watchedmeatsafe，settlesonourwindowpanesandkeepsupasolemnbuzzing，anxioustobeoffinthesunandripenafreshemissionofgerms。Howdoesshelayhereggs，theoriginoftheloathsomemaggotthatbattenspoisonouslyonourprovisions，whetherofgameorbutcher’smeat？Whatareherstratagemsandhowcanwefoilthem？ThisiswhatIproposetoinvestigate。
Thebluebottlefrequentsourhomesduringautumnandapartofwinter，untilthecoldbecomessevere;butherappearanceinthefieldsdatesbackmuchearlier。OnthefirstfinedayinFebruary，weshallseeherwarmingherself，chillily，againstthesunnywalls。InApril，Inoticeherinconsiderablenumbersonthelaurestinus。Itisherethatsheseemstopair，whilesippingthesugaryexudationsofthesmallwhiteflowers。Thewholeofthesummerseasonisspentoutofdoors，inbriefflightsfromonerefreshmentbartothenext。Whenautumncomes，withitsgame，shemakesherwayintoourhousesandremainsuntilthehardfrosts。
Thissuitsmystay—at—homehabitsandespeciallymylegs，whicharebendingundertheweightofyears。Ineednotrunafterthesubjectsofmypresentstudy;theycallonme。Besides，Ihavevigilantassistants。Thehouseholdknowsofmyplans。Everyonebringsme，inalittlescrewofpaper，thenoisyvisitorjustcapturedagainstthepanes。
ThusdoIfillmyvivarium，whichconsistsofalarge，bell—shapedcageofwiregauze，standinginanearthenwarepanfullofsand。A
mugcontaininghoneyisthediningroomoftheestablishment。Herethecaptivescometorecruitthemselvesintheirhoursofleisure。
Tooccupytheirmaternalcares，Iemploysmallbirds——chaffinches，linnets，sparrows——broughtdown，intheenclosure，bymyson’sgun。
IhavejustservedupaLinnetshottwodaysago。Inextplaceinthecageabluebottle，oneonly，toavoidconfusion。Herfatbellyproclaimstheadventofalayingtime。Anhourlater，whentheexcitementofbeingputinprisonisallayed，mycaptiveisinlabor。Witheager，jerkysteps，sheexploresthemorselofgame，goesfromtheheadtothetail，returnsfromthetailtothehead，repeatstheactionseveraltimesandatlastsettlesnearaneye，adimmedeyesunkintoitssocket。
Theovipositorbendsatarightangleanddivesintothejunctionofthebeak，straightdowntotheroot。Thentheeggsareemittedfornearlyhalfanhour。Thelayer，utterlyabsorbedinherseriousbusiness，remainsstationaryandimpassiveandiseasilyobservedthroughmylens。Amovementonmypartwoulddoubtlessscareher;butmyrestfulpresencegiveshernoanxiety。Iamnothingtoher。
Thedischargedoesnotgooncontinuouslyuntiltheovariesareexhausted;itisintermittentandperformedinsomanypackets。
Severaltimesover，theflyleavesthebird’sbeakandcomestotakearestuponthewiregauze，whereshebrushesherhindlegsoneagainsttheother。Inparticular，beforeusingitagain，shecleans，smoothesandpolishesherlayingtool，theprobethatplacestheeggs。Then，feelingherwombstillteeming，shereturnstothesamespotatthejointofthebeak。Thedeliveryisresumed，toceasepresentlyandthenbeginanew。Acoupleofhoursarethusspentinalternatestandingneartheeyeandrestingonthewiregauze。
Atlast，itisover。Theflydoesnotgobacktothebird，aproofthatherovariesareexhausted。Thenextday，sheisdead。Theeggsaredabbedinacontinuouslayer，attheentrancetothethroat，attherootofthetongue，onthemembraneofthepalate。
Theirnumberappearsconsiderable;thewholeinsideofthegulletiswhitewiththem。Ifixalittlewoodenpropbetweenthetwomandiblesofthebeak，tokeepthemopenandenablemetoseewhathappens。
