspeciesoftheSouthernHemisphere，andthoughtitquiteanewfact。Bytheway，youspeakofasheepwithabrokenlegnothavingflukes:Ihaveheardmyfatheraverthatafever，oranySERIOUSACCIDENT，asabrokenlimb，willcauseinamanalltheintestinalwormstobeevacuated。Mightnotthispossiblyhavebeenthecasewiththeflukesintheirearlystate？
IhopeyouwerenonetheworseforSouthampton（ThemeetingoftheBritishAssociation。）;IwishIhadseenyoulookingratherfatter。Ienjoyedmyweekextremely，anditdidmegood。Imissedyouthelastfewdays，andwenevermanagedtoseemuchofeachother;butthereweresomanypeoplethere，thatIforonehardlysawanythingofanyone。OnceagainIthankyouverycordiallyforyourkindpresent，andthepleasureithasgivenme，andbelieveme，Evermosttrulyyours，C。DARWIN。
P。S。——IhavequiteforgottentosayhowgreatlyinterestedIwaswithyourdiscussiononthestatisticsofanimals:whenwillNaturalHistorybesoperfectthatsuchpointsasyoudiscusswillbeperfectlyknownaboutanyoneanimal？
CHARLESDARWINTOJ。D。HOOKER。
Malvern，June13[1849]……AtlastIamgoingtopresswithasmallpoorfirst—fruitofmyconfoundedCirripedia，viz。thefossilpedunculatecirripedia。Youaskwhateffectstudyingspecieshashadonmyvariationtheories;Idonotthinkmuch——Ihavefeltsomedifficultiesmore。Ontheotherhand，Ihavebeenstruck（andprobablyunfairlyfromtheclass）withthevariabilityofeverypartinsomeslightdegreeofeveryspecies。WhenthesameorganisRIGOROUSLYcomparedinmanyindividuals，Ialwaysfindsomeslightvariability，andconsequentlythatthediagnosisofspeciesfromminutedifferencesisalwaysdangerous。Ihadthoughtthesamepartsofthesamespeciesmoreresemble（thantheydoanyhowinCirripedia）objectscastinthesamemould。Systematicworkwouldbeeasywereitnotforthisconfoundedvariation，which，however，ispleasanttomeasaspeculatist，thoughodioustomeasasystematist。Yourremarksonthedistinctness（sounpleasanttome）oftheHimalayanRubi，willows，etc。，comparedwiththoseofnorthern[Europe？]，etc。，areveryinteresting;ifmyrudespecies—
sketchhadanySMALLshareinleadingyoutotheseobservations，ithasalreadydonegoodandampleservice，andmaylayitsbonesintheearthinpeace。IneverheardanythingsostrangeasFalconer’sneglectofyourletters;Iamextremelygladyouarecordialwithhimagain，thoughitmusthavecostyouaneffort。Falconerisamanonemustlove……Mayyouprosperineveryway，mydearHooker。
Youraffectionatefriend，C。DARWIN。
CHARLESDARWINTOJ。D。HOOKER。
Down，Wednesday[September，n。d。]……Manythanksforyourletterreceivedyesterday，which，asalways，setmethinking:IlaughedatyourattackatmystinginessinchangesofleveltowardsForbes（EdwardForbes，1815—1854，bornintheIsleofMan。HisbestknownworkwashisReportonthedistributionofmarineanimalsatdifferentdepthsintheMediterranean。Animportantmemoirofhisisreferredtoinmyfather’s’Autobiography。’HeheldsuccessivelythepostsofCuratortotheGeologicalSociety’sMuseum，andProfessorofNaturalHistoryintheMuseumofPracticalGeology;shortlybeforehediedhewasappointedProfessorofNaturalHistoryintheUniversityofEdinburgh。Heseemstohaveimpressedhiscontemporariesasamanofstrikinglyversatileandvigorousmind。TheaboveallusiontochangesoflevelreferstoForbes’stendencytoexplainthefactsofgeographicaldistributionbymeansofanactivegeologicalimagination。），beingsoliberaltowardsmyself;butImustmaintain，thatIhaveneverletdownorupheavedourmother—earth’ssurface，forthesakeofexplaininganyonephenomenon，andItrustIhaveveryseldomdonesowithoutsomedistinctevidence。SoI
