第5章

InthiswayIobtainedsomemagnificentseriesofAnthidiaandMegachiles,runninguptoadozen。Therewasamelancholysidetothissuccess。Allmyseries,withnotoneexception,wereravagedbyparasites。ThoseoftheMegachile（M。sericans,FONSCOL）,whofashionshergobletswithrobinia—,holm—,andterebinth—leaves,wereinhabitedbyCoelioxysoctodentata（AParasiticBee。——Translator\'sNote。）;thoseoftheAnthidium（A。florentinum,LATR。）wereoccupiedbyaLeucopsis。BothkindswereswarmingwithacolonyofpigmyparasiteswhosenameIhavenotyetbeenabletodiscover。Inshort,mypan—pipehives,thoughveryusefultomefromotherpointsofview,taughtmenothingabouttheorderofthesexesamongtheLeaf—

cuttersandthecotton—weavers。

IwasmorefortunatewiththreeOsmiae（O。tricornis,LATR。,O。

cornuta,LATR。,andO。Latreillii,SPIN。）,allofwhomgavemesplendidresults,withreed—stumpsarrangedeitheragainstthewallsofmygarden,asIhavejustsaid,orneartheircustomaryabode,thehugenestsoftheMason—beeoftheSheds。Oneofthem,theThree—

hornedOsmia,didbetterstill:asIhavedescribed,shebuilthernestsinmystudy,asplentifullyasIcouldwish,usingreeds,glasstubesandotherretreatsofmyselectingforhergalleries。

Wewillconsultthislast,whohasfurnishedmewithdocumentsbeyondmyfondesthopes,andbeginbyaskingherofhowmanyeggsheraveragelayingconsists。Ofthewholeheapofcolonizedtubesinmystudy,orelseoutofdoors,inthehurdle—reedsandthepan—pipeappliances,thebest—filledcontainsfifteencells,withafreespaceabovetheseries,aspaceshowingthatthelayingisended,for,ifthemotherhadanymoreeggsavailable,shewouldhavelodgedthemintheroomwhichsheleavesunoccupied。Thisstringoffifteenappearstoberare;itwastheonlyonethatIfound。Myattemptsatindoorrearing,pursuedduringtwoyearswithglasstubesorreeds,taughtmethattheThree—hornedOsmiaisnotmuchaddictedtolongseries。

Asthoughtodecreasethedifficultiesofthecomingdeliverance,sheprefersshortgalleries,inwhichonlyapartofthelayingisstacked。Wemustthenfollowthesamemotherinhermigrationfromonedwellingtothenextifwewouldobtainacompletecensusofherfamily。Aspotofcolour,droppedontheBee\'sthoraxwithapaint—

brushwhilesheisabsorbedinclosingupthemouthofthetunnel,enablesustorecognizetheOsmiainhervarioushomes。

Inthisway,theswarmthatresidedinmystudyfurnishedme,inthefirstyear,withanaverageoftwelvecells。Nextyear,thesummerappearedtobemorefavourableandtheaveragebecameratherhigher,reachingfifteen。Themostnumerouslayingperformedundermyeyes,notinatube,butinasuccessionofSnail—shells,reachedthefigureoftwenty—six。Ontheotherhand,layingsofbetweeneightandtenarenotuncommon。Lastly,takingallmyrecordstogether,theresultisthatthefamilyoftheOsmiafluctuatesroundaboutfifteeninnumber。

Ihavealreadyspokenofthegreatdifferencesinsizeapparentinthecellsofoneandthesameseries。Thepartitions,atfirstwidelyspaced,drawgraduallynearertooneanotherastheycomeclosertotheaperture,whichimpliesroomycellsatthebackandnarrowcellsinfront。Thecontentsofthesecompartmentsarenolessunevenbetweenoneportionandanotherofthestring。Withoutanyexceptionknowntome,thelargecells,thosewithwhichtheseriesstarts,havemoreabundantprovisionsthanthestraitenedcellswithwhichtheseriesends。Theheapofhoneyandpolleninthefirstistwiceoreventhriceaslargeasthatinthesecond。Inthelastcells,themostrecentindate,thevictualsarebutapinchofpollen,soniggardlyinamountthatwewonderwhatwillbecomeofthelarvawiththatmeagreration。

