TheOsmiaisworkingatherbigpartition,withherbodyoutsidethecellwhichsheispreparing。Fromtimetotime,withapelletofmortarinhermandibles,shegoesinandtouchesthepreviousceilingwithherforehead,whilethetipofherabdomenquiversandfeelsthepadincourseofconstruction。Onemightwellsaythatsheisusingthelengthofherbodyasameasure,inordertofixthenextceilingattheproperdistance。Thensheresumesherwork。Perhapsthemeasurewasnotcorrectlytaken;perhapshermemory,afewsecondsold,hasalreadybecomemuddled。TheBeeoncemoreceaseslayingherplasterandagaingoesandtouchesthefrontwallwithherforeheadandthebackwallwiththetipofherabdomen。Lookingatthatbodytremblingwitheagerness,extendedtoitsfulllengthtotouchthetwoendsoftheroom,howcanwefailtograspthearchitect\'sgraveproblem？TheOsmiaismeasuring;andhermeasureisherbody。Hasshequitedone,thistime？Ohdearno！Tentimes,twentytimes,ateverymoment,fortheleastparticleofmortarwhichshelays,sherepeatshermensuration,neverbeingquitecertainthathertrowelisgoingjustwhereitshould。
Meanwhile,amidthesefrequentinterruptions,theworkprogressesandthepartitiongainsinwidth。Theworkerisbentintoahook,withhermandiblesontheinnersurfaceofthewallandthetipofherabdomenontheoutersurface。Thesoftmasonrystandsbetweenthetwopointsofpurchase。Theinsectthusformsasortofrolling—press,inwhichthemudwallisflattenedandshaped。Themandiblestapandfurnishmortar;theendoftheabdomenalsopatsandgivesbrisktrowel—touches。Thisanalextremityisabuilder\'stool;Iseeitfacingthemandiblesontheothersideofthepartition,kneadingandsmoothingitallover,flatteningthelittlelumpofclay。Itisasingularimplement,whichIshouldneverhaveexpectedtoseeusedforthispurpose。Ittakesaninsecttoconceivesuchanoriginalidea,todomason\'sworkwithitsbehind！Duringthiscuriousperformance,theonlyfunctionofthelegsistokeeptheworkersteadybyspreadingoutandclingingtothewallsofthetunnel。
Thepartitionwiththeholeinitisfinished。LetusgobacktothemeasuringofwhichtheOsmiawassolavish。Whatamagnificentargumentinfavourofthereasoning—powerofanimals！Tofindgeometry,thesurveyor\'sart,inanOsmia\'stinybrain！Aninsectthatbeginsbytakingthemeasurementsoftheroomtobeconstructed,justasanymaster—buildermightdo！Why,it\'ssplendid,it\'senoughtocoverwithconfusionthosehorriblescepticswhopersistinrefusingtoadmittheanimal\'s\'continuouslittleflashesofatomsofreason！\'
Ocommon—sense,veilyourface！Itiswiththisgibberishaboutcontinuousflashesofatomsofreasonthatmenpretendtobuildupscienceto—day！Verywell,mymasters;themagnificentargumentwithwhichIamsupplyingyoulacksbutonelittledetail,themeresttrifle:truth！NotthatIhavenotseenandplainlyseenallthatI
amrelating;butmeasuringhasnothingtodowiththecase。AndIcanproveitbyfacts。
If,inordertoseetheOsmia\'snestasawhole,wesplitareedlengthwise,takingcarenottodisturbitscontents;or,betterstill,ifweselectforexaminationthestringofcellsbuiltinaglasstube,weareforthwithstruckbyonedetail,namely,theunevendistancesbetweenthepartitions,whichareplacedalmostatrightanglestotheaxisofthecylinder。Itisthesedistanceswhichfixthesizeofthechambers,which,withasimilarbase,havedifferentheightsandconsequentlyunequalholding—capacities。Thebottompartitions,theoldest,arefartherapart;thoseofthefrontpart,neartheorifice,areclosertogether。Moreover,theprovisionsareplentifulintheloftiercells,whereastheyareniggardlyandreducedtoone—halforevenone—thirdinthecellsoflesserheight。
