Inanycase,theattemptwasnotimitated;Ineversawanotherinstallationofthekind。Thereisonedefiniteconclusiontobedrawnfrommytwodiscoveries。Despitetheoddityoftheirstructure,whichisunparalleledamongthelocalflora,thetwoAmericanimportationsdidnotcompeltheinsecttogothroughanapprenticeshipofgropingandhesitation。Theonewhichfounditselfinthepresenceofthosenovelgrowths,andwhichwasperhapsthefirstofitsracetodoso,tookpossessionoftheirlobesandstalksjustasitwouldhavedoneofafamiliarsite。Fromthestart,thefleshyplantsfromtheNewWorldsuiteditaswellasthetrunkofanativetree。
　　TheMason—beeofthePebbles（Chalicodomaparietina）hasnoneofthiselasticityinthechoiceofasite。Inhercase,thesmoothstoneoftheparcheduplandsisthealmostinvariablefoundationofherstructures。Elsewhere,underalessclementsky,sheprefersthesupportofawall,whichprotectsthenestagainsttheprolongedsnows。Lastly,theMason—beeoftheShrubs（Chalicodomarufescens,PEREZ）fixesherballofclaytoatwigofanyligneousplant,fromthethyme,therock—roseandtheheathtotheoak,theelmandthepine。Thelistofthesitesthatsuitherwouldalmostformacompletecatalogueoftheligneousflora。
　　Thevarietyofplaceswhereintheinsectinstalsitself,soeloquentofthepartplayedbydiscernmentintheirselection,becomesstillmoreremarkablewhenitisaccompaniedbyacorrespondingvarietyinthearchitectureofthecells。ThisismoreparticularlythecasewiththeThree—hornedOsmia,who,assheusesclayeymaterialsveryeasilyaffectedbytherain,requires,likethePelopaeus,adryshelterforhercells,ashelterwhichshefindsready—madeandusesjustasitis,afterafewtouchesbywayofsweepingandcleansing。
　　ThehomeswhichIseeheradoptareespeciallytheshellsofSnailsthathavediedunderthestone—heapsandinthelow,unmortaredwallswhichsupportthecultivatedearthofthehillsinshelvesorterraces。TheuseofSnail—shellsisaccompaniedbythenolessactiveuseoftheoldcellsofboththeMason—beeoftheShedsandofcertainAnthophorae（A。pilipes,A。parietinaandA。personata）。
　　Wemustnotforgetthereed,whichishighlyappreciatedwhen——ararefind——itappearsundertherequisiteconditions。Initsnaturalstate,theplantwiththemightyhollowcylindersisofnopossibleusetotheOsmia,whoknowsnothingoftheartofperforatingawoodywall。Thegalleryofaninternodehastobewideopenbeforetheinsectcantakepossessionofit。Also,theclean—cutstumpmustbehorizontal,otherwisetherainwouldsoftenthefragileedificeofclayandsoonlayitlow;also,thestumpmustnotbelyingonthegroundandmustbekeptatsomedistancefromthedampnessofthesoil。Weseethereforethat,withouttheinterventionofman,involuntaryinthevastmajorityofcasesanddeliberateonlyontheexperimenter'spart,theOsmiawouldhardlyeverfindareed—stumpsuitedtotheinstallationofherfamily。Itistoheracasualacquisition,ahomeunknowntoherracebeforementookitintotheirheadstocutreedsandmakethemintohurdlesfordryingfigsinthesun。
　　Howdidtheworkofman'spruning—knifebringabouttheabandonmentofthenaturallodging？HowwasthespiralstaircaseoftheSnail—
　　shellreplacedbythecylindricalgalleryofthereed？Wasthechangefromonekindofhousetoanothereffectedbygradualtransitions,byattemptsmade,abandoned,resumed,becomingmoreandmoredefiniteintheirresultsasgenerationsucceededgeneration？OrdidtheOsmia,findingthecutreedthatansweredherrequirements,instalherselftherestraightway,scorningherancientdwelling,theSnail—shell？
　　Thesequestionscalledforareply;andtheyhavereceivedone。Letusdescribehowthingshappened。
　　NearSerignanaresomegreatquarriesofcoarselimestone,characteristicofthemioceneformationoftheRhonevalley。Thesehavebeenworkedformanygenerations。TheancientpublicbuildingsofOrange,notablythecolossalfrontageofthetheatrewhitheralltheintellectualworldonceflockedtohearSophocles'"OedipusTyrannus,"derivemostoftheirmaterialfromthesequarries。Otherevidenceconfirmswhatthesimilarityofthehewnstonetellsus。