muststillthinkitaboldstep（perhapsaverytrueone）tosinkintothedepthsofocean，withintheperiodofexistingspecies，solargeatractofsurface。Butthereisnoamountorextentofchangeoflevel，whichIamnotfullypreparedtoadmit，butImustsayIshouldlikebetterevidence，thantheidentityofafewplants，whichPOSSIBLY（Idonotsayprobably）
mighthavebeenotherwisetransported。Particularthanksforyourattempttogetmeacopyof’L’Espece’（ProbablyGodron’sessay，publishedbytheAcademyofNancyin1848—49，andafterwardsasaseparatebookin1859。），andalmostequalthanksforyourcriticismsonhim:Irathermisdoubtedhim，andfeltnotmuchinclinedtotakeasgospelhisfacts。Ifindthisoneofmygreatestdifficultieswithforeignauthors，viz。judgingoftheircredibility。Howpainfully（tome）trueisyourremark，thatnoonehashardlyarighttoexaminethequestionofspecieswhohasnotminutelydescribedmany。Iwas，however，pleasedtohearfromOwen（whoisvehementlyopposedtoanymutabilityinspecies），thathethoughtitwasaveryfairsubject，andthattherewasamassoffactstobebroughttobearonthequestion，nothithertocollected。Myonlycomfortis（asImeantoattemptthesubject），thatIhavedabbledinseveralbranchesofNaturalHistory，andseengoodspecificmenworkoutmyspecies，andknowsomethingofgeology（anindispensableunion）;andthoughIshallgetmorekicksthanhalf—pennies，Iwill，lifeserving，attemptmywork。Lamarckistheonlyexception，thatIcanthinkof，ofanaccuratedescriberofspeciesatleastintheInvertebrateKingdom，whohasdisbelievedinpermanentspecies，butheinhisabsurdthoughcleverworkhasdonethesubjectharm，ashasMr。Vestiges，and，as（somefutureloosenaturalistattemptingthesamespeculationswillperhapssay）hasMr。D……
C。DARWIN。
CHARLESDARWINTOJ。D。HOOKER。
Down，September25th[1853]。
MydearHooker，Ihavereadyourpaperwithgreatinterest;itseemsallveryclear，andwillformanadmirableintroductiontotheNewZealandFlora，ortoanyFloraintheworld。Howfewgeneralizersthereareamongsystematists;I
reallysuspectthereissomethingabsolutelyopposedtoeachotherandhostileinthetwoframesofmindrequiredforsystematisingandreasoningonlargecollectionsoffacts。Manyofyourargumentsappeartomeverywellput，and，asfarasmyexperiencegoes，thecandidwayinwhichyoudiscussthesubjectisunique。ThewholewillbeveryusefultomewheneverIundertakemyvolume，thoughpartstakethewindverycompletelyoutofmysails;itwillbeallnutstome……forIhaveforsometimedeterminedtogivetheargumentsonBOTHsides（asfarasIcould），insteadofarguingonthemutabilitysidealone。
InmyownCirripedialwork（bytheway，thankyouforthedoseofsoftsolder;itdoesone——oratleastme——agreatdealofgood）——inmyownworkIhavenotfeltconsciousthatdisbelievinginthemerePERMANENCEofspecieshasmademuchdifferenceonewayortheother;insomefewcases（ifpublishingavowedlyondoctrineofnon—permanence），IshouldNOThaveaffixednames，andinsomefewcasesshouldhaveaffixednamestoremarkablevarieties。CertainlyIhavefeltithumiliating，discussinganddoubting，andexaminingoverandoveragain，wheninmyownmindtheonlydoubthasbeenwhethertheformvariedTO—DAYORYESTERDAY（nottoputtoofineapointonit，asSnagsby（In’BleakHouse。’）wouldsay）。Afterdescribingasetofformsasdistinctspecies，tearingupmyMS。，andmakingthemonespecies，tearingthatupandmakingthemseparate，andthenmakingthemoneagain（whichhashappenedtome），Ihavegnashedmyteeth，cursedspecies，andaskedwhatsinIhadcommittedtobesopunished。ButImustconfessthatperhapsnearlythesamethingwouldhavehappenedtomeonanyschemeofwork。
