Ifasinglestrokeofmydagger，fashionedfromthepointofaneedle，resultsinimmediatedeathandearlyputrefaction；iftherepeatedbitesoftheScoliagutthecreature\'sbodyandreduceitalmosttoaskinwithoutcompletelykillingit，thestrikingcontrastbetweenthesetworesultsmustbeduetotherelativeimportanceoftheorgansinjured。Idestroythenerve-centresandinevitablykillmylarva，whichisputridbythefollowingday；theScoliaattacksthereservesoffat，theblood，themusclesanddoesnotkillitsvictim，whichwillprovideitwithwholesomefooduntiltheend。Butitisclearthat，iftheScoliaweretosettoworkasIdid，therewouldbenothingleft，afterthefirstfewbites，butanactualcorpse，dischargingfluidswhichwouldbefataltoitwithintwenty-
fourhours。Themother，itistrue，inordertoassuretheimmobilityofherprey，hasinjectedthepoisonofherstingintothenerve-centres。Heroperationcannotbecomparedwithmineinanyrespect。Shepractisesthemethodoftheskilfulphysiologistwhoinducesanaesthesia；Igotoworklikethebutcherwhochops，cutsanddisembowels。Thestingleavesthenerve-centresintact。Deprivedofsensibilitybythepoison，theyhavelostthepowerofprovokingmuscularcontractions；butwhocansaythat，numbedastheyare，theynolongerservetomaintainafaintvitality？Theflameisextinguished，butthereisstillaglowingspeckuponthewick。I，aroughblunderer，domorethanblowoutthelamp:Ithrowawaythewickandallisover。Thegrubwoulddothesameifitbitstraightintothemassofnerves。
Everythingconfirmsthefact:theScoliaandtheotherHuntingWaspswhoseprovisionsconsistofbulkyheadsofgamearegiftedwithaspecialartofeating，anexquisitelydelicateartwhichsavesaremnantoflifeinthepreydevoured，untilitisallconsumed。Whenthepreyisasmallone，thisprecautionissuperfluous。Consider，forinstance，theBembex-grubsinthemidstoftheirheapofFlies。Thepreyseizeduponisbroachedontheback，thebelly，thehead，thethorax，indifferently。Thelarvamunchesagivenspot，whichitleavestomunchasecond，passingtoathirdandafourth，atthebiddingofitschangingwhims。Itseemstotasteandselect，byrepeatedtrials，themouthfulsmosttoitsliking。Thusbittonatseveralpoints，coveredwithwounds，theFlyissoonashapelessmasswhichwouldputrefyveryquicklyifthemeagredishwerenotdevouredatasinglemeal。
AllowtheScolia-grubthesameunlicensedgluttony:itwouldperishbesideitscorpulentvictim，whichshouldhavekeptfreshforafortnight，butwhichalmostfromthebeginningwouldbenomorethanafilthyputrescence。
Thisartofcarefuleatingdoesnotseemeasytopractise:atleast，thelarva，ifeversolittledivertedfromitsusualcourses，isnolongerabletoapplyitstalentasacapabletrencherman。Thiswillbeprovedbyexperiment。Imustbeginbyobservingthat，whenIspokeofmylarvawhichturnedputridwithintwenty-fourhours，Iadoptedanextremecaseforthesakeofgreaterclearness。TheScolia，takingitsfirstbite，doesnotandcannotgotosuchlengths。Neverthelessitbehoovesustoenquirewhether，intheconsumptionofthevictuals，theinitialpointofattackisamatterofindifferenceandwhethertherummagingthroughtheentrailsofthevictimentailsadeterminedorder，withoutwhichsuccessisuncertainorevenimpossible。Tothesedelicatequestionsnoone，Ithink，canreply。
Wherescienceissilent，perhapsthegrubwillspeak。Wewilltry。
ImovefromitspositionaScolia-grubwhichhasattainedaquarterorathirdofitsfullgrowth。Thelongneckplungedintothevictim\'sbellyisratherdifficulttoextract，becauseoftheneedofmolestingthecreatureaslittleaspossible。Isucceed，bymeansofalittlepatienceandrepeatedstrokeswiththetipofapaint-brush。InowturntheCetonia-
larvaover，backuppermost，atthebottomofthelittlehollowmadebypressingmyfingerinthelayerofmould。Lastly，IplacetheScoliaonitsvictim\'sback。Hereismygrubunderthesameconditionsasjustnow，withthisdifference，thatthebackandnotthebellyofitsvictimispresentedtoitsmandibles。
Iwatchitforawholeafternoon。Itwrithesabout；itmovesitslittleheadnowinthisdirection，nowinthat，frequentlylayingitontheCetonia，butwithoutfixingitanywhere。Thedaydrawstoaclose；andstillithasaccomplishednothing。Therearerestlessmovements，nothingmore。Hunger，Itellmyself，willeventuallyinduceittobite。Iamwrong。
NextmorningIfinditmoreanxiousthanthedaybeforeandstillgropingabout，withoutresolvingtofixitsmandiblesanywhere。Ileaveitaloneforhalfadaylongerwithoutobtaininganyresult。Yettwenty-fourhoursofabstinencemusthaveawakenedagoodappetite，aboveallinacreaturewhich，ifleftundisturbed，wouldnothaveceasedeating。
Excessivehungercannotinduceittonibbleatanunlawfulspot。Isthisduetofeeblenessoftheteeth？Bynomeans:theCetonia\'sskinisnotougheronthebackthanonthebelly；moreover，thegrubiscapableofperforatingtheskinwhenitleavestheegg；afortiori，itmustbemorecapableofdoingsonowthatithasattainedasturdygrowth。Thusweseenolackofability，butanobstinaterefusaltonibbleatapointwhichoughttoberespected。Whoknows？Onthissideperhapsthegrub\'sdorsalvesselwouldbewounded，itsheart，anorganindispensabletolife。Thefactremainsthatmyattemptstomakethegrubtackleitsvictimfromthebackhavefailed。Doesthismeanthatitentertainstheleastsuspicionofthedangerwhichitmightincurwereittoproduceputrefactionbyawkwardlycarvingitsvictualsfromtheback？Itwouldbeabsurdtogivesuchanideaamoment\'sconsideration。Itsrefusalisdictatedbyapreordaineddecreewhichitisboundtoobey。
MyScolia-grubswoulddieofstarvationifIleftthemontheirvictim\'sback。Ithereforerestoremattersastheywere，withtheCetonia-larvabellyuppermostandtheyoungScoliaontop。Imightutilisethesubjectsofmypreviousexperiments；but，asIhavetotakeprecautionsagainstthedisturbancewhichmayhavebeencausedbythetestalreadyundergone，I
prefertooperateonnewpatients，aluxuryinwhichtherichnessofmymenagerieallowsmetoindulge。ImovetheScoliafromitsposition，extractitsheadfromtheentrailsoftheCetonia-larvaandleaveittoitsownresourcesonitsvictim\'sbelly。Betrayingeverysymptomofuneasiness，thegrubgropes，hesitates，castsaboutanddoesnotinsertitsmandiblesanywhere，thoughitisnowtheventralsurfacewhichitisexploring。Itwouldnotdisplaygreaterhesitationifplacedonthebackofthelarva。I
repeat，whoknows？Onthissideitmightperhapsinjurethenervousplexus，whichisevenmoreessentialthanthedorsalvessel。Theinexperiencedgrubmustnotdriveinitsmandiblesatrandom；itsfutureisjeopardizedifitgivesasingleill-judgedbite。IfitgnawsatthespotwhereImyselfoperatedwithmyneedlewroughtintoascalpel，itsvictualswillverysoonturnputrid。Oncemore，then，wewitnessanabsoluterefusaltoperforatetheskinofthevictimelsewherethanattheverypointwheretheeggwasfixed。
Themotherselectsthispoint，whichisundoubtedlythatmostfavourabletothefutureprosperityofthelarva，thoughIamnotableclearlytodiscernthereasonsforherchoice；shefixestheeggtoit；andtheplacewheretheopeningistobemadeishenceforthdetermined。Itisherethatthegrubmustbite:onlyhere，neverelsewhere。ItsinvinciblerefusaltotackletheCetoniainanyotherpart，eventhoughitshoulddieofstarvation，shewsushowrigorousistheruleofconductwithwhichitsinstinctisinspired。
Asitgropesabout，thegrublaidonthevictim\'sventralsurfacesoonerorlaterrediscoversthegapingwoundfromwhichIhaveremovedit。Ifthistakestoolongformypatience，Icanmyselfguideitsheadtotheplacewiththepointofapaint-brush。Thegrubthenrecognizestheholeofitsownmaking，slipsitsneckintoitandlittlebylittledivesintotheCetonia\'sbelly，sothattheoriginalstateofaffairsappearstobeexactlyrestored。Andyetitssuccessfulrearingishenceforthhighlyproblematical。Itispossiblethatthelarvawillprosper，completeitsdevelopmentandspinitscocoon；itisalsopossible——andthecaseisnotunusual——thattheCetonia-larvawillsoonturnbrownandputrid。WethenseetheScoliaitselfturnbrown，distendedasitiswithputrescentfoodstuffs，andthenceaseallmovement，withoutattemptingtowithdrawfromthesanies。Itdiesonthespot，poisonedbyitsexcessivelyhighgame。
Whatcanbethemeaningofthissuddencorruptionofthevictuals，followedbythedeathoftheScolia，wheneverythingappearedtohavereturnedtoitsnormalcondition？Iseeonlyoneexplanation。Disturbedinitsactivitiesanddivertedfromitsusualcoursesbymyinterference，thegrub，whenreplacedonthewoundfromwhichIextractedit，wasunabletorediscoverthelodeatwhichitwasworkingafewminutesearlier；itthrustitswayatrandomintothevictim\'sentrails；andafewuntimelybitesextinguishedthelastsparksofvitality。Itsconfusionrendereditclumsy；andthemistakecostititslife。Itdiespoisonedbytherichfoodwhich，ifconsumedaccordingtotherules，shouldhavemadeitgrowplumpandlusty。
Iwasanxioustoobservethedeadlyeffectsofadisturbedmealinanotherfashion。Thistimethevictimitselfshalldisorderthegrub\'sactivities。
