pilipes,diglongcorridorsleadingtothecells,whicharescatteredhereandthereandonebyone。Thesepassagesremainopenatallseasonsoftheyear。Whenspringcomes,thenewcolonyusesthemjustastheyare,providedthattheyarewellpreservedintheclayeymassbakedbythesun;itincreasestheirlengthifnecessary,runsoutafewmorebranches,butdoesnotdecidetostartboringinnewgrounduntiltheoldcity,which,withitsmanylabyrinths,resemblessomemonstroussponge,istoomuchunderminedforsafety。Theovalniches,thecellsthatopenonthosecorridors,arealsoprofitablyemployed。
TheAnthophorarestorestheirentrance,whichhasbeendestroyedbytheinsect'srecentemergence;shesmoothstheirwallswithafreshcoatofwhitewash,afterwhichthelodgingisfittoreceivetheheapofhoneyandtheegg。Whentheoldcells,insufficientinnumberandmoreoverpartlyinhabitedbydiverseintruders,arealloccupied,theboringofnewcellsbegins,intheextendedsectionsofthegalleries,andtherestoftheeggsarehoused。Inthisway,theswarmissettledataminimumofexpense。
Toconcludethisbriefaccount,letuschangethezoologicalsettingand,aswehavealreadyspokenoftheSparrow,seewhathecandoasabuilder。Thesimplestformofhisnestisthegreatroundballofstraw,deadleavesandfeathers,intheforkofafewbranches。Itiscostlyinmaterial,butcanbesetupanywhere,whentheholeinthewallortheshelterofatilearelacking。Whatreasonsinducedhimtogiveupthesphericaledifice？Toallseeming,thesamereasonsthatledtheOsmiatoabandontheSnail—shell'sspiral,whichrequiresafatiguingexpenditureofclay,infavouroftheeconomicalcylinderofthereed。Bymakinghishomeinaholeinthewall,theSparrowescapesthegreaterpartofhiswork。Here,thedomethatservesasaprotectionfromtherainandthethickwallsthatofferresistancetothewindbothbecomesuperfluous。Ameremattressissufficient;thecavityinthewallprovidestherest。Thesavingisgreat;andtheSparrowappreciatesitquiteasmuchastheOsmia。
Thisdoesnotmeanthattheprimitivearthasdisappeared,lostthroughneglect;itremainsanineffaceablecharacteristicofthespecies,everreadytodeclareitselfshouldcircumstancesdemandit。
Thegenerationsofto—dayareasmuchendowedwithitasthegenerationsofyore;withoutapprenticeship,withouttheexampleofothers,theyhavewithinthemselves,inthepotentialstate,theindustrialaptitudeoftheirancestors。Ifarousedbythestimulusofnecessity,thisaptitudewillpasssuddenlyfrominactiontoaction。
When,therefore,theSparrowstillfromtimetotimeindulgesinsphericalbuilding,thisisnotprogressonhispart,asissometimescontended;itis,onthecontrary,aretrogression,areturntotheancientcustoms,soprodigaloflabour。HeisbehavingliketheOsmiawho,indefaultofareed,makesshiftwithaSnail—shell,whichismoredifficulttoutilizebuteasiertofind。Thecylinderandtheholeinthewallstandforprogress;thespiraloftheSnail—shellandtheball—shapednestrepresentthestarting—point。
Ihave,Ithink,sufficientlyillustratedtheinferencewhichisborneoutbythewholemassofanalogousfacts。Animalindustrymanifestsatendencytoachievetheessentialwithaminimumofexpenditure;afteritsownfashion,theinsectbearswitnesstotheeconomyofenergy。Ontheonehand,instinctimposesuponitacraftthatisunchangeableinitsfundamentalfeatures;ontheotherhand,itisleftacertainlatitudeinthedetails,soastotakeadvantageoffavourablecircumstancesandattaintheobjectaimedatwiththeleastpossibleexpenditureoftime,materialsandwork,thethreeelementsofmechanicallabour。TheprobleminhighergeometrysolvedbytheHive—beeisonlyaparticularcase——true,amagnificentcase,—
—ofthisgenerallawofeconomywhichseemstogovernthewholeanimalworld。Thewaxcells,withtheirmaximumcapacityasagainstaminimumwall—space,aretheequivalent,withthesuperadditionofamarvellousscientificskill,oftheOsmia'scompartmentsinwhichthestoneworkisreducedtoaminimumthroughtheselectionofareed。
Theartificerinmudandtheartificerinwaxobeythesametendency:
theyeconomize。Dotheyknowwhattheyaredoing？WhowouldventuretosuggestitinthecaseoftheBeegrapplingwithhertranscendentalproblem？Theothers,pursuingtheirrusticart,arenowiser。Withallofthem,thereisnocalculation,nopremeditation,butsimplyblindobediencetothelawofgeneralharmony。
CHAPTER8。THELEAF—CUTTERS。
Itisnotenoughthatanimalindustryshouldbeable,toacertainextent,toadaptitselftocasualexigencieswhenchoosingthesiteofanest;iftheraceistothrive,somethingelseisrequired,somethingwhichhide—boundinstinctisunabletoprovide。TheChaffinch,forinstance,introducesagreatquantityoflichenintotheouterlayerofhisnest。Thisishismethodofstrengtheningtheedificeandmakingastoutframeworkinwhichtoplacefirstthebottommattressofmoss,finestrawandrootletsandthenthesoftbedoffeathers,woolanddown。But,shouldthetime—honouredlichenbelacking,willthebirdrefrainfrombuildingitsnest？Willitforgothedelightofhatchingitsbroodbecauseithasnotthewherewithaltosettleitsfamilyintheorthodoxfashion？
No,thechaffinchisnotperplexedbysosmallamatter;heisanexpertinmaterials,heunderstandsbotanicalequivalents。Intheabsenceofthebranchesoftheevernias,hepicksthelongbeardsoftheusneas,thewartlikerosettesoftheparmelias,themembranesofthestictisestornawayinshreds;ifhecanfindnothingbetter,hemakesshiftwiththebushytuftsofthecladonias。Asapracticallichenologist,whenonespeciesisrareorlackingintheneighbourhood,heisabletofallbackonothers,varyinggreatlyinshape,colourandtexture。And,iftheimpossiblehappenedandlichenfailedentirely,IcredittheChaffinchwithsufficienttalenttobeabletodispensewithitandtobuildthefoundationsofhisnestwithsomecoarsemossorother。
Whattheworkerinlichenstellsustheotherweaversoftextilematerialsconfirm。Eachhashisfavouriteflora,whichhardlyevervarieswhentheplantiseasilyaccessibleandwhichcanbesupplementedbyplentyofotherswhenitisnot。Thebird'sbotanywouldbeworthexamining;itwouldbeinterestingtodrawuptheindustrialherbalofeachspecies。Inthisconnection,Iwillquotejustoneinstance,soasnottostraytoofarfromthesubjectinhand。
TheRed—backedShrike（Laniuscollurio）,thecommonestvarietyinmydistrict,isnoteworthybecauseofhissavagemaniaforforkedgibbets,thethornsinthehedgerowswhereonheimpalesthevoluminouscontentsofhisgame—bag——littlehalf—fledgedbirds,smallLizards,Grasshoppers,caterpillars,Beetles——andleavesthemtogethigh。Tothispassionforthegallows,whichhaspassedunnoticedbythecountry—folk,atleastinmypart,headdsanother,aninnocentbotanicalpassion,whichissomuchinevidencethateverybody,downtotheyoungestbird's—nester,knowsallaboutit。Hisnest,amassivestructure,ismadeofhardlyanyothermaterialsthanagreyishandveryfluffyplant,whichisfoundeverywhereamongthecorn。ThisistheFilagospathulataofthebotanists;andthebirdalsomakesuse,thoughlessfrequently,oftheFilagogermanica,orcommoncotton—rose。BothareknowninProvencalbythenameherbodoutarnagas,orShrike—herb。Thispopulardesignationtellsusplainlyhowfaithfulthebirdistoitsplant。Tohavestrucktheagriculturallabourer,averyindifferentobserver,theShrike'schoiceofmaterialsmustberemarkablypersistent。