　　Amongtherubbishthatfillsupthespacesbetweenthetiersofseats,theyoccasionallydiscovertheMarseillesobol,abitofsilverstampedwiththefour—spokedwheel,orafewbronzecoinsbearingtheeffigyofAugustusorTiberius。Scatteredalsohereandthereamongthemonumentsofantiquityareheapsofrefuse,accumulationsofbrokenstonesinwhichvariousHymenoptera,includingtheThree—hornedOsmiainparticular,takepossessionofthedeadSnail—shell。
　　Thequarriesformpartofanextensiveplateauwhichissoaridastobenearlydeserted。Intheseconditions,theOsmia,atalltimesfaithfultoherbirth—place,haslittleornoneedtoemigratefromherheapofstonesandleavetheshellforanotherdwellingwhichshewouldhavetogoandseekatadistance。Sincethereareheapsofstonethere,sheprobablyhasnootherdwellingthantheSnail—shell。
　　Nothingtellsusthatthepresent—daygenerationsarenotdescendedinthedirectlinefromthegenerationscontemporarywiththequarrymanwholosthisasorhisobolatthisspot。Allthecircumstancesseemtopointtoit:theOsmiaofthequarriesisaninveterateuserofSnail—shells;sofarasheredityisconcerned,sheknowsnothingwhateverofreeds。Well,wemustplaceherinthepresenceofthesenewlodgings。
　　Icollectduringthewinterabouttwodozenwell—stockedSnail—shellsandinstaltheminaquietcornerofmystudy,asIdidatthetimeofmyenquiriesintothedistributionofthesexes。Thelittlehivewithitsfrontpiercedwithfortyholeshasbitsofreedfittedtoit。AtthefootofthefiverowsofcylindersIplacetheinhabitedshellsandwiththeseImixafewsmallstones,thebettertoimitatethenaturalconditions。IaddanassortmentofemptySnail—shells,aftercarefullycleaningtheinteriorsoastomaketheOsmia'sstaymorepleasant。Whenthetimecomesfornest—building,thestay—at—
　　homeinsectwillhave,closebesidethehouseofitsbirth,achoiceoftwohabitations:thecylinder,anoveltyunknowntoitsrace;andthespiralstaircase,theancientancestralhome。
　　ThenestswerefinishedattheendofMayandtheOsmiaebegantoanswermylistofquestions。Some,thegreatmajority,settledexclusivelyinthereeds;theothersremainedfaithfultotheSnail—
　　shellorelseentrustedtheireggspartlytothespiralsandpartlytothecylinders。Withthefirst,whowerethepioneersofcylindricalarchitecture,therewasnohesitationthatIcouldperceive:afterexploringthestumpofreedforatimeandrecognizingitasserviceable,theinsectinstalsitselfthereand,anexpertfromthefirsttouch,withoutapprenticeship,withoutgroping,withoutanytendenciesbequeathedbythelongpracticeofitspredecessors,buildsitsstraightrowofcellsonaverydifferentplanfromthatdemandedbythespiralcavityoftheshellwhichincreasesinsizeasitgoeson。
　　Theslowschooloftheages,thegradualacquisitionsofthepast,thelegaciesofhereditycountfornothingthereforeintheOsmia'seducation。Withoutanynovitiateonitsownpartorthatofitsforebears,theinsectisversedstraightawayinthecallingwhichithastopursue;itpossesses,inseparablefromitsnature,thequalitiesdemandedbyitscraft:somewhichareinvariableandbelongtothedomainofinstinct;others,flexible,belongingtotheprovinceofdiscernment。Todivideafreelodgingintochambersbymeansofmudpartitions;tofillthosechamberswithaheapofpollen—flour,withafewsupsofhoneyinthecentralpartwheretheeggistolie;inshort,toprepareboardandlodgingfortheunknown,forafamilywhichthemothershaveneverseeninthepastandwillneverseeinthefuture:this,initsessentialfeatures,isthefunctionoftheOsmia'sinstinct。Here,everythingisharmoniously,inflexibly,permanentlypreordained;theinsecthasbuttofollowitsblindimpulsetoattainthegoal。