TheCetonia-larva，asserveduptotheyoungScoliabyitsmother，isprofoundlyparalysed。Itsinertiaiscompleteandsostrikingthatitconstitutesoneoftheleadingfeaturesofthisnarrative。Butwewillnotanticipate。Forthemoment，thethingistosubstituteforthisinertlarvaasimilarlarva，butonenotparalysed，oneverymuchalive。Toensurethatitshallnotdoubleupandcrushthegrub，Iconfinemyselftoreducingittohelplessness，leavingitotherwisejustasIextracteditfromitsburrow。Imustalsobecarefulofitslegsandmandibles，theleasttouchofwhichwouldripopenthenurseling。WithafewturnsofthefinestwireIfixittoalittleslabofcork，withitsbellyintheair。Next，toprovidethegrubwithaready-madehole，knowingthatitwillrefusetomakeoneforitself，Icontriveaslightincisionintheskin，atthepointwheretheScolialaysheregg。Inowplacethegrubuponthelarva，withitsheadtouchingthebleedingwound，andlaythewholeonabedofmouldinatransparentbeakerprotectedbyapaneofglass。
Unabletomove，towriggle，toscratchwithitslegsorsnapwithitsmandibles，theCetonia-larva，anewPrometheusbound，offersitsdefencelessflankstothelittleVulturedestinedtodevouritsentrails。
Withouttoomuchhesitation，theyoungScoliasettlesdowntothewoundmadebymyscalpel，whichtothegrubrepresentsthewoundwhenceIhavejustremovedit。Itthrustsitsneckintothebellyofitsprey；andforacoupleofdaysallseemstogowell。Then，loandbehold，theCetoniaturnsputridandtheScoliadies，poisonedbytheptomainesofthedecomposinggame！Asbefore，Iseeitturnbrownanddieonthespot，stillhalfinsidethetoxiccorpse。
Thefatalissueofmyexperimentiseasilyexplained。TheCetonia-larvaisaliveineverysense。True，Ihave，bymeansofbonds，suppresseditsoutwardmovements，inordertoprovidethenurselingwithaquietmeal，devoidofdanger；butitwasnotinmypowertosubdueitsinternalmovements，thequiveringofthevisceraandmusclesirritatedbyitsforcedimmobilityandbytheScolia\'sbites。Thevictimisinpossessionofitsfullpowerofsensation；anditexpressesthepainexperiencedasbestitmay，bycontractions。Embarrassedbythesetremors，thesetwitchesofsufferingflesh，incommodedateverymouthful，thegrubchewsawayatrandomandkillsthelarvaalmostassoonasithasstartedonit。Inavictimparalysedbytheregulationsting，theconditionswouldbeverydifferent。Therearenoexternalmovements，noranyinternalmovementseither，whenthemandiblesbite，becausethevictimisinsensible。Thegrub，undisturbedinanyway，isthenable，withanunfalteringtooth，topursueitsscientificmethodofeating。
ThesemarvellousresultsinterestedmetoomuchnottoinspiremewithfreshdeviceswhenIpursuedmyinvestigations。EarlierenquirieshadtaughtmethatthelarvaeoftheDigger-waspsarefairlyindifferenttothenatureofthegame，thoughthemotheralwayssuppliesthemwiththesamediet。Ihadsucceededinrearingthemonagreatvarietyofprey，withoutpayingregardtotheirnormalfare。Ishallreturntothissubjectlater，whenIhopetodemonstrateitsgreatphilosophicalsignificance。LetusprofitbythesedataandtrytodiscoverwhathappenswhenwegivetheScoliafoodwhichisnotproperlyitsown。
Iselectfrommyheapofgarden-mould，thatinexhaustiblemine，twolarvaeoftheRhinocerosBeetle，Oryctesnasicornis，aboutone-thirdfull-grown，sothattheirsizemaynotbeoutofproportiontotheScolia\'s。ItisinfactalmostidenticalwiththesizeoftheCetonia。Iparalyseoneofthembygivinganinjectionofammoniainthenerve-centres。ImakeafineincisioninitsbellyandIplacetheScoliaontheopening。Thedishpleasesmycharge；anditwouldbestrangeindeedifthiswerenotso，consideringthatanotherScolia-grub，thelarvaoftheGardenScolia，feedsontheOryctes。Thedishsuitsit，forbeforelongithasburrowedhalf-wayintothesucculentpaunch。Thistimeallgoeswell。Willtherearingbesuccessful？Notabitofit！Onthethirdday，theOryctesdecomposesandtheScoliadies。Whichshallweholdresponsibleforthefailure，myselforthegrub？Myselfwho，perhapstoounskilfully，administeredtheinjectionofammonia，orthegrubwhich，anoviceatdissectingapreydifferingfromitsown，didnotknowhowtopractiseitscraftuponachangedvictimandbegantobitebeforethepropertime？
Inmyuncertainty，Itryagain。ThistimeIshallnotinterfere，sothatmyclumsinesscannotbetoblame。AsIdescribedwhenspeakingoftheCetonia-
larva，theOryctes-larvanowliesbound，quitealive，onastripofcork。
Asusual，Imakeasmallopeninginthebelly，toenticethegrubbymeansofableedingwoundandfacilitateitsaccess。Iobtainthesamenegativeresult。Inalittlewhile，theOryctesisanoisomemassonwhichthenurselingliespoisoned。Thefailurewasforeseen:tothedifficultiespresentedbyapreyunknowntomychargewasaddedthecommotioncausedbythewrigglingofanunparalysedanimal。
Wewilltryoncemore，thistimewithavictimparalysednotbyme，anunskilledoperator，butbyanadeptwhoseabilityrankssohighthatitisbeyonddiscussion。Chancefavoursmetoperfection:yesterday，inawarmshelteredcorner，atthefootofasandybank，IdiscoveredthreecellsoftheLanguedocianSphex，eachwithitsEphippigerandtherecentlylaidegg。
ThisisthegameIwant，acorpulentprey，ofasizesuitedtotheScoliaand，whatismore，insplendidcondition，artisticallyparalysedaccordingtorulebyamasteramongmasters。
Asusual，IinstallmythreeEphippigersinaglassjar，onabedofmould；
IremovetheeggoftheSphexandoneachvictim，afterslightlyincisingtheskinofthebelly，IplaceayoungScolia-grub。Forthreeorfourdaysmychargesfeeduponthisgame，sonoveltothem，withoutanysignofrepugnanceorhesitation。BythefluctuationsofthedigestivecanalI
perceivethattheworkofnutritionisproceedingasitshould；thingsarehappeningjustasifthedishwereaCetonia-larva。Thechangeofdiet，completethoughitis，hasinnowayaffectedtheappetiteoftheScolia-
grubs。Butthisprosperousconditiondoesnotlastlong。Aboutthefourthday，alittlesoonerinonecase，alittlelaterinanother，thethreeEphippigersbecomeputridandtheScoliaedieatthesametime。
Thisresultiseloquent。HadIlefttheeggoftheSphextohatch，thelarvacomingoutofitwouldhavefedupontheEphippiger；andforthehundredthtimeIshouldhavewitnessedanincomprehensiblespectacle，thatofananimalwhich，devouredpiecemealfornearlyafortnight，growsthinandempty，shrivelsupandyetretainstotheveryendthefreshnesspeculiartolivingflesh。SubstituteforthisSphex-larvaaScolia-larvaofalmostthesamesize；letthedishbethesamethoughtheguestisdifferent；andhealthylivefleshispromptlyreplacedbypestilentrottenflesh。ThatwhichunderthemandiblesoftheSphexwouldforalongwhilehaveremainedwholesomefoodpromptlybecomesapoisonousliquescenceunderthemandiblesoftheScolia。
ItisimpossibletoexplainthepreservationofthevictualsuntilfinallyconsumedbysupposingthatthevenominjectedbytheWaspwhenshedeliversherparalysingstingspossessesantisepticproperties。ThethreeEphippigerswereoperatedonbytheSphex。AbletokeepfreshunderthemandiblesoftheSphex-larvae，whydidtheypromptlygobadunderthemandiblesoftheScolia-larvae？Anyideaofanantisepticmustneedsberejected:aliquidpreservativewhichwouldactinthefirstcasecouldnotfailtoactinthesecond，asitsvirtueswouldnotdependontheteethoftheconsumer。
Thoseofyouwhoareversedintheknowledgeattachingtothisproblem，investigate，Ibegyou，search，sift，seeifyoucandiscoverthereasonwhythevictualskeepfreshwhenconsumedbyaSphex，whereastheypromptlybecomeputridwhenconsumedbyaScolia。Forme，Iseeonlyonereason；andIverymuchdoubtwhetheranyonecansuggestanother。
Bothlarvaepractiseaspecialartofeating，whichisdeterminedbythenatureofthegame。TheSphex，whensittingdowntoanEphippiger，thefoodthathasfallentoitslot，knowsthoroughlyhowtoconsumeitandhowtopreserve，totheveryend，theglimmeroflifewhichkeepsitfresh；but，ifithastobrowseuponaCetonia-grub，whosedifferentstructurewouldconfuseitstalentsasadissector，itwouldsoonhavenothingbeforeitbutaheapofputrescence。TheScolia，initsturn，isfamiliarwiththemethodofeatingtheCetonia-grub，itsinvariableportion；butitdoesnotunderstandtheartofeatingtheEphippiger，thoughthedishistoitstaste。Unabletodissectthisunknownspeciesofgame，itsmandiblesslashawayatrandom，killingthecreatureoutrightassoonastheytaketheirfirstbitesofthedeepertissuesofthevictim。Thatisthewholesecret。
Onemoreword，onwhichIshallenlargeinanotherchapter。IobservethattheScoliaetowhichIgiveEphippigersparalysedbytheSphexkeepinexcellentcondition，despitethechangeofdiet，solongastheprovisionsretaintheirfreshness。Theylanguishwhenthegamegoeshigh；andtheydiewhenputriditysupervenes。Theirdeath，therefore，isduenottoanunaccustomeddiet，buttopoisoningbyoneorotherofthoseterribletoxinswhichareengenderedbyanimalcorruptionandwhichchemistrycallsbythenameofptomaines。Therefore，notwithstandingthefataloutcomeofmythreeattempts，IremainpersuadedthattheunfamiliarmethodofrearingwouldhavebeenperfectlysuccessfulhadtheEphippigersnotgonebad，thatis，iftheScoliaehadknownhowtoeatthemaccordingtotherules。