Ilearninthiswaythatthehatchingtakesplaceinacoupleofdays。Assoonastheyareborn，theyoungvermin，aswarmingmass，leavetheplacewheretheyareanddisappeardownthethroat。Toinquirefurtherintotheworkisuselessforthemoment。Weshalllearnmoreaboutitlater，underconditionsthatmakeexaminationeasier。
Thebeakofthebirdinvadedwasclosedatthestart，asfarasthenaturalcontactofthemandiblesallowed。Thereremainedanarrowslitatthebase，sufficientatmosttoadmitthepassageofahorsehair。Itwasthroughthisthatthelayingwasperformed。
Lengtheningherovipositorlikeatelescope，themotherinsertedthepointofherimplement，apointslightlyhardenedwithahornyarmor。Thefinenessoftheprobeequalsthefinenessoftheaperture。But，ifthebeakwereentirelyclosed，wherewouldtheeggsbelaidthen？
Withatiedthread，Ikeepthetwomandiblesinabsolutecontact;
andIplaceasecondbluebottleinthepresenceofthelinnet，whichthecolonistshavealreadyenteredbythebeak。Thistime，thelayingtakesplaceononeoftheeyes，betweenthelidandtheeyeball。Atthehatching，whichagainoccursacoupleofdayslater，thegrubsmaketheirwayintothefleshydepthsofthesocket。Theeyesandthebeak，therefore，formthetwochiefentrancesintofeatheredgame。
Thereareothers;andthesearethewounds。Icoverthelinnet’sheadwithapaperhoodwhichwillpreventinvasionthroughthebeakandeyes。Iserveit，underthewiregauzebell，toathirdegglayer。Thebirdhasbeenstruckbyashotinthebreast，butthesoreisnotbleeding:noouterstainmarkstheinjuredspot。
Moreover，Iamcarefultoarrangethefeathers，tosmooththemwithahairpencil，sothatthebirdlooksquitesmartandhaseveryappearanceofbeinguntouched。
Theflyissoonthere。Sheinspectsthelinnetfromendtoend;
withherfronttarsishefumblesatthebreastandbelly。Itisasortofauscultationbysenseoftouch。Theinsectbecomesawareofwhatisunderthefeathersbythemannerinwhichthesereact。
Ifscentcomestoherassistance，itcanonlybeveryslightly，forthegameisnotyethigh。Thewoundissoonfound。Nodropofbloodisnearit，foritisclosedbyaplugofdownrammedintoitbytheshot。Theflytakesupherpositionwithoutseparatingthefeathersoruncoveringthewound。Sheremainsherefortwohourswithoutstirring，motionless，withherabdomenconcealedbeneaththeplumage。Myeagercuriositydoesnotdistractherfromherbusinessforamoment。
Whenshehasfinished，Itakeherplace。Thereisnothingeitherontheskinoratthemouthofthewound。Ihavetowithdrawthedownypluganddigtosomedepthbeforediscoveringtheeggs。Theovipositorhasthereforelengtheneditsextensibletubeandpushedbeyondthefeatherstopperdriveninbythelead。Theeggsareinonepacket;theynumberaboutthreehundred。
Whenthebeakandeyesarerenderedinaccessible，whenthebody，moreover，hasnowounds，thelayingstilltakesplace，but，thistime，inahesitatingandniggardlyfashion。Ipluckthebirdcompletely，thebettertowatchwhathappens;also，Icovertheheadwithapaperhoodtoclosetheusualmeansofaccess。Foralongtime，withjerkysteps，themotherexploresthebodyineverydirection;shetakesherstandbypreferenceonthehead，whichshesoundsbytappingonitwithherfronttarsi。Sheknowsthattheopeningswhichsheneedsarethere，underthepaper;butshealsoknowshowfrailarehergrubs，howpowerlesstopiercetheirwaythroughthestrangeobstaclewhichstopsheraswellandinterfereswiththeworkofherovipositor。Thecowlinspiresherwithprofounddistrust。Despitethetemptingbaitoftheveiledhead，notaneggislaidonthewrapper，slightthoughitmaybe。