Butthefreelodgingofferedbychancevariesexceedinglyinhygienicconditions,inshapeandincapacity。Instinct,whichdoesnotchoose,whichdoesnotcontrive,would,ifitwerealone,leavetheinsect'sexistenceinperil。Tohelpheroutofherpredicament,inthesecomplexcircumstances,theOsmiapossessesherlittlestockofdiscernment,whichdistinguishesbetweenthedryandthewet,thesolidandthefragile,theshelteredandtheexposed;whichrecognizestheworthortheworthlessnessofasiteandknowshowtosprinkleitwithcellsaccordingtothesizeandshapeofthespaceatdisposal。Here,slightindustrialvariationsarenecessaryandinevitable;andtheinsectexcelsinthemwithoutanyapprenticeship,astheexperimentwiththenativeOsmiaofthequarrieshasjustproved。
　　Animalresourceshaveacertainelasticity,withinnarrowlimits。
　　Whatwelearnfromtheanimals'industryatagivenmomentisnotalwaysthefullmeasureoftheirskill。Theypossesslatentpowersheldinreserveforcertainemergencies。Longgenerationscansucceedoneanotherwithoutemployingthem;but,shouldsomecircumstancerequireit,suddenlythosepowersburstforth,freeofanypreviousattempts,evenasthesparkpotentiallycontainedintheflintflashesforthindependentlyofallprecedinggleams。CouldonewhoknewnothingoftheSparrowbuthernestundertheeavessuspecttheball—shapednestatthetopofatree？WouldonewhoknewnothingoftheOsmiasaveherhomeintheSnail—shellexpecttoseeheracceptasherdwellingastumpofreed,apaperfunnel,aglasstube？MyneighbourtheSparrow,impulsivelytakingitintoherheadtoleavetherooffortheplane—tree,theOsmiaofthequarries,rejectinghernatalcabin,thespiraloftheshell,formycylinder,alikeshowushowsuddenandspontaneousaretheindustrialvariationsofanimals。
　　CHAPTER7。ECONOMYOFENERGY。
　　Whatstimulusdoestheinsectobeywhenitemploysthereservepowersthatslumberinitsrace？Ofwhatuseareitsindustrialvariations？
　　TheOsmiawillyieldushersecretwithnogreatdifficulty。Letusexamineherworkinacylindricalhabitation。Ihavedescribedinfulldetail,intheforegoingpages,thestructureofhernestswhenthedwellingadoptedisareed—stumporanyothercylinder;andI
　　willcontentmyselfherewithrecapitulatingtheessentialfeaturesofthatnest—building。
　　Wemustfirstdistinguishthreeclassesofreedsaccordingtotheirdiameter:thesmall,themedium—sizedandthelarge。IcallsmallthosewhosenarrowwidthjustallowstheOsmiatogoaboutherhouseholddutieswithoutdiscomfort。Shemustbeabletoturnwhereshestandsinordertobrushherabdomenandruboffitsloadofpollen,afterdisgorgingthehoneyinthecentreoftheheapofflouralreadycollected。Ifthewidthofthetubedoesnotadmitofthisoperation,iftheinsectisobligedtogooutandthencomeinagainbackwardsinordertoplaceitselfinafavourablepostureforthedischargeofthepollen,thenthereedistoonarrowandtheOsmiaisratherreluctanttoacceptit。Themiddle—sizedreedsandafortiorithelargeonesleavethevictuallerentirelibertyofaction;buttheformerdonotexceedthewidthofacell,awidthagreeingwiththebulkofthefuturecocoon,whereasthelatter,withtheirexcessivediameter,requiremorethanonechamberonthesamefloor。
　　Whenfreetochoose,theOsmiasettlesbypreferenceinthesmallreeds。Here,theworkofbuildingisreducedtoitssimplestexpressionandconsistsindividingthetubebymeansofearthenpartitionsintoastraightrowofcells。Againstthepartitionformingthebackwalloftheprecedingcellthemotherplacesfirstaheapofhoneyandpollen;next,whentheportionisseentobeenough,shelaysanegginthecentreofit。Thenandthenonlysheresumesherplasterer'sworkandmarksoutthelengthofthenewcellwithamudpartition。Thispartitioninitsturnservesastherear—
　　wallofanotherchamber,whichisfirstvictualledandthenclosed;