Havewehereatastethatisexclusive？Notintheleast。Thoughcotton—rosesofallspeciesareplentifulonlevelground,theybecomescarceandimpossibletofindontheparchedhills。Thebird,onitsside,isnotgiventojourneysofexplorationandtakeswhatitfindstosuititintheneighbourhoodofitstreeorhedge。Butonaridground,theMicropuserectus,oruprightmicropus,aboundsandisasatisfactorysubstitutefortheFilagosofarasitstiny,cottonyleavesanditslittlefluffyballsofflowersareconcerned。
True,itisshortanddoesnotlenditselfwelltoweaver'swork。A
fewlongsprigsofanothercottonyplant,theHelichrysumstaechas,orwildeverlasting,insertedhereandthere,willgivebodytothestructure。ThusdoestheShrikemanagewhenhardupforhisfavouritematerials:keepingtothesamebotanicalfamily,heisabletofindandemploysubstitutesamongthefinecotton—cladstalks。
HeisevenabletoleavethefamilyoftheCompositaeandtogogleaningmoreorlesseverywhere。Hereistheresultofmybotanizingsattheexpenseofhisnests。WemustdistinguishbetweentwogeneraintheShrike'sroughclassification:thecottonyplantsandthesmoothplants。Amongthefirst,mynotesmentionthefollowing:Convolvuluscantabrica,orflax—leavedbindweed;Lotussymmetricus,orbird's—foottrefoil;Teucriumpolium,orpoly;andthefloweryheadsofthePhragmitescommunis,orcommonreed。Amongthesecondarethese:Medicagolupulina,ornonesuch;Trifoliumrepens,orwhiteclover;Lathyruspratensis,ormeadowlathyrus;
Capsellabursapastoris,orshepherd'spurse;Viciaperegrina,orbroad—poddedvetch;Convolvulusarvensis,orsmallbindweed;
Pterothecanemausensis,asortofhawkweed;andPoapratensis,orsmooth—stalkedmeadow—grass。Whenitisdowny,theplantformsalmostthewholenest,asisthecasewiththeflax—leavedbindweed;whensmooth,itformsonlytheframework,destinedtosupportacrumblingmassofmicropus,asisthecasewiththesmallbindweed。Whenmakingthiscollection,whichIamfarfromgivingasthebirds'completeherbarium,Iwasstruckbyawhollyunexpecteddetail:ofthevariousplants,Ifoundonlytheheadsstillinbud;moreover,allthesprigs,thoughdry,possessedthegreencolouringofthegrowingplant,asignofswiftdesiccationinthesun。Saveinafewcases,therefore,theShrikedoesnotcollectthedeadandwitheredremains:
itisfromthegrowingplantsthathereapshisharvest,mowingthemdownwithhisbeakandleavingthesheavestodryinthesunbeforeusingthem。IcaughthimonedayhoppingaboutandpeckingatthetwigsofaBiscayanbindweed。Hewasgettinginhishay,strewingthegroundwithit。
TheevidenceoftheShrike,confirmedbythatofalltheotherworkers——weavers,basket—makersorwoodcutters——whomwemaycaretocallaswitnesses,showsuswhatalargepartmustbeassignedtodiscernmentinthebird'schoiceofmaterialsforitsnest。Istheinsectashighlygifted？Whenitworkswithvegetablematter,isitexclusiveinitstastes？Doesitknowonlyonedefiniteplant,itsspecialprovince？Orhasit,foremploymentinitsmanufactures,avariedflora,inwhichitsdiscernmentexercisesafreechoice？Foranswerstothesequestionswemaylook,aboveall,totheLeaf—
cuttingBees,theMegachiles。Reaumurhastoldthestoryoftheirindustryindetail;andIreferthereaderwhowishesforfurtherparticularstothemaster'sMemoirs。
Themanwhoknowshowtousehiseyesinhisgardenwillobserve,somedayorother,anumberofcuriousholesintheleavesofhislilac—androse—trees,someofthemround,someoval,asifidlebutskilfulhandshadbeenatworkwiththepinking—iron。Insomeplaces,thereisscarcelyanythingbuttheveinsoftheleavesleft。Theauthorofthemischiefisagrey—cladBee,aMegachile。Forscissors,shehashermandibles;forcompasses,producingnowanovalandanonacircle,shehashereyeandthepivotofherbody。Thepiecescutoutaremadeintothimble—shapedwallets,destinedtocontainthehoneyandtheegg:thelarger,ovalpiecessupplythefloorandsides;thesmaller,roundpiecesarereservedforthelid。Arowofthesethimbles,placedoneontopoftheother,uptoadozenormore,thoughoftenthereareless:thatis,roughly,thestructureoftheLeaf—cutter'snest。
Whentakenoutoftherecessinwhichthemotherhasmanufacturedit,thecylinderofcellsseemstobeanindivisiblewhole,asortoftunnelobtainedbyliningwithleavessomegallerydugunderground。
Therealthingdoesnotcorrespondwithitsappearance:undertheleastpressureofthefingers,thecylinderbreaksupintoequalsections,whicharesomanycompartmentsindependentoftheirneighboursasregardsbothfloorandlid。Thisspontaneousbreakupshowsushowtheworkisdone。ThemethodagreeswiththoseadoptedbytheotherBees。Insteadofageneralscabbardofleaves,afterwardssubdividedintocompartmentsbytransversepartitions,theMegachileconstructsastringofseparatewallets,eachofwhichisfinishedbeforethenextisbegun。
Astructureofthissortneedsasheathtokeepthepiecesinplacewhilegivingthemthepropershape。Thebagofleaves,infact,asturnedoutbytheworker,lacksstability;itsnumerouspieces,notgluedtogether,butsimplyplacedoneaftertheother,comeapartandgivewayassoonastheylosethesupportofthetunnelthatkeepsthemunited。Later,whenitspinsitscocoon,thelarvainfusesalittleofitsfluidsilkintothegapsandsoldersthepiecestooneanother,especiallytheinnerones,somuchsothattheinsecurebaginduecoursebecomesasolidcasketwhosecomponentpartsitisnolongerpossibletoseparateentirely。
Theprotectivesheath,whichisalsoaframework,isnottheworkofthemother。LikethegreatmajorityoftheOsmiae,theMegachilesdonotunderstandtheartofmakingthemselvesahomestraightaway:
theywantaborrowedlodging,whichmayvaryconsiderablyincharacter。ThedesertedgalleriesoftheAnthophorae,theburrowsofthefatEarth—worms,thetunnelsboredinthetrunksoftreesbythelarvaoftheCerambyx—beetle（TheCapricorn,theessayonwhichhasnotyetbeenpublishedinEnglish。——Translator'sNote。）,theruineddwellingsoftheMason—beeofthePebbles,theSnail—shellnestsoftheThree—hornedOsmia,reed—stumps,whenthesearehandy,andcrevicesinthewallsareallsomanyhomesfortheLeaf—cutters,whochoosethisorthatestablishmentaccordingtothetastesoftheirparticulargenus。