Wearyofvainattemptstocompassthisobstacle，theFlyatlastdecidesinfavorofotherpoints，butnotonthebreast，bellyorback，wherethehidewouldseemtootoughandthelighttoointrusive。Sheneedsdarkhidingplaces，cornerswheretheskinisverydelicate。Thespotschosenarethecavityoftheaxilla，correspondingwithourarmpit，andthecreasewherethethighjoinsthebelly。Eggsarelaidinbothplaces，butnotmany，showingthatthegroinandtheaxillaareadoptedonlyreluctantlyandforlackofabetterspot。
Withanunpluckedbird，alsohooded，thesameexperimentfailed:
thefeatherspreventtheflyfromslippingintothosedeepplaces。
Letusadd，inconclusion，that，onaskinnedbird，orsimplyonapieceofbutcher’smeat，thelayingiseffectedonanypartwhatever，providedthatitbedark。Thegloomiestcornersarethefavoriteones。
Itfollowsfromallthisthat，tolaytheeggs，theBluebottlepicksouteithernakedwoundsorelsethemucousmembranesofthemouthoreyes，whicharenotprotectedbyaskinofanythickness。
Shealsoneedsdarkness。Weshallseethereasonsforherpreferencelateron。
Theperfectefficiencyofthepaperbag，whichpreventstheinroadsofthewormsthroughtheeyesocketsorthebeak，suggestsasimilarexperimentwiththewholebird。Itisamatterofwrappingthebodyinasortofartificialskinwhichwillbeasdiscouragingtotheflyasthenaturalskin。Linnets，somewithdeepwounds，othersalmostintact，areplacedonebyoneinpaperenvelopessimilartothoseinwhichthenurserygardenerkeepshisseeds，envelopesjustfolded，withoutbeingstuck。Thepaperisquiteordinaryandofaveragethickness。Tornpiecesofnewspaperservethepurpose。
Thesesheathswiththecorpsesinsidethemarefreelyexposedtotheair，onthetableinmystudy，wheretheyarevisited，accordingtothetimeofday，indenseshadeandinbrightsunlight。Attractedbytheeffluviafromthedeadmeat，thebluebottleshauntmylaboratory，thewindowsofwhicharealwaysopen。Iseethemdailyalightingontheenvelopesandverybusilyexploringthem，apprisedofthecontentsbythegamysmell。Theirincessantcomingandgoingisasignofintensecupidity;andyetnoneofthemdecidestolayonthebags。Theydonotevenattempttoslidetheirovipositorthroughtheslitsofthefolds。Thefavorableseasonpassesandnotaneggislaidonthetemptingwrappers。Allthemothersabstain，judgingtheslenderobstacleofthepapertobemorethantheverminwillbeabletoovercome。
Thiscautiononthefly’spartdoesnotatallsurpriseme:
motherhoodeverywherehasgleamsofgreatperspicacity。Whatdoesastonishmeisthefollowingresult。Theparcelscontainingthelinnetsareleftforawholeyearuncoveredonthetable;theyremainthereforasecondyearandathird。Iinspectthecontentsfromtimetotime。Thelittlebirdsareintact，withunrumpledfeathers，freefromsmell，dryandlight，likemummies。Theyhavebecomenotdecomposed，butmummified。
Iexpectedtoseethemputrefying，runningintosanies，likecorpseslefttorotintheopenair。Onthecontrary，thebirdshavedriedandhardened，withoutundergoinganychange。Whatdidtheywantfortheirputrefaction？Simplytheinterventionofthefly。Themaggot，therefore，istheprimarycauseofdissolutionafterdeath;itis，aboveall，theputrefactivechemist。
Aconclusionnotdevoidofvaluemaybedrawnfrommypapergamebags。Inourmarkets，especiallyinthoseoftheSouth，thegameishungunprotectedfromthehooksonthestalls。Larksstrungupbythedozenwithawirethroughtheirnostrils，thrushes，plovers，teal，partridges，snipe，inshort，allthegloriesofthespitwhichtheautumnmigrationbringsus，remainfordaysandweeksatthemercyoftheflies。Thebuyerallowshimselftobetemptedbyagoodlyexterior;hemakeshispurchaseand，backathome，justwhenthebirdisbeingpreparedforroasting，hediscoversthatthepromiseddaintyisalivewithworms。Ohorror！Thereisnothingforitbuttothrowtheloathsome，verminousthingaway。
Thebluebottleistheculprithere。Everybodyknowsit;andnobodythinksofseriouslyshakingoffhertyranny:nottheretailer，northewholesaledealer，northekillerofthegame。Whatiswantedtokeepthemaggotsout？Hardlyanything:toslipeachbirdintoapapersheath。Ifthisprecautionweretakenatthestart，beforethefliesarrive，anygamewouldbesafeandcouldbeleftindefinitelytoattainthedegreeofripenessrequiredbytheepicure’spalate。
Stuffedwitholivesandmyrtleberries，theCorsicanblackbirdsareexquisiteeating。WesometimesreceivethematOrange，layersofthem，packedinbasketsthroughwhichtheaircirculatesfreelyandeachcontainedinapaperwrapper。Theyareinastateofperfectpreservation，complyingwiththemostexactingdemandsofthekitchen。Icongratulatethenamelessshipperwhoconceivedthebrightideaofclothinghisblackbirdsinpaper。Willhisexamplefindimitators？Idoubtit。
Thereis，ofcourse，aseriousobjectiontothismethodofpreservation。Initspapershroud，thearticleisinvisible;itisnotenticing;itdoesnotinformthepasserbyofitsnatureandqualities。Thereisoneresourceleftwhichwouldleavethebirduncovered:simplytocasetheheadinapapercap。Theheadbeingthepartmostthreatened，becauseofthemucusmembraneofthethroatandeyes，itwouldbesufficient，asarule，toprotectthehead，inordertokeepofftheFliesandtothwarttheirattempts。
Letuscontinuetostudythebluebottle，whilevaryingourmeansofinformation。Atin，aboutfourinchesdeep，containsapieceofbutcher’smeat。Thelidisnotputinquitestraightandleavesanarrowslitatonepointofitscircumference，allowing，atmost，ofthepassageofafineneedle。Whenthebaitbeginstogiveoffagamyscent，themotherscome。Singlyorinnumbers。Theyareattractedbytheodorwhich，transmittedthroughathincrevice，hardlyreachesmynostrils。
Theyexplorethemetalreceptacleforsometime，seekinganentrance。Findingnaughtthatenablesthemtoreachthecovetedmorsel，theydecidetolaytheireggsonthetin，justbesidetheaperture。Sometimes，whenthewidthofthepassageallowsofit，theyinserttheovipositorintothetinandlaytheeggsinside，ontheveryedgesoftheslit。Whetheroutsideorin，theeggsaredabbeddowninafairlyregularandabsolutelywhitelayer。Iasitwereshovelthemupwithalittlepaperscoop。IthusobtainallthegermsthatIrequireformyexperiments，eggsbearingnotraceofthestainswhichwouldbeinevitableifIhadtocollectthemontaintedmeat。
Wehaveseenthebluebottlerefusingtolayhereggsonthepaperbag，notwithstandingthecarrionfumesoftheLinnetenclosed;yetnow，withouthesitation，shelaysthemonasheetofmetal。Canthenatureofthefloormakeanydifferencetoher？Ireplacethetinlidbyapapercoverstretchedandpastedovertheorifice。
Withthepointofmyknife，Imakeanarrowslitinthisnewlid。
Thatisquiteenough:theparentacceptsthepaper。
Whatdeterminedher，therefore，isnotsimplythesmell，whichcaneasilybeperceivedeventhroughtheuncutpaper，but，aboveall，thecrevice，whichwillprovideanentranceforthevermin，hatchedoutside，nearthenarrowpassage。Themaggots’motherhasherownlogic，herprudentforesight。Sheknowshowfeebleherweegrubswillbe，howpowerlesstocuttheirwaythroughanobstacleofanyresistance;andso，despitethetemptationofthesmell，sherefrainsfromlayingsolongasshefindsnoentrancethroughwhichthenewbornwormscanslipunaided。
