Ontheotherhand，withmaleanimals，itisnotoriousthatthesecondarysexualcharactersaremoreorlesscompletelylostwhentheyaresubjectedtocastration。Thus，iftheoperationbeperformedonayoungcock，henever，asYarrellstates，crowsagain;thecomb，wattles，andspursdonotgrowtotheirfullsize，andthehacklesassumeanintermediateappearancebetweentruehacklesandthefeathersofthehen。Casesarerecordedofconfinement，whichoftenaffectsthereproductivesystem，causinganalogousresults。Butcharactersproperlyconfinedtothefemalearelikewiseacquiredbythemale;
thecapontakestosittingoneggs，andwillbringupchickens;andwhatismorecurious，theutterlysterilemalehybridsfromthepheasantandthefowlactinthesamemanner，\"theirdelightbeingtowatchwhenthehensleavetheirnests，andtotakeonthemselvestheofficeofasitter。\"（13/57。
’CottageGardener’1860page379。）ThatadmirableobserverReaumur（13/58。
’ArtdefaireEclore’etc。1749tome2page8。）assertsthatacock，bybeinglongconfinedinsolitudeanddarkness，canbetaughttotakechargeofyoungchickens;hethenuttersapeculiarcry，andretainsduringhiswholelifethisnewlyacquiredmaternalinstinct。Themanywell—ascertainedcasesofvariousmalemammalsgivingmilkshowsthattheirrudimentarymammaryglandsretainthiscapacityinalatentcondition。
Wethusseethatinmany，probablyinallcases，thesecondarycharactersofeachsexliedormantorlatentintheoppositesex，readytobeevolvedunderpeculiarcircumstances。Wecanthusunderstandhow，forinstance，itispossibleforagoodmilkingcowtotransmithergoodqualitiesthroughhermaleoffspringtofuturegenerations;forwemayconfidentlybelievethatthesequalitiesarepresent，thoughlatent，inthemalesofeachgeneration。
Soitiswiththegame—cock，whocantransmithissuperiorityincourageandvigourthroughhisfemaletohismaleoffspring;andwithmanitisknown（13/59。SirH。Holland’MedicalNotesandReflections’3rdedition1855page31。）thatdiseases，suchashydrocele，necessarilyconfinedtothemalesex，canbetransmittedthroughthefemaletothegrandson。Suchcasesastheseoffer，aswasremarkedatthecommencementofthischapter，thesimplestpossibleexamplesofreversion;andtheyareintelligibleonthebeliefthatcharacterscommontothegrandparentandgrandchildofthesamesexarepresent，thoughlatent，intheintermediateparentoftheoppositesex。
Thesubjectoflatentcharactersissoimportant，asweshallseeinafuturechapter，thatIwillgiveanotherillustration。Manyanimalshavetherightandleftsidesoftheirbodyunequallydeveloped:thisiswellknowntobethecasewithflat—fish，inwhichtheonesidediffersinthicknessandcolourandintheshapeofthefins，fromtheother，andduringthegrowthoftheyoungfishoneeyeisgraduallytwistedfromthelowertotheuppersurface。（13/60。
SeeSteenstruponthe’ObliquityofFlounders’inAnnalsandMag。ofNat。
Hist。’May1865page361。IhavegivenanabstractofMalm’sexplanationofthiswonderfulphenomenoninthe’OriginofSpecies’6thEditionpage186。）Inmostflat—fishestheleftistheblindside，butinsomeitistheright;
thoughinbothcasesreversedor\"wrongfishes，\"areoccasionallydeveloped;
andinPlatessaflesustherightorleftsideisindifferentlytheupperone。
Withgasteropodsorshell—fish，therightandleftsidesareextremelyunlike;
thefargreaternumberofspeciesaredextral，withrareandoccasionalreversalsofdevelopment;andsomefewarenormallysinistral;butcertainspeciesofBulimus，andmanyAchatinellae（13/61。Dr。E。vonMartensin’AnnalsandMag。ofNat。Hist。’March1866page209。）areasoftensinistralasdextral。Iwillgiveananalogouscaseinthegreatarticulatekingdom:thetwosidesofVerruca（13/62。Darwin’Balanidae’RaySoc。1854page499:seealsotheappendedremarksontheapparentlycapriciousdevelopmentofthethoraciclimbsontherightandleftsidesinthehighercrustaceans。）aresowonderfullyunlike，thatwithoutcarefuldissectionitisextremelydifficulttorecognisethecorrespondingpartsontheoppositesidesofthebody;yetitisapparentlyamerematterofchancewhetheritbetherightortheleftsidethatundergoessosingularamountofchange。Oneplantisknowntome（13/63。
Mormodesignea:Darwin’FertilisationofOrchids’1862page251。）inwhichtheflower，accordingasitstandsontheoneorothersideofthespike，isunequallydeveloped。Inalltheforegoingcasesthetwosidesareperfectlysymmetricalatanearlyperiodofgrowth。Now，wheneveraspeciesisasliabletobeunequallydevelopedontheoneasontheotherside，wemayinferthatthecapacityforsuchdevelopmentispresent，thoughlatent，intheundevelopedside。Andasareversalofdevelopmentoccasionallyoccursinanimalsofmanykinds，thislatentcapacityisprobablyverycommon。
Thebestyetsimplestcasesofcharacterslyingdormantare，perhaps，thosepreviouslygiven，inwhichchickensandyoungpigeons，raisedfromacrossbetweendifferentlycolouredbirds，areatfirstofonecolour，butinayearortwoacquirefeathersofthecolouroftheotherparent;forinthiscasethetendencytoachangeofplumageisclearlylatentintheyoungbird。Soitiswithhornlessbreedsofcattle，someofwhichacquiresmallhornsastheygrowold。Purelybredblackandwhitebantams，andsomeotherfowls，occasionallyassume，withadvancingyears，theredfeathersoftheparent—
species。Iwillhereaddasomewhatdifferentcase，asitconnectsinastrikingmannerlatentcharactersoftwoclasses。Mr。Hewitt（13/64。’JournalofHorticulture’July1864page38。IhavehadtheopportunityofexