Gallinaceousbirdsofmanygeneralikewiseshowaneminentcapacityforbreedingundercaptivity。Thisisparticularlythecasewithpheasants，yetourEnglishspeciesseldomlaysmorethanteneggsinconfinement;whilstfromeighteentotwentyistheusualnumberinthewildstate。（18/48。Mowbrayon’Poultry’7theditionpage133。）WiththeGallinaceae，aswithallotherorders，therearemarkedandinexplicableexceptionsinregardtothefertilityofcertainspeciesandgeneraunderconfinement。Althoughmanytrialshavebeenmadewiththecommonpartridge，ithasrarelybred，evenwhenrearedinlargeaviaries;andthehenwillneverhatchherowneggs。（18/49。
Temminck’Hist。Nat。Gen。desPigeons’etc。1813tome3pages288，382;
’AnnalsandMag。ofNat。Hist。’volume121843page453。Otherspeciesofpartridgehaveoccasionallybred;asthered—legged（P。rubra），whenkeptinalargecourtinFrance（seeJournaldePhysique’tome25page294），andintheZoologicalGardensin1856。）TheAmericantribeofGuansorCracidaearetamedwithremarkableease，butareveryshybreedersinthiscountry（18/50。Rev。
E。S。Dixon’TheDovecote’1851pages243—252。）;butwithcarevariousspecieswereformerlymadetobreedratherfreelyinHolland。（18/51。Temminck’Hist。
Nat。Gen。desPigeons’etc。tome2pages456，458;tome3pages2，13，47。）
BirdsofthistribeareoftenkeptinaperfectlytamedconditionintheirnativecountrybytheIndians，buttheyneverbreed。（18/52。Bates’TheNaturalistontheAmazons’volume1page193;volume2page112。）Itmighthavebeenexpectedthatgrousefromtheirhabitsoflifewouldnothavebredincaptivity，moreespeciallyastheyaresaidsoontolanguishanddie。
（18/53。Temminck’Hist。Nat。Gen。’etc。tome2page125。ForTetraourogallusseeL。Lloyd’FieldSportsofNorthofEurope’volume1pages287，314;andBull。delaSoc。d’Acclimat。’tome71860page600。ForT。scoticusThompson’Nat。Hist。ofIreland’volume21850page49。ForT。cupido’BostonJournalofNat。Hist。’volume3page199。）Butmanycasesarerecordedoftheirbreeding:thecapercailzie（Tetraourogallus）hasbredintheZoologicalGardens;itbreedswithoutmuchdifficultywhenconfinedinNorway，andinRussiafivesuccessivegenerationshavebeenreared:TetraotetrixhaslikewisebredinNorway;T。scoticusinIreland;T。umbellusatLordDerby’s;
andT。cupidoinNorthAmerica。
Itisscarcelypossibletoimagineagreaterchangeinhabitsthanthatwhichthemembersoftheostrichfamilymustsuffer，whencoopedupinsmallenclosuresunderatemperateclimate，afterfreelyroamingoverdesertandtropicalplainsorentangledforests;yetalmostallthekindshavefrequentlyproducedyounginthevariousEuropeanmenageries，eventhemooruk（Casuariusbennetii）fromNewIreland。TheAfricanostrich，thoughperfectlyhealthyandlivinglongintheSouthofFrance，neverlaysmorethanfromtwelvetofifteeneggs，thoughinitsnativecountryitlaysfromtwenty—fivetothirty。
（18/54。MarceldeSerres’AnnalesdesSc。Nat。’2ndseriesZoolog。tome13
page175。）Herewehaveanotherinstanceoffertilityimpaired，butnotlost，underconfinement，aswiththeflyingsquirrel，thehen—pheasant，andtwospeciesofAmericanpigeons。
MostWaderscanbetamed，astheRev。E。S。Dixoninformsme，withremarkablefacility;butseveralofthemareshort—livedunderconfinement，sothattheirsterilityinthisstateisnotsurprising。Thecranesbreedmorereadilythanothergenera:GrusmontigresiahasbredseveraltimesinParisandintheZoologicalGardens，ashasG。cinereaatthelatterplace，andG。antigoneatCalcutta。Ofothermembersofthisgreatorder，TetrapteryxparadiseahasbredatKnowsley，aPorphyrioinSicily，andtheGallinulachloropusintheZoologicalGardens。Ontheotherhand，severalbirdsbelongingtothisorderwillnotbreedintheirnativecountry，Jamaica;andthePsophia，thoughoftenkeptbytheIndiansofGuianaabouttheirhouses，"isseldomorneverknowntobreed。"（18/55。Dr。Hancockin’Charlesworth’sMag。ofNat。Hist。’volume2
1838page491;R。Hill’AWeekatPortRoyal’page8;’GuidetotheZoologicalGardens’byP。L。Sclater1859pages11，12;’TheKnowsleyMenagerie’byD。
Gray1846p1。14;E。Blyth’ReportAsiaticSoc。ofBengal’May1855。）
ThemembersofthegreatDuckfamilybreedasreadilyinconfinementasdotheColumbaeandGallinaeandthis，consideringtheiraquaticandwanderinghabits，andthenatureoftheirfood，couldnothavebeenanticipated。EvensometimeagoabovetwodozenspecieshadbredintheZoologicalGardens;andM。Selys—Longchampshasrecordedtheproductionofhybridsfromforty—fourdifferentmembersofthefamily;andtotheseProfessorNewtonhasaddedafewmorecases。（18/56。Prof。Newtonin’Proc。Zoolog。Soc。’1860page336。）
"Thereisnot，"saysMr。Dixon（18/57。’TheDovecoteandAviary’page428。），"inthewideworld，agoosewhichisnotinthestrictsenseoftheworddomesticable;"thatis，capableofbreedingunderconfinement;butthisstatementisprobablytoobold。Thecapacitytobreedsometimesvariesinindividualsofthesamespecies;thusAudubon（18/58。’OrnithologicalBiography’volume3page9。）keptformorethaneightyearssomewildgeese（Ansercanadensis），buttheywouldnotmate;whilstotherindividualsofthesamespeciesproducedyoungduringthesecondyear。Iknowofbutoneinstanceinthewholefamilyofaspecieswhichabsolutelyrefusestobreedincaptivity，namely，theDendrocygnaviduata，although，accordingtoSirR。
Schomburgk（18/59。’Geograph。Journal’volume131844page32。），itiseasilytamed，andisfrequentlykeptbytheIndiansofGuiana。Lastly，withrespecttoGulls，thoughmanyhavebeenkeptintheZoologicalGardensandintheoldSurreyGardens，noinstancewasknownbeforetheyear1848oftheircouplingorbreeding;butsincethatperiodtheherringgull（Larusargentatus）hasbredmanytimesintheZoologicalGardensandatKnowsley。