Iwantedtoknowwhetherthecolor，theshininess，thedegreeofhardnessandotherqualitiesoftheobstaclewouldinfluencethedecisionofamotherobligedtolayhereggsunderexceptionalconditions。Withthisobjectinview，Iemployedsmalljars，eachbaitedwithabitofbutcher’smeat。Therespectivelidsweremadeofdifferentcoloredpaper，ofoilskin，orofsomeofthattinfoil，withitsgoldorcopperysheen，whichisusedforsealingliqueurbottles。Onnotoneofthesecoversdidthemothersstop，withanydesiretodeposittheireggs;but，fromthemomentthattheknifehadmadethenarrowslit，allthelidswere，soonerorlater，visitedandallofthem，soonerorlater，receivedthewhiteshowersomewherenearthegash。Thelookoftheobstacle，therefore，doesnotcount;dullorbrilliant，draborcolored:thesearedetailsofnoimportance;thethingthatmattersisthatthereshouldbeapassagetoallowthegrubstoenter。
Thoughhatchedoutside，atadistancefromthecovetedmorsel，thenewbornwormsarewellabletofindtheirrefectory。Astheyreleasethemselvesfromtheegg，withouthesitation，soaccurateistheirscent，theyslipbeneaththeedgeoftheill—joinedlid，orthroughthepassagecutbytheknife。Beholdthementeringupontheirpromisedland，theirreekingparadise。
Eagertoarrive，dotheydropfromthetopofthewall？Notthey！
Slowlycreeping，theymaketheirwaydownthesideofthejar;theyusetheirforepart，everinquestofinformation，asacrutchandgrapnelinone。Theyreachthemeatandatonceinstallthemselvesuponit。
Letuscontinueourinvestigation，varyingtheconditions。Alargetest—tube，measuringnineincheshigh，isbaitedatthebottomwithalumpofbutcher’smeat。Itisclosedwithwiregauze，whosemeshes，twomillimeterswide，donotpermitofthefly’spassage。
Thebluebottlecomestomyapparatus，guidedbyscentratherthansight。Shehastenstothetesttubewhosecontentsareveiledunderanopaquecoverwiththesamealacrityastotheopentube。
Theinvisibleattractsherquiteasmuchasthevisible。
Shestaysawhileonthelatticeofthemouth，inspectsitattentively;but，whetherbecausecircumstanceshavefailedtoserveme，orbecausethewirenetworkinspiresherwithdistrust，I
neversawherdabhereggsuponitforcertain。Asherevidencewasdoubtful，Ihadrecoursetothefleshfly（Sarcophagacarnaria）。
Thisflyislessfinickyinherpreparations，shehasmorefaithinthestrengthofherworms，whicharebornready—formedandvigorous，andeasilyshowsmewhatIwishtosee。Sheexploresthetrellis—work，choosesameshthroughwhichsheinsertsthetipofherabdomenand，undisturbedbymypresence，emits，oneaftertheother，acertainnumberofgrubs，abouttenorso。True，hervisitswillberepeated，increasingthefamilyatarateofwhichI
amignorant。
Thenewbornworms，thankstoaslightviscidity，clingforamomenttothewiregauze;theyswarm，wriggle，releasethemselvesandleapintothechasm。Itisanineinchdropatleast。Whenthisisdone，themothermakesoff，knowingforacertaintythatheroffspringwillshiftforthemselves。Iftheyfallonthemeat，wellandgood;iftheyfallelsewhere，theycanreachthemorselbycrawling。
Thisconfidenceintheunknownfactoroftheprecipice，withnoindicationbutthatofsmell，deservesfuller，investigation。Fromwhatheightwillthefleshflydaretoletherchildrendrop？I