Hereareafewexamplesoftheseinequalities。Aglasstubewithadiameterof12millimetres（。468inch。——Translator\'sNote。）,insidemeasurement,containstencells。Thefivelowerones,beginningwiththebottom—most,haveastherespectivedistancesbetweentheirpartitions,inmillimetres:
11,12,16,13,11。（。429,。468,。624,。507,。429inch。——Translator\'sNote。）
Thefiveupperonesmeasurebetweentheirpartitions:
7,7,5,6,7。（。273,。273,。195,。234,。273inch。——Translator\'sNote。）
Areed—stump11millimetres（。429inch。——Translator\'sNote。）acrosstheinsidecontainsfifteencells;andtherespectivedistancesbetweenthepartitionsofthosecells,startingfromthebottom,are:
13,12,12,9,9,11,8,8,7,7,7,6,6,6,7。（。507,。468,。468,。351,。351,。429,。312,。312,。273,。273,。273,。234,。234,。234,。273inch。——Translator\'sNote。）
Whenthediameterofthetunnelisless,thepartitionscanbestillfurtherapart,thoughtheyretainthegeneralcharacteristicofbeingclosertooneanotherthenearertheyaretotheorifice。Areedoffivemillimetres（。195inch。——Translator\'sNote。）indiameter,givesmethefollowingdistances,alwaysstartingfromthebottom:
22,22,20,20,12,14。（。858,。858,。78,。78,。468,。546inch。——
Translator\'sNote。）
Another,of9millimetres（。351inch。——Translator\'sNote。）,givesme:
15,14,11,10,10,9,10。（。585,。546,。429,。39,。39,。351,。39
inch。——Translator\'sNote。）
Aglasstubeof8millimetres（。312inch。——Translator\'sNote。）
yields:
15,14,20,10,10,10。（。585,。546,。78,。39,。39,。39inch。——
Translator\'sNote。）。
Icouldfillpagesandpageswithsuchfigures,ifIcaredtoprintallmynotes。DotheyprovethattheOsmiaisageometrician,employingastrictmeasurebasedonthelengthofherbody？Certainlynot,becausemanyofthosefiguresexceedthelengthoftheinsect;
becausesometimesahighernumberfollowssuddenlyuponalower;
becausethesamestringcontainsafigureofonevalueandanotherfigureofbuthalfthatvalue。Theyproveonlyonething:themarkedtendencyoftheinsecttoshortenthedistancebetweentheparty—
wallsastheworkproceeds。Weshallseelaterthatthelargecellsaredestinedforthefemalesandthesmallonesforthemales。
Istherenotatleastameasuringadaptedtoeachsex？Again,notso;
forinthefirstseries,wherethefemalesarehoused,insteadoftheintervalof11millimetres,whichoccursatthebeginningandtheend,wefind,inthemiddleoftheseries,anintervalof16
millimetres,whileinthesecondseries,reservedforthemales,insteadoftheintervalof7millimetresatthebeginningandtheend,wehaveanintervalof5millimetresinthemiddle。Itisthesamewiththeotherseries,eachofwhichshowsastrikingdiscrepancyinitsfigures。IftheOsmiareallystudiedthedimensionsofherchambersandmeasuredthemwiththecompassesofherbody,howcouldshe,withherdelicatemechanism,failtonoticemistakesof5millimetres,almosthalfherownlength？
Besides,allideaofgeometryvanishesifweconsidertheworkinatubeofmoderatewidth。Here,theOsmiadoesnotfixthefrontpartitioninadvance;shedoesnotevenlayitsfoundation。Withoutanyboundary—pad,withnoguidingmarkforthecapacityofthecell,shebusiesherselfstraightwaywiththeprovisioning。WhentheheapofBee—breadisjudgedsufficient,thatis,Iimagine,whenhertiredbodytellsherthatshehasdoneenoughharvesting,sheclosesupthechamber。Inthiscase,thereisnomeasuring;andyetthecapacityofthecellandthequantityofthevictualsfulfiltheregularrequirementsofoneortheothersex。