Whatadelicateanddangerousthingistheartofeatinginthesecarnivorouslarvaesuppliedwithasinglevictim，whichtheyhavetospendafortnightinconsuming，ontheexpressconditionofnotkillingituntiltheveryend！Couldourphysiologicalscience，ofwhich，withgoodreason，wearesoproud，describe，withoutblundering，themethodtobefollowedinthesuccessivemouthfuls？Howhasamiserablegrublearntwhatourknowledgecannottellus？Byhabit，theDarwinianswillreply，whoseeininstinctanacquiredhabit。
Beforedecidingthisseriousmatter，IwillaskyoutoreflectthatthefirstWasp，ofwhateverkind，thatthoughtoffeedingherprogenyonaCetonia-gruboronanyotherlargepieceofgamedemandinglongpreservationcouldnecessarilyhaveleftnodescendantsunlesstheartofconsumingfoodwithoutcausingputrescencehadbeenpractised，withallitsscrupulouscaution，fromthefirstgenerationonwards。Havingasyetlearntnothingbyhabitorbyatavistictransmission，sinceitwasmakingafirstbeginning，thenurselingwouldbiteintoitsprovenderatrandom。Itwouldbestarving，itwouldhavenorespectforitsprey。Itwouldcarveitsjointatrandom；andwehavejustseenthefatalconsequenceofanill-
directedbite。Itwouldperish——Ihavejustprovedthisinthemostpositivemanner——itwouldperish，poisonedbyitsvictim，alreadydeadandputrid。
Toprosper，itwouldhave，althoughanovice，toknowwhatwaspermittedandwhatforbiddeninransackingthecreature\'sentrails；norwoulditbeenoughforthelarvatobeapproximatelyinpossessionofthisdifficultsecret:itwouldbeindispensablethatitshouldpossessthesecretcompletely，forasinglebite，ifdeliveredbeforetherightmoment，wouldinevitablyinvolveitsowndemise。TheScoliaeofmyexperimentsarenotnovices，farfromit:theyarethedescendantsofcarversthathavepractisedtheirartsinceScoliaefirstcameintotheworld；neverthelesstheyallperishfromthedecompositionoftherationssupplied，whenItrytofeedthemonEphippigersparalysedbytheSphex。VeryexpertinthemethodofattackingtheCetonia，theydonotknowhowtosetaboutthebusinessofdiscreetlyconsumingaspeciesofgamenewtothem。Allthatescapesthemisafewdetails，forthetradeofanogrefedonlivefleshisfamiliartotheminitsgeneralfeatures；andtheseunheededdetailsareenoughtoturntheirfoodintopoison。What，then，happenedinthebeginning，whenthelarvabitforthefirsttimeintoalusciousvictim？
Theinexperiencedcreatureperished；ofthatthereisnotashadowofdoubt，unlessweadmitanabsurdityandimaginethelarvaofantiquityfeedinguponthoseterribleptomaineswhichsoswiftlykillitsdescendantsto-day。
Nothingwillevermakemeadmitandnounprejudicedmindcanadmitthatwhatwasoncefoodhasbecomeahorriblepoison。Whatthelarvaofantiquityatewaslivefleshandnotputrescence。Norcanitbeadmittedthatthechancesoffortunecanhaveledatthefirsttrialtosuccessinasystemofnourishmentsofullofpit-falls:fortuitousresultsarepreposterousamidsomanycomplications。Eitherthefeedingisstrictlymethodicalatthebeginning，inconformitywiththeorganicexigenciesofthepreydevoured，andtheWaspestablishedherrace；orelseitwashesitating，withoutdeterminedrules，andtheWaspleftnosuccessor。Inthefirstcasewebeholdinnateinstinct；inthesecondacquiredhabit。
Astrangeacquisition，truly！Anacquisitionpresumedtobemadebyanimpossiblecreature；anacquisitionsupposedtodevelopinnolessimpossiblesuccessors！Thoughthesnow-ball，slowlyrolling，atlastbecomesanenormoussphere，itisstillnecessarythatthestarting-pointshallnothavebeenNIL。Thebigballimpliesthelittleball，assmallasyouplease。Now，inharkingbacktotheoriginoftheseacquiredhabits，ifIinterrogatethepossibilitiesIobtainzeroastheonlyanswer。Iftheanimaldoesnotknowitstradethoroughly，ifithastoacquiresomething，allthemoreifithastoacquireeverything，itperishes:thatisinevitable；withoutthelittlesnow-ballthebigsnow-ballcannotberolled。Ifithasnothingtoacquire，ifitknowsallthatitneedstoknow，itflourishesandleavesdescendantsbehindit。Butthenitpossessesinnateinstinct，theinstinctwhichlearnsnothingandforgetsnothing，theinstinctwhichissteadfastthroughouttime。
Thebuildingupoftheorieshasneverappealedtome:Isuspectthemoneandall。Toarguenebulouslyupondubiouspremiseslikesmenobetter。I
observe，IexperimentandIletthefactsspeakforthemselves。Wehavejustheardthesefacts。Leteachnowdecideforhimselfwhetherinstinctisaninnatefacultyoranacquiredhabit。
CHAPTER4。THECETONIA-LARVA。
TheScolia\'sfeeding-periodlasts，ontheaverage，foradozendaysorso。
Bythenthevictualsarenomorethanacrumpledbag，askinemptiedofthelastscrapofnutriment。Alittleearlier，therusset-yellowtintannouncestheextinctionofthelastsparkoflifeinthecreaturethatisbeingdevoured。Theemptyskinispushedbacktomakespace；thedining-room，ashapelesscavitywithcrumblingwalls，istidiedupalittle；andtheScolia-grubsetstoworkonitscocoonwithoutfurtherdelay。
Thefirstcoursesformageneralscaffolding，whichfindsasupporthereandthereontheearthenwalls，andconsistofarough，blood-redfabric。
Whenthelarvaismerelylaid，asrequiredbymyinvestigations，inahollowmadewiththefinger-tipinthebedofmould，itisnotabletospinitscocoon，forwantofaceilingtowhichtofastentheupperthreadsofitsnetwork。Toweaveitscocoon，everyspinninglarvaiscompelledtoisolateitselfinahammockslunginanopen-workenclosure，whichenablesittodistributeitsthreaduniformlyinalldirections。Iftherebenoceiling，theupperpartofthecocooncannotbefashioned，becausetheworkerlacksthenecessarypointsofsupport。UndertheseconditionsmyScolia-grubscontriveatmosttoupholstertheirlittlepitwithathickdownofreddishsilk。Discouragedbyfutileendeavours，someofthemdie。
Itisasiftheyhadbeenkilledbythesilkwhichtheyomittodisgorgebecausetheyareunabletomaketherightuseofit。This，ifwewerenotwatchful，wouldbeaveryfrequentcauseoffailureinourattemptsatartificialrearing。But，oncethedangerhasbeenperceived，theremedyissimple。Imakeaceilingoverthecavitybylayingashortstripofpaperaboveit。IfIwanttoseehowmattersareprogressing，Ibendthestripintoasemicircle，intoahalf-cylinderwithopenends。Thosewhowishtoplaythebreederforthemselveswillbeabletoprofitbytheselittlepracticaldetails。
Intwenty-fourhoursthecocoonisfinished；atleast，itnolongerallowsustoseethegrub，whichisdoubtlessmakingthewallsofitsdwellingstillthicker。Atfirstthecocoonisavividred；lateritchangestoalightchestnut-brown。Itsformisthatofanellipsoid，withamajoraxis26millimetresinlength，whiletheminoraxismeasures11millimetres。
(1。014x。429inch——Translator\'sNote。)Thesedimensions，whichincidentallyareinclinedtovaryslightly，arethoseofthefemalecocoons。Intheothersextheyaresmallerandmaymeasureaslittleas17
millimetresinlengthby7millimetresinwidth。(。663x。273inch——
Translator\'sNote。)
Thetwoendsoftheellipsoidhavethesameform，somuchsothatitisonlythankstoanindividualpeculiarity，independentoftheshape，thatwecantellthecephalicfromtheanalextremity。Thecephalicpoleisflexibleandyieldstothepressureofmytweezers；theanalpoleishardandunyielding。Thewrapperisdouble，asinthecocoonsoftheSphex。(Cf。
“TheHuntingWasps“:chapters4to10etpassim——Translator\'sNote。)Theouterenvelope，consistingofpuresilk，isthin，flexibleandofferslittleresistance。Itiscloselysuperimposedupontheinnerenvelopeandiseasilyseparatedfromiteverywhere，exceptattheanalend，whereitadherestothesecondenvelope。Theadhesionofthetwowrappersatoneendandthenon-adhesionattheotherarethecauseofthedifferenceswhichthetweezersrevealwhenpinchingthetwoendsofthecocoon。
Theinnerenvelopeisfirm，elastic，rigidand，toacertainpoint，brittle。Idonothesitatetolookuponitasconsistingofasilkentissuewhichthelarva，towardstheendofitstask，hassteepedthoroughlyinasortofvarnishpreparednotbythesilk-glandsbutbythestomach。ThecocoonsoftheSphexhavealreadyshownusasimilarvarnish。Thisproductofthechylificventricleischestnut-brown。Itisthiswhich，saturatingthethicknessofthetissue，effacesthebrightredofthebeginningandreplacesitbyabrowntint。Itisthisagainwhich，disgorgedmoreprofuselyatthelowerendofthecocoon，gluesthetwowrapperstogetheratthatpoint。
TheperfectinsectishatchedatthebeginningofJuly。Theemergencetakesplacewithoutanyviolenteffraction，withoutanyraggedrents。Aclean，circularfissureappearsatsomedistancefromthetop；andthecephalicendisdetachedallofapiece，asalooselidmightbe。Itisasthoughthereclusehadonlytoraiseacoverbybuttingitwithherhead，soexactisthelineofdivision，atleastasregardstheinnerenvelope，thestrongerandmoreimportantofthetwo。Asfortheouterwrapper，itslackofresistanceenablesittoyieldwithoutdifficultywhentheothergivesway。
IcannotquitemakeoutbywhatknacktheWaspcontrivestodetachthecapoftheinnershellwithsuchaccuracy。Isittheartpractisedbythetailorwhencuttinghisstuff，withmandiblestakingtheplaceofscissors？
Ihardlyventuretoadmitasmuch:thetissueissotoughandthecircleofdivisionsoprecise。Themandiblesarenotsharpenoughtocutwithoutleavingaraggededge；andthenwhatgeometricalcertaintytheywouldneedforanoperationsoperfectthatitmightwellhavebeenperformedwiththecompasses！
IsuspectthereforethattheScoliafirstfashionstheoutersacinaccordancewiththeusualmethod，thatis，bydistributingthesilkuniformly，withoutanyspecialpreparationofonepartofthewallmorethanofanother，andthatitafterwardschangesitsmethodofweavinginordertoattendtothemainwork，theinnershell。InthisitapparentlyimitatestheBembex(Cf。“TheHuntingWasps“:chapters14to16——
Translator\'sNote。)，whichweavesasortofeel-trap，whoseamplemeshallowsittogathergrainsofsandoutsideandencrustthemonebyoneinthesilkynetwork，andcompletestheperformancewithacapfittingtheentrancetothetrap。Thisprovidesacircularlineofleastresistance，alongwhichthecasketbreaksopenafterwards。IftheScoliareallyworksinthesamemanner，everythingisexplained:theeel-trap，whilestillopen，enablesittosoakwithvarnishboththeinsideandtheoutsideoftheinnershell，whichhastoacquiretheconsistencyofparchment；lastly，thecapwhichcompletesandclosesthestructureleavesforthefutureacircularlinecapableofsplittingeasilyandneatly。
ThisisenoughonthesubjectoftheScolia-grub。Letusgobacktoitsprovender，ofwhoseremarkablestructureweasyetknownothing。Inorderthatitmaybeconsumedwiththedelicateanatomicaldiscretionimposedbythenecessityofhavingfreshfoodtothelast，theCetonia-grubmustbeplungedintoastateofabsoluteimmobility:anytwitchingsonitspart——astheexperimentswhichIhaveundertakengotoprove——woulddiscourageournibblinglarvaandimpedetheworkofcarving，whichhastobeeffectedwithsomuchcircumspection。Itisnotenoughforthevictimtobeunabletomovefromplacetoplacebeneaththesoil:inadditiontothis，thecontractiblepowerinitssturdymuscularorganismmustbesuppressed。
Initsnormalstate，thislarva，attheveryleastdisturbance，curlsitselfup，almostastheHedgehogdoes；andthetwohalvesoftheventralsurfacearelaidoneagainsttheother。Youarequitesurprisedatthestrengthwhichthecreaturedisplaysinkeepingitselfthuscontracted。Ifyoutrytounrollit，yourfingersencounteraresistancefargreaterthanthesizeoftheanimalwouldhavecausedyoutosuspect。Toovercometheresistanceofthissortofspringcoileduponitself，youhavetoforceit，somuchsothatyouareafraid，ifyoupersist，ofseeingtheindomitablespiralsuddenlyburstandshootforthitsentrails。
AsimilarmuscularenergyisfoundinthelarvaeoftheOryctes(AlsoknownastheRhinocerosBeetle——Translator\'sNote。)，theAnoxia(ABeetleakintotheCockchafer——Translator\'sNote。)，theCockchafer。Weigheddownbyaheavybellyandlivingunderground，wheretheyfeedeitheronleaf-mouldoronroots，theselarvaeallpossessthevigorousconstitutionneededtodragtheircorpulencethrougharesistingmedium。Allofthemalsorollthemselvesintoahookwhichisnotstraightenedwithoutaneffort。
Nowwhatwouldbecomeoftheeggandthenew-borngruboftheScoliae，fixedunderthebelly，atthecentreoftheCetonia\'sspiral，orinsidethehookoftheOryctesortheAnoxia？Theywouldbecrushedbetweenthejawsofthelivingvice。Itisessentialthatthearcshouldslackenandthehookunbend，withouttheleastpossibilityoftheirreturningtoastateoftension。Indeed，thewell-beingoftheScoliaedemandssomethingmore:
thosepowerfulbodiesmustnotretaineventhepowertoquiver，lesttheyderangeamethodoffeedingwhichhastobeconductedwiththegreatestcaution。
TheCetonia-grubtowhichtheTwo-bandedScolia\'seggisfastenedfulfilstherequiredconditionsadmirably。Itislyingonitsback，inthemidstofthemould，withitsbellyfullyextended。LongaccustomedthoughIbetothisspectacleofvictimsparalysedbythestingoftheHuntingWasp，I
cannotsuppressmyastonishmentattheprofoundimmobilityofthepreybeforemyeyes。Intheothervictimswithflexibleskins，Caterpillars，Crickets，Mantes，Ephippigers，Iperceivedatleastsomepulsationsoftheabdomen，afewfeeblecontortionsunderthestimulusofaneedle。Thereisnothingofthesorthere，nothingbutabsoluteinertia，exceptinthehead，whereIsee，fromtimetotime，themouth-partsopenandclose，thepalpigiveatremor，theshortantennaeswaytoandfro。Aprickwiththepointofaneedlecausesnocontraction，nomatterwhatthespotpricked。ThoughIstabitthroughandthrough，thecreaturedoesnotstir，beiteversolittle。Acorpseisnotmoreinert。Never，sincemyremotestinvestigations，haveIwitnessedsoprofoundaparalysis。IhaveseenmanywondersduetothesurgicaltalentoftheWasp；butto-day\'smarvelsurpassesthemall。
IamdoublysurprisedwhenIconsidertheunfavourableconditionsunderwhichtheScoliaoperates。Theotherparalysersworkintheopenair，inthefulllightofday。Thereisnothingtohinderthem。Theyenjoyfulllibertyofactioninseizingtheprey，holdingitinpositionandsacrificingit；theyareabletoseethevictimandtoparryitsmeansofdefence，toavoiditsspears，itspincers。Thespotorspotstobeattainedarewithintheirreach；theydrivethedaggerinwithoutletorhindrance。
Whatdifficulties，ontheotherhand，awaittheScolia！Shehuntsunderground，intheblackestdarkness。Hermovementsarelabouredanduncertain，owingtothemould，whichiscontinuallygivingwayallroundher；shecannotkeephereyesontheterriblemandibles，whicharecapableofcuttingherbodyintwowithasinglebite。Moreover，theCetonia-grub，perceivingthattheenemyisapproaching，assumesitsdefensiveposture，rollsitselfupandmakesashieldforitsonlyvulnerablepart，theventralsurface，withitsconvexback。No，itcannotbeaneasyoperationtosubduethepowerfullarvainitsundergroundretreatandtostabwiththeprecisionwhichimmediateparalysisrequires。
Wewishthatwemightwitnessthestrugglebetweenthetwoadversariesandseeatfirsthandwhathappens，butwecannothopetosucceed。Italltakesplaceinthemysteriousdarknessofthesoil；inbroaddaylight，theattackwouldnotbedelivered，forthevictimmustremainwhereitisandthenandtherereceivetheegg，whichisunabletothriveanddevelopexceptunderthewarmcoverofvegetablemould。Ifdirectobservationisimpracticable，wecanatleastforeseethemainoutlinesofthedramabyallowingourselvestobeguidedbythewarlikemanoeuvresofotherburrowers。
Ipicturethingsthus:diggingandrummagingthroughtheheapofmould，guidedperhapsbythatsingularsensibilityoftheantennaewhichenablestheHairyAmmophilatodiscovertheGreyWorm(ThecaterpillaroftheTurnipMoth。Cf。“TheHuntingWasps“:chapters18to20——Translator\'sNote。)underground，theScoliaendsbyfindingaCetonia-larva，agoodplumpone，inthepinkofcondition，havingreacheditsfullgrowth，justwhatthegrubwhichistofeedonitrequires。Forthwith，theassaultedvictim，contractingdesperately，rollsitselfintoaball。Theotherseizesitbytheskinoftheneck。Tounrollitisimpossibletotheinsect，forI
myselfhavesometroubleindoingso。Onesinglepointisaccessibletothesting:theunderpartofthehead，orratherofthefirstsegments，whichareplacedoutsidethecoil，sothatthegrub\'shardcraniummakesarampartforthehinderextremity，whichislesswelldefended。HeretheWasp\'sstingentersandhereonlycanitenter，withinanarrowlycircumscribedarea。Onestabonlyofthelancetisgivenatthispoint，oneonlybecausethereisnoroomformore；andthisisenough:thelarvaisabsolutelyparalysed。
Thenervousfunctionsareabolishedinstantly；themuscularcontractionscease；andtheanimaluncoilslikeabrokenspring。Henceforthmotionless，itliesonitsback，itsventralsurfacefullyexposedfromendtoend。Onthemedianlineofthissurface，towardstherear，nearthebrownpatchduetothealimentarybrothcontainedintheintestine，theScolialayshereggandwithoutmoreado，leaveseverythinglyingontheactualspotwherethemurderwascommitted，inordertogoinsearchofanothervictim。
Thisishowthedeedmustbedone:theresultsproveitemphatically。ButthentheCetonia-grubmustpossessaveryexceptionalstructureinitsnervousorganization。Thelarva\'sviolentcontractionleavesbutasinglepointofattackopentothesting，theunderpartoftheneck，whichisdoubtlessuncoveredwhenthevictimtriestodefenditselfwithitsmandibles；andyetastabinthisonepointproducesthemostthoroughparalysisthatIhaveeverseen。Itisthegeneralrulethatlarvaepossessacentreofinnervationforeachsegment。ThisissoinparticularwiththeGreyWorm，thesacrificialvictimoftheHairyAmmophila。TheWaspisacquaintedwiththisanatomicalsecret:shestabsthecaterpillaragainandagain，fromendtoend，segmentbysegment，ganglionbyganglion。WithsuchanorganizationtheCetonia-grub，unconquerablycoileduponitselfwoulddefytheparalyser\'ssurgicalskill。