Forthesakeofclearness,letusceasegeneralizinganddirectourattentiontoadefinitespecies。IfirstselectedtheWhite—girdledLeaf—cutter（Megachilealbocincta,PEREZ）,notonaccountofanyexceptionalpeculiarities,butsolelybecausethisistheBeemostoftenmentionedinmynotes。HercustomarydwellingisthetunnelofanEarth—wormopeningonsomeclaybank。Whetherperpendicularorslanting,thistunnelrunsdowntoanindefinitedepth,wheretheclimatewouldbetoodampfortheBee。Besides,whenthetimecomesforthehatchingoftheadultinsect,itsemergencewouldbefraughtwithperilifithadtoclimbupfromadeeppitthroughcrumblingrubbish。TheLeaf—cutter,therefore,usesonlythefrontportionoftheWorm'sgallery,twodecimetresatmost。（7。8inches。——
Translator'sNote。）Whatistobedonewiththerestofthetunnel？
Itisanascendingshaft,temptingtoanenemy;andsomeundergroundravagermightcomethiswayanddestroythenestbyattackingtherowofcellsattheback。
Thedangerisforeseen。Beforefashioningherfirsthoney—bag,theBeeblocksthepassagewithastrongbarricadecomposedoftheonlymaterialsusedintheLeaf—cutter'sguild。Fragmentsofleavesarepiledupinnoparticularorder,butinsufficientquantitiestomakeaseriousobstacle。Itisnotunusualtofindintheleafyrampartsomedozensofpiecesrolledintoscrewsandfittingintooneanotherlikeastackofcylindricalwafers。Forthisworkoffortification,artisticrefinementseemssuperfluous;atanyrate,thepiecesofleavesareforthemostpartirregular。Youcanseethattheinsecthascutthemouthurriedly,unmethodicallyandonadifferentpatternfromthatofthepiecesintendedforthecells。
Iamstruckwithanotherdetailinthebarricade。Itsconstituentsaretakenfromstout,thick,strong—veinedleaves。Irecognizeyoungvine—leaves,pale—colouredandvelvety;theleavesofthewhitishrock—rose（Cistusalbidus）,linedwithahairyfelt;thoseoftheholm—oak,selectedamongtheyoungandbristlyones;thoseofthehawthorn,smoothbuttough;thoseofthecultivatedreed,theonlyoneoftheMonocotyledonesexploited,asfarasIknow,bytheMegachiles。Intheconstructionofcells,ontheotherhand,Iseesmoothleavespredominating,notablythoseofthewildbriarandofthecommonacacia,therobinia。Itwouldappear,therefore,thattheinsectdistinguishesbetweentwokindsofmaterials,withoutbeinganabsolutepuristandsternlyexcludinganysortofblending。Theverymuchindentedleaves,whoseprojectionscanbecompletelyremovedwithadexteroussnipofthescissors,generallyfurnishthevariouslayersofthebarricade;thelittlerobinia—leaves,withtheirfinetextureandtheirunbrokenedges,arebettersuitedtothemoredelicateworkofthecells。
ArampartatthebackoftheEarth—worm'sshaftisawiseprecautionandtheLeaf—cutterdeservesallcreditforit;onlyitisapityfortheMegachiles'reputationthatthisprotectivebarrieroftenprotectsnothingatall。Herewesee,underanewguise,thataberrationofinstinctofwhichIgavesomeexamplesinanearlierchapter。Mynotescontainmemorandaofvariousgalleriescrammedwithpiecesofleavesrightuptotheorifice,whichisonalevelwiththeground,andentirelydevoidofcells,evenofanunfinishedone。
Thesewereridiculousfortifications,ofnousewhatever;andyettheBeetreatedthematterwiththeutmostseriousnessandtookinfinitepainsoverherfutiletask。Oneoftheseuselesslybarricadedgalleriesfurnishedmewithsomehundredpiecesofleavesarrangedlikeastackofwafers;anothergavemeasmanyasahundredandfifty。Forthedefenceofatenantednest,twodozenandevenfewerareample。ThenwhatwastheobjectoftheLeaf—cutter'sridiculouspile？