Thereisreasontobelievethatinsectsareaffectedbyconfinementlikethehigheranimals。ItiswellknownthattheSphingidaerarelybreedwhenthustreated。Anentomologist（18/60。Loudon’s’Mag。ofNat。Hist。’volume51832
page153。）inPariskepttwenty—fivespecimensofSaturniapyri，butdidnotsucceedingettingasinglefertileegg。AnumberoffemalesofOrthosiamundaandofMamestrasuasarearedinconfinementwereunattractivetothemales。
（18/61。’Zoologist’volumes5—61847—48page1660。）Mr。NewportkeptnearlyahundredindividualsoftwospeciesofVanessa，butnotonepaired;this，however，mighthavebeenduetotheirhabitofcouplingonthewing。（18/62。
’Transact。Entomolog。Soc。’volume41845page60。）Mr。AtkinsoncouldneversucceedinIndiainmakingtheTarroosilk—mothbreedinconfinement。（18/63。
’Transact。Linn。Soc。’volume7page40。）Itappearsthatanumberofmoths，especiallytheSphingidae，whenhatchedintheautumnoutoftheirproperseason，arecompletelybarren;butthislattercaseisstillinvolvedinsomeobscurity。（18/64。SeeaninterestingpaperbyMr。Newmaninthe’Zoologist’
1857page5764;andDr。Wallacein’Proc。Entomolog。Soc。’June4，1860page119。）]
Independentlyofthefactofmanyanimalsunderconfinementnotcoupling，or，iftheycouple，notproducingyoung，thereisevidenceofanotherkindthattheirsexualfunctionsaredisturbed。Formanycaseshavebeenrecordedofthelossbymalebirdswhenconfinedoftheircharacteristicplumage。Thusthecommonlinnet（Linotacannabina）whencageddoesnotacquirethefinecrimsoncolouronitsbreast，andoneofthebuntings（Emberizapasserina）losestheblackonitshead。APyrrhulaandanOriolushavebeenobservedtoassumethequietplumageofthehen—bird;andtheFalcoalbidusreturnedtothedressofanearlierage。（18/65。Yarrell’BritishBirds’volume1page506;Bechstein’Stubenvogel’s。185;’Philosoph。Transact。’1772page271。Bronn’GeschichtederNatur’b。2s。96hascollectedanumberofcases。Forthecaseofthedeersee’PennyCyclop。’volume8page350。）Mr。Thompson，thesuperintendentoftheKnowsleymenagerie，informedmethathehadoftenobservedanalogousfacts。Thehornsofamaledeer（Cervuscanadensis）duringthevoyagefromAmericawerebadlydeveloped;butsubsequentlyinParisperfecthornswereproduced。
Whenconceptiontakesplaceunderconfinement，theyoungareoftenborndead，ordiesoon，orareill—formed。ThisfrequentlyoccursintheZoologicalGardens，and，accordingtoRengger，withnativeanimalsconfinedinParaguay。
Themother’smilkoftenfails。Wemayalsoattributetothedisturbanceofthesexualfunctionsthefrequentoccurrenceofthatmonstrousinstinctwhichleadsthemothertodevourherownoffspring，——amysteriouscaseofperversion，asitatfirstappears。
Sufficientevidencehasnowbeenadvancedtoprovethatanimalswhenfirstconfinedareeminentlyliabletosufferintheirreproductivesystems。Wefeelatfirstnaturallyinclinedtoattributetheresulttolossofhealth，oratleasttolossofvigour;butthisviewcanhardlybeadmittedwhenwereflecthowhealthy，long—lived，andvigorousmanyanimalsareundercaptivity，suchasparrots，andhawkswhenusedforhawking，cheetahswhenusedforhunting，andelephants。Thereproductiveorgansthemselvesarenotdiseased;andthediseases，fromwhichanimalsinmenageriesusuallyperish，arenotthosewhichinanywayaffecttheirfertility。Nodomesticanimalismoresubjecttodiseasethanthesheep，yetitisremarkablyprolific。Thefailureofanimalstobreedunderconfinementhasbeensometimesattributedexclusivelytoafailureintheirsexualinstincts:thismayoccasionallycomeintoplay，butthereisnoobviousreasonwhythisinstinctshouldbeespeciallyliabletobeaffectedwithperfectlytamedanimals，except，indeed，indirectlythroughthereproductivesystemitselfbeingdisturbed。Moreover，numerouscaseshavebeengivenofvariousanimalswhichcouplefreelyunderconfinement，butneverconceive;or，iftheyconceiveandproduceyoung，thesearefewerinnumberthanisnaturaltothespecies。Inthevegetablekingdominstinctofcoursecanplaynopart;andweshallpresentlyseethatplantswhenremovedfromtheirnaturalconditionsareaffectedinnearlythesamemannerasanimals。
Changeofclimatecannotbethecauseofthelossoffertility，for，whilstmanyanimalsimportedintoEuropefromextremelydifferentclimatesbreedfreely，manyotherswhenconfinedintheirnativelandarecompletelysterile。
Changeoffoodcannotbethechiefcause;forostriches，ducks，andmanyotheranimals，whichmusthaveundergoneagreatchangeinthisrespect，breedfreely。Carnivorousbirdswhenconfinedareextremelysterile，whilstmostcarnivorousmammals，exceptplantigrades，aremoderatelyfertile。Norcantheamountoffoodbethecause;forasufficientsupplywillcertainlybegiventovaluableanimals;andthereisnoreasontosupposethatmuchmorefoodwouldbegiventothemthantoourchoicedomesticproductionswhichretaintheirfullfertility。Lastly，wemayinferfromthecaseoftheelephant，cheetah，varioushawks，andofmanyanimalswhichareallowedtoleadanalmostfreelifeintheirnativeland，thatwantofexerciseisnotthesolecause。
Itwouldappearthatanychangeinthehabitsoflife，whateverthesehabitsmaybe，ifgreatenough，tendstoaffectinaninexplicablemannerthepowersofreproduction。Theresultdependsmoreontheconstitutionofthespeciesthanonthenatureofthechange;forcertainwholegroupsareaffectedmorethanothers;butexceptionsalwaysoccur，forsomespeciesinthemostfertilegroupsrefusetobreed，andsomeinthemoststerilegroupsbreedfreely。