　　andsoonuntilthecylinderissufficientlycolonizedandreceivesathickterminalstopperatitsorifice。Inaword,thechiefcharacteristicofthismethodofnest—building,theroughestofall,isthatthepartitioninfrontisnotundertakensolongasthevictuallingisstillincomplete,or,inotherwords,thattheprovisionsandtheeggaredepositedbeforetheBeesetstoworkonthepartition。
　　Atfirstsight,thislatterdetailhardlydeservesattention:isitnotrighttofillthepotbeforeweputalidon？TheOsmiawhoownsamedium—sizedreedisnotatallofthisopinion;andotherplasterersshareherviews,asweshallseewhenwewatchtheOdynerusbuildinghernest。（AgenusofMason—wasps,theessaysonwhichhavenotyetbeentranslatedintoEnglish。——Translator'sNote。）
　　Herewehaveanexcellentillustrationofoneofthoselatentpowersheldinreserveforexceptionaloccasionsandsuddenlybroughtintoplay,althoughoftenveryfarremovedfromtheinsect'sregularmethods。Ifthereed,withoutbeingofinordinatewidthfromthepointofviewofthecocoon,isneverthelesstoospacioustoaffordtheBeeasuitablepurchaseagainstthewallatthemomentwhensheisdisgorginghoneyandbrushingoffherloadofpollen;theOsmiaaltogetherchangestheorderofherwork;shesetsupthepartitionfirstandthendoesthevictualling。
　　Allroundtheinsideofthetubesheplacesaringofmud,which,astheresultofherconstantvisitstothemortar,endsbybecomingacompletediaphragmminusanorificeattheside,asortofrounddog—
　　hole,justlargeenoughfortheinsecttopassthrough。Whenthecellisthusmarkedoutandalmostwhollyclosed,theOsmiaattendstothestoringofherprovisionsandthelayingofhereggs。Steadyingherselfagainstthemarginoftheholeatonetimewithherfore—legsandatanotherwithherhind—legs,sheisabletoemptyhercropandtobrushherabdomen;bypressingagainstit,sheobtainsafootholdforherlittleeffortsinthesevariousoperations。Whenthetubewasnarrow,theouterwallsuppliedthisfootholdandtheearthenpartitionwaspostponeduntiltheheapofprovisionswascompletedandsurmountedbytheegg;butinthepresentcasethepassageistoowideandwouldleavetheinsectflounderinghelplesslyinspace,sothepartitionwithitsserving—hatchtakesprecedenceofthevictuals。Thismethodisalittlemoreexpensivethantheother,firstinmaterials,becauseofthediameterofthereed,andsecondlyintime,ifonlybecauseofthedog—hole,adelicatepieceofmortar—
　　workwhichistoosoftatfirstandcannotbeuseduntilithasdriedandbecomeharder。ThereforetheOsmia,whoissparingofhertimeandstrength,acceptsmedium—sizedreedsonlywhentherearenosmallonesavailable。
　　ThelargetubesshewilluseonlyingraveemergenciesandIamunabletostateexactlywhattheseexceptionalcircumstancesare。
　　Perhapsshedecidestomakeuseofthoseroomydwellingswhentheeggshavetobelaidatonceandthereisnoothershelterintheneighbourhood。Whilemycylinder—hivesgavemeplentyofwell—filledreedsofthefirstandsecondclass,theyprovidedmewithbuthalf—
　　a—dozenatmostofthethird,notwithstandingmyprecautiontofurnishtheapparatuswithavariedassortment。
　　TheOsmia'srepugnancetobigcylindersisquitejustified。Theworkinfactislongerandmorecostlywhenthetubesarewide。Aninspectionofanestconstructedundertheseconditionsisenoughtoconvinceus。Itnowconsistsnotofastringofchambersobtainedbysimpletransversepartitions,butofaconfusedheapofclumsy,many—
　　sidedcompartments,standingbacktoback,withatendencytogroupthemselvesinstoreyswithoutsucceedingindoingso,becauseanyregulararrangementwouldmeanthattheceilingspossessedaspanwhichitisnotinthebuilder'spowertoachieve。Theedificeisnotageometricalmasterpieceanditisevenlesssatisfactoryfromthepointofviewofeconomy。Inthepreviousconstructions,thesidesofthereedsuppliedthegreaterpartofthewallsandtheworkwaslimitedtoonepartitionforeachcell。Here,exceptattheactualperiphery,wherethetubeitselfsuppliesafoundation,everythinghastobeobtainedbysheerbuilding:thefloor,theceiling,thewallsofthemany—sidedcompartmentareoneandallmadeofmortar。