OnewouldthinkthattheOsmia,whennearingtheendofthelaying,attachesnoimportancetoherlast—born,towhomshedolesoutspaceandfoodsosparingly。Thefirst—bornreceivethebenefitofherearlyenthusiasm:theirsisthewell—spreadtable,theirsthespaciousapartments。Theworkhasbeguntopallbythetimethatthelasteggsarelaid;andthelast—comershavetoputupwithascurvyportionoffoodandatinycorner。

Thedifferenceshowsitselfinanotherwayafterthecocoonsarespun。Thelargecells,thoseattheback,receivethebulkycocoons;

thesmallones,thoseinfront,havecocoonsonlyahalforathirdasbig。BeforeopeningthemandascertainingthesexoftheOsmiainside,letuswaitforthetransformationintotheperfectinsect,whichwilltakeplacetowardstheendofsummer。Ifimpatiencegetsthebetterofus,wecanopenthemattheendofJulyorinAugust。

Theinsectistheninthenymphalstage;anditiseasy,underthisform,todistinguishthetwosexesbythelengthoftheantennae,whicharelargerinthemales,andbytheglassyprotuberancesontheforehead,thesignofthefuturearmourofthefemales。Well,thesmallcocoons,thoseinthenarrowfrontcells,withtheirscantystoreofprovisions,allbelongtomales;thebigcocoons,thoseinthespaciousandwell—stockedcellsattheback,allbelongtofemales。

Theconclusionisdefinite:thelayingoftheThree—hornedOsmiaconsistsoftwodistinctgroups,firstagroupoffemalesandthenagroupofmales。

Withmypan—pipeapparatusdisplayedonthewallsofmyenclosureandwitholdhurdle—reedsleftlyingflatoutofdoors,IobtainedtheHornedOsmiainfairquantities。IpersuadedLatreille\'sOsmiatobuildhernestinreeds,whichshedidwithazealwhichIwasfarfromexpecting。AllthatIhadtodowastolaysomereed—stumpshorizontallywithinherreach,intheimmediateneighbourhoodofherusualhaunts,namely,thenestsoftheMason—beeoftheSheds。

Lastly,Isucceededwithoutdifficultyinmakingherbuildhernestsintheprivacyofmystudy,withglasstubesforahouse。Theresultsurpassedmyhopes。

WithboththeseOsmiae,thedivisionofthegalleryisthesameaswiththeThree—hornedOsmia。Atthebackarelargecellswithplentifulprovisionsandwidely—spacedpartitions;infront,smallcells,withscantyprovisionsandpartitionsclosetogether。Also,thelargercellssuppliedmewithbigcocoonsandfemales;thesmallercellsgavemelittlecocoonsandmales。TheconclusionthereforeisexactlythesameinthecaseofallthreeOsmiae。

BeforedismissingtheOsmiae,letusdevoteamomenttotheircocoons,acomparisonofwhich,inthematterofbulk,willfurnishuswithfairlyaccurateevidenceastotherelativesizeofthetwosexes,forthethingcontained,theperfectinsect,isevidentlyproportionatetothesilkenwrapperinwhichitisenclosed。Thesecocoonsareoval—shapedandmayberegardedasellipsoidsformedbyarevolutionaroundthemajoraxis。Thevolumeofoneofthesesolidsisexpressedinthefollowingformula:

4/3xpixax（bsquared）,inwhich2aisthemajoraxisand2btheminoraxis。

Now,theaveragedimensionsofthecocoonsoftheThree—hornedOsmiaareasfollows:

2a=13mm。（。507inch。——Translator\'sNote。）,2b=7mm。（。273inch。—

—Translator\'sNote。）inthefemales;

2a=9mm。（。351inch。——Translator\'sNote。）,2b=5mm。（。195inch。——

Translator\'sNote。）inthemales。

Theratiothereforebetween13x7x7=637and9x5x5=225willbemoreorlesstheratiobetweenthesizesofthetwosexes。Thisratioissomewherebetween2to1and3to1。Thefemalesthereforearetwoorthreetimeslargerthanthemales,aproportionalreadysuggestedbyacomparisonofthemassofprovisions,estimatedsimplybytheeye。