Ifthefirstganglionwerewounded，theotherswouldremainuninjured；andthepowerfulbody，actuatedbytheselast，wouldlosenoneofitspowersofcontraction。Woethentotheegg，totheyounggrubheldfastinitsembrace！AndhowinsurmountablewouldbethedifficultiesiftheScolia，workingintheprofounddarknessamidthecrumblingsoilandconfrontedbyaterriblepairofmandibles，hadtostabeachsegmentinturnwithhersting，withthecertaintyofmethoddisplayedbytheAmmophila！Thedelicateoperationispossibleintheopenair，wherenothingstandsintheway，inbroaddaylight，wherethesightguidesthescalpel，andwithapatientwhichcanalwaysbereleasedifitbecomesdangerous。Butinthedark，underground，amidsttheruinsofaceilingwhichcrumblesinconsequenceoftheconflictandatclosequarterswithanopponentgreatlyhersuperiorinstrength，howistheScoliatoguideherstingwiththeaccuracythatisessentialifthestabsaretoberepeated？
Soprofoundaparalysis；thedifficultyofvivisectionunderground；thedesperatecoilingofthevictim:allthesethingstellmethattheCetonia-
grub，asregardsitsnervoussystem，mustpossessastructurepeculiartoitself。Thewholeofthegangliamustbeconcentratedinalimitedareainthefirstsegments，almostundertheneck。Iseethisasclearlyasthoughithadbeenrevealedtomebyapost-mortemdissection。
Neverwasanatomicalforecastmorefullyconfirmedbydirectexamination。
Afterforty-eighthoursinbenzine，whichdissolvesthefatandrendersthenervoussystemmoreplainlyvisible，theCetonia-grubissubjectedtodissection。Thoseofmyreaderswhoarefamiliarwiththeseinvestigationswillunderstandmydelight。WhatacleverschoolistheScolia\'s！ItisjustasIthought！Admirable！Thethoracicandabdominalgangliaaregatheredintoasinglenervousmass，situatedwithinthequadrilateralboundedbythefourhinderlegs，whichlegsareverynearthehead。Itisatiny，dull-whitecylinder，aboutthreemillimetreslongbyhalfamillimetrewide。(。117x。019inch——Translator\'sNote。)ThisistheorganwhichtheScolia\'sstingmustattackinordertosecuretheparalysisofthewholebody，exceptingthehead，whichisprovidedwithspecialganglia。
>Fromitrunnumbersoffilamentswhichactuatethefeetandthepowerfulmuscularlayerwhichisthecreature\'sessentialmotororgan。Whenexaminedmerelythroughthepocket-lens，thiscylinderappearstobeslightlyfurrowedtransversely，aproofofitscomplexstructure。Underthemicroscope，itisseentobeformedbytheclosejuxtaposition，thewelding，endtoend，oftheganglia，whichcanbedistinguishedonefromtheotherbyaslightintermediategroove。Thebulkiestarethefirst，thefourthandthetenth，orlast；theseareallverynearlyofequalsize。Therestarebarelyhalforevenathirdaslargeasthosementioned。
TheInterruptedScoliaexperiencesthesamehuntingandsurgicaldifficultieswhensheattacks，inthecrumbling，sandysoil，thelarvaeoftheShaggyAnoxiaoroftheMorningAnoxia，accordingtothedistrict；andthesedifficulties，iftheyaretobeovercome，demandinthevictimaconcentratednervoussystem，liketheCetonia\'s。Suchismylogicalconvictionbeforemakingmyexamination；suchalsoistheresultofdirectobservation。Whensubjectedtothescalpel，thelarvaoftheMorningAnoxiashowsmeitscentresofinnervationforthethoraxandtheabdomen，gatheredintoashortcylinder，which，placedveryfarforward，almostimmediatelyafterthehead，doesnotrunbackbeyondthelevelofthesecondpairoflegs。Thevulnerablepointisthuseasilyaccessibletothesting，despitethecreature\'spostureofdefence，inwhichitcontractsandcoilsup。InthiscylinderIrecognizeelevenganglia，onemorethanintheCetonia。Thefirstthree，orthoracic，gangliaareplainlydistinguishablefromoneanother，althoughtheyaresetveryclosetogether；therestareallincontact。Thelargestarethethreethoracicgangliaandtheeleventh。
Afterascertainingthesefacts，IrememberedSwammerdam\'sinvestigationsintothegruboftheMonoceros，ourOryctesnasicornis。(JanSwammerdam(1637-1680)，theDutchnaturalistandanatomist——Translator\'sNote。)I
chancedtopossessanabridgementofthe“Biblianaturae，“themasterlyworkofthefatherofinsectanatomy。Iconsultedthevenerablevolume。ItinformedmethatthelearnedDutchmanhadbeenstruck，longbeforeIwas，byananatomicalpeculiaritysimilartothatwhichthelarvaeoftheCetoniaeandAnoxiaehadshownmeintheirnerve-centres。HavingobservedintheSilk-wormanervoussystemformedofgangliadistinctonefromtheother，hewasquitesurprisedtofindthat，inthegruboftheOryctes，thesamesystemwasconcentratedintoashortchainofgangliainjuxtaposition。Hiswasthesurpriseoftheanatomistwho，studyingtheorganquaorgan，seesforthefirsttimeanunusualconformation。Minewasofadifferentnature:IwasamazedtoseetheprecisionwithwhichtheparalysisofthevictimsacrificedbytheScolia，aparalysissoprofoundinspiteofthedifficultiesofanundergroundoperation，hadguidedmyforecastastostructurewhen，anticipatingthedissection，Ideclaredinfavourofanexceptionalconcentrationofthenervoussystem。Physiologyperceivedwhatanatomyhadnotyetrevealed，atalleventstomyeyes，forsincethen，ondippingintomybooks，Ihavelearntthattheseanatomicalpeculiarities，whichwerethensonewtome，arenowwithinthedomainofcurrentscience。Weknowthat，intheScarabaeidae，boththelarvaandtheperfectinsectareendowedwithaconcentratednervoussystem。
TheGardenScoliaattacksOryctesnasicornis；theTwo-bandedScoliatheCetonia；theInterruptedScoliatheAnoxia。Allthreeoperatebelowground，underthemostunfavourableconditions；andallthreehavefortheirvictimalarvaofoneoftheScarabaeidae，which，thankstotheexceptionalarrangementofitsnerve-centres，lendsitself，aloneofalllarvae，totheWasp\'ssuccessfulenterprises。Inthepresenceofthisundergroundgame，sogreatlyvariedinsizeandshapeandyetsojudiciouslyselectedtofacilitateparalysis，IdonothesitatetogeneralizeandIaccept，astherationoftheotherScoliae，larvaeofLamellicornswhosespecieswillbedeterminedbyfutureobservation。Perhapsoneofthemwillbefoundtogivechasetotheterribleenemyofmycrops，thevoraciousWhiteWorm，thegruboftheCockchafer；perhapstheHemorrhoidalScolia，rivallinginsizetheGardenScoliaandlikeher，nodoubt，requiringacopiousdiet，willbeenteredintheinsects\'“Who\'sWho“asthedestroyerofthePine-chafer，thatmagnificentBeetle，fleckedwithwhiteuponablackorbrownground，whoofanevening，duringthesummersolstice，browsesonthefoliageofthefir-trees。Thoughunabletospeakwithcertaintyorprecision，IaminclinedtolookuponthesedevourersofScarabaeus-grubsasvaliantagriculturalauxiliaries。
TheCetonia-larvahasfiguredhithertoonlyinitsqualityofaparalysedvictim。Wewillnowconsideritinitsnormalstate。Withitsconvexbackanditsalmostflatventralsurface，thecreatureislikeasemi-cylinderinshape，fullerinthehinderportion。Ontheback，eachofthesegments，exceptthelast，oranal，segment，puckersintothreethickpads，bristlingwithstiff，tawnyhairs。Theanalsegment，muchwiderthantherest，isroundedattheendandcolouredadeepbrownbythecontentsoftheintestine，whichshowthroughthetranslucentskin；itbristleswithhairsliketheothersegments，butislevel，withoutpads。Ontheventralsurface，thesegmentshavenocreases；andthehairs，thoughabundant，areratherlesssothanontheback。Thelegs，whicharequitewell-formed，areshortandfeebleincomparisonwiththeanimal\'ssize。Theheadhasastrong，hornycapforacranium。Themandiblesarepowerful，withbevelledtipsandthreeorfourteethontheedgeofthebevel。
Itsmodeoflocomotionmarksitasanidiosyncratic，exceptional，fantasticcreature，havingnofellow，thatIknowof，intheinsectworld。Thoughendowedwithlegs——atrifleshort，itistrue，butafterallasgoodasthoseofahostofotherlarvae——itneverusesthemforwalking。Itprogressesonitsback，alwaysonitsback，neverotherwise。Bymeansofwrigglingmovementsandthepurchaseaffordedbythedorsalbristles，itmakesitswaybellyupwards，withitslegskickingtheemptyair。Thespectatortowhomthesetopsy-turvygymnasticsareanoveltythinksatfirstthatthecreaturemusthavehadafrightofsomesortandthatitisstrugglingasbestitcaninthefaceofdanger。Heputsitbackonitsbelly；helaysitonitsside。Nothingisofanyuse；itobstinatelyturnsoverandresumesitsdorsalprogress。Thatisitsmanneroftravellingoveraflatsurface；ithasnoother。
ThisreversaloftheusualmodeofwalkingissopeculiartotheCetonia-
larvathatitisenoughinitselftorevealthegrub\'sidentitytotheleastexperteyes。Digintothevegetablemouldformedbythedecayedwoodinthehollowtrunksofoldwillow-trees，searchatthefootofrottenstumpsorinheapsofcompost；and，ifyoucomeuponaplumpishgrubmovingalongonitsback，thereisnoroomfordoubt:yourdiscoveryisaCetonia-
larva。