　　ThestructureisalmostascostlyinmaterialsasthatoftheChalicodomaorthePelopaeus。
　　Itmustbeprettydifficult,too,whenonethinksofitsirregularity。Fittingasbestshecantheprojectinganglesofthenewcellintotherecessedcornersofthecellalreadybuilt,theOsmiarunsupwallsmoreorlesscurved,uprightorslanting,whichintersectoneanotheratvariouspoints,sothateachcompartmentrequiresanewandcomplicatedplanofconstruction,whichisverydifferentfromthecircular—partitionstyleofarchitecture,withitsrowofparalleldividing—disks。Moreover,inthiscompositearrangement,thesizeoftherecessesleftavailablebytheearlierworktosomeextentdecidestheassessmentofthesexes,for,accordingtothedimensionsofthoserecesses,thewallserectedtakeinnowalargerspace,thehomeofafemale,andnowasmallerspace,thehomeofamale。RoomyquartersthereforehaveadoubledrawbackfortheOsmia:theygreatlyincreasetheoutlayinmaterials;andalsotheyestablishinthelowerlayers,amongthefemales,maleswho,becauseoftheirearlierhatching,wouldbemuchbetterplacednearthemouthofthenest。Iamconvincedofit:iftheOsmiarefusesbigreedsandacceptsthemonlyinthelastresort,whentherearenoothers,itisbecausesheobjectstoadditionallabourandtothemixtureofthesexes。
　　TheSnail—shell,then,isbutanindifferenthomeforher,whichsheisquitereadytoabandonshouldabetteroffer。Itsexpandingcavityrepresentsanaveragebetweenthefavouritesmallcylinderandtheunpopularlargecylinder,whichisacceptedonlywhenthereisnootherobtainable。ThefirstwhorlsofthespiralaretoonarrowtobeofusetotheOsmia,butthemiddleoneshavetherightdiameterforcocoonsarrangedinsinglefile。Herethingshappenasinafirst—
　　classreed,forthehelicalcurveinnowayaffectsthemethodofstructureemployedforarectilinearseriesofcells。Circularpartitionsareerectedattherequireddistances,withorwithoutaserving—hatch,accordingtothediameter。Thesemarkoutthefirstcells,oneaftertheother,whicharereservedsolelyforthefemales。Thencomesthelastwhorl,whichismuchtoowideforasinglerowofcells;andhereweoncemorefind,exactlyasinawidereed,acostlyprofusionofmasonry,anirregulararrangementofthecellsandamixtureofthesexes。
　　Havingsaidsomuch,letusgobacktotheOsmiaofthequarries。
　　Why,whenIofferthemsimultaneouslySnail—shellsandreedsofasuitablesize,dotheoldfrequentersoftheshellspreferthereeds,whichinallprobabilityhaveneverbeforebeenutilizedbytheirrace？Mostofthemscorntheancestraldwellingandenthusiasticallyacceptmyreeds。Some,itistrue,takeuptheirquartersintheSnail—shell;butevenamongtheseagoodlynumberrefusemynewshellsandreturntotheirbirth—place,theoldSnail—shell,inordertoutilizethefamilyproperty,withoutmuchlabour,atthecostofafewrepairs。Whence,Iask,comesthisgeneralpreferenceforthecylinder,neverusedhitherto？Theanswercanbeonlythis:oftwolodgingsatherdisposaltheOsmiaselectstheonethatprovidesacomfortablehomeataminimumoutlay。Sheeconomizesherstrengthwhenrestoringanoldnest;sheeconomizesitwhenreplacingtheSnail—shellbythereed。
　　Cananimalindustry,likeourown,obeythelawofeconomy,thesovranlawthatgovernsourindustrialmachineevenasitgoverns,atleasttoallappearances,thesublimemachineoftheuniverse？Letusgodeeperintothequestionandbringotherworkersintoevidence,thoseespeciallywho,betterequippedperhapsandatanyratebetterfittedforhardwork,attackthedifficultiesoftheirtradeboldlyandlookdownuponalienestablishmentswithscorn。OfthisnumberaretheChalicodomae,theMason—beesproper。