TheHornedOsmiagivesusthefollowingaveragedimensions:

2a=15mm。（。585inch。——Translator\'sNote。）,2b=9mm。（。351inch。—

—Translator\'sNote。）inthefemales;

2a=12mm。（。468inch。——Translator\'sNote。）,2b=7mm。（。273inch。—

—Translator\'sNote。）inthemales。

Onceagain,theratiobetween15x9x9=1215and12x7x7=588

liesbetween2to1and3to1。

BesidestheBeeswhoarrangetheirlayinginarow,Ihaveconsultedotherswhosecellsaregroupedinawaythatmakesitpossibletoascertaintherelativeorderofthetwosexes,thoughnotquitesoprecisely。OneoftheseistheMason—beeoftheWalls。Ineednotdescribeagainherdome—shapednest,builtonapebble,whichisnowsowell—knowntous。（Cf。"TheMason—bees":chapter1。——Translator\'sNote。）

Eachmotherchoosesherstoneandworksonitinsolitude。Sheisanungraciouslandownerandguardshersitejealously,drivingawayanyMasonwhoevenlooksasthoughshemightalightonit。Theinhabitantsofthesamenestarethereforealwaysbrothersandsisters;theyarethefamilyofonemother。

Moreover,ifthestonepresentsalargeenoughsurface——aconditioneasilyfulfilled——theMason—beehasnoreasontoleavethesupportonwhichshebeganherlayingandgoinsearchofanotherwhereontodeposittherestofhereggs。Sheistoothriftyofhertimeandofhermortartoinvolveherselfinsuchexpenditureexceptforgravereasons。Consequently,eachnest,atleastwhenitisnew,whentheBeeherselfhaslaidthefirstfoundations,containstheentirelaying。Itisadifferentthingwhenanoldnestisrestoredandmadeintoaplacefordepositingtheeggs。Ishallcomebacklatertosuchhouses。

Anewly—builtnestthen,withrareexceptions,containstheentirelayingofonefemale。Countthecellsandweshallhavethetotallistofthefamily。Theirmaximumnumberfluctuatesroundaboutfifteen。Themostluxuriantserieswilloccasionallyreachasmanyaseighteen,thoughtheseareveryscarce。

Whenthesurfaceofthestoneisregularallaroundthesiteofthefirstcell,whenthemasoncanaddtoherbuildingwiththesamefacilityineverydirection,itisobviousthatthegroupsofcells,whenfinished,willhavetheoldestinthecentralportionandthemorerecentinthesurroundingportion。Becauseofthisjuxtapositionofthecells,whichservepartlyasawalltothosewhichcomenext,itispossibletoformsomeestimateofthechronologicalorderofthecellsintheChalicodoma\'snestandthustodiscoverthesequenceofthetwosexes。

Inwinter,bywhichtimetheBeehaslongbeenintheperfectstate,IcollectChalicodoma—nests,removingthembodilyfromtheirsupportwithafewsmartsidewardtapsofthehammeronthepebbles。Atthebaseofthemortardomethecellsarewideagapeanddisplaytheircontents。Itakethecocoonfromitsbox,openitandtakenoteofthesexoftheinsectenclosed。

IshouldprobablybeaccusedofexaggerationifImentionedthetotalnumberofthenestswhichIhavegatheredandthecellswhichIhaveinspectedbythismethodduringthelastsixorsevenyears。IwillcontentmyselfwithsayingthattheharvestofasinglemorningsometimesconsistedofasmanyassixtynestsoftheMason—bee。Ihadtohavehelpincarryinghomemyspoils,eventhoughthenestswereremovedfromtheirstonesonthespot。