Thistopsy-turvyprogressisfairlyswiftandisnotlessinspeedtothatofanequallyfatgrubtravellingonitslegs。Itwouldevenbegreateronapolishedsurface，wherewalkingonfootishamperedbyincessantslips，whereasthenumeroushairsofthedorsalpadsfindthenecessarysupportbymultiplyingthepointsofcontact。Onpolishedwood，onasheetofpaperandevenonastripofglass，Iseemygrubsmovingfrompointtopointwiththesameeaseasonasurfaceofgardenmould。Inthespaceofoneminute，onthewoodofmytable，theycoveradistanceofeightinches。Thepaceisnoswifteronahorizontalbedofsiftedmould。Astripofglassreducesthedistancecoveredbyonehalf。Theslipperysurfaceonlyhalfparalysesthisstrangemethodoflocomotion。
WewillnowplacesidebysidewiththeCetonia-grubthelarvaoftheMorningAnoxia，thepreyoftheInterruptedScolia。ItisverylikethelarvaoftheCommonCockchafer。Itisafat，pot-belliedgrub，withathick，redcaponitsheadandarmedwithstrong，blackmandibles，whicharepowerfulimplementsfordiggingandcuttingthroughroots。Thelegsaresturdyandendinahookednail。Thecreaturehasalong，heavy，brownpaunch。Whenplacedonthetable，itliesonitsside；itstruggleswithoutbeingabletoadvanceoreventoremainonitsbellyorback。Initsusualpostureitiscurledupintoanarrowhook。Ihaveneverseenitstraightenitselfcompletely；thebulkyabdomenpreventsit。Whenplacedonasurfaceofmoistsand，theventripotentcreatureisnobetterabletoshiftitsposition:curvedintoafish-hook，itliesonitsside。
Todigintotheearthandburyitself，itusesthefore-edgeofitshead，asortofweeding-hoewiththetwomandiblesforpoints。Thelegstakepartinthiswork，butfarlesseffectually。Inthiswayitcontrivestodigitselfashallowpit。Then，bracingitselfagainstthewallofthepit，withtheaidofwrigglingmovementswhicharefavouredbytheshort，stiffhairsbristlingalloveritsbody，thegrubchangesitspositionandplungesintothesand，butstillwithdifficulty。
Apartfromafewdetails，whichareofnoimportancehere，wemayrepeatthissketchoftheAnoxia-grubandweshallhave，ifthesizebeatleastquadrupled，apictureofthelarvaofOryctesnasicornis，themonstrouspreyoftheGardenScolia。Itsgeneralappearanceisthesame:thereisthesameexaggerationofthebelly；thesamehook-likecurve；thesameincapacityforstandingonitslegs。AndasmuchmaybesaidofthelarvaofScarabaeuspentodon，afellow-boarderoftheOryctesandtheCetonia。
CHAPTER5。THEPROBLEMOFTHESCOLIAE。
Nowthatallthefactshavebeensetforth，itistimetocollatethem。WealreadyknowthattheBeetle-hunters，theCerceres(Cf。“TheHuntingWasps“:chapters1to3——Translator\'sNote。)，preyexclusivelyontheWeevilsandtheBuprestes，thatis，onthefamilieswhosenervoussystempresentsadegreeofconcentrationwhichmaybecomparedwiththatoftheScolia\'svictims。Thosepredatoryinsects，workingintheopenair，areexemptfromthedifficultieswhichtheiremulators，workingunderground，havetoovercome。Theirmovementsarefreeandaredirectedbythesenseofsight；buttheirsurgeryisconfrontedinanotherrespectwithamostarduousproblem。
Thevictim，aBeetle，iscoveredatallpointswithasuitofarmourwhichthestingisunabletopenetrate。Thejointsalonewillallowthepoisonedlancettopass。Thoseofthelegsdonotinanywaycomplywiththeconditionsimposed:theresultofstingingthemwouldbemerelyapartialdisorderwhichfarfromsubduingtheinsect，wouldrenderitmoredangerousbyirritatingityetfurther。Astinginthejointoftheneckisnotadmissible:itwouldinjurethecervicalgangliaandleadtodeath，followedbyputrefaction。Thereremainsonlythejointbetweenthecorseletandtheabdomen。
Thesting，inenteringhere，hastoabolishallmovementwithasinglestab，foranymovementwouldimperiltherearingofthelarva。Thesuccessoftheparalysis，therefore，demandsthatthemotorganglia，atleastthethreethoracicganglia，shallbepackedinclosecontactoppositethispoint。ThisdeterminestheselectionofWeevilsandBuprestes，bothofwhicharesostronglyarmoured。
Butwherethepreyhasonlyasoftskin，incapableofstoppingthesting，theconcentratednervoussystemisnolongernecessary，fortheoperator，versedintheanatomicalsecretsofhervictim，knowstoperfectionwherethecentresofinnervationlie；andshewoundsthemoneafteranother，ifneedbefromthefirsttothelast。ThusdotheAmmophilaegotoworkwhendealingwiththeircaterpillarsandtheSphex-waspswhendealingwiththeirLocusts，EphippigersandCrickets。
WiththeScoliaewecomeonceagaintoasoftprey，withaskinpenetrablebythestingnomatterwhereitbeattacked。Willthetacticsofthecaterpillar-hunters，whostabandstabagain，berepeatedhere？No，forthedifficultyofmovementundergroundprohibitssocomplicatedanoperation。
Onlythetacticsoftheparalysersofarmour-cladinsectsarepracticablenow，for，sincethereisbutonethrustofthedagger，thefeatofsurgeryisreducedtoitssimplestterms，anecessaryconsequenceofthedifficultiesofanundergroundoperation。TheScoliae，then，whosedestinyitistohuntandparalyseunderthesoilthevictualsfortheirfamily，requireapreymadehighlyvulnerablebythecloseassemblageofthenerve-
centres，asaretheWeevilsandBuprestesoftheCerceres；andthisiswhyithasfallentotheirlottoshareamongthemthelarvaeoftheScarabaeidae。
Beforetheyobtainedtheirallottedportion，socloselyrestrictedandsojudiciouslyselected；beforetheydiscoveredthepreciseandalmostmathematicalpointatwhichthestingmustentertoproduceasuddenandalastingimmobility；beforetheylearnthowtoconsume，withoutincurringtheriskofputrefaction，socorpulentaprey:inbrief，beforetheycombinedthesethreeconditionsofsuccess，whatdidtheScoliaedo？
TheDarwinianschoolwillreplythattheywerehesitating，essaying，experimenting。Alongseriesofblindgropingseventuallyhituponthemostfavourablecombination，acombinationhenceforthtobeperpetuatedbyhereditarytransmission。Theskilfulco-ordinationbetweentheendandthemeanswasoriginallytheresultofanaccident。
Chance！Aconvenientrefuge！IshrugmyshoulderswhenIhearitinvokedtoexplainthegenesisofaninstinctsocomplexasthatoftheScoliae。Inthebeginning，yousay，thecreaturegropesandfeelsitsway；thereisnothingsettledaboutitspreferences。Tofeeditscarnivorouslarvaeitleviestributeoneveryspeciesofgamewhichisnottoomuchforthehuntress\'powerorthenurseling\'sappetite；itsdescendantstrynowthis，nowthat，nowsomethingelse，atrandom，untiltheaccumulatedcenturiesleadtotheselectionwhichbestsuitstherace。Thenhabitgrowsfixedandbecomesinstinct。
Verywell。LetusagreethattheScoliaofantiquitysoughtadifferentpreyfromthatadoptedbythemodernhuntress。Ifthefamilythroveuponadietnowdiscontinued，wefailtoseethatthedescendantshadanyreasontochangeit:animalshavenotthegastronomicfanciesofanepicurewhomsatietymakesdifficulttoplease。Becausetheracedidwelluponthisfare，itbecamehabitual；andinstinctbecamedifferentlyfixedfromwhatitisto-day。If，ontheotherhand，theoriginalfoodwasunsuitable，theexistenceofthefamilywasjeopardized；andanyattemptatfutureimprovementbecameimpossible，becauseanunhappilyinspiredmotherwouldleavenoheirs。
Toescapefallingintothistwofoldtrap，thetheoristswillreplythattheScoliaearedescendedfromaprecursor，anindeterminatecreature，ofchangeablehabitsandchangingform，modifyingitselfinaccordancewithitsenvironmentandwiththeregionalandclimaticconditionsandbranchingoutintoraceseachofwhichhasbecomeaspecieswiththeattributeswhichdistinguishitto-day。Theprecursoristhedeusexmachinaofevolution。
Whenthedifficultybecomesaltogethertooimportunate，quick，aprecursor，tofillupthegaps，quick，animaginarycreature，thenebulousplaythingofthemind！Thisisseekingtolightenthedarknesswithastilldeeperobscurity；toilluminethedaybypilingclouduponcloud。Precursorsareeasiertofindthansoundarguments。Nevertheless，letusputtheprecursoroftheScoliaetothetest。
Whatdidshedo？Beingcapableofeverything，shedidabitofeverything。
Amongitsdescendantswereinnovatorswhodevelopedatastefortunnellinginsandandvegetablemould。TheretheyencounteredthelarvaeoftheCetonia，theOryctes，theAnoxia，succulentmorselsonwhichtoreartheirfamilies。BydegreestheindeterminateWaspadoptedthesturdyproportionsdemandedbyundergroundlabour。Bydegreesshelearnttostabherplumpneighboursinscientificfashion；bydegreessheacquiredthedifficultartofconsumingherpreywithoutkillingit；atlength，bydegrees，aidedbytherichnessofherdiet，shebecamethepowerfulScoliawithwhomwearefamiliar。Havingreachedthispoint，thespeciesassumesapermanentform，asdoesitsinstinct。
Herewehaveamultiplicityofstages，alloftheslowest，allofthemostincrediblenature，whereastheWaspcannotfoundaraceexceptontheexpressconditionofcompletesuccessfromthefirstattempt。Wewillnotinsistfurtherupontheinsurmountableobjection；wewilladmitthat，amidsomanyunfavourablechances，afewfavouredindividualssurvive，becomingmoreandmorenumerousfromonegenerationtothenext，inproportionasthedangerousartofrearingtheyoungisperfected。Slightvariationsinoneandthesamedirectionformadefinitewhole；andatlonglasttheancientprecursorhasbecometheScoliaofourowntimes。