IamheartilygladtohearyourJournal（SirJ。D。Hooker’s’HimalayanJournal。’）issomuchadvanced;howmagnificentlyitseemstobeillustrated！An\"OrientalNaturalist，\"withlotsofimaginationandnottoomuchregardtofacts，isjustthemantodiscussspecies！Ithinkyourtitleof’AJournalofaNaturalistintheEast’verygood;butwhether\"intheHimalaya\"wouldnotbebetter，Ihavedoubted，fortheEastsoundsrathervague……
CHARLESDARWINTOJ。D。HOOKER。
[1853]。
MydearHooker，Ihavenoremarksatallworthsendingyou，nor，indeed，wasitlikelythatIshould，consideringhowperfectandelaboratedanessayitis。（’NewZealandFlora，’1853。）Asfarasmyjudgmentgoes，itisthemostimportantdiscussiononthepointsinquestioneverpublished。Icansaynomore。Iagreewithalmosteverythingyousay;butIrequiremuchtimetodigestanessayofsuchquality。Italmostmademegloomy，partlyfromfeelingIcouldnotanswersomepointswhichtheoreticallyIshouldhavelikedtohavebeendifferent，andpartlyfromseeingSOFARBETTERDONE
thanICOULDhavedone，discussionsonsomepointswhichIhadintendedtohavetakenup……
Imuchenjoyedtheslapsyouhavegiventotheprovincialspecies—mongers。
IwishIcouldhavebeenoftheslightestuse:Ihavebeendeeplyinterestedbythewholeessay，andcongratulateyouonhavingproducedamemoirwhichIbelievewillbememorable。Iwasdeepinitwhenyourmostconsideratenotearrived，beggingmenottohurry。IthankMrs。Hookerandyourselfmostsincerelyforyourwishtoseeme。IwillnotletanothersummerpasswithoutseeingyouatKew，forindeedIshouldenjoyitmuch……
YoudomereallymorehonourthanIhaveanyclaimto，puttingmeinafterLyellonupsanddowns。Inayearortwo’stime，whenIshallbeatmyspeciesbook（ifIdonotbreakdown），Ishallgnashmyteethandabuseyouforhavingputsomanyhostilefactssoconfoundedlywell。
Everyoursaffectionately，C。DARWIN。
CHARLESDARWINTOJ。D。HOOKER。
Down，March26th[1854]。
MydearHooker，Ihadhopedthatyouwouldhavehadalittlebreathing—timeafteryourJournal，butthisseemstobeveryfarfromthecase;andIamthemoreobliged（andsomewhatcontrite）forthelongletterreceivedthismorning，MOSTjuicywithnewsandMOSTinterestingtomeinmanyways。Iamverygladindeedtohearofthereforms，etc。，intheRoyalSociety。WithrespecttotheClub（ThePhilosophicalClub，towhichmyfatherwaselected（asProfessorBonneyisgoodenoughtoinformme）onApril24，1854。Heresignedhismembershipin1864。TheClubwasfoundedin1847。Thenumberofmembersbeinglimitedto47，itwasproposedtochristenit\"theClubof47，\"butthenamewasneveradopted。ThenatureoftheClubmaybegatheredfromitsfirstrule:\"ThepurposeoftheClubistopromoteasmuchaspossiblethescientificobjectsoftheRoyalSociety;tofacilitateintercoursebetweenthoseFellowswhoareactivelyengagedincultivatingthevariousbranchesofNaturalScience，andwhohavecontributedtoitsprogress;toincreasetheattendanceattheeveningmeetings，andtoencouragethecontributionanddiscussionofpapers。\"TheClubmetfordinner（atfirst）at6，andthechairwastobequittedat8。15，itbeingexpectedthatmemberswouldgototheRoyalSociety。Oflateyearsthedinnerhasbeenat6。