ThenwhatdoestheOsmiadowhensherepeatedlystopstotouchthefrontpartitionwithherforeheadandthebackpartition,theoneinthecourseofbuilding,withthetipofherabdomen？Ihavenoideawhatshedoesorwhatshehasinview。Ileavetheinterpretationofthisperformancetoothers,moreventuresomethanI。Plentyoftheoriesarebasedonequallyshakyfoundations。Blowonthemandtheysinkintothequagmireofoblivion。
Thelayingisfinished,orperhapsthecylinderisfull。Afinalpartitionclosesthelastcell。Arampartisnowbuilt,attheorificeofthetubeitself,toforbidtheill—disposedallaccesstothehome。Thisisathickplug,amassyworkoffortification,whereontheOsmiaspendsenoughmortartopartitionoffanynumberofcells。Awholedayisnottoolongformakingthisbarricade,especiallyinviewoftheminutefinishing—touches,whentheOsmiafillsupwithputtyeverychinkthroughwhichtheleastatomcouldslip。Themasoncompletingawallsmoothshisplasterandbringsittoafinesurfacewhileitisstillwet;theOsmiadoesthesame,oralmost。Withlittletapsofthemandiblesandacontinualshakingofherhead,asignofherzestforthework,shesmoothsandpolishesthesurfaceofthelidforhoursatatime。Aftersuchpains,whatfoecouldvisitthedwelling？
Andyetthereisone,anAnthrax,A。sinuata（Cf。\"TheLifeoftheFly\":chapters2and4。——Translator\'sNote。）,whowillcomelateron,intheheightofsummer,andsucceed,invisiblebitofthreadthatsheis,inmakingherwaytothegrubthroughthethicknessofthedoorandthewebofthecocoon。Inmanycells,mischiefofanotherkindhasalreadybeendone。Duringtheprogressoftheworks,animpudentMidge,oneoftheTachina—flies,whofeedsherfamilyonthevictualsamassedbytheBee,hoversinfrontofthegalleries。Doesshepenetratetothecellsandlayhereggsthereinthemother\'sabsence？Icouldnevercatchthesneakintheact。Doesshe,likethatotherTachinawhoravagescellsstockedwithgame（ThecellsoftheHuntingWasps。——Translator\'sNote。）,nimblydeposithereggsontheOsmia\'sharvestatthemomentwhentheBeeisgoingindoors？Itispossible,thoughIcannotsayforcertain。ThefactremainsthatwesoonseetheMidge\'sgrub—wormsswarmingaroundthelarva,thedaughterofthehouse。Thereareten,fifteen,twentyormoreofthemgnawingwiththeirpointedmouthsatthecommondishandturningthefoodintoaheapoffine,orange—colouredvermicelli。TheBee\'sgrubdiesofstarvation。Itislife,lifeinallitsferocityeveninthesetinycreatures。Whatanexpenditureofardentlabour,ofdelicatecares,ofwiseprecautions,toarriveat……what？HeroffspringsuckedanddraineddrybythehatefulAnthrax;herfamilysweatedandstarvedbytheinfernalTachina。
Thevictualsconsistmostlyofyellowflour。Inthecentreoftheheap,alittlehoneyisdisgorged,whichturnsthepollen—dustintoafirm,reddishpaste。Onthispastetheeggislaid,notflat,butupright,withthefore—endfreeandthehind—endlightlyheldandfixedintheplasticmass。Whenhatched,theyounggrub,keptinitsplacebyitsrear—end,needonlybenditsneckalittletofindthehoney—soakedpasteunderitsmouth。Whenitgrowsstronger,itwillreleaseitselffromitssupportandeatupthesurroundingflour。