>FromtheenormousnumberofnestswhichIhaveexamined,Iamabletostatethat,whentheclusterisregular,thefemalecellsoccupythecentreandthemalecellstheedges。Wheretheirregularityofthepebblehaspreventedanevendistributionaroundtheinitialpoint,thesamerulehasbeenobserved。Amalecellisneversurroundedoneverysidebyfemalecells:eitheritoccupiestheedgesofthenest,orelseitadjoins,atleastonsomesides,othermalecells,ofwhichthelastformpartoftheexteriorofthecluster。Asthesurroundingcellsareobviouslyofalaterdatethantheinnercells,itfollowsthattheMason—beeactsliketheOsmiae:shebeginsherlayingwithfemalesandendsitwithmales,eachofthesexesformingaseriesofitsown,independentoftheother。

Somefurthercircumstancesaddtheirtestimonytothatofthesurroundedandsurroundingcells。Whenthepebbleprojectssharplyandformsasortofdihedralangle,oneofwhosefacesismoreorlessverticalandtheotherhorizontal,thisangleisafavouritesitewiththeMason,whothusfindsgreaterstabilityforheredificeinthesupportgivenherbythedoubleplane。ThesesitesappeartometobeingreatrequestwiththeChalicodoma,consideringthenumberofnestswhichIfindthusdoublysupported。Innestsofthiskind,allthecells,asusual,havetheirfoundationsfixedtothehorizontalsurface;butthefirstrow,therowofcellsfirstbuilt,standswithitsbackagainsttheverticalsurface。

Well,theseoldercells,whichoccupytheactualedgeofthedihedralangle,arealwaysfemale,withtheexceptionofthoseateitherendoftherow,which,astheybelongtotheoutside,maybemalecells。

Infrontofthisfirstrowcomeothers。Thefemalecellsoccupythemiddleportionandthemaletheends。Finally,thelastrow,closingintheremainder,containsonlymalecells。Theprogressoftheworkisveryvisiblehere:theMasonhasbegunbyattendingtothecentralgroupoffemalecells,thefirstrowofwhichoccupiesthedihedralangle,andhasfinishedhertaskbydistributingthemalecellsroundtheoutside。

Iftheperpendicularfaceofthedihedralanglebehighenough,itsometimeshappensthatasecondrowofcellsisplacedabovethefirstrowbackingontothatplane;athirdrowoccurslessoften。

Thenestisthenoneofseveralstoreys。Thelowerstoreys,theolder,containonlyfemales;theupper,themorerecentstorey,containsnonebutmales。Itgoeswithoutsayingthatthesurfacelayer,evenofthelowerstoreys,cancontainmaleswithoutinvalidatingtherule,forthislayermayalwaysbelookeduponastheChalicodoma\'slastwork。

Everythingthereforecontributestoshowthat,intheMason—bee,thefemalestaketheleadintheorderofprimogeniture。Theirsisthecentralandbest—protectedpartoftheclayfortress;theouterpart,thatmostexposedtotheinclemenciesoftheweatherandtoaccidents,isforthemales。

Themales\'cellsdonotdifferfromthefemales\'onlybybeingplacedattheoutsideofthecluster;theydifferalsointheircapacity,whichismuchsmaller。Toestimatetherespectivecapacitiesofthetwosortsofcells,Igotoworkasfollows:Ifilltheemptycellwithveryfinesandandpourthissandbackintoaglasstubemeasuring5millimetres（。195inch。——Translator\'sNote。）indiameter。

>Fromtheheightofthecolumnofsandwecanestimatethecomparativecapacityofthetwokindsofcells。Iwilltakeoneatrandomamongmynumerousexamplesofcellsthusgauged。

Itcomprisesthirteencellsandoccupiesadihedralangle。Thefemalecellsgivemethefollowingfigures,inmillimetres,astheheightofthecolumnsofsand:

40,44,43,48,48,46,47

（1。56,1。71,1。67,1。87,1。87,1。79,1。83inches。——Translator\'sNote。）,averaging45。（1。75inches。——Translator\'sNote。）

Themalecellsgiveme:

32,35,28,30,30,31

（1。24,1。36,1。09,1。17,1。17,1。21inches。——Translator\'sNote。）,averaging31。（1。21inches。——Translator\'sNote。）