30，theSocietymeetingintheafternoon。），Iamdeeplyinterested;onlytwoorthreedaysago，Iwasregrettingtomywife，howIwaslettingdropandbeingdroppedbynearlyallmyacquaintances，andthatIwouldendeavourtogooftenertoLondon;IwasnotthenthinkingoftheClub，which，asfarasanyonethinggoes，wouldanswermyexactobjectinkeepingupoldandmakingsomenewacquaintances。IwillthereforecomeuptoLondonforevery（withrareexceptions）Club—day，andthenmyhead，Ithink，willallowmeonanaveragetogotoeveryothermeeting。Butitisgrievoushowoftenanychangeknocksmeup。Iwillfurtherpledgemyself，asItoldLyell，toresignafterayear，ifIdidnotattendprettyoften，sothatIshouldATWORSTencumbertheClubtemporarily。Ifyoucangetmeelected，Icertainlyshallbeverymuchpleased。VerymanythanksforanswersaboutGlaciers。IamverygladtohearofthesecondEdition（OftheHimalayanJournal。）soverysoon;butamnotsurprised，forIhaveheardofseveral，inoursmallcircle，readingitwithverymuchpleasure。IshallbecurioustohearwhatHumboldtwillsay:itwill，Ishouldthink，delighthim，andmeetwithmorepraisefromhimthananyotherbookofTravels，forIcannotrememberone，whichhassomanysubjectsincommonwithhim。Whatawonderfuloldfellowheis……Bytheway，Ihope，whenyougotoHitcham，towardstheendofMay，youwillbeforcedtohavesomerest。IamgrievedtohearthatallthebadsymptomshavenotleftHenslow;itissostrangeandnewtofeelanyuneasinessabouthishealth。IamparticularlyobligedtoyouforsendingmeAsaGray’sletter;howverypleasantlyhewrites。Toseehisandyourcautiononthespecies—questionoughttooverwhelmmeinconfusionandshame;itdoesmakemefeeldeuceduncomfortable……ItisdelightfultohearallthathesaysonAgassiz:howverysingularitisthatsoEMINENTLY
cleveraman，withsuchIMMENSEknowledgeonmanybranchesofNaturalHistory，shouldwriteashedoes。Lyelltoldmethathewassodelightedwithoneofhis（Agassiz）lecturesonprogressivedevelopment，etc。，etc。，thathewenttohimafterwardsandtoldhim，\"thatitwassodelightful，thathecouldnothelpallthetimewishingitwastrue。\"IseldomseeaZoologicalpaperfromNorthAmerica，withoutobservingtheimpressofAgassiz’sdoctrines——anotherproof，bytheway，ofhowgreatamanheis。
IwaspleasedandsurprisedtoseeA。Gray’sremarksoncrossing，obliteratingvarieties，onwhich，asyouknow，Ihavebeencollectingfactsforthesedozenyears。HowawfullyflatIshallfeel，ifwhenIgetmynotestogetheronspecies，etc。，etc。，thewholethingexplodeslikeanemptypuff—ball。Donotworkyourselftodeath。
Everyoursmosttruly，C。DARWIN。
CHARLESDARWINTOJ。D。HOOKER。
Down，November5th[1854]。
MydearHooker，Iwasdelightedtogetyournoteyesterday。Icongratulateyouveryheartily（OntheawardtohimoftheRoyalSociety’sMedal。），andwhetheryoucaremuchorlittle，Irejoicetoseethehighestscientificjudgment—
courtinGreatBritainrecogniseyourclaims。IdohopeMrs。Hookerispleased，andE。desiresmeparticularlytosendhercordialcongratulations……Ipityyoufromtheverybottomofmyheartaboutyourafter—dinnerspeech，whichIfearIshallnothear。WithoutyouhaveaverymuchgreatersoulthanIhave（andIbelievethatyouhave），youwillfindthemedalapleasantlittlestimulus，whenworkgoesbadly，andoneruminatesthatallisvanity，itispleasanttohavesometangibleproof，thatothershavethoughtsomethingofone’slabours。
Good—byemydearHooker，Icanassure[you]thatwebothmosttrulyenjoyedyourandMrs。Hooker’svisithere。Farewell。
MydearHooker，yoursincerefriend，C。DARWIN。