Allthisistouching,initsmaternallogic。Forthenew—born,daintybread—and—honey;fortheadolescent,drybread。Incaseswheretheprovisionsareallofakind,thesedelicateprecautionsaresuperfluous。ThevictualsoftheAnthophoraeandtheChalicodomaeconsistofflowinghoney,thesamethroughout。Theeggisthenlaidatfulllengthonthesurface,withoutanyparticulararrangement,thuscompellingthenew—borngrubtotakeitsfirstmouthfulsatrandom。Thishasnodrawback,asthefoodisofthesamequalitythroughout。But,withtheOsmia\'sprovisions——drypowderontheedges,jaminthecentre——thegrubwouldbeindangerifitsfirstmealwerenotregulatedinadvance。Tobeginwithpollennotseasonedwithhoneywouldbefataltoitsstomach。Havingnochoiceofitsmouthfulsbecauseofitsimmobilityandbeingobligedtofeedonthespotwhereitwashatched,theyounggrubmustneedsbebornonthecentralmass,whereithasonlytobenditsheadalittlewayinordertofindwhatitsdelicatestomachcallsfor。Theplaceoftheegg,therefore,fixeduprightbyitsbaseinthemiddleoftheredjam,ismostjudiciouslychosen。WhatacontrastbetweenthisexquisitematernalforethoughtandthehorribledestructionbytheAnthraxandtheMidge！
TheeggisratherlargeforthesizeoftheOsmia。Itiscylindrical,slightlycurved,roundedatbothendsandtransparent。Itsoonbecomescloudy,whileremainingdiaphanousateachextremity。Finelines,hardlyperceptibletothemostpenetratinglens,showthemselvesintransversecircles。Thesearethefirstsignsofsegmentation。Acontractionappearsinthefronthyalinepart,markingthehead。Anextremelythinopaquethreadrunsdowneitherside。Thisisthecordoftracheaecommunicatingbetweenonebreathing—holeandanother。Atlast,thesegmentsshowdistinctly,withtheirlateralpads。Thegrubisborn。
Atfirst,onewouldthinkthattherewasnohatchinginthepropersenseoftheword——thatistosay,noburstingandcastingofawrapper。Themostminuteattentionisnecessarytoshowthatappearancesaredeceptiveandthatactuallyafinemembraneisthrownofffromfronttoback。Thisinfinitesimalshredistheshelloftheegg。
Thegrubisborn。Fixedbyitsbase,itcurvesintoanarcandbendsitshead,untilnowhelderect,downtotheredmass。Themealbegins。Soonayellowcordoccupyingthefronttwo—thirdsofthebodyproclaimsthatthedigestiveapparatusisswellingoutwithfood。Forafortnight,consumeyourprovenderinpeace,mychild;thenspinyourcocoon:youarenowsafefromtheTachina！ShallyoubesafefromtheAnthrax\'suckerlateron？Alack！
CHAPTER3。THEDISTRIBUTIONOFTHESEXES。
Doestheinsectknowbeforehandthesexoftheeggwhichitisabouttolay？Whenexaminingthestockoffoodinthecellsjustnow,webegantosuspectthatitdoes,foreachlittleheapofprovisionsiscarefullyproportionedtotheneedsatonetimeofamaleandatanotherofafemale。Whatwehavetodoistoturnthissuspicionintoacertaintydemonstratedbyexperiment。Andfirstletusfindouthowthesexesarearranged。
Itisnotpossibletoascertainthechronologicalorderofalaying,exceptbygoingtosuitably—chosenspecies。DigginguptheburrowsofCerceris—,Bembex—orPhilanthus—waspswillnevertellusthatthisgrubhastakenprecedenceofthatinpointoftimenorenableustodecidewhetheronecocooninacolonybelongstothesamefamilyasanother。Tocompilearegisterofbirthsisabsolutelyimpossiblehere。Fortunatelythereareafewspeciesinwhichwedonotfindthisdifficulty:thesearetheBeeswhokeeptoonegalleryandbuildtheircellsinstoreys。Amongthenumberarethedifferentinhabitantsofthebramble—stumps,notablytheThree—prongedOsmiae,whoformanexcellentsubjectforobservation,partlybecausetheyareofimposing—size——biggerthananyotherbramble—dwellersinmyneighbourhood——partlybecausetheyaresoplentiful。