topthetest—tubewithanothertube，thewidthoftheneckofaclaretbottle。Themouthisclosedeitherwithwiregauze，orwithapapercoverwithaslightcutinit。Altogether，theapparatusmeasurestwenty—fiveinchesinheight。Nomatter:thefallisnotseriousforthelithebacksoftheyounggrubs;and，inafewdays，thetest—tubeisfilledwithlarvae，inwhichitiseasytorecognizethefleshfly’sfamilybythefringedcoronetthatopensandshutsatthemaggot’ssternlikethepetalsofalittleflower。
Ididnotseethemotheroperating:Iwasnotthereatthetime;
butthereisnodoubtpossibleofhercomingnorofthegreatdivetakenbythefamily:thecontentsofthetest—tubefurnishmewithadulyauthenticatedcertificate。
Iadmiretheleapand，toobtainonebetterstill，Ireplacethetubebyanother，sothattheapparatusnowstandsforty—sixincheshigh。Thecolumniserectedataspotfrequentedbyflies，inadimlight。Itsmouth，closedwithawiregauzecover，reachesthelevelofvariousotherappliances，test—tubesandjars，whicharealreadystockedorawaitingtheircolonyofvermin。Whenthepositioniswellknowntotheflies，Iremovetheothertubesandleavethecolumn，lestthevisitorsshouldturnasidetoeasierground。
Fromtimetotime，thebluebottleandthefleshflyperchonthetrellis—work，makeashortinvestigationandthendecamp。
Throughoutthesummerseason，forthreewholemonths，theapparatusremainswhereitis，withouttheleastresult:neveraworm。Whatisthereason？Doesthestenchofthemeatnotspread，comingfromthatdepth？Certainlyitspreads:itisunmistakabletomydullednostrilsandstillmoresotothenostrilsofmychildren，whomI
calltobearwitness。Thenwhydoesthefleshfly，whobutnowwasdroppinghergrubsfromagoodlyheight，refusetoletthemfallfromthetopofacolumntwiceashigh？Doesshefearlestherwormsshouldbebruisedbyanexcessivedrop？Thereisnothingabouthertopointtoanxietyarousedbythelengthoftheshaft。
Ineverseeherexplorethetubeortakeitssize。Shestandsonthetrellisedorifice;andtherethematterends。Canshebeapprisedofthedepthofthechasmbythecomparativefaintnessoftheoffensiveodorsthatarisefromit？Canthesenseofsmellmeasurethedistanceandjudgewhetheritbeacceptableornot？
Perhaps。
Thefactremainsthat，despitetheattractionofthescent，thefleshflydoesnotexposeherwormstodisproportionatefalls。Cansheknowbeforehandthat，whenthechrysalidesbreak，herwingedfamily，knockingwithasuddenflightagainstthesidesofatallchimney，willbeunabletogetout？Thisforesightwouldbeinagreementwiththeruleswhichordermaternalinstinctaccordingtofutureneeds。
Butwhenthefalldoesnotexceedacertaindepth，thebuddingwormsofthefleshflyaredroppedwithoutaqualm，asallourexperimentsshow。Thisprinciplehasapracticalapplicationwhichisnotwithoutitsvalueinmattersofdomesticeconomy。Itisaswellthatthewondersofentomologyshouldsometimesgiveusahintofcommonplaceutility。
Theusualmeatsafeisasortoflargecagewithatopandbottomofwoodandfourwiregauzesides。Hooksfixedintothetopareusedwherebytohangpieceswhichwewishtoprotectfromtheflies。Often，soastoemploythespacetothebestadvantage，thesepiecesaresimplylaidontheflooronthecage。Withthesearrangements，arewesureofwardingofftheflyandhervermin？
Notatall。WemayprotectourselvesagainsttheBluebottle，whoisnotmuchinclinedtolayhereggsatadistancefromthemeat;
butthereisstillthefleshfly，whoismoreventuresomeandgoesmorebrisklytoworkandwhowillslipthegrubsthroughaholeinthemeshesanddroptheminsidethesafe。Agileastheyareandwellabletocrawl，thewormswilleasilyreachanythingonthefloor;theonlythingssecurefromtheirattackswillbethepieceshangingfromtheceiling。Itisnotinthenatureofmaggotstoexploretheheights，especiallyifthisimpliesclimbingdownastringinaddition。