Thoseanimalswhichusuallybreedfreelyunderconfinement，rarelybreed，asI
wasassured，intheZoologicalGardens，withinayearortwoaftertheirfirstimportation。Whenananimalwhichisgenerallysterileunderconfinementhappenstobreed，theyoungapparentlydonotinheritthispower:forhadthisbeenthecase，variousquadrupedsandbirds，whicharevaluableforexhibition，wouldhavebecomecommon。Dr。Brocaevenaffirms（18/66。’JournaldePhysiologie’tome2page347。）thatmanyanimalsintheJardindesPlantes，afterhavingproducedyoungforthreeorfoursuccessivegenerations，becomesterile;butthismaybetheresultoftoocloseinterbreeding。Itisaremarkablecircumstancethatmanymammalsandbirdshaveproducedhybridsunderconfinementquiteasreadilyas，orevenmorereadilythan，theyhaveprocreatedtheirownkind。Ofthisfactmanyinstanceshavebeengiven（18/67。
ForadditionalevidenceonthissubjectseeF。Cuvierin’AnnalesduMuseum’
tome12page119。）;andwearethusremindedofthoseplantswhichwhencultivatedrefusetobefertilisedbytheirownpollen，butcaneasilybefertilisedbythatofadistinctspecies。Finally，wemustconclude，limitedastheconclusionis，thatchangedconditionsoflifehaveanespecialpowerofactinginjuriouslyonthereproductivesystem。Thewholecaseisquitepeculiar，fortheseorgans，thoughnotdiseased，arethusrenderedincapableofperformingtheirproperfunctions，orperformthemimperfectly。
[STERILITYOFDOMESTICATEDANIMALSFROMCHANGEDCONDITIONS。
Withrespecttodomesticatedanimals，astheirdomesticationmainlydependsontheaccidentoftheirbreedingfreelyundercaptivity，weoughtnottoexpectthattheirreproductivesystemwouldbeaffectedbyanymoderatedegreeofchange。Thoseordersofquadrupedsandbirds，ofwhichthewildspeciesbreedmostreadilyinourmenageries，haveaffordedusthegreatestnumberofdomesticatedproductions。Savagesinmostpartsoftheworldarefondoftaminganimals（18/68。Numerousinstancescouldbegiven。ThusLivingstone（’Travels’page217）statesthattheKingoftheBarotse，aninlandtribewhichneverhadanycommunicationwithwhitemen，wasextremelyfondoftaminganimals，andeveryyoungantelopewasbroughttohim。Mr。GaltoninformsmethattheDamarasarelikewisefondofkeepingpets。TheIndiansofSouthAmericafollowthesamehabit。Capt。WilkesstatesthatthePolynesiansoftheSamoanIslandstamedpigeons;andtheNewZealanders，asMr。Mantellinformsme，keptvariouskindsofbirds。）;andifanyoftheseregularlyproducedyoung，andwereatthesametimeuseful，theywouldbeatoncedomesticated。
If，whentheirmastersmigratedintoothercountries，theywereinadditionfoundcapableofwithstandingvariousclimates，theywouldbestillmorevaluable;anditappearsthattheanimalswhichbreedreadilyincaptivitycangenerallywithstanddifferentclimates。Somefewdomesticatedanimals，suchasthereindeerandcamel，offeranexceptiontothisrule。Manyofourdomesticatedanimalscanbearwithundiminishedfertilitythemostunnaturalconditions;forinstance，rabbits，guinea—pigs，andferretsbreedinmiserablyconfinedhutches。FewEuropeandogsofanykindwithstandtheclimateofIndiawithoutdegenerating，butaslongastheysurvive，theyretain，asIhearfromDr。Falconer，theirfertility;soitis，accordingtoDr。Daniell，withEnglishdogstakentoSierraLeone。Thefowl，anativeofthehotjunglesofIndia，becomesmorefertilethanitsparent—stockineveryquarteroftheworld，untilweadvanceasfarnorthasGreenlandandNorthernSiberia，wherethisbirdwillnotbreed。Bothfowlsandpigeons，whichIreceivedduringtheautumndirectfromSierraLeone，wereatoncereadytocouple。（18/69。ForanalogouscaseswiththefowlseeReaumur’L’ArtdefaireEclore’etc。1749
page243;andCol。Sykesin’Proc。Zoolog。Soc。’1832etc。WithrespecttothefowlnotbreedinginnorthernregionsseeLatham’Hist。ofBirds’volume8
1823page169。）Ihave，also，seenpigeonsbreedingasfreelyasthecommonkindswithinayearaftertheirimportationfromtheupperNile。Theguinea—
fowl，anaboriginalofthehotanddrydesertsofAfrica，whilstlivingunderourdampandcoolclimate，producesalargesupplyofeggs。
Nevertheless，ourdomesticatedanimalsundernewconditionsoccasionallyshowsignsoflessenedfertility。RoulinassertsthatinthehotvalleysoftheequatorialCordillerasheeparenotfullyfecund（18/70。"Mem。pardiversSavans"’Acad。desSciences’tome61835page347。）;andaccordingtoLordSomerville（18/71。’YouattonSheep’page181。）themerino—sheepwhichheimportedfromSpainwerenotatfirstperfectlyfertile，itissaid（18/72。J。
Mills’TreatiseonCattle’1776page72。）thatmaresbroughtupondryfoodinthestable，andturnedouttograss，donotatfirstbreed。Thepeahen，aswehaveseen，issaidnottolaysomanyeggsinEnglandasinIndia。Itwaslongbeforethecanary—birdwasfullyfertile，andevennowfirst—ratebreedingbirdsarenotcommon。（18/73。Bechstein’Stubenvogel’s。242。）InthehotanddryprovinceofDelhi，asIhearfromDr。Falconer，theeggsoftheturkey，thoughplacedunderahen，areextremelyliabletofail。AccordingtoRoulin，geesetakentotheloftyplateauofBogota，atfirstlaidseldom，andthenonlyafeweggs;ofthesescarcelyafourthwerehatched，andhalftheyoungbirdsdied;inthesecondgenerationtheyweremorefertile;andwhenRoulinwrotetheywerebecomingasfertileasourgeeseinEurope。WithrespecttothevalleyofQuito，Mr。Ortonsays（18/74。’TheAndesandtheAmazon’1870
page107。）"theonlygeeseinthevalleyareafewimportedfromEurope，andtheserefusetopropagate。"InthePhilippineArchipelagothegoose，itisasserted，willnotbreedorevenlayeggs。（18/75。Crawford’DescriptiveDict。