LetusbrieflyrecalltheOsmia\'shabits。Amidthetangleofahedge,abramble—stalkisselected,stillstanding,butamerewitheredstump。Inthistheinsectdigsamoreorlessdeeptunnel,aneasypieceofworkowingtotheabundanceofsoftpith。Provisionsareheapeduprightatthebottomofthetunnelandaneggislaidonthesurfaceofthefood:thatisthefirst—bornofthefamily。Ataheightofsometwelvemillimetres（Abouthalfaninch。——Translator\'sNote。）,apartitionisfixed,formedofbramblesaw—dustandofagreenpasteobtainedbymasticatingparticlesoftheleavesofsomeplantthathasnotyetbeenidentified。Thisgivesasecondstorey,whichinitsturnreceivesprovisionsandanegg,thesecondinorderofprimogeniture。Andsoitgoeson,storeybystorey,untilthecylinderisfull。Thenathickplugofthesamegreenmaterialofwhichthepartitionsareformedclosesthehomeandkeepsoutmarauders。
Inthiscommoncradle,thechronologicalorderofbirthsisperfectlyclear。Thefirst—bornofthefamilyisatthebottomoftheseries;
thelast—bornisatthetop,nearthecloseddoor。Theothersfollowfrombottomtotopinthesameorderinwhichtheyfollowedinpointoftime。Thelayingisnumberedautomatically;eachcocoontellsusitsrespectiveagebytheplacewhichitoccupies。
Toknowthesexes,wemustwaitforthemonthofJune。Butitwouldbeunwisetopostponeourinvestigationsuntilthatperiod。Osmia—
nestsarenotsocommonthatwecanhopetopickoneupeachtimethatwegooutwiththatobject;besides,ifwewaitforthehatching—periodbeforeexaminingthebrambles,itmayhappenthattheorderhasbeendisturbedthroughsomeinsects\'havingtriedtomaketheirescapeassoonaspossibleafterburstingtheircocoons;itmayhappenthatthemaleOsmiae,whoaremoreforwardthanthefemales,arealreadygone。Ithereforesettoworkalongtimebeforehandanddevotemyleisureinwintertotheseinvestigations。
Thebramble—sticksaresplitandthecocoonstakenoutonebyoneandmethodicallytransferredtoglasstubes,ofapproximatelythesamediameterasthenativecylinder。Thesecocoonsarearrangedoneontopoftheotherinexactlythesameorderthattheyoccupiedinthebramble;theyareseparatedfromoneanotherbyacottonplug,aninsuperableobstacletothefutureinsect。Thereisthusnofearthatthecontentsofthecellsmaybecomemixedortransposed;andIamsavedthetroubleofkeepingalaboriouswatch。Eachinsectcanhatchatitsowntime,inmypresenceornot:Iamsureofalwaysfindingitinitsplace,initsproperorder,heldfastforeandaftbythecottonbarrier。Acorkorsorghum—pithpartitionwouldnotfulfilthesamepurpose:theinsectwouldperforateitandtheregisterofbirthswouldbemuddledbychangesofposition。Anyreaderwishingtoundertakesimilarinvestigationswillexcusethesepracticaldetails,whichmayfacilitatehiswork。
Wedonotoftencomeuponcompleteseries,comprisingthewholelaying,fromthefirst—borntotheyoungest。Asarule,wefindpartofalaying,inwhichthenumberofcocoonsvariesgreatly,sometimesfallingaslowastwo,orevenone。Themotherhasnotdeemeditadvisabletoconfideherwholefamilytoasinglebramble—stump;inordertomaketheexitlesstoilsome,orelseforreasonswhichescapeme,shehasleftthefirsthomeandelectedtomakeasecondhome,perhapsathirdormore。
Wealsofindserieswithbreaksinthem。Sometimes,incellsdistributedatrandom,theegghasnotdevelopedandtheprovisionshaveremaineduntouched,butmildewed;sometimes,thelarvahasdiedbeforespinningitscocoon,orafterspinningit。Lastly,thereareparasites,suchastheUnarmedZonitis（Zonitismutica,oneoftheOil—beetles。——Translator\'sNote。）andtheSpottedSapyga（ADigger—