Peoplealsousewiregauzedishcovers。Thetrelliseddomeprotectsthecontentsevenlessthandoesthemeatsafe。Thefleshflytakesnoheedofit。Shecandropherwormsthroughthemeshesonthecoveredjoint。
Thenwhatarewetodo？Nothingcouldbesimpler。Weneedonlywrapthebirdswhichwewishtopreserve——thrushes，partridges，snipeandsoon——inseparatepaperenvelopes;andthesamewithourbeefandmutton。Thisdefensivearmoralone，whileleavingampleroomfortheairtocirculate，makesanyinvasionbythewormsimpossible，evenwithoutacoverorameatsafe:notthatpaperpossessesanyspecialpreservativevirtues，butsolelybecauseitformsanimpenetrablebarrier。TheBluebottlecarefullyrefrainsfromlayinghereggsuponitandthefleshflyfrombringingforthheroffspring，bothofthemknowingthattheirnewbornyoungareincapableofpiercingtheobstacle。
PaperisequallysuccessfulinourstrifeagainsttheMoths，thoseplaguesofourfursandclothes。Tokeepawaythesewholesaleravages，peoplegenerallyusecamphor，naphthalene，tobacco，bunchesoflavenderandotherstrong—scentedremedies。Withoutwishingtomalignthosepreservatives，weareboundtoadmitthatthemeansemployedarenonetooeffective。Thesmelldoesverylittletopreventthehavocofthemoths。
Iwouldthereforecounselourhousewives，insteadofallthischemist’sstuff，tousenewspapersofasuitableshapeandsize。
Takewhateveryouwishtoprotect——yourfurs，yourflanneloryourclothes——andpackeacharticlecarefullyinanewspaper，joiningtheedgeswithadoublefold，wellpinned。Ifthisjoiningisproperlydone，theMothwillnevergetinside。Sincemyadvicehasbeentakenandthismethodemployedinmyhousehold，theolddamagehasneverbeenrepeated。
Toreturntothefly。Apieceofmeatishiddeninajarunderalayeroffine，drysand，afinger’s—breadththick。Thejarhasawidemouthandisleftquiteopen。Letwhoevercomethatwill，attractedbythesmell。TheBluebottlesarenotlongininspectingwhatIhavepreparedforthem:theyenterthejar，gooutandcomebackagain，inquiringintotheinvisiblethingrevealedbyitsfragrance。Adiligentwatchenablesmetoseethemfussingabout，exploringthesandyexpanse，tappingitwiththeirfeet，soundingitwiththeirproboscis。Ileavethevisitorsundisturbedforafortnightorthreeweeks。Noneofthemlaysanyeggs。
Thisisarepetitionofwhatthepaperbag，withitsdeadbird，showedme。Thefliesrefusetolayonthesand，apparentlyforthesamereasons。Thepaperwasconsideredanobstaclewhichthefrailverminwouldnotbeabletoovercome。Withsand，thecaseisworse。Itsgrittinesswouldhurtthenewbornweaklings，itsdrynesswouldabsorbthemoistureindispensabletotheirmovements。
Later，whenpreparingforthemetamorphosis，whentheirstrengthhascometothem，thegrubswilldigtheearthquitewellandbeabletodescend;but，atthestart，thatwouldbeverydangerousforthem。Knowingthesedifficulties，themothers，howevergreatlytemptedbythesmell，abstainfrombreeding。Asamatteroffact，afterlongwaiting，fearinglestsomepacketsofeggsmayhaveescapedmyattention，Iinspectthecontentsofthejarfromtoptobottom。Meatandsandcontainneitherlarvaenorpupae:thewholeisabsolutelydeserted。
Thelayerofsandbeingonlyafinger’s—breadththick，thisexperimentrequirescertainprecautions。Themeatmayexpandalittle，ingoingbad，andprotrudeinoneortwoplaces。Howeversmallthefleshyeyotsthatshowabovethesurface，thefliescometothemandbreed。Sometimesalsothejuicesoozingfromtheputridmeatsoakasmallextentofthesandyfloor。Thatisenoughforthemaggot’sfirstestablishment。Thesecausesoffailureareavoidedwithalayerofsandaboutaninchthick。Thenthebluebottle，thefleshflyandotherflieswhosegrubsbattenondeadbodiesarekeptataproperdistance。