IwishIcouldbelievethat,seeingthattheplacewasdangerous,shemadeherheapbiggersothattherampartmightbeinproportiontothedanger。Then,perhaps,atthemomentofstartingonthecells,shedisappeared,thevictimofanaccident,blownoutofhercoursebyagustofwind。ButthislineofdefenceisnotadmissibleintheMegachile'scase。Theproofispalpable:thegalleriesaforesaidarebarricadeduptotheleveloftheground;thereisnoroom,absolutelynone,tolodgeevenasingleegg。Whatwasherobject,I
askagain,whenshepersistedinobstinatelypilingupherwafers？
Hasshereallyanobject？
Idonothesitatetosayno。AndmyanswerisbaseduponwhattheOsmiaetaughtme。IhavedescribedabovehowtheThree—hornedOsmia,towardstheendofherlife,whenherovariesaredepleted,expendsonuselessoperationssuchenergyasremainstoher。Bornaworker,sheisboredbytheinactivityofretirement;herleisurerequiresanoccupation。Havingnothingbettertodo,shesetsuppartitions;shedividesatunnelintocellsthatwillremainempty;shecloseswithathickplugreedscontainingnothing。Thusisthemodicumofstrengthofherdeclineexhaustedinvainlabours。TheotherBuilder—beesbehavelikewise。IseeAnthidialaboriouslyprovidenumerousbalesofcottontostopgallerieswhereinneveraneggwaslaid;IseeMason—beesbuildandthenreligiouslyclosecellsthatwillremainunvictualledanduncolonized。
ThelonganduselessbarricadesthenbelongtothelasthoursoftheMegachile'slife,whentheeggsarealllaid;themother,whoseovariesareexhausted,persistsinbuilding。Herinstinctistocutoutandheapuppiecesofleaves;obeyingthisimpulse,shecutsoutandheapsupevenwhenthesupremereasonforthislabourceases。Theeggsarenolongerthere,butsomestrengthremains;andthatstrengthisexpendedasthesafetyofthespeciesdemandedinthebeginning。Thewheelsofactiongoonturningintheabsenceofthemotivesforaction;theycontinuetheirmovementasthoughbyasortofacquiredvelocity。Whatclearerproofcanwehopetofindoftheunconsciousnessoftheanimalstimulatedbyinstinct？
LetusreturntotheLeaf—cutter'sworkundernormalconditions。
Immediatelyafteraprotectivebarriercomestherowofcells,whichvaryconsiderablyinnumber,likethoseoftheOsmiainherreed。
Stringsofaboutadozenarerare;themostfrequentconsistoffiveorsix。Nolesssubjecttovariationisthenumberofpiecesjoinedtomakeacell:piecesoftwokinds,some,theovalones,formingthehoney—pot;others,theroundones,servingasalid。Icount,onanaverage,eighttotenpiecesofthefirstkind。Thoughallcutonthepatternofanellipse,theyarenotequalindimensionsandcomeundertwocategories。Thelarger,outsideonesareeachofthemalmostathirdofthecircumferenceandoverlaponeanotherslightly。
Theirlowerendbendsintoaconcavecurvetoformthebottomofthebag。Thoseinside,whichareconsiderablysmaller,increasethethicknessofthesidesandfillupthegapsleftbythefirst。
TheLeaf—cutterthereforeisabletouseherscissorsaccordingtothetaskbeforeher:first,thelargepieces,whichhelptheworkforward,butleaveemptyspaces;next,thesmallpieces,whichfitintothedefectiveportions。Thebottomofthecellparticularlycomesinforafter—touches。Asthenaturalcurveofthelargerpiecesisnotenoughtoprovideacupwithoutcracksinit,theBeedoesnotfailtoimprovetheworkwithtwoorthreesmallovalpiecesappliedtotheimperfectjoins。