wasp。——Translator\'sNote。）,whointerrupttheseriesbysubstitutingthemselvesfortheoriginaloccupant。AllthesedisturbingfactorsmakeitnecessarytoexaminealargenumberofnestsoftheThree—
prongedOsmia,ifwewouldobtainadefiniteresult。
Ihavebeenstudyingthebramble—dwellersforsevenoreightyearsandIcouldnotsayhowmanystringsofcocoonshavepassedthroughmyhands。Duringarecentwinter,inviewparticularlyofthedistributionofthesexes,IcollectedsomefortyofthisOsmia\'snests,transferredtheircontentsintoglasstubesandmadeacarefulsummaryofthesexes。Igivesomeofmyresults。Thefiguresstartintheirorderfromthebottomofthetunnelduginthebrambleandproceedupwardstotheorifice。Thefigure1thereforedenotesthefirst—bornoftheseries,theoldestindate;thehighestfiguredenotesthelast—born。TheletterM,placedunderthecorrespondingfigure,representsthemaleandtheletterFthefemalesex。
123456789101112131415
FFMFMFMMFFFFMFM
ThisisthelongestseriesthatIhaveeverbeenabletoprocure。Itisalsocomplete,inasmuchasitcomprisestheentirelayingoftheOsmia。Mystatementrequiresexplaining,otherwiseitwouldseemimpossibletoknowwhetheramotherwhoseactsonehasnotwatched,naymore,whomonehasneverseen,hasorhasnotfinishedlayinghereggs。Thebramble—stumpunderconsiderationleavesafreespaceofnearlyfourinchesabovethecontinuousstringofcocoons。Beyondit,attheactualorifice,istheterminalstopper,thethickplugwhichclosestheentrancetothegallery。Inthisemptyportionofthetunnelthereisampleaccommodationfornumerouscocoons。Thefactthatthemotherhasnotmadeuseofitprovesthatherovarieswereexhausted;foritisexceedinglyunlikelythatshehasabandonedfirst—ratelodgingstogolaboriouslydigginganewgalleryelsewhereandtherecontinueherlaying。
Youmaysaythat,iftheunoccupiedspacemarkstheendofthelaying,nothingtellsusthatthebeginningisactuallyatthebottomofthecul—de—sac,attheotherendofthetunnel。Youmayalsosaythatthelayingisdoneinshifts,separatedbyintervalsofrest。
Thespaceleftemptyinthechannelwouldmeanthatoneoftheseshiftswasfinishedandnotthattherewerenomoreeggsripeforhatching。Inanswertotheseveryplausibleexplanations,Iwillsaythat,thesumofmyobservations——andtheyhavebeenextremelynumerous——isthatthetotalnumberofeggslaidnotonlybytheOsmiaebutbyahostofotherBeesfluctuatesroundaboutfifteen。
Besides,whenweconsiderthattheactivelifeoftheseinsectslastshardlyamonth;whenwerememberthatthisperiodofactivityisdisturbedbydark,rainyorverywindydays,duringwhichallworkissuspended;whenlastlyweascertain,asIhavedoneadnauseaminthecaseoftheThree—hornedOsmia,thetimerequiredforbuildingandvictuallingacell,itbecomesobviousthatthetotallayingmustbekeptwithinnarrowboundsandthatthemotherhasnotimetoloseifshewishestogetfifteencellssatisfactorilybuiltinthreeorfourweeksinterruptedbycompulsoryrests。Ishallgivesomefactslaterwhichwilldispelyourdoubts,ifanyremain。
Iassume,therefore,thatanumberofeggsborderingonfifteenrepresentstheentirefamilyofanOsmia,asitdoesofmanyotherBees。
Letusconsultsomeothercompleteseries。Herearetwo:
12345678910111213
FFMFMFMFFFFMF
FMFFFMFFMFM
Inbothcases,thelayingistakenascomplete,forthesamereasonsasabove。