　　TheMason—beeofthePebblesdoesnotmakeuphermindtobuildabrand—newdomeunlesstherebeadearthofoldandnotquitedilapidatednests。Themothers,sistersapparentlyandheirs—at—lawtothedomain,disputefiercelyfortheancestralabode。Thefirstwho,bysheerbruteforce,takespossessionofthedome,perchesuponitand,forlonghours,watcheseventswhilepolishingherwings。Ifsomeclaimantputsinanappearance,forthwiththeotherturnsheroutwithavolleyofblows。Inthiswaytheoldnestsareemployedsolongastheyhavenotbecomeuninhabitablehovels。
　　Withoutbeingequallyjealousofthematernalinheritance,theMason—
　　beeoftheShedseagerlyusesthecellswhencehergenerationissued。
　　Theworkinthehugecityundertheeavesbeginsthus:theoldcells,ofwhich,bytheway,thegood—naturedowneryieldsaportiontoLatreille'sOsmiaandtotheThree—hornedOsmiaalike,arefirstmadecleanandwholesomeandclearedofbrokenplasterandthenprovisionedandshut。Whenalltheaccessiblechambersareoccupied,theactualbuildingbeginswithanewstratumofcellsupontheformeredifice,whichbecomesmoreandmoremassivefromyeartoyear。
　　TheMason—beeoftheShrubs,withhersphericalnestshardlylargerthanwalnuts,puzzledmeatfirst。Doessheusetheoldbuildingsordoessheabandonthemforgood？To—dayperplexitymakeswayforcertainty:sheusesthemveryreadily。Ihaveseveraltimessurprisedherlodgingherfamilyintheemptyroomsofanestwhereshewasdoubtlessbornherself。LikeherkinswomanofthePebbles,shereturnstothenativedwellingandfightsforitspossession。Also,likethedome—builder,sheisananchoriteandpreferstocultivatetheleaninheritancealone。Sometimes,however,thenestisofexceptionalsizeandharboursacrowdofoccupants,wholiveinpeace,eachattendingtoherbusiness,asinthecolossalhivesinthesheds。Shouldthecolonybeatallnumerousandtheestatedescendtotwoorthreegenerationsinsuccession,withafreshlayerofmasonryeachyear,thenormalwalnut—sizednestbecomesaballaslargeasaman'stwofists。Ihavegatheredonapine—treeanestoftheMason—beeoftheShrubsthatweighedakilogram（2。205poundsavoirdupois。——Translator'sNote。）andwasthesizeofachild'shead。
　　Atwighardlythickerthanastrawservedasitssupport。ThecasualsightofthatlumpswingingoverthespotonwhichIhadsatdownmademethinkofthemishapthatbefellGaro。（TheheroofLaFontaine'sfable,"LeGlandetlaCitrouille,"whowonderedwhyacornsgrewonsuchtalltreesandpumpkinsonsuchlowvines,untilhefellasleepunderoneofthelatterandapumpkindroppeduponhisnose。——Translator'sNote。）Ifsuchnestswereplentifulinthetrees,anyoneseekingtheshadewouldrunaseriousriskofhavinghisheadsmashed。
　　AftertheMasons,theCarpenters。Amongtheguildofwood—workers,themostpowerfulistheCarpenter—bee（Xylocopaviolacea（Cf。"TheLifeoftheSpider":chapter1。——Translator'sNote。））,averylargeBeeofformidableappearance,cladinblackvelvetwithviolet—
　　colouredwings。Themothergivesherlarvaeasadwellingacylindricalgallerywhichshedigsinrottenwood。Uselesstimberlyingexposedtotheair,vine—poles,largelogsoffire—woodseasoningoutofdoors,heapedupinfrontofthefarmhouseporch,stumpsoftrees,vine—stocksandbigbranchesofallkindsareherfavouritebuilding—yards。Asolitaryandindustriousworker,shebores,bitbybit,circularpassagesthewidthofone'sthumb,asclear—cutasthoughtheyweremadewithanauger。Aheapofsaw—dustaccumulatesonthegroundandbearswitnesstotheseverityofthetask。Usually,thesameapertureistheentrancetotwoorthreeparallelcorridors。Withseveralgalleriesthereisaccommodationfortheentirelaying,thougheachgalleryisquiteshort;andtheBeethusavoidsthoselongserieswhichalwayscreatedifficultieswhenthemomentofhatchingarrives。Thelaggardsandtheinsectseagertoemergearelesslikelytogetineachother'sway。