Theratioofthecapacityofthecellsforthetwosexesisthereforeroughlyaratioof4to3。Theactualcontentsofthecellbeingproportionatetoitscapacity,theaboveratiomustalsobemoreorlesstheratioofprovisionsandsizesbetweenfemalesandmales。

Thesefigureswillassistuspresentlytotellwhetheranoldcell,occupiedforasecondorthirdtime,belongedoriginallytoafemaleoramale。

TheChalicodomaoftheShedscannotgiveusanyinformationonthismatter。Shebuildsunderthesameeaves,inexcessivelypopulouscolonies;anditisimpossibletofollowthelaboursofanysingleMason,whosecells,distributedhereandthere,aresooncoveredupwiththeworkofherneighbours。Allismuddleandconfusionintheindividualoutputoftheswarmingthrong。

IhavenotwatchedtheworkoftheChalicodomaoftheShrubswithcloseenoughattentiontobeabletostatedefinitelythatthisBeeisasolitarybuilder。Hernestisaballofclayhangingfromabough。Sometimes,thisnestisthesizeofalargewalnutandthenappearstobetheworkofonealone;sometimes,itisthesizeofaman\'sfist,inwhichcaseIhavenodoubtthatitistheworkofseveral。Thosebulkynests,comprisingmorethanfiftycells,cantellusnothingexact,asanumberofworkersmustcertainlyhavecollaboratedtoproducethem。

Thewalnut—sizednestsaremoretrustworthy,foreverythingseemstoindicatethattheywerebuiltbyasingleBee。Herefemalesarefoundinthecentreofthegroupandmalesatthecircumference,insomewhatsmallercells,thusrepeatingwhattheMason—beeofthePebbleshastoldus。

Oneclearandsimplerulestandsoutfromthiscollectionoffacts。

ApartfromthestrangeexceptionoftheThree—prongedOsmia,whomixesthesexeswithoutanyorder,theBeeswhomIstudiedandprobablyacrowdofothersproducefirstacontinuousseriesoffemalesandthenacontinuousseriesofmales,thelatterwithlessprovisionsandsmallercells。ThisdistributionofthesexesagreeswithwhatwehavelongknownoftheHive—bee,whobeginsherlayingwithalongsequenceofworkers,orsterilefemales,andendsitwithalongsequenceofmales。Theanalogycontinuesdowntothecapacityofthecellsandthequantitiesofprovisions。Therealfemales,theQueen—bees,havewaxcellsincomparablymorespaciousthanthecellsofthemalesandreceiveamuchlargeramountoffood。Everythingthereforedemonstratesthatwearehereinthepresenceofageneralrule。

Butdoesthisruleexpressthewholetruth？Istherenothingbeyondalayingintwoseries？AretheOsmiae,theChalicodomaeandtherestofthemfatallyboundbythisdistributionofthesexesintotwodistinctgroups,themalegroupfollowinguponthefemalegroup,withoutanymixingofthetwo？Isthemotherabsolutelypowerlesstomakeachangeinthisarrangement,shouldcircumstancesrequireit？

TheThree—prongedOsmiaalreadyshowsusthattheproblemisfarfrombeingsolved。Inthesamebramble—stump,thetwosexesoccurveryirregularly,asthoughatrandom。WhythismixtureintheseriesofcocoonsofaBeecloselyrelatedtotheHornedOsmiaandtheThree—

hornedOsmia,whostacktheirsmethodicallybyseparatesexesinthehollowofareed？WhattheBeeofthebramblesdoescannotherkinswomenofthereedsdotoo？Nothing,sofarasIknow,canexplainthisdifferenceinaphysiologicalactofprimaryimportance。ThethreeBeesbelongtothesamegenus;theyresembleoneanotheringeneraloutline,internalstructureandhabits;and,withthisclosesimilarity,wesuddenlyfindastrangedissimilarity。

ThereisjustonethingthatmightpossiblyarouseasuspicionofthecauseofthisirregularityintheThree—prongedOsmia\'slaying。IfI

openabramble—stumpinthewintertoexaminetheOsmia\'snest,I

finditimpossible,inthevastmajorityofcases,todistinguishpositivelybetweenafemaleandamalecocoon:thedifferenceinsizeissosmall。Thecells,moreover,havethesamecapacity:thediameterofthecylinderisthesamethroughoutandthepartitionsarealmostalwaysthesamedistanceapart。IfIopenitinJuly,thevictualling—period,itisimpossibleformetodistinguishbetweentheprovisionsdestinedforthemalesandthosedestinedforthefemales。Themeasurementofthecolumnofhoneygivespracticallythesamedepthinallthecells。Wefindanequalquantityofspaceandfoodforbothsexes。

Thisresultmakesusforeseewhatadirectexaminationofthetwosexesintheadultformtellsus。Themaledoesnotdiffermateriallyfromthefemaleinrespectofsize。Ifheisatriflesmaller,itisscarcelynoticeable,whereas,intheHornedOsmiaandtheThree—

hornedOsmia,themaleisonlyhalforathirdthesizeofthefemale,aswehaveseenfromtherespectivebulkoftheircocoons。IntheMason—beeoftheWallsthereisalsoadifferenceinsize,thoughlesspronounced。

TheThree—prongedOsmiahasnotthereforetotroubleaboutadjustingthedimensionsofthedwellingandthequantityofthefoodtothesexoftheeggwhichsheisabouttolay;themeasureisthesamefromoneendoftheseriestotheother。Itdoesnotmatterifthesexesalternatewithoutorder:oneandallwillfindwhattheyneed,whatevertheirpositionintherow。ThetwootherOsmiae,withtheirgreatdisparityinsizebetweenthetwosexes,havetobecarefulaboutthetwofoldconsiderationofboardandlodging。Andthat,I

think,iswhytheybeginwithspaciouscellsandgenerousrationsforthehomesofthefemalesandendwithnarrow,scantily—provisionedcells,thehomesofthemales。Withthissequence,sharplydefinedforthetwosexes,thereislessfearofmistakeswhichmightgivetoonewhatbelongstoanother。Ifthisisnottheexplanationofthefacts,Iseenoother。

ThemoreIthoughtaboutthiscuriousquestion,themoreprobableitappearedtomethattheirregularseriesoftheThree—prongedOsmiaandtheregularseriesoftheotherOsmiae,oftheChalicodomaeandoftheBeesingeneralwerealltraceabletoacommonlaw。Itseemedtomethatthearrangementinasuccessionfirstoffemalesandthenofmalesdidnotaccountforeverything。Theremustbesomethingmore。AndIwasright:thatarrangementinseriesisonlyatinyfractionofthereality,whichisremarkableinaverydifferentway。

ThisiswhatIamgoingtoprovebyexperiment。

CHAPTER4。THEMOTHERDECIDESTHESEXOFTHEEGG。

IwillbeginwiththeMason—beeofthePebbles。（ThisisthesameinsectastheMason—beeoftheWalls。Cf。"TheMason—bees":passim。——

Translator\'sNote。）Theoldnestsareoftenused,whentheyareingoodenoughrepair。Earlyintheseasonthemothersquarrelfiercelyoverthem;and,whenoneoftheBeeshastakenpossessionofthecoveteddome,shedrivesanystrangerawayfromit。Theoldhouseisfarfrombeingaruin,onlyitisperforatedwithasmanyholesasitoncehadoccupants。Theworkofrestorationisnogreatmatter。Theheapofearthduetothedestructionofthelidbytheoutgoingtenantistakenoutofthecellandflungawayatadistance,atombyatom。Theremnantsofthecocoonarealsothrownaway,butnotalways,forthedelicatesilkenwrappersometimesadherescloselytothemasonry。

Thevictuallingoftherenovatedcellisnowbegun。Nextcomesthelaying;andlastlytheorificeissealedwithamortarplug。Asecondcellisutilizedinthesameway,followedbyathirdandsoon,oneaftertheother,aslongasanyremainunoccupiedandthemother\'sovariesarenotexhausted。Finally,thedomereceives,mainlyovertheaperturesalreadyplugged,acoatofplasterwhichmakesthenestlooklikenew。Ifshehasnotfinishedherlaying,themothergoesinsearchofotheroldneststocompleteit。Perhapsshedoesnotdecidetofoundanewestablishmentexceptwhenshecanfindnosecond—handdwellings,whichmeanagreateconomyoftimeandlabour。Inshort,amongthecountlessnumberofnestswhichIhavecollected,Ifindmanymoreancientthanrecentones。