Wewillendwithsomeseriesthatappeartomeincomplete,inviewofthesmallnumberofcellsandtheabsenceofanyfreespaceabovethepileofcocoons:
12345678
MMFMMMMM
MMFMFMMM
FMFFMM
MMMFM
FFFF
MMM
FM
Theseexamplesaremorethansufficient。Itisquiteevidentthatthedistributionofthesexesisnotgovernedbyanyrule。AllthatIcansayonconsultingthewholeofmynotes,whichcontainagoodmanyinstancesofcompletelayings——mostofthem,unfortunately,spoiltthroughgapscausedbyparasites,thedeathofthelarva,thefailureoftheeggtohatchandotheraccidents——allthatIcansayingeneralisthatthecompleteseriesbeginswithfemalesandnearlyalwaysendswithmales。Theincompleteseriescanteachusnothinginthisrespect,fortheyareonlyfragmentsstartingweknownotwhence;anditisimpossibletotellwhethertheyshouldbeascribedtothebeginning,totheend,ortoanintermediateperiodofthelaying。Tosumup:inthelayingoftheThree—prongedOsmia,noordergovernsthesuccessionofthesexes;only,theserieshasamarkedtendencytobeginwithfemalesandtofinishwithmales。
Thebrambles,inmydistrict,harbourtwootherOsmiae,bothofmuchsmallersize:O。detrita,PEREZ,andO。parvula,DUF。Thefirstisverycommon,thesecondveryrare;anduntilnowIhavefoundonlyoneofhernests,placedaboveanestofO。detrita,inthesamebramble。Here,insteadofthelackoforderinthedistributionofthesexeswhichwefindwithO。tridentata,wehaveanorderremarkableforconsistencyandsimplicity。IhavebeforemethelistoftheseriesofO。detritacollectedlastwinter。Herearesomeofthem:
1。Aseriesoftwelve:sevenfemales,beginningwiththebottomofthetunnel,andthenfivemales。
2。Aseriesofnine:threefemalesfirst,thensixmales。
3。Aseriesofeight:fivefemalesfollowedbythreemales。
4。Aseriesofeight:sevenfemalesfollowedbyonemale。
5。Aseriesofeight:onefemalefollowedbysevenmales。
6。Aseriesofseven:sixfemalesfollowedbyonemale。
Thefirstseriesmightverywellbecomplete。Thesecondandfifthappeartobetheendoflayings,ofwhichthebeginninghastakenplaceelsewhere,inanotherbramble—stump。Themalespredominateandfinishofftheseries。Nos。3,4and6,ontheotherhand,looklikethebeginningsoflayings:thefemalespredominateandareattheheadoftheseries。Eveniftheseinterpretationsshouldbeopentodoubt,oneresultatleastiscertain:withO。detrita,thelayingisdividedintotwogroups,withnointerminglingofthesexes;thefirstgrouplaidyieldsnothingbutfemales,thesecond,ormorerecent,yieldsnothingbutmales。
WhatwasonlyasortofattemptwiththeThree—prongedOsmia——who,itistrue,beginswithfemalesandendswithmales,butmuddlesuptheorderandmixesthetwosexesanyhowbetweentheextremepoints——
becomesaregularlawwithherkinswoman。Themotheroccupiesherselfatthestartwiththestrongersex,themorenecessary,thebetter—
gifted,thefemalesex,towhichshedevotesthefirstflushofherlayingandthefullnessofhervigour;later,whensheisperhapsalreadyattheendofherstrength,shebestowswhatremainsofhermaternalsolicitudeupontheweakersex,theless—gifted,almostnegligiblemalesex。
O。parvula,ofwhomIunfortunatelypossessbutoneseries,repeatswhatthepreviouswitnesshasjustshownus。Thisseries,oneofninecocoons,comprisesfivefemalesfollowedbyfourmales,withoutanymixingofthesexes。