Inthehopeofawakeningustoapropersenseofourinsignificance，pulpitoratorssometimesmakeanunfairuseofthegraveanditsworms。Letusputnofaithintheirdolefulrhetoric。Thechemistryofman’sfinaldissolutioniseloquentenoughofouremptiness:thereisnoneedtoaddimaginaryhorrors。
Thewormofthesepulchreisaninventionofcantankerousminds，incapableofseeingthingsastheyare。Coveredbybutafewinchesofearth，thedeadcansleeptheirquietsleep:noflywillevercometotakeadvantageofthem。
Atthesurfaceofthesoil，exposedtotheair，thehideousinvasionispossible;ay，itistheinvariablerule。Forthemeltingdownandremoldingofmatter，manisnobetter，corpseforcorpse，thanthelowestofthebrutes。Thentheflyexercisesherrightsanddealswithusasshedoeswithanyordinaryanimalrefuse。Naturetreatsuswithmagnificentindifferenceinhergreatregeneratingfactory:placedinhercrucibles，animalsandmen，beggarsandkingsareoneandallalike。Thereyouhavetrueequality，theonlyequalityinthisworldofours:equalityinthepresenceofthemaggot。
CHAPTERXVTHEBLUEBOTTLE:THEGRUB
Thelarvaeofthebluebottlehatchwithintwodaysinthewarmweather。Whetherinsidemyapparatus，indirectcontactwiththepieceofmeat，oroutside，ontheedgeofaslitthatenablesthemtoenter，theysettoworkatonce。Theydonoteat，inthestrictsenseoftheword，thatistosay，theydonotteartheirfood，donotchewitbymeansofimplementsofmastication。Theirmouthpartsdonotlendthemselvestothissortofwork。Thesemouthpartsaretwohornyspikes，slidingoneupontheother，withcurvedendsthatdonotface，thusexcludingthepossibilityofanyfunctionsuchasseizingandgrinding。
Thetwogutturalgrapnelsserveforwalkingmuchratherthanforfeeding。Thewormplantsthemalternatelyintheroadtraversedand，bycontractingitscrupper，advancesjustthatdistance。Itcarriesinitstubularthroattheequivalentofourirontippedstickswhichgivesupportandassistprogress。
Thankstothismachineryofthemouth，themaggotnotonlymovesoverthesurface，butalsoeasilypenetratesthemeat:Iseeitdisappearasthoughitweredippingintobutter。Itcutsitsway，levying，asitgoes，apreliminarytoll，butonlyofliquidmouthfuls。Notthesmallestsolidparticleisdetachedandswallowed。Thatisnotthemaggot’sdiet。Itwantsabroth，asoup，asortoffluidextractofbeefwhichitpreparesitself。Asdigestion，afterall，merelymeansliquefaction，wemaysay，withoutbeingguiltyofparadox，thatthegrubofthebluebottledigestsitsfoodbeforeswallowingit。
Withtheobjectofrelievinggastrictroubles，ourmanufacturingchemistsscrapethestomachsofthepigandsheepandthusobtainpepsin，adigestiveagentwhichpossessesthepropertyofliquefyingalbuminousmattersandleanmeatinparticular。Whycannottheyraspthestomachofthemaggot！Theywouldobtainaproductofthehighestquality，forthecarnivorouswormalsoownsitspepsin，pepsinofasingularlyactivekind，asthefollowingexperimentswillshowus。
Idividethewhiteofahard—boiledeggintotinycubesandplacetheminalittletest—tube。Onthetopofthecontents，Isprinkletheeggsofthebluebottle，eggsfreefromtheleaststain，takenfromthoselaidontheoutsideoftinsbaitedwithmeatandnotabsolutelyshut。Asimilartest—tubeisfilledwithwhiteofegg，butreceivesnogerms。Bothareclosedwithaplugofcotton—woolandleftinadarkcorner。