Bytheaidofavaguephraseologywhichjuggleswiththesecretofthecenturiesandtheunknownthingsoflife，itiseasytobuildupatheoryinwhichourmentalslothdelights，afterbeingdiscouragedbydifficultresearcheswhosefinalresultisdoubtratherthanpositivestatement。Butif，sofarfrombeingsatisfiedwithhazygeneralitiesandadoptingascurrentcointhetermsconsecratedbyfashion，wehavetheperseverancetoexplorethetruthasfarasliesinourpower，theaspectofthingswillundergoagreatchangeandweshalldiscoverthattheyarefarlesssimplethanouroverprecipitateviewsdeclaredthemtobe。Generalizationiscertainlyamostvaluableinstrument:scienceindeedexistsonlybyvirtueofit。Letusnonethelessbewareofgeneralizationswhicharenotbaseduponveryfirmandmanifoldfoundations。
Whenthesefoundationsarelacking，thechildisthegreatgeneralizer。Forhim，thefeatheredworldconsistsmerelyofbirds；theraceofreptilesmerelyofsnakes，theonlydifferencebeingthatsomearebigandsomearelittle。Knowingnothing，hegeneralizesinthehighestdegree；hesimplifies，inhisinabilitytoperceivethecomplex。LaterhewilllearnthattheSparrowisnottheBullfinch，thattheLinnetisnottheGreenfinch；hewillparticularizeandtoagreaterdegreeeachday，ashisfacultyofobservationbecomesmorefullytrained。Inthebeginninghesawnothingbutresemblances；henowseesdifferences，butstillnotplainlyenoughtoavoidincongruouscomparisons。
Inhisadultyearshewillalmosttoacertaintycommitzoologicalblunderssimilartothosewhichmygardenerretailstome。Favier，anoldsoldier，hasneveropenedabook，forthebestofreasons。Hebarelyknowshowtocipher:arithmeticratherthanreadingisforceduponusbythebrutalitiesoflife。Havingfollowedtheflagoverthree-quartersoftheglobe，hehasanopenmindandamemorycrammedwithreminiscences，whichdoesnotpreventhim，whenwechataboutanimals，frommakingthemostcrazyassertions。ForhimtheBatisaRatthathasgrownwings；theCuckooisaSparrow-hawkretiredfrombusiness；theSlugisaSnailwhohaslosthisshellwiththeadvanceofyears；theNightjar(KnownalsoastheGoatsucker，becauseofthemistakenbeliefthatthebirdsucksthemilkofGoats，and，inAmerica，astheWhippoorwill——Translator\'sNote。)，theChaoucho-grapaou，ashecallsher，isanelderlyToad，who，becomingenamouredofmilk-food，hasgrownfeathers，sothatshemayenterthebyresandmilktheGoats。Itisimpossibletodrivethesefantasticideasoutofhishead。Favierhimself，aswillbeseen，isanevolutionistafterhisownfashion，anevolutionistofaverydaringtype。Inaccountingfortheoriginofanimalsnothinggiveshimpause。Hehasareplytoeverything:
“this“comesfrom“that。“Ifyouaskhimwhy，heanswers:
“Lookattheresemblance！“
Shallwereproachhimwiththeseinsanities，whenwehearanother，misledbytheMonkey\'sbuild，acclaimthePithecanthropusasman\'sprecursor？
ShallwerejectthemetamorphosisoftheChaoucho-grapaou，whenpeopletellusinallseriousnessthat，inthepresentstageofscientificknowledge，itisabsolutelyprovedthatmanisdescendedfromsomerough-hewnApe？Ofthetwotransformations，Favier\'sstrikesmeasthemorecredible。A
painterofmyacquaintance，abrotherofthegreatcomposerFelicienDavid(FelicienCesarDavid(1810-1876)。Hischiefworkwasthechoralsymphony“LeDesert“:——Translator\'sNote。)，favouredmeonedaywithhisreflectionsonthehumanstructure:
“Ve，mounbelami，“hesaid。“Ve，l\'homealoudintred\'unporetloudeferod\'unomounino。““See，mydearfriend，see:manhastheinsideofapigandtheoutsideofamonkey。“
Irecommendthepainter\'saphorismtothosewhomightliketodiscoverman\'soriginintheHogwhentheApehasgoneoutoffashion。AccordingtoDavid，descentisprovedbyinternalresemblances:
“L\'homealoudintred\'unpor。“
Theinventoryofprecursorytypesseesnothingbutorganicresemblancesanddisdainsthedifferencesofaptitude。Byconsultingonlythebones，thevertebrae，thehair，thenervuresofthewings，thejointsoftheantennae，theimaginationmaybuildupanysortofgenealogicaltreethatwillfitwithourtheoriesofclassification，for，whenallissaid，theanimal，initswidestgeneralization，isrepresentedbyadigestivetube。Withthiscommonfactor，thewayliesopentoeverykindoferror。Amachineisjudgednotbythisorthattrainofwheels，butbythenatureoftheworkaccomplished。Themonumentalroasting-jackofawaggoners\'innandaBreguetchronometerbothhavetrainsofcogwheelsgearedinalmostasimilarfashion。(LouisBreguet(1803-1883)，afamousParisianwatchmakerandphysicist——Translator\'sNote。)Arewetoclassthetwomechanismstogether？Shallweforgetthattheoneturnsashoulderofmuttonbeforethehearth，whiletheotherdividestimeintoseconds？
Inthesameway，theorganicscaffoldingisdominatedfromonhighbytheaptitudesoftheanimal，especiallythatsuperiorcharacteristic，thepsychicalaptitudes。ThattheChimpanzeeandthehideousGorillapossesscloseresemblancesofstructuretoourownisobvious。Butletusforamomentconsidertheiraptitudes。Whatdifferences，whatadividinggulf！
WithoutexaltingourselvesashighasthefamousreedofwhichPascalspeaks，thatreedwhich，initsweakness，bythemerefactthatitknowsitselftobecrushed，issuperiortotheworldthatcrushesit，wemayatleastasktobeshown，somewhere，ananimalmakinganimplement，whichwillmultiplyitsskillanditsstrength，ortakingpossessionoffire，theprimordialelementofprogress。(BlaisePascal(1623-1662)。Theallusionistoapassageinthephilosopher\'s“Pensees。“Pascaldescribesmanasareed，theweakestthinginnature，but“athinkingreed。“——Translator\'sNote。)Masterofimplementsandoffire！Thesetwoaptitudes，simplethoughtheybe，characterizemanbetterthanthenumberofhisvertebraeandhismolars。
Youtellusthatman，atfirstahairybrute，walkingonallfours，hasrisenonhishind-legsandshedhisfur；andyoucomplacentlydemonstratehowtheeliminationofthehairypeltwaseffected。Insteadofbolsteringupatheorywithahandfuloffluffgainedorlost，itwouldperhapsbebettertosettlehowtheoriginalbrutebecamethepossessorofimplementsandfire。Aptitudesaremoreimportantthanhair；andyouneglectthembecauseitistherethattheinsurmountabledifficultyreallyresides。Seehowthegreatmasterofevolutionhesitatesandstammerswhenhetries，byfairmeansorfoul，tofitinstinctintothemouldofhisformulae。Itisnotsoeasytohandleasthecolourofthepelt，thelengthofthetail，theearthatdroopsorstandserect。Yes，ourmasterwellknowsthatthisiswheretheshoepinches！Instinctescapeshimandbringshistheorycrumblingtotheground。
LetusreturntowhattheScoliaeteachusonthisquestion，whichincidentallytouchesonourownorigin。InconformitywiththeDarwinianideas，wehaveacceptedanunknownprecursor，whobydintofrepeatedexperiment，adoptedasthevictualstobehoardedthelarvaeoftheScarabaeidae。Thisprecursor，modifiedbyvaryingcircumstances，issupposedtohavesubdividedherselfintoramifications，oneofwhich，diggingintovegetablemouldandpreferringtheCetoniatoanyothergameinhabitingthesameheap，becametheTwo-bandedScolia；another，alsoaddictedtoexploringthesoil，butselectingtheOryctes，leftasitsdescendanttheGardenScolia；andathird，establishingitselfinsandyground，whereitfoundtheAnoxia，wastheancestressoftheInterruptedScolia。TothesethreeramificationswemustbeyondadoubtaddotherswhichcompletetheseriesoftheScolia。Astheirhabitsareknowntomeonlybyanalogy，Iconfinemyselftomentioningthem。
Thethreespeciesatleast，therefore，withwhichIamfamiliarwouldappeartobederivedfromacommonprecursor。Totraversethedistancefromthestarting-pointtothegoal，allthreehavehadtocontendwithdifficulties，whichareextremelygraveifconsideredonebyoneandareaggravatedevenmorebythiscircumstance，thattheovercomingofonewouldleadtonothingunlesstheothersweresurmountedassuccessfully。Success，then，iscontingentuponaseriesofconditions，eachoneofwhichoffersalmostnochanceofvictory，sothatthefulfilmentofthemallbecomesamathematicalabsurdityifwearetoinvokeaccidentalone。
And，inthefirstplace，howwasitthattheScoliaofantiquity，havingtoproviderationsforhercarnivorousfamily，adoptedforherpreyonlythoselarvaewhich，owingtotheconcentrationoftheirnervoussystems，formsoremarkableandsorareanexceptionintheinsectorder？Whatchancewouldhazardofferherofobtainingthisprey，themostsuitableofallbecausethemostvulnerable？Thechancerepresentedbyunitycomparedwiththeindefinitenumberofentomologicalspecies。Theoddsareasonetoimmensity。
Letuscontinue。ThelarvaoftheScarabaeidissnappedupunderground，forthefirsttime。Thevictimprotests，defendsitselfafteritsfashion，coilsitselfupandpresentstothestingoneverysideasurfaceonwhichawoundentailsnoseriousdanger。AndyettheWasp，anabsolutenovice，hastoselect，forthethrustofitspoisonedweapon，onesinglepoint，narrowlyrestrictedandhiddeninthefoldsofthelarva\'sbody。Ifshemiscalculates，shemaybekilled:thelarva，irritatedbythesmartingpuncture，isstrongenoughtodisembowelherwiththetusksofitsmandibles。Ifsheescapesthedanger，shewillneverthelessperishwithoutleavinganyoffspring，sincethenecessaryprovisionswillbelacking。