Nexttothesedisgorgersofhoneyandgleanersofpollen—dust,itwouldbewelltoconsultotherHymenoptera,Waspswhodevotethemselvestothechaseandpiletheircellsoneaftertheother,inarow,showingtherelativeageofthecocoons。Thebrambleshouseseveralofthese:Soleniusvagus,whostoresupFlies;Psenatratus,whoprovideshergrubswithaheapofPlant—lice;Trypoxylonfigulus,whofeedsthemwithSpiders。
Soleniusvagusdigshergalleryinabramble—stickthatisloppedshort,butstillfreshandgreen。ThehouseofthisFly—huntress,therefore,suffersfromdamp,asthesapenters,especiallyonthelowerfloors。Thisseemstomeratherinsanitary。Toavoidthehumidity,orforotherreasonswhichescapeme,theSoleniusdoesnotdigveryfarintoherbramble—stumpandconsequentlycanstackbutasmallnumberofcellsinit。Aseriesoffivecocoonsgivesmefirstfourfemalesandthenonemale;anotherseries,alsooffive,containsfirstthreefemales,withtwomalesfollowing。ThesearethemostcompletethatIhaveforthemoment。
IreckonedontheBlackPsen,orPsenatratus,whoseseriesareprettylong;itisapitythattheyarenearlyalwaysgreatlyinterferedwithbyaparasitecalledEphialtesmediator。（Cf。\"TheLifeoftheFly\":chapter2。——Translator\'sNote。）Iobtainedonlythreeseriesfreefromgaps:oneofeightcocoons,comprisingonlyfemales;oneofsix,likewiseconsistingwhollyoffemales;lastly,oneofeight,formedexclusivelyofmales。TheseinstancesseemtoshowthatthePsenarrangesherlayinginasuccessionoffemalesandasuccessionofmales;buttheytellusnothingoftherelativeorderofthetwoseries。
>FromtheSpider—huntress,Trypoxylonfigulus,Ilearntnothingdecisive。Sheappearedtometoroveaboutfromonebrambletothenext,utilizinggallerieswhichshehasnotdugherself。Nottroublingtobeeconomicalwithalodgingwhichithascosthernothingtoacquire,shecarelesslybuildsafewpartitionsatveryunequalheights,stuffsthreeorfourcompartmentswithSpidersandpassesontoanotherbramble—stump,withnoreason,sofarasIknow,forabandoningthefirst。Hercells,therefore,occurinseriesthataretooshorttogiveusanyusefulinformation。
Thisisallthatthebramble—dwellershavetotellus;Ihaveenumeratedthelistoftheprincipalonesinmydistrict。WewillnowlookintosomeotherBeeswhoarrangetheircocoonsinsinglefiles:
theMegachiles（Cf。Chapter8ofthepresentvolume。——Translator\'sNote。）,whocutdisksoutofleavesandfashionthedisksintothimble—shapedreceptacles;theAnthidia（Cf。Chapters9and10ofthepresentvolume。——Translator\'sNote。）,whoweavetheirhoney—
walletsoutofcotton—woolandarrangetheircellsoneaftertheotherinsomecylindricalgallery。Inmostcases,thehomeistheproduceofneithertheonenortheother。Atunnelintheupright,earthybanks,theoldworkofsomeAnthophora,istheusualdwelling。
Thereisnogreatdepthtotheseretreats;andallmysearches,zealouslyprosecutedduringanumberofwinters,procuredmeonlyseriescontainingasmallnumberofcocoons,fourorfiveatmost,oftenonealone。And,whatisquiteasserious,nearlyalltheseseriesarespoiltbyparasitesandallowmetodrawnowell—foundeddeductions。
Irememberedfinding,atrareintervals,nestsofboththeAnthidiumandtheMegachileinthehollowsofcutreeds。Ithereuponinstalledsomehivesofanewkindonthesunniestwallsofmyenclosure。Theyconsistedofstumpsofthegreatreedofthesouth,openatoneend,closedattheotherbythenaturalknotandgatheredintoasortofenormouspan—pipe,suchasPolyphemusmighthaveemployed。Theinvitationwasaccepted:Osmiae,AnthidiaandMegachilescameinfairlylargenumbers,especiallythefirst,tobenefitbythequeerinstallation。