oftheIndianIslands’1856page145。）Amorecuriouscaseisthatofthefowl，which，accordingtoRoulin，whenfirstintroducedwouldnotbreedatCuscoinBolivia，butsubsequentlybecamequitefertile;andtheEnglishGamefowl，latelyintroduced，hadnotasyetarrivedatitsfullfertility，fortoraisetwoorthreechickensfromanestofeggswasthoughtfortunate。InEuropecloseconfinementhasamarkedeffectonthefertilityofthefowl:ithasbeenfoundinFrancethatwithfowlsallowedconsiderablefreedomonlytwentypercentoftheeggsfailed;whenallowedlessfreedomfortypercentfailed;andincloseconfinementsixtyoutofthehundredwerenothatched。
（18/76。’Bull。delaSoc。d’Acclimat。’tome91862pages380，384。）Soweseethatunnaturalandchangedconditionsoflifeproducesomeeffectonthefertilityofourmostthoroughlydomesticatedanimals，inthesamemanner，thoughinafarlessdegree，aswithcaptivewildanimals。
Itisbynomeansraretofindcertainmalesandfemaleswhichwillnotbreedtogether，thoughbothareknowntobeperfectlyfertilewithothermalesandfemales。Wehavenoreasontosupposethatthisiscausedbytheseanimalshavingbeensubjectedtoanychangeintheirhabitsoflife;thereforesuchcasesarehardlyrelatedtoourpresentsubject。Thecauseapparentlyliesinaninnatesexualincompatibilityofthepairwhicharematched。SeveralinstanceshavebeencommunicatedtomebyMr。W。C。Spooner（wellknownforhisessayonCross—breeding），byMr。EytonofEyton，byMr。Wickstedandotherbreeders，andespeciallybyMr。WaringofChelsfield，inrelationtohorses，cattle，pigs，foxhounds，otherdogs，andpigeons。（18/77。ForpigeonsseeDr。
Chapuis’LePigeonVoyageurBelge’1865page66。）Inthesecases，females，whicheitherpreviouslyorsubsequentlywereprovedtobefertile，failedtobreedwithcertainmales，withwhomitwasparticularlydesiredtomatchthem。
Achangeintheconstitutionofthefemalemaysometimeshaveoccurredbeforeshewasputtothesecondmale;butinothercasesthisexplanationishardlytenable，forafemale，knownnottobebarren，hasbeenunsuccessfullypairedsevenoreighttimeswiththesamemalelikewiseknowntobeperfectlyfertile。Withcart—mares，whichsometimeswillnotbreedwithstallionsofpureblood，butsubsequentlyhavebredwithcart—stallions，Mr。Spoonerisinclinedtoattributethefailuretothelessersexualpoweroftheracehorse。
ButIhaveheardfromthegreatestbreederofracehorsesatthepresentday，throughMr。Waring，that"itfrequentlyoccurswithamaretobeputseveraltimesduringoneortwoseasonstoaparticularstallionofacknowledgedpower，andyetprovebarren;themareafterwardsbreedingatoncewithsomeotherhorse。"Thesefactsareworthrecording，astheyshow，likesomanypreviousfacts，onwhatslightconstitutionaldifferencesthefertilityofananimaloftendepends。]
STERILITYOFPLANTSFROMCHANGEDCONDITIONSOFLIFE，ANDFROMOTHERCAUSES。
Inthevegetablekingdomcasesofsterilityfrequentlyoccur，analogouswiththosepreviouslygivenintheanimalkingdom。Butthesubjectisobscuredbyseveralcircumstances，presentlytobediscussed，namely，thecontabescenceoftheanthers，asGartnerhasnamedacertainaffection——monstrosities——
doublenessoftheflower——much—enlargedfruit——andlong—continuedorexcessivepropagationbybuds。
[Itisnotoriousthatmanyplantsinourgardensandhot—houses，thoughpreservedinthemostperfecthealth，rarelyorneverproduceseed。Idonotalludetoplantswhichruntoleaves，frombeingkepttoodamp，ortoowarm，ortoomuchmanured;forthesedonotflower，andthecasemaybewhollydifferent。NordoIalludetofruitnotripeningfromwantofheatorrottingfromtoomuchmoisture。Butmanyexoticplants，withtheirovulesandpollenappearingperfectlysound，willnotsetanyseed。Thesterilityinmanycases，asIknowfrommyownobservation，issimplyduetotheabsenceoftheproperinsectsforcarryingthepollentothestigma。Butafterexcludingtheseveralcasesjustspecified，therearemanyplantsinwhichthereproductivesystemhasbeenseriouslyaffectedbythealteredconditionsoflifetowhichtheyhavebeensubjected。
Itwouldbetedioustoenteronmanydetails。Linnaeuslongagoobserved（18/78。’SwedishActs’volume11739page3。Pallasmakesthesameremarkinhis’Travels’Englishtranslationvolume1page292。）thatAlpineplants，althoughnaturallyloadedwithseed，produceeitherfewornonewhencultivatedingardens。Butexceptionsoftenoccur:theDrabasylvestris，oneofourmostthoroughlyAlpineplants，multipliesitselfbyseedinMr。H。C。
Watson’sgarden，nearLondon;andKerner，whohasparticularlyattendedtothecultivationofAlpineplants，foundthatvariouskinds，whencultivated，spontaneouslysowedthemselves。（18/79。A。Kerner’DieCulturderAlpenpflanzen’1864s。139;Watson’CybeleBritannica’volume1page131;Mr。
D。CameronalsohaswrittenonthecultureofAlpineplantsin’Gard。
Chronicle’1848pages253，268，andmentionsafewwhichseed。）Manyplantswhichnaturallygrowinpeat—earthareentirelysterileinourgardens。Ihavenoticedthesamefactwithseveralliliaceousplants，whichneverthelessgrewvigorously。
Toomuchmanurerenderssomekindsutterlysterile，asIhavemyselfobserved。
Thetendencytosterilityfromthiscauserunsinfamilies;thus，accordingtoGartner（18/80。’BeitragezurKenntnissderBefruchtung’1844s。333。），itishardlypossibletogivetoomuchmanuretomostGramineae，Cruciferae，andLeguminosae，whilstsucculentandbulbous—rootedplantsareeasilyaffected。
