Prof。H。Lecoq，whohasmadeagreatnumberofcrossingsbetweenthedifferentlycolouredvarietiesofMirabilisjalapa（11/122。’Geograph。Bot。
del’Europe’tome31854page405;and’DelaFecondation’1862page302。）
findsthatintheseedlingsthecoloursrarelycombine，butformdistinctstripes;orhalftheflowerisofonecolourandhalfofadifferentcolour。Somevarietiesregularlybearflowersstripedwithyellow，white，andred;butplantsofsuchvarietiesoccasionallyproduceonthesamerootbrancheswithuniformlycolouredflowersofallthreetints，andotherbrancheswithhalf—and—halfcolouredflowers，andotherswithmarbledflowers。Gallesio（11/123。’TraiteduCitrus’1811page45。）crossedreciprocallywhiteandredcarnations，andtheseedlingswerestriped;butsomeofthestripedplantsalsoboreentirelywhiteandentirelyredflowers。Someoftheseplantsproducedoneyearredflowersalone，andinthefollowingyearstripedflowers;orconversely，someplants，afterhavingbornefortwoorthreeyearsstripedflowers，wouldrevertandbearexclusivelyredflowers。ItmaybeworthmentioningthatIfertilisedthePURPLESWEET—PEA（Lathyrusodoratus）withpollenfromthelight—colouredPAINTEDLADY:seedlingsraisedfromthesamepodwerenotintermediateincharacter，butperfectlyresembledeitherparent。Laterinthesummer，theplantswhichhadatfirstborneflowersidenticalwiththoseofthePAINTED
LADY，producedflowersstreakedandblotchedwithpurple;showinginthesedarkermarksatendencytoreversiontothemother—variety。AndrewKnight（11/124。’Transact。Linn。Soc。’volume9page268。）fertilisedtwowhitegrapeswithpollenoftheAleppogrape，whichisdarklyvariegatedbothinitsleavesandfruit。Theresultwasthattheyoungseedlingswerenotatfirstvariegated，butallbecamevariegatedduringthesucceedingsummer;
besidesthis，manyproducedonthesameplantbunchesofgrapeswhichwereallblack，orallwhite，orlead—colouredstripedwithwhite，orwhitedottedwithminuteblackstripes;andgrapesofalltheseshadescouldfrequentlybefoundonthesamefoot—stalk。
Iwillappendaverycuriouscase，notofbud—variation，butoftwocoheringembryos，differentincharacterandcontainedwithinthesameseed。Adistinguishedbotanist，Mr。G。H。Thwaites（11/125。’AnnalsandMag。
ofNat。Hist。’March1848。）statesthataseedfromFuchsiacoccineafertilisedbyF。fulgens，containedtwoembryos，andwas"atruevegetabletwin。"Thetwoplantsproducedfromthetwoembryoswere"extremelydifferentinappearanceandcharacter，"thoughbothresembledotherhybridsofthesameparentageproducedatthesametime。Thesetwinplants"werecloselycoherent，belowthetwopairsofcotyledon—leaves，intoasinglecylindricalstem，sothattheyhadsubsequentlytheappearanceofbeingbranchesononetrunk。"Hadthetwounitedstemsgrownuptotheirfullheight，insteadofdying，acuriouslymixedhybridwouldhavebeenproduced。AmongrelmelondescribedbySageret（11/126。’PomologiePhysiolog。’1830page126。）mayperhapshavethusoriginated;forthetwomainbranches，whicharosefromtwocotyledon—buds，producedverydifferentfruit，——ontheonebranchlikethatofthepaternalvariety，andontheotherbranchliketoacertainextentthatofthematernalvariety，themelonofChina。]
Inmostofthesecasesofcrossedvarieties，andinsomeofthecasesofcrossedspecies，thecolourspropertobothparentsappearedintheseedlings，assoonastheyfirstflowered，intheformofstripesorlargersegments，oraswholeflowersorfruitofdifferentkindsborneonthesameplant;andinthiscasetheappearanceofthetwocolourscannotstrictlybesaidtobeduetoreversion，buttosomeincapacityoffusion。When，however，thelaterflowersorfruitproducedduringthesameseason，orduringasucceedingyearorgeneration，becomestripedorhalf—and—half，etc。，thesegregationofthetwocoloursisstrictlyacaseofreversionbybud—variation。Whetherallthemanyrecordedcasesofstripedflowersandfruitareduetoprevioushybridisationandreversionisbynomeansclear，forinstancewithpeachesandnectarines，moss—roses，etc。InafuturechapterIshallshowthat，withanimalsofcrossedparentage，thesameindividualhasbeenknowntochangeitscharacterduringgrowth，andtoreverttooneofitsparentswhichitdidnotatfirstresemble。Finally，fromthevariousfactsnowgiven，therecanbenodoubtthatthesameindividualplant，whetherahybridoramongrel，sometimesreturnsinitsleaves，flowers，andfruit，eitherwhollyorbysegments，tobothparent—
forms。
ONTHEDIRECTORIMMEDIATEACTIONOFTHEMALEELEMENTONTHEMOTHERFORM。
Anotherremarkableclassoffactsmustbehereconsidered，firstly，becausetheyhaveahighphysiologicalimportance，andsecondly，becausetheyhavebeensupposedtoaccountforsomecasesofbud—variation。Irefertothedirectactionofthemaleelement，notintheordinarywayontheovules，butoncertainpartsofthefemaleplant，orincaseofanimalsonthesubsequentprogenyofthefemalebyasecondmale。Imaypremisethatwithplantstheovariumandthecoatsoftheovulesareobviouslypartsofthefemale，anditcouldnothavebeenanticipatedthattheywouldhavebeenaffectedbythepollenofaforeignvarietyorspecies，althoughthedevelopmentoftheembryo，insidetheembryonicsack，insidetheovuleandovarium，ofcourse，dependsonthemaleelement。
[Evenaslongagoas1729itwasobserved（11/127。’PhilosophicalTransact。’volume431744—45page525。）thatwhiteandbluevarietiesofthePea，whenplantedneareachother，mutuallycrossed，nodoubtthroughtheagencyofbees，andintheautumnblueandwhitepeaswerefoundwithinthesamepods。Wiegmannmadeanexactlysimilarobservationinthepresentcentury。Thesameresulthasfollowedseveraltimeswhenavarietywithpeasofonecolourhasbeenartificiallycrossedbyadifferently—colouredvariety。（11/128。Mr。Goss’Transact。Hort。Soc。’volume5page234:andGartner’Bastarderzeugung’1849ss。81and499。）ThesestatementsledGartner，whowashighlyscepticalonthesubject，carefullytotryalongseriesofexperiments:heselectedthemostconstantvarieties，andtheresultconclusivelyshowedthatthecolouroftheskinofthepeaismodifiedwhenpollenofadifferentlycolouredvarietyisused。ThisconclusionhassincebeenconfirmedbyexperimentsmadebytheRev。J。M。
Berkeley。（11/129。’Gardener’sChronicle’1854page404。）
Mr。LaxtonofStamford，whilstmakingexperimentsonpeasfortheexpresspurposeofascertainingtheinfluenceofforeignpollenonthemother—
plant，hasrecently（11/130。Ibid1866page900。）observedanimportantadditionalfact。HefertilisedtheTallSugar—pea，whichbearsverythingreenpods，becomingbrownish—whitewhendry，withpollenofthePurple—
poddedpea，which，asitsnameexpresses，hasdark—purplepodswithverythickskin，becomingpalereddishpurplewhendry。Mr。Laxtonhascultivatedthetallsugar—peaduringtwentyyears，andhasneverseenorheardofitproducingapurplepod:nevertheless，aflowerfertilisedbypollenfromthepurple—podyieldedapodcloudedwithpurplish—redwhichMr。Laxtonkindlygavetome。Aspaceofabouttwoinchesinlengthtowardstheextremityofthepod，andasmallerspacenearthestalk，werethuscoloured。Oncomparingthecolourwiththatofthepurplepod，bothpodshavingbeenfirstdriedandthensoakedinwater，itwasfoundtobeidenticallythesame;andinboththecolourwasconfinedtothecellslyingimmediatelybeneaththeouterskinofthepod。Thevalvesofthecrossedpodwerealsodecidedlythickerandstrongerthanthoseofthepodsofthemother—plant，butthismaypossiblyhavebeenanaccidentalcircumstance，forIknownothowfartheirthicknessisavariablecharacterintheTallSugar—pea。
ThepeasoftheTallSugar—pea，whendry，arepalegreenish—brown，thicklycoveredwithdotsofdarkpurplesominuteastobevisibleonlythroughalens，andMr。Laxtonhasneverseenorheardofthisvarietyproducingapurplepea;butinthecrossedpodoneofthepeaswasofauniformbeautifulviolet—purpletint，andasecondwasirregularlycloudedwithpalepurple。Thecolourliesintheouterofthetwocoatswhichsurroundthepea。Asthepeasofthepurple—poddedvarietywhendryareofapalegreenish—buff，itwouldatfirstappearthatthisremarkablechangeofcolourinthepeasinthecrossedpodcouldnothavebeencausedbythedirectactionofthepollenofthepurple—pod:butwhenwebearinmindthatthislattervarietyhaspurpleflowers，purplemarksonitsstipules，andpurplepods;andthattheTallSugar—pealikewisehaspurpleflowersandstipules，andmicroscopicallyminutepurpledotsonthepeas，wecanhardlydoubtthatthetendencytotheproductionofpurpleinbothparentshasincombinationmodifiedthecolourofthepeasinthecrossedpod。
Afterhavingexaminedthesespecimens，Icrossedthesametwovarieties，andthepeasinonepodbutnotthepodsthemselves，werecloudedandtintedwithpurplish—redinamuchmoreconspicuousmannerthanthepeasintheuncrossedpodsproducedatthesametimebythesameplants。ImaynoticeasacautionthatMr。Laxtonsentmevariousothercrossedpeasslightly，orevengreatly，modifiedincolour;butthechangeinthesecaseswasdue，ashadbeensuspectedbyMr。Laxton，tothealteredcolourofthecotyledons，seenthroughthetransparentcoatsofthepeas;andasthecotyledonsarepartsoftheembryo，thesecasesarenotinanywayremarkable。
TurningnowtothegenusMatthiola。Thepollenofonekindofstocksometimesaffectsthecolouroftheseedsofanotherkind，usedasthemother—plant。Igivethefollowingcasethemorereadily，asGartnerdoubtedsimilarstatementspreviouslymadewithrespecttothestockbyotherobservers。Awell—knownhorticulturist，MajorTrevorClarke，informsme（11/131。SeealsoapaperbythisobserverreadbeforetheInternationalHort。andBot。CongressofLondon1866。）thattheseedsofthelargered—
floweredBIENNIALstock，Matthiolaannua（CocardeauoftheFrench），arelightbrown，andthoseofthepurplebranchingQueenstock（M。incana）areviolet—black;andhefoundthat，whenflowersoftheredstockwerefertilisedbypollenfromthepurplestock，theyyieldedaboutfiftypercentofBLACKseeds。Hesentmefourpodsfromaredfloweredplant，twoofwhichhadbeenfertilisedbytheirownpollen，andtheyincludedpalebrownseed;andtwowhichhadbeencrossedbypollenfromthepurplekind，andtheyincludedseedsalldeeplytingedwithblack。Theselatterseedsyieldedpurple—floweredplantsliketheirfather;whilstthepalebrownseedsyieldednormalred—floweredplants;andMajorClarke，bysowingsimilarseeds，hasobservedonagreaterscalethesameresult。Theevidenceinthiscaseofthedirectactionofthepollenofonespeciesonthecolouroftheseedsofanotherspeciesappearstomeconclusive。
Gallesio（11/132。’TraiteduCitrus’page40。）fertilisedtheflowersofanorangewithpollenfromthelemon;andonefruitthusproducedborealongitudinalstripeofpeelhavingthecolour，flavour，andothercharactersofthelemon。Mr。Anderson（11/133。’Transact。Hort。Soc。’
volume3page318。Seealsovolume5page65。）fertilisedagreen—fleshedmelonwithpollenfromascarlet—fleshedkind;intwoofthefruits"asensiblechangewasperceptible:andfourotherfruitsweresomewhatalteredbothinternallyandexternally。"Theseedsofthetwofirst—