Anotheradvantageresultsfromthesnippetsofunequalsize。Thethreeorfourouterpieces,whicharethefirstplacedinposition,beingthelongestofall,projectbeyondthemouth,whereasthenext,beingshorter,donotcomequiteuptoit。Abrimisthusobtained,aledgeonwhichtherounddisksofthelidrestandarepreventedfromtouchingthehoneywhentheBeepressesthemintoaconcavecover。Inotherwords,atthemouththecircumferencecomprisesonlyonerowofleaves;lowerdownittakestwoorthree,thusrestrictingthediameterandsecuringanhermeticclosing。
Thecoverofthepotconsistssolelyofroundpieces,verynearlyalikeandmoreorlessnumerous。SometimesIfindonlytwo,sometimesIcountasmanyasten,closelystacked。Attimes,thediameterofthesepiecesisofanalmostmathematicalprecision,somuchsothattheedgesofthediskrestupontheledge。Nobetterresultwouldbeobtainedhadtheybeencutoutwiththeaidofcompasses。Attimes,again,thepieceprojectsslightlybeyondthemouth,sothat,toenter,ithastobepresseddownandcurvedcupwise。Thereisnovariationinthediameterofthefirstpiecesplacedinposition,thosenearesttothehoney。Theyareallofthesamesizeandthusformaflatcoverwhichdoesnotencroachonthecellandwillnotafterwardsinterferewiththelarva,asaconvexceilingwould。Thesubsequentdisks,whenthepileisnumerous,arealittlelarger;
theyonlyfitthemouthbyyieldingtopressureandbecomingconcave。
TheBeeseemstomakeapointofthisconcavity,foritservesasamouldtoreceivethecurvedbottomofthenextcell。
Whentherowofcellsisfinished,thetaskstillremainsofblockinguptheentrancetothegallerywithasafety—stoppersimilartotheearthenplugwithwhichtheOsmiaclosesherreeds。TheBeethenreturnstothefreeandeasyuseofthescissorswhichwenoticedatthebeginningwhenshewasfencingoffthebackpartoftheEarth—
worm'stoodeepburrow;shecutsoutofthefoliageirregularpiecesofdifferentshapesandsizesandoftenretainingtheiroriginaldeeply—indentedmargins;andwithallthesepieces,veryfewofwhichfitatallcloselytheorificetobeblocked,shesucceedsinmakinganinviolabledoor,thankstothehugenumberoflayers。
LetusleavetheLeaf—cuttertofinishdepositinghereggsinothergalleries,whichwillbecolonizedinthesamemanner,andconsiderforamomentherskillasacutter。Heredificesconsistofamultitudeoffragmentsbelongingtothreecategories:ovalpiecesforthesidesofthecells;roundpiecesforthelids;andirregularpiecesforthebarricadesatthefrontandback。Thelastpresentnodifficulty:theBeeobtainsthembyremovingfromtheleafsomeprojectingportion,asitstands,aserratelobewhich,owingtoitsnotches,shortenstheinsect'staskandlendsitselfbettertoscissor—work。Sofar,thereisnothingtodeserveattention:itisunskilledlabour,inwhichaninexperiencedapprenticemightexcel。
Withtheovalpieces,itbecomesanothermatter。WhatmodelhastheMegachilewhencuttingherneatellipsesoutofthedelicatematerialforherwallets,therobinia—leaves？Whatmentalpatternguidesherscissors？Whatsystemofmeasurementtellsherthedimensions？Onewouldliketopicturetheinsectasalivingpairofcompasses,capableoftracinganellipticcurvebyacertainnaturalinflexionofitsbody,evenasourarmtracesacirclebyswingingfromtheshoulder。Ablindmechanism,themereoutcomeofitsorganization,wouldaloneberesponsibleforitsgeometry。Thisexplanationwouldtemptmeifthelargeovalpieceswerenotaccompaniedbymuchsmallerones,alsooval,whichareusedtofilltheemptyspaces。A