Extremepovertyofsoilislessapttoinducesterility;butdwarfedplantsofTrifoliumminusandrepens，growingonalawnoftenmownandnevermanured，werefoundbymenottoproduceanyseed。Thetemperatureofthesoil，andtheseasonatwhichplantsarewatered，oftenhaveamarkedeffectontheirfertility，aswasobservedbyKolreuterinthecaseofMirabilis。（18/81。
’NovaActaPetrop。’1793page391。）Mr。Scott，intheBotanicGardensofEdinburgh，observedthatOncidiumdivaricatumwouldnotsetseedwhengrowninabasketinwhichitthrove，butwascapableoffertilisationinapotwhereitwasalittledamper。Pelargoniumfulgidum，formanyyearsafteritsintroduction，seededfreely;itthenbecamesterile;nowitisfertile（18/82。
’CottageGardener’1856pages44，109。）ifkeptinadrystoveduringthewinter。Othervarietiesofpelargoniumaresterileandothersfertilewithoutourbeingabletoassignanycause。Veryslightchangesinthepositionofaplant，whetherplantedonabankoratitsbase，sometimesmakeallthedifferenceinitsproducingseed。Temperatureapparentlyhasamuchmorepowerfulinfluenceonthefertilityofplantsthanonthatofanimals。
Neverthelessitiswonderfulwhatchangessomefewplantswillwithstandwithundiminishedfertility:thustheZephyranthescandida，anativeofthemoderatelywarmbanksofthePlata，sowsitselfinthehotdrycountrynearLima，andinYorkshireresiststheseverestfrosts，andIhaveseenseedsgatheredfrompodswhichhadbeencoveredwithsnowduringthreeweeks。
（18/83。Dr。Herbert’Amaryllidaceae’page176。）Berberiswallichii，fromthehotKhasiarangeinIndia，isuninjuredbyoursharpestfrosts，andripensitsfruitunderourcoolsummers。Nevertheless，Ipresumewemustattributetochangeofclimatethesterilityofmanyforeignplants;thus，thePersianandChineselilacs（Syringapersicaandchinensis），thoughperfectlyhardyhere，neverproduceaseed;thecommonlilac（S。vulgaris）seedswithusmoderatelywell，butinpartsofGermanythecapsulesnevercontainseed。（18/84。Gartner’BeitragezurKenntniss’etc。s。560，564。）Somefewofthecases，giveninthelastchapter，ofself—impotentplants，mighthavebeenhereintroduced，astheirstateseemsduetotheconditionstowhichtheyhavebeensubjected。
Theliabilityofplantstobeaffectedintheirfertilitybyslightlychangedconditionsisthemoreremarkable，asthepollenwhenonceinprocessofformationisnoteasilyinjured;aplantmaybetransplanted，orabranchwithflower—budsbecutoffandplacedinwater，andthepollenwillbematured。
Pollen，also，whenoncemature，maybekeptforweeksorevenmonths。（18/85。
’Gardener’sChronicle’1844page215;1850page470。Faivregivesagoodresumeonthissubjectinhis’LaVariabilitedesEspeces’1868page155。）Thefemaleorgansaremoresensitive，forGartner（18/86。’BeitragezurKenntniss’
etc。s。252，338。）foundthatdicotyledonousplants，whencarefullyremovedsothattheydidnotintheleastflag，couldseldombefertilised;thisoccurredevenwithpottedplantsiftherootshadgrownoutoftheholeatthebottom。
Insomefewcases，however，aswithDigitalis，transplantationdidnotpreventfertilisation;andaccordingtothetestimonyofMawz，Brassicarapa，whenpulledupbyitsrootsandplacedinwater，ripeneditsseed。Flower—stemsofseveralmonocotyledonousplantswhencutoffandplacedinwaterlikewiseproduceseed。ButinthesecasesIpresumethattheflowershadbeenalreadyfertilised，forHerbert（18/87。’JournalofHort。Soc。’volume21847page83。）foundwiththeCrocusthattheplantsmightberemovedormutilatedaftertheactoffertilisation，andwouldstillperfecttheirseeds;butthat，iftransplantedbeforebeingfertilised，theapplicationofpollenwaspowerless。
Plantswhichhavebeenlongcultivatedcangenerallyendurewithundiminishedfertilityvariousandgreatchanges;butnotinmostcasessogreatachangeofclimateasdomesticatedanimals。Itisremarkablethatmanyplantsunderthesecircumstancesaresomuchaffectedthattheproportionandthenatureoftheirchemicalingredientsaremodified，yettheirfertilityisunimpaired。
Thus，asDr。Falconerinformsme，thereisagreatdifferenceinthecharacterofthefibreinhemp，inthequantityofoilintheseedoftheLinum，intheproportionofnarcotintomorphineinthepoppy，inglutentostarchinwheat，whentheseplantsarecultivatedontheplainsandonthemountainsofIndia;
nevertheless，theyallremainfullyfertile。
CONTABESCENCE。
Gartnerhasdesignatedbythistermapeculiarconditionoftheanthersincertainplants，inwhichtheyareshrivelled，orbecomebrownandtough，andcontainnogoodpollen。Wheninthisstatetheyexactlyresembletheanthersofthemoststerilehybrids。Gartner（18/88。’BeitragezurKenntniss’etc。s。
117etseq。;Kolreuter’ZweiteFortsetzung’s。10，121;’DritteFortsetzung’
s。57。Herbert’Amaryllidaceae’page355。Wiegmann’UeberdieBastarderzeugung’s。27。），inhisdiscussiononthissubject，hasshownthatplantsofmanyordersareoccasionallythusaffected;buttheCaryophyllaceaeandLiliaceaesuffermost，andtotheseorders，Ithink，theEricaceaemaybeadded。Contabescencevariesindegree，butonthesameplantalltheflowersaregenerallyaffectedtonearlythesameextent。Theanthersareaffectedataveryearlyperiodintheflower—bud，andremaininthesamestate（withonerecordedexception）duringthelifeoftheplant。Theaffectioncannotbecuredbyanychangeoftreatment，andispropagatedbylayers，cuttings，etc。，andperhapsevenbyseed。Incontabescentplantsthefemaleorgansareseldomaffected，ormerelybecomeprecociousintheirdevelopment。Thecauseofthisaffectionisdoubtful，andisdifferentindifferentcases。UntilIreadGartner’sdiscussionIattributedit，asapparentlydidHerbert，totheunnaturaltreatmentoftheplants;butitspermanenceunderchangedconditions，andthefemaleorgansnotbeingaffected，seemincompatiblewiththisview。Thefactofseveralendemicplantsbecomingcontabescentinourgardensseems，atfirstsight，equallyincompatiblewiththisview;butKolreuterbelievesthatthisistheresultoftheirtransplantation。ThecontabescentplantsofDianthusandVerbascum，foundwildbyWiegmann，grewonadryandsterilebank。Thefactthatexoticplantsareeminentlyliabletothisaffectionalsoseemstoshowthatitisinsomemannercausedbytheirunnaturaltreatment。Insomeinstances，aswithSilene，Gartner’sviewseemsthemostprobable，namely，thatitiscausedbyaninherenttendencyinthespeciestobecomedioecious。Icanaddanothercause，namely，theillegitimateunionsofheterostyledplants，forIhaveobservedseedlingsofthreespeciesofPrimulaandofLythrumsalicaria，whichhadbeenraisedfromplantsillegitimatelyfertilisedbytheirown—formpollen，withsomeoralltheiranthersinacontabescentstate。Thereisperhapsanadditionalcause，namely，self—fertilisation;formanyplantsofDianthusandLobelia，whichhadbeenraisedfromself—fertilisedseeds，hadtheiranthersinthisstate;buttheseinstancesarenotconclusive，asbothgeneraareliablefromothercausestothisaffection。
Casesofanoppositenaturelikewiseoccur，namely，plantswiththefemaleorgansstruckwithsterility，whilstthemaleorgansremainperfect。Dianthusjaponicus，aPassiflora，andNicotiana，havebeendescribedbyGartner（18/89。
’Bastarderzengung’s。356。）asbeinginthisunusualcondition。
MONSTROSITIESASACAUSEOFSTERILITY。
Greatdeviationsofstructure，evenwhenthereproductiveorgansthemselvesarenotseriouslyaffected，sometimescauseplantstobecomesterile。Butinothercasesplantsmaybecomemonstroustoanextremedegreeandyetretaintheirfullfertility。Gallesio，whocertainlyhadgreatexperience（18/90。
’TeoriadellaRiproduzione’1816page84;’TraiteduCitrus’1811page67。），oftenattributessterilitytothiscause;butitmaybesuspectedthatinsomeofhiscasessterilitywasthecause，andnottheresult，ofthemonstrousgrowths。ThecuriousSt。Valeryapple，althoughitbearsfruit，rarelyproducesseed。ThewonderfullyanomalousflowersofBegoniafrigida，formerlydescribed，thoughtheyappearfitforfructification，aresterile。（18/91。Mr。
C。W。Crockerin’Gardener’sChronicle’1861page1092。）SpeciesofPrimulainwhichthecalyxisbrightlycolouredaresaid（18/92。Verlot’DesVarietes’
1865page80。）tobeoftensterile，thoughIhaveknownthemtobefertile。Ontheotherhand，Verlotgivesseveralcasesofproliferousflowerswhichcanbepropagatedbyseed。Thiswasthecasewithapoppy，whichhadbecomemonopetalousbytheunionofitspetals。（18/93。Verlotibidpage88。）Anotherextraordinarypoppy，withthestamensreplacedbynumeroussmallsupplementarycapsules，likewisereproducesitselfbyseed。ThishasalsooccurredwithaplantofSaxifragageum，inwhichaseriesofadventitiouscarpels，bearingovulesontheirmargins，hadbeendevelopedbetweenthestamensandthenormalcarpels（18/94。Prof。Allman，Brit。Assoc。，quotedinthe’Phytologist’volume2page483。Prof。Harvey，ontheauthorityofMr。Andrews，whodiscoveredtheplant，informedmethatthismonstrositycouldbepropagatedbyseed。WithrespecttothepoppyseeProf。Goeppertasquotedin’JournalofHorticulture’
July1，1863page171。）Lastly，withrespecttopeloricflowers，whichdepartwonderfullyfromthenaturalstructure，——thoseofLinariavulgarisseemgenerallytobemoreorlesssterile，whilstthosebeforedescribedofAntirrhinummajus，whenartificiallyfertilisedwiththeirownpollen，areperfectlyfertile，thoughsterilewhenlefttothemselves，forbeesareunabletocrawlintothenarrowtubularflower。ThepeloricflowersofCorydalissolida，accordingtoGodron（18/95。’ComptesRendus’December19，1864page1039。），aresometimesbarrenandsometimesfertile;whilstthoseofGloxiniaarewellknowntoyieldplentyofseed。InourgreenhousePelargoniums，thecentralflowerofthetrussisoftenpeloric，andMr。Mastersinformsmethathetriedinvainduringseveralyearstogetseedfromtheseflowers。I
likewisemademanyvainattempts，butsometimessucceededinfertilisingthemwithpollenfromanormalflowerofanothervariety;andconverselyIseveraltimesfertilisedordinaryflowerswithpeloricpollen。OnlyonceIsucceededinraisingaplantfromapeloricflowerfertilisedbypollenfromapeloricflowerbornebyanothervariety;buttheplant，itmaybeadded，presentednothingparticularinitsstructure。Hencewemayconcludethatnogeneralrulecanbelaiddown;butanygreatdeviationfromthenormalstructure，evenwhenthereproductiveorgansthemselvesarenotseriouslyaffected，certainlyoftenleadstosexualimpotence。
DOUBLEFLOWERS。
Whenthestamensareconvertedintopetals，theplantbecomesonthemalesidesterile;whenbothstamensandpistilsarethuschanged，theplantbecomescompletelybarren。Symmetricalflowershavingnumerousstamensandpetalsarethemostliabletobecomedouble，asperhapsfollowsfromallmultipleorgansbeingthemostsubjecttovariability。Butflowersfurnishedwithonlyafewstamens，andotherswhichareasymmetricalinstructure，sometimesbecomedouble，asweseewiththedoublegorseorUlex，andAntirrhinum。TheCompositaebearwhatarecalleddoubleflowersbytheabnormaldevelopmentofthecorollaoftheircentralflorets。Doublenessissometimesconnectedwithprolification（18/96。’Gardener’sChronicle’1866page681。），orthecontinuedgrowthoftheaxisoftheflower。Doublenessisstronglyinherited。Noonehasproduced，asLindleyremarks（18/97。’TheoryofHorticulture’page333。），doubleflowersbypromotingtheperfecthealthoftheplant。Onthecontrary，unnaturalconditionsoflifefavourtheirproduction。Thereissomereasontobelievethatseedskeptduringmanyyears，andseedsbelievedtobeimperfectlyfertilised，yielddoubleflowersmorefreelythanfreshandperfectlyfertilisedseed。（18/98。Mr。Fairweather’Transact。Hort。Soc。’