Salvationforherselfandherracedependsonthis:whetheratthefirstthrustsheisabletoreachthelittlenervousplexuswhichmeasuresbarelyone-fiftiethofaninchinwidth。Whatchancehassheofplungingherlancetintoit，ifthereisnothingtoguideher？Thechancerepresentedbyunitycomparedwiththenumberofpointscomposingthevictim\'sbody。Theoddsareasoneagainstimmensity。
Letusproceedstillfurther。Thestinghasreachedthemark；thefatgrubisdeprivedofmovement。Atwhatspotsshouldtheeggnowbelaid？Infront，behind，onthesides，thebackorthebelly？Thechoiceisnotamatterofindifference。Theyounggrubwillpiercetheskinofitsprovenderattheveryspotonwhichtheeggwasfixed；and，onceanopeningismade，itwillgoaheadwithouthesitation。Ifthispointofattackisill-chosen，thenurselingrunstheriskofpresentlyfindingunderitsmandiblessomeessentialorgan，whichshouldhavebeenrespecteduntiltheendinordertokeepthevictualsfresh。Rememberhowdifficultitistocompletetherearingwhenthetinylarvaismovedfromtheplacechosenbythemother。ThegamepromptlybecomesputridandtheScoliadies。
Itisimpossibleformetostatetheprecisemotiveswhichleadtotheadoptionofthespotonwhichtheeggislaid；Icanperceivegeneralreasons，butthedetailsescapeme，asIamnotwellenoughversedinthemoredelicatequestionsofanatomyandentomologicalphysiology。WhatIdoknowwithabsolutecertaintyisthatthesamespotisinvariablychosenforlayingtheegg。Withnotasingleexception，onallthevictimsextractedfromtheheapofgardenmould——andtheyarenumerous——theeggisfixedbehindtheventralsurface，onthevergeofthebrownpatchformedbythecontentsofthedigestivesystem。
Iftherebenothingtoguideher，whatchancehasthemotherofgluinghereggtothispoint，whichisalwaysthesamebecauseitisthatmostfavourabletosuccessfulrearing？Averysmallpoint，representedbytheratiooftwoorthreesquaremillimetres(About1/100squareinch——
Translator\'sNote。)totheentiresurfaceofthevictim\'sbody。
Isthisall？Notyet。Thegrubishatched；itpiercesthebellyoftheCetonia-larvaattherequisitepoint；itplungesitslongneckintotheentrails，ransackingthemandfillingitselftorepletion。Ifitbiteatrandom，ifithavenootherguideintheselectionoftit-bitsthanthepreferenceofthemomentandtheviolenceofanimperiousappetite，itwillinfalliblyincurthedangerofbeingpoisonedbyputridfood，forthevictim，ifwoundedinthoseorganswhichpreservearemnantoflifeinit，willdieforgoodandallatthefirstmouthfuls。
Theamplejointmustbeconsumedwithprudentskill:thispartmustbeeatenbeforethatand，afterthat，someotherportion，alwaysaccordingtomethod，untilthetimeapproachesforthelastbites。ThismarkstheendoflifefortheCetonia，butitalsomarkstheendoftheScolia\'sfeasting。
Ifthegrubbeanoviceintheartofeating，ifnospecialinstinctguideitsmandiblesinthebellyoftheprey，whatchancehasitofcompletingitsperilousmeal？AsmuchasastarvingWolfwouldhaveofdaintilydissectinghisSheep，whenhetearsathergluttonously，rendsherintoshredsandgulpsthemdown。
Thesefourconditionsofsuccess，withchancesoneartozeroineachcase，mustallberealizedtogether，orthegrubwillneverbereared。TheScoliamayhavecapturedalarvawithclose-packednerve-centres，aCetonia-grub，forinstance；butthiswillgofornothingunlessshedirectherstingtowardstheonlyvulnerablepoint。Shemayknowthewholesecretoftheartofstabbinghervictim，butthismeansnothingifshedoesnotknowwheretofastenheregg。Thesuitablespotmaybefound，butalltheforegoingwillbeuselessifthegrubbenotversedinthemethodtobefollowedindevouringitspreywhilekeepingitalive。Itisallornothing。
WhowouldventuretocalculatethefinalchanceonwhichthefutureoftheScolia，orofherprecursor，isbased，thatcomplexchancewhosefactorsarefourinfinitelyimprobableoccurrences，onemightalmostsayfourimpossibilities？Andsuchaconjunctionissupposedtobeafortuitousresult，towhichthepresentinstinctisdue！Come，come！
>Fromanotherpointofviewagain，theDarwiniantheoryisatvariancewiththeScoliaeandtheirprey。IntheheapofgardenmouldwhichIexploitedinordertowritethisrecord，threekindsoflarvaedwelltogether，belongingtotheScarabaeidgroup:theCetonia，theOryctesandScarabeuspentodon。Theirinternalstructureisverynearlysimilar；theirfoodisthesame，consistingofdecomposingvegetablematter；theirhabitsareidentical:theyliveundergroundintunnelswhicharefrequentlyrenewed；
theymakearoughegg-shapedcocoonofearthymaterials。Environment，diet，industryandinternalstructureareallsimilar；andyetoneofthesethreelarvae，theCetonia\'s，revealsamostsingulardissimilarityfromitsfellow-trenchermen:aloneamongtheScarabaeidaeand，morethanthat，aloneinalltheimmenseorderofinsects，itwalksuponitsback。
Ifthedifferenceswereamatterofafewpettystructuraldetails，fallingwithinthefinicaldepartmentoftheclassifier，wemightpassthemoverwithouthesitation；butacreaturethatturnsitselfupsidedowninordertowalkwithitsbellyintheairandneveradoptsanyothermethodoflocomotion，thoughitpossesseslegsandgoodlegsatthat，assuredlydeservesexamination。Howdidtheanimalacquireitsfantasticmodeofprogressandwhydoesitthinkfittowalkinafashiontheexactcontraryofthatadoptedbyotherbeasts？
Tothesequestionsthesciencenowinfashionalwayshasareplyready:
adaptationtoenvironment。TheCetonia-larvalivesincrumblinggallerieswhichitboresinthedepthsofthesoil。Likethesweepwhoobtainsapurchasewithhisback，loinsandkneestohoisthimselfupthenarrowpassageofachimney，itgathersitselfup，appliesthetipofitsbellytoonewallofitsgalleryanditssturdybacktoanother；andthecombinedeffortofthesetwoleversresultsinmovingitforward。Thelegs，whichareusedverylittle，indeedhardlyatall，wasteawayandtendtodisappear，asdoesanyorganwhichisleftunemployed；theback，ontheotherhand，theprincipalmotiveagent，growsstronger，isfurrowedwithpowerfulfoldsandbristleswithgrappling-hooksorhairs；andgradually，byadaptationtoitsenvironment，thecreaturelosestheartofwalking，whichitdoesnotpractise，andreplacesitbythatofcrawlingonitsback，aformofprogressbettersuitedtoundergroundcorridors。
Sofarsogood。Butnowtellme，ifyouplease，whythelarvaeoftheOryctesandtheScarabaeus，livinginvegetablemould，thelarvaoftheAnoxia，dwellinginthesand，andthelarvaoftheCockchaferinourcultivatedfieldshavenotalsoacquiredthefacultyofwalkingontheirbacks？Intheirgalleriestheyfollowthechimney-sweep\'smethodsquiteascleverlyastheCetonia-grub；tomoveforwardtheymakevaliantuseoftheirbackswithoutyethavingcometoamblingwiththeirbelliesintheair。Cantheyhaveneglectedtoaccommodatethemselvestothedemandsoftheirenvironment？Ifevolutionandenvironmentcausethetopsy-turvyprogressoftheone，Ihavetheright，ifwordshaveanymeaningwhatever，todemandasmuchoftheothers，sincetheirorganizationissomuchalikeandtheirmodeoflifeidentical。
Ihavebutlittlerespectfortheorieswhich，whenconfrontedwithtwosimilarcases，areunabletointerprettheonewithoutcontradictingtheother。Theymakemelaughwhentheybecomemerelychildish。Forexample:
whyhasthetigeracoatstreakedblackandyellow？Amatterofenvironment，repliesoneofourevolutionarymasters。Ambushedinbamboothicketswherethegoldenradianceofthesunisintersectedbystripesofshadowcastbythefoliage，theanimal，thebettertoconcealitself，assumedthecolourofitsenvironment。Theraysofthesunproducedthetawnyyellowofthecoat；thestripesofshadowaddedtheblackbars。
Andthereyouhaveit。Anyonewhorefusestoaccepttheexplanationmustbeveryhardtoplease。Iamoneofthesedifficultpersons。Ifitwereadinner-tablejest，madeoverthewalnutsandthewine，Iwouldwillinglysingditto；butalasandalack，itisutteredwithoutasmile，inasolemnandmagisterialmanner，asthelastwordinscience！Toussenel，inhisday，askedthenaturalistsaninsidiousquestion。(AlphonseToussenel(1803-
1885)，theauthorofanumberoflearnedandcuriousworksonornithology——
Translator\'sNote。)Why，heenquired，haveDucksalittlecurlyfeatherontherump？Noone，sofarasIknow，hadananswerfortheteasingcross-
examiner:evolutionhadnotbeeninventedthen。Inourtimethereasonwhywouldbeforthcominginamoment，aslucidandaswell-foundedasthereasonwhyofthetiger\'scoat。
Enoughofchildishnonsense。TheCetonia-grubwalksonitsbackbecauseithasalwaysdoneso。Theenvironmentdoesnotmaketheanimal；itistheanimalthatismadefortheenvironment。Tothissimplephilosophy，whichisquiteantiquatednowadays，Iwilladdanother，whichSocratesexpressedinthesewords:
“WhatIknowbestisthatIknownothing。“