pairofcompasseswhichchangesitsradiusofitsownaccordandaltersthecurveaccordingtotheplanbeforeitappearstomeaninstrumentsomewhatdifficulttobelievein。Theremustbesomethingbetterthanthat。Thecircularpiecesofthelidsuggestittous。
If,bythemereflexioninherentinherstructure,theLeaf—cuttersucceedsincuttingoutovals,howdoesshesucceedincuttingoutrounds？Canweadmitthepresenceofotherwheelsinthemachineryforthenewpattern,sodifferentinshapeandsize？Besides,therealpointofthedifficultydoesnotliethere。Theserounds,forthemostpart,fitthemouthofthejarwithalmostexactprecision。
Whenthecellisfinished,theBeeflieshundredsofyardsawaytomakethelid。Shearrivesattheleaffromwhichthediskistobecut。Whatpicture,whatrecollectionhassheofthepottobecovered？Why,noneatall:shehasneverseenit;shedoesherworkunderground,inutterdarkness！Attheutmost,shecanhavetheindicationsoftouch:notactualindications,ofcourse,forthepotisnotthere,butpastindications,uselessinaworkofprecision。
Andyetthedisktobecutoutmusthaveafixeddiameter:ifitweretoolarge,itwouldnotgoin;iftoosmall,itwouldclosebadly,itwouldslipdownonthehoneyandsuffocatetheegg。Howshallitbegivenitscorrectdimensionswithoutapattern？TheBeedoesnothesitateforamoment。Shecutsoutherdiskwiththesameceleritywhichshewoulddisplayindetachinganyshapelesslobethatmightdoforastopper;andthatdisk,withoutfurthermeasurement,isoftherightsizetofitthepot。Letwhosowillexplainthisgeometry,whichinmyopinionisinexplicable,evenwhenweallowformemorybegottenoftouchandsight。
Onewinterevening,asweweresittingroundthefire,whosecheerfulblazeunloosedourtongues,IputtheproblemoftheLeaf—cuttertomyfamily:
'Amongyourkitchen—utensils,'Isaid,'youhaveapotindailyuse;
butithaslostitslid,whichwasknockedoverandbrokenbytheTomcatplayingamongtheshelves。To—morrowismarket—dayandoneofyouwillbegoingtoOrangetobuytheweek'sprovisions。Wouldsheundertake,withoutameasureofanykind,withthesoleaidofmemory,whichwewouldallowhertorefreshbeforestartingbyacarefulexaminationoftheobject,tobringbackexactlywhatthepotwants,alidneithertoolargenortoosmall,inshortthesamesizeasthetop？'
Itwasadmittedwithoneaccordthatnobodywouldacceptsuchacommissionwithouttakingameasurewithher,oratleastabitofstringgivingthewidth。Ourmemoryforsizesisnotaccurateenough。
Shewouldcomebackfromthetownwithsomethingthat'mightdo';anditwouldbethemerestchanceifthisturnedouttobetherightsize。
Well,theLeaf—cutterisevenlesswell—offthanourselves。Shehasnomentalpictureofherpot,becauseshehasneverseenit;sheisnotabletopickandchooseinthecrockery—dealer'sheap,whichactsassomethingofaguidetoourmemorybycomparison;shemust,withouthesitation,farawayfromherhome,cutoutadiskthatfitsthetopofherjar。Whatisimpossibletousischild's—playtoher。
Wherewecouldnotdowithoutameasureofsomekind,abitofstring,apatternorascrapofpaperwithfiguresuponit,thelittleBeeneedsnothingatall。Inhousekeepingmatterssheisclevererthanweare。
Oneobjectionwasraised。WasitnotpossiblethattheBee,whenatworkontheshrub,shouldfirstcutaroundpieceofanapproximatediameter,largerthanthatoftheneckofthejar,andthatafterwards,onreturninghome,sheshouldgnawawaythesuperfluouspartuntilthelidexactlyfittedthepot？Thesealterationsmadewiththemodelinfrontofherwouldexplaineverything。