volume3page406:BossequotedbyBronn’GeschichtederNatur’b。2s。77。OntheeffectsoftheremovaloftheanthersseeMr。LeitnerinSilliman’s’NorthAmericanJourn。ofScience’volume23page47;andVerlot’DesVarietes’1865
page84。）Long—continuedcultivationinrichsoilseemstobethecommonestexcitingcause。AdoublenarcissusandadoubleAnthemisnobilis，transplantedintoverypoorsoil，hasbeenobservedtobecomesingle（18/99。Lindley’s’TheoryofHorticulture’page3？3。）;andIhaveseenacompletelydoublewhiteprimroserenderedpermanentlysinglebybeingdividedandtransplantedwhilstinfullflower。IthasbeenobservedbyProfessorE。Morrenthatdoublenessoftheflowersandvariegationoftheleavesareantagonisticstates;butsomanyexceptionstotherulehavelatelybeenrecorded（18/100。’Gardener’sChronicle’1865page626;1866pages290，730;andVerlot’DesVarietes’page75。），that，thoughgeneral，itcannotbelookedatasinvariable。Variegationseemsgenerallytoresultfromafeebleoratrophiedconditionoftheplant，andalargeproportionoftheseedlingsraisedfromparents，ifbotharevariegated，usuallyperishatanearlyage;hencewemayperhapsinferthatdoubleness，whichistheantagonisticstate，commonlyarisesfromaplethoriccondition。Ontheotherhand，extremelypoorsoilsometimes，thoughrarely，appearstocausedoubleness:Iformerlydescribed（18/101。’Gardener’sChronicle’1843page628。InthisarticleIsuggestedthetheoryabovegivenonthedoublenessofflowers。ThisviewisadoptedbyCarriere’ProductionetFix。desVarietes’1865page67。）somecompletelydouble，bud—like，flowersproducedinlargenumbersbystuntedwildplantsofGentianaamarellagrowingonapoorchalkybank。IhavealsonoticedadistincttendencytodoublenessintheflowersofaRanunculus，Horse—chestnut，andBladder—nut（Ranunculusrepens，Aesculuspavia，andStaphylea），growingunderveryunfavourableconditions。ProfessorLehmann（18/102。QuotedbyGartner’Bastarderzeugung’s。
567。）foundseveralwildplantsgrowingnearahotspringwithdoubleflowers。
Withrespecttothecauseofdoubleness，whicharises，aswesee，underwidelydifferentcircumstances，Ishallpresentlyattempttoshowthatthemostprobableviewisthatunnaturalconditionsfirstgiveatendencytosterility，andthatthen，ontheprincipleofcompensation，asthereproductiveorgansdonotperformtheirproperfunctions，theyeitherbecomedevelopedintopetals，oradditionalpetalsareformed。ThisviewhaslatelybeensupportedbyMr。
Laxton（18/103。’Gardener’sChronicle’1866page901。）whoadvancesthecaseofsomecommonpeas，which，afterlong—continuedheavyrain，floweredasecondtime，andproduceddoubleflowers。
SEEDLESSFRUIT。
Manyofourmostvaluablefruits，althoughconsistinginahomologicalsenseofwidelydifferentorgans，areeitherquitesterile，orproduceextremelyfewseeds。Thisisnotoriouslythecasewithourbestpears，grapes，andfigs，withthepine—apple，banana，bread—fruit，pomegranate，azarole，date—palms，andsomemembersoftheorange—tribe。Poorervarietiesofthesesamefruitseitherhabituallyoroccasionallyyieldseed。（18/104。Lindley’TheoryofHorticulture’pages175—179;Godron’Del’Espece’tome2page106;Pickering’RacesofMan;’Gallesio’TeoriadellaRiproduzione’l816pages101—110。Meyen’ReiseumErde’Th。2s。214statesthatatManillaonevarietyofthebananaisfullofseeds:andChamisso（Hooker’s’Bot。Misc。’volume1page310）
describesavarietyofthebread—fruitintheMarianaIslandswithsmallfruit，containingseedswhicharefrequentlyperfect。Burnesinhis’TravelsinBokhara’remarksonthepomegranateseedinginMazenderan，asaremarkablepeculiarity。）Mosthorticulturistslookatthegreatsizeandanomalousdevelopmentofthefruitasthecause，andsterilityastheresult;buttheoppositeview，asweshallpresentlysee，ismoreprobable。
STERILITYFROMTHEEXCESSIVEDEVELOPMENTOFTHEORGANSOFGROWTHOR
VEGETATION。
Plantswhichfromanycausegrowtooluxuriantly，andproduceleaves，stems，runners，suckers，tubers，bulbs，etc。，inexcess，sometimesdonotflower，oriftheyflowerdonotyieldseed。TomakeEuropeanvegetablesunderthehotclimateofIndiayieldseed，itisnecessarytochecktheirgrowth;and，whenone—thirdgrown，theyaretakenup，andtheirstemsandtap—rootsarecutormutilated。（18/105。Ingledewin’Transact。ofAgricult。andHort。Soc。ofIndia’volume2。）Soitiswithhybrids;forinstance，Prof。Lecoq（18/106。
’DelaFecondation’1862page308。）hadthreeplantsofMirabilis，which，thoughtheygrewluxuriantlyandflowered，werequitesterile;butafterbeatingonewithastickuntilafewbranchesalonewereleft，theseatonceyieldedgoodseed。Thesugar—cane，whichgrowsvigorouslyandproducesalargesupplyofsucculentstems，never，accordingtovariousobservers，bearsseedintheWestIndies，Malaga，India，CochinChina，Mauritius，ortheMalayArchipelago。（18/107。Hooker’Bot。Misc。’volume1page99;Gallesio’TeoriadellaRiproduzione’page110。Dr。J。deCordemoyin’Transact。oftheR。Soc。
ofMauritius’newseriesvolume61873pages60—67，givesalargenumberofcasesofplantswhichneverseed，includingseveralspeciesindigenousinMauritius。）Plantswhichproducealargenumberoftubersareapttobesterile，asoccurs，toacertainextent，withthecommonpotato;andMr。