　　Afterobtainingthedwelling,theCarpenter—beebehavesliketheOsmiawhoisinpossessionofareed。Provisionsarecollected,theeggislaidandthechamberiswalledinfrontwithasaw—dustpartition。Theworkispursuedinthiswayuntilthetwoorthreepassagescomposingthehousearecompletelystocked。HeapingupprovisionsanderectingpartitionsareaninvariablefeatureoftheXylocopa'sprogramme;nocircumstancecanreleasethemotherfromthedutyofprovidingforthefutureofherfamily,inthematterbothofready—preparedfoodandofseparatecompartmentsfortherearingofeachlarva。Itisonlyintheboringofthegalleries,themostlaboriouspartofthework,thateconomycanoccasionallybeexercisedbyapieceofluck。Well,isthepowerfulCarpenter,allunheedingoffatigue,abletotakeadvantageofsuchfortunateoccasions？Doessheknowhowtomakeuseofhouseswhichshehasnottunnelledherself？Why,yes:afreelodgingsuitsherjustasmuchasitdoesthevariousMason—bees。Sheknowsaswellastheytheeconomicadvantagesofanoldnestthatisstillingoodcondition:
　　shesettlesdown,asfaraspossible,inherpredecessors'galleries,afterfresheningupthesideswithasuperficialscraping。Andshedoesbetterstill。Shereadilyacceptslodgingswhichhaveneverknownadrill,nomatterwhose。Thestoutreedsusedinthetrellis—
　　workthatsupportsthevinesarevaluablediscoveries,providingastheydosumptuousgalleriesfreeofcost。Nopreliminaryworkornexttononeisrequiredwiththese。Indeed,theinsectdoesnoteventroubletomakeaside—opening,whichwouldenableittooccupythecavitycontainedwithintwonodes;itpreferstheopeningattheendcutbyman'spruning—knife。Ifthenextpartitionbetooneartogiveachamberofsufficientlength,theXylocopadestroysit,whichiseasywork,nottobecomparedwiththelabourofcuttinganentrancethroughtheside。Inthisway,aspaciousgallery,followingontheshortvestibulemadebythepruning—knife,isobtainedwiththeleastpossibleexpenditureofenergy。
　　Guidedbywhatwashappeningonthetrellises,IofferedtheblackBeethehospitalityofmyreed—hives。Fromtheverybeginning,theinsectgladlywelcomedmyadvances;eachspring,Iseeitinspectmyrowsofcylinders,pickoutthebestonesandinstalitselfthere。
　　Itswork,reducedtoaminimumbymyintervention,islimitedtothepartitions,thematerialsforwhichareobtainedbyscrapingtheinnersidesofthereed。
　　Asfirst—ratejoiners,nexttotheCarpenter—beescometheLithurgi,ofwhommydistrictpossessestwospecies:L。cornutus,FAB。,andL。
　　chrysurus,BOY。BywhataberrationofnomenclaturewasthenameofLithurgus,aworkerinstone,giventoinsectswhichworksolelyinwood？Ihavecaughtthefirst,thestrongerofthetwo,digginggalleriesinalargeblockofoakthatservedasanarchforastable—door;Ihavealwaysfoundthesecond,whoismorewidelydistributed,settlingindeadwood——mulberry,cherry,almond,poplar—
　　—thatwasstillstanding。HerworkisexactlythesameastheXylocopa's,onasmallerscale。Asingleentrance—holegivesaccesstothreeorfourparallelgalleries,assembledinaserriedgroup;
　　andthesegalleriesaresubdividedintocellsbymeansofsaw—dustpartitions。FollowingtheexampleofthebigCarpenter—bee,Lithurguschrysurusknowshowtoavoidthelaboriousworkofboring,whenoccasionoffers:Ifindhercocoonslodgedalmostasofteninolddormitoriesasinnewones。Shetoohasthetendencytoeconomizeherstrengthbyturningtheworkofherpredecessorstoaccount。Idonotdespairofseeingheradoptthereedif,oneday,whenIpossessalargeenoughcolony,Idecidetotrythisexperimentonher。IwillsaynothingaboutL。cornutus,whomIonlyoncesurprisedathercarpentering。
　　TheAnthophorae,thosechildrenoftheprecipitousearthybanks,showthesamethriftyspiritastheothermembersoftheminingcorporation。Threespecies,A。parietina,A。personataandA。