Howshallwedistinguishonefromtheother？Theoutwardaspecttellsyounothing,owingtothegreatcaretakenbytheMasontorestorethesurfaceoftheolddwellingequaltonew。Toresisttherigoursofthewinter,thissurfacemustbeimpregnable。Themotherknowsthatandthereforerepairsthedome。Inside,itisanothermatter:

theoldneststandsrevealedatonce。Therearecellswhoseprovisions,atleastayearold,areintact,butdriedupormusty,becausetheegghasneverdeveloped。Thereareotherscontainingadeadlarva,reducedbytimetoablackened,curled—upcylinder。Therearesomewhencetheperfectinsectwasneverabletoissue:theChalicodomaworeherselfoutintryingtopiercetheceilingofherchamber;herstrengthfailedherandsheperishedintheattempt。

Othersagainandverymanyareoccupiedbyravagers,Leucopses（Cf。

"TheMason—bees":chapter11。——Translator\'sNote。）andAnthrax—flies,whowillcomeoutagooddeallater,inJuly。Altogether,thehouseisfarfromhavingeveryroomvacant;therearenearlyalwaysaconsiderablenumberoccupiedeitherbyparasitesthatwerestillintheegg—stageatthetimewhentheMason—beewasatworkorbydamagedprovisions,driedgrubsorChalicodomaeintheperfectstatewhohavediedwithoutbeingabletoeffecttheirdeliverance。

Shouldalltheroomsbeavailable,arareoccurrence,therestillremainsamethodofdistinguishingbetweenanancientnestandarecentone。Thecocoon,asIhavesaid,adheresprettycloselytothewalls;andthemotherdoesnotalwaystakeawaythisremnant,eitherbecausesheisunabletodoso,orbecausesheconsiderstheremovalunnecessary。Thusthebaseofthenewcocoonissetinthebottomoftheoldcocoon。Thisdoublewrapperpointsveryclearlytotwogenerations,twoseparateyears。Ihaveevenfoundasmanyasthreecocoonsfittingoneintoanotherattheirbases。Consequently,thenestsoftheMason—beeofthePebblesareabletododutyforthreeyears,ifnotmore。Eventuallytheybecomeutterruins,abandonedtotheSpidersandtovarioussmallerBeesorWasps,whotakeuptheirquartersinthecrumblingrooms。

Aswesee,anoldnestishardlyevercapableofcontainingtheMason—bee\'sentirelaying,whichcallsforsomefifteenapartments。

Thenumberofroomsatherdisposalismostunequal,butalwaysverysmall。Itissayingmuchwhenthereareenoughtoreceiveabouthalfthelaying。Fourorfivecells,sometimestwoorevenone:thatiswhattheMasonusuallyfindsinanestthatisnotherownwork。ThislargereductionisexplainedwhenwerememberthenumerousparasitesthatliveupontheunfortunateBee。

Now,howarethesexesdistributedinthoselayingswhicharenecessarilybrokenupbetweenoneoldnestandanother？Theyaredistributedinsuchawayasutterlytoupsettheideaofaninvariablesuccessionfirstoffemalesandthenofmales,theideawhichoccurstousonexaminingthenewnests。Ifthisrulewereaconstantone,weshouldbeboundtofindintheolddomesatonetimeonlyfemales,atanotheronlymales,accordingasthelayingwasatitsfirstoratitssecondstage。Thesimultaneouspresenceofthetwosexeswouldthencorrespondwiththetransitionperiodbetweenonestageandthenextandshouldbeveryunusual。Onthecontrary,itisverycommon;and,howeverfewcellstheremaybe,wealwaysfindbothfemalesandmalesintheoldnests,onthesoleconditionthatthecompartmentshavetheregulationholding—capacity,alargecapacityforthefemales,alesserforthemales,aswehaveseen。