Fortuneinformsmethatthesweetpotato（Convolvulusbatatas）inChinanever，asfarashehasseen，yieldsseed。Dr。Royleremarks（18/108。’Transact。
Linn。Soc。’volume17page563。）thatinIndiatheAgavevivipara，whengrowninrichsoil，invariablyproducesbulbs，butnoseeds;whilstapoorsoilanddryclimateleadtoanoppositeresult。InChina，accordingtoMr。Fortune，anextraordinarynumberoflittlebulbsaredevelopedintheaxilsoftheleavesoftheyam，andthisplantdoesnotbearseed。Whetherinthesecases，asinthoseofdoubleflowersandseedlessfruit，sexualsterilityfromchangedconditionsoflifeistheprimarycausewhichleadstotheexcessivedevelopmentoftheorgansofvegetation，isdoubtful;thoughsomeevidencemightbeadvancedinfavourofthisview。Itisperhapsamoreprobableviewthatplantswhichpropagatethemselveslargelybyonemethod，namelybybuds，havenotsufficientvitalpowerororganisedmatterfortheothermethodofsexualgeneration。
Severaldistinguishedbotanistsandgoodpracticaljudgesbelievethatlong—
continuedpropagationbycuttings，runners，tubers，bulbs，etc。，independentlyofanyexcessivedevelopmentoftheseparts，isthecauseofmanyplantsfailingtoproduceflowers，orproducingonlybarrenflowers，——itisasiftheyhadlostthehabitofsexualgeneration。（18/109。Godron’Del’Espece’
tome2page106;HerbertonCrocusin’JournalofHort。Soc。’volume11846
page254:Dr。Wight，fromwhathehasseeninIndia，believesinthisview;
’MadrasJournalofLit。andScience’volume41836page61。）Thatmanyplantswhenthuspropagatedaresteriletherecanbenodoubt，butastowhetherthelongcontinuanceofthisformofpropagationistheactualcauseoftheirsterility，Iwillnotventure，fromthewantofsufficientevidence，toexpressanopinion。
Thatplantsmaybepropagatedforlongperiodsbybuds，withouttheaidofsexualgeneration，wemaysafelyinferfromthisbeingthecasewithmanyplantswhichmusthavelongsurvivedinastateofnature。AsIhavehadoccasionbeforetoalludetothissubject，IwillheregivesuchcasesasI
havecollected。Manyalpineplantsascendmountainsbeyondtheheightatwhichtheycanproduceseed。（18/110。WahlenbergspecifieseightspeciesinthisstateontheLaplandAlps:seeAppendixtoLinnaeus’TourinLapland’
translatedbySirJ。E。Smithvolume2pages274—280。）CertainspeciesofPoaandFestuca，whengrowingonmountain—pastures，propagatethemselves，asI
hearfromMr。Bentham，almostexclusivelybybulblets。Kalmgivesamorecuriousinstance（18/111。’TravelsinNorthAmerica’Englishtranslationvolume3page175。）ofseveralAmericantrees，whichgrowsoplentifullyinmarshesorinthickwoods，thattheyarecertainlywelladaptedforthesestations，yetscarcelyeverproduceseeds;butwhenaccidentallygrowingontheoutsideofthemarshorwood，areloadedwithseed。ThecommonivyisfoundinNorthernSwedenandRussia，butflowersandfruitsonlyinthesouthernprovinces。TheAcoruscalamusextendsoveralargeportionoftheglobe，butsorarelyperfectsfruitthatthishasbeenseenonlybyafewbotanists;accordingtoCaspary，allitspollen—grainsareinaworthlesscondition。（18/112。WithrespecttotheivyandAcorusseeDr。Broomfieldinthe’Phytologist’volume3page376。AlsoLindleyandVaucherontheAcorusandseeCasparyasbelow。）TheHypericumcalycinum，whichpropagatesitselfsofreelyinourshrubberiesbyrhizomes，andisnaturalisedinIreland，blossomsprofusely，butrarelysetsanyseed，andthisonlyduringcertainyears;nordiditsetanywhenfertilisedinmygardenbypollenfromplantsgrowingatadistance。TheLysimachianummularia，whichisfurnishedwithlongrunners，soseldomproducesseed—capsules，thatProf。Decaisne（18/113。’Annal。desSc。
Nat。’3rdseriesZool。tome4page280。Prof。DecaisnerefersalsotoanalogouscaseswithmossesandlichensnearParis。），whohasespeciallyattendedtothisplant，hasneverseenitinfruit。TheCarexrigidaoftenfailstoperfectitsseedinScotland，Lapland，Greenland，Germany，andNewHampshireintheUnitedStates。（18/114。Mr。TuckermanninSilliman’s’AmericanJournalofScience’volume65page1。）Theperiwinkle（Vincaminor），whichspreadslargelybyrunners，issaidscarcelyevertoproducefruitinEngland（18/115。SirJ。E。Smith’EnglishFlora’volume1page339。）;butthisplantrequiresinsect—aidforitsfertilisation，andtheproperinsectsmaybeabsentorrare。TheJussiaeagrandiflorahasbecomenaturalisedinSouthernFrance，andhasspreadbyitsrhizomessoextensivelyastoimpedethenavigationofthewaters，butneverproducesfertileseed。（18/116。G。
Planchon’FloradeMontpellier’1864page20。）Thehorse—radish（Cochleriaarmoracia）spreadspertinaciouslyandisnaturalisedinvariouspartsofEurope;thoughitbearsflowers，theserarelyproducecapsules:ProfessorCasparyinformsmethathehaswatchedthisplantsince1851，buthasneverseenitsfruit;65percentofitspollen—grainsarebad。ThecommonRanunculusficariararelybearsseedinEngland，France，orSwitzerland;butin1863Iobservedseedsonseveralplantsgrowingnearmyhouse。（18/117。Onthenon—productionofseedsinEnglandseeMr。Crockerin’Gardener’sWeeklyMagazine’1852page70;Vaucher’Hist。Phys。Plantesd’Europe’tome1page33;
Lecoq’Geograph。Bot。d’Europe’tome4page466;Dr。D。Closin’Annal。desSc。Nat。’3rdseriesBot。tome171852page129:thislatterauthorreferstootheranalogouscases。SeemoreespeciallyonthisplantandonotheralliedcasesProf。Caspary"DieNuphar"’Abhand。Naturw。Gesellsch。zuHalle’b。11
1870page40，78。）Othercasesanalogouswiththeforegoingcouldbegiven;