mentionedfruitsproducedplantspartakingofthegoodpropertiesofbothparents。IntheUnitedStates，whereCucurbitaceaearelargelycultivated，itisthepopularbelief（11/134。Prof。AsaGray’Proc。Acad。Sc。’Bostonvolume41860page21。IhavereceivedstatementstothesameeffectfromotherpersonsintheUnitedStates。）thatthefruitisthusdirectlyaffectedhyforeignpollen;andIhavereceivedasimilarstatementwithrespecttothecucumberinEngland。Itisbelievedthatgrapeshavebeenthusaffectedincolour，size，andshape:inFranceapale—colouredgrapehaditsjuicetintedbythepollenofthedark—colouredTeinturier;inGermanyavarietyboreberrieswhichwereaffectedbythepollenoftwoadjoiningkinds;someoftheberriesbeingonlypartiallyaffectedormottled。（11/135。FortheFrenchcasesee’Journ。Hort。Soc。’volume1newseries1866page50。ForGermanyseeM。JackquotedinHenfrey’s’BotanicalGazette’volume1page277。AcaseinEnglandhasrecentlybeenalludedtobytheRev。J。M。BerkeleybeforetheHort。Soc。ofLondon。）
Aslongagoas1751（11/136。’PhilosophicalTransactions’volume471751—52
page206。）itwasobservedthat，whendifferently—colouredvarietiesofmaizegrewneareachother，theymutuallyaffectedeachother’sseeds，andthisisnowapopularbeliefintheUnitedStates。Dr。Savi（11/137。
Gallesio’TeoriadellaRiproduzione’1816page95。）triedtheexperimentwithcare:hesowedyellowandblack—seededmaizetogether，andonthesameearsomeoftheseedswereyellow，someblack，andsomemottled，thedifferentlycolouredseedsbeingarrangedirregularlyorinrows。Prof。
Hildebrandhasrepeatedtheexperiment（11/138。’Bot。Zeitung’May1868
page326。）withtheprecautionofascertainingthatthemother—plantwastrue。Akindbearingyellowgrainswasfertilisedwithpollenofakindhavingbrowngrains，andtwoearsproducedyellowgrainsmingledwithothersofadirtyviolettint。Athirdearhadonlyyellowgrains，butonesideofthespindlewastintedofareddish—brown;sothatherewehavetheimportantfactoftheinfluenceoftheforeignpollenextendingtotheaxis。Mr。Arnold，inCanada，variedtheexperimentinaninterestingmanner:"afemaleflowerwassubjectedfirsttotheactionofpollenfromayellowvariety，andthentothatfromawhitevariety;theresultwasanear，eachgrainofwhichwasyellowbelowandwhiteabove。"（11/139。SeeDr。J。Stockton—Hough’AmericanNaturalist’January1874page29。）Withotherplantsithasoccasionallybeenobservedthatthecrossedoffspringshowedtheinfluenceoftwokindsofpollen，butinthiscasethetwokindsaffectedthemother—plant。
Mr。Sabinestates（11/140。’Transact。Hort。Soc。’volume5page69。）thathehasseentheformofthenearlyglobularseed—capsuleofAmaryllisvittataalteredbytheapplicationofthepollenofanotherspecies，ofwhichthecapsulehasgibbousangles。Withanalliedgenus，awell—knownbotanist，Maximowicz，hasdescribedindetailthestrikingresultsofreciprocallyfertilisingLiliumbulbiferumanddavuricumwitheachother’spollen。Eachspeciesproducedfruitnotlikeitsown，butalmostidenticalwiththatofthepollen—bearingspecies;butfromanaccidentonlythefruitofthelatterspecieswascarefullyexamined;theseedswereintermediateinthedevelopmentoftheirwings。（11/141。’Bull。del’Acad。
Imp。deSt。Petersburg’tome17page275，1872。TheauthorgivesreferencestothosecasesintheSo1anaceaeoffruitaffectedbyforeignpollen，butasitdoesnotappearthatthemother—plantwasartificiallyfertilised，I
havenotenteredintodetails。）
FritzMullerfertilisedCattleyaleopoldiwithpollenofEpidendroncinnabarinum;andthecapsulescontainedveryfewseeds;butthesepresentedamostwonderfulappearance，which，fromthedescriptiongiven，twobotanists，HildebrandandMaximowicz，attributetothedirectactionofthepollenoftheEpidendron。（11/142。’Bot。Zeitung’September1868page631。ForMaximowicz’sjudgmentseethepaperlastreferredto。）
Mr。J。AndersonHenry（11/143。’JournalofHorticulture’January20，1863
page46。）crossedRhododendrondalhousiaewiththepollenofR。nuttallii，whichisoneofthelargest—floweredandnoblestspeciesofthegenus。Thelargestpodproducedbytheformerspecies，whenfertilisedwithitsownpolle...完整阅读请扫描二维码下载丁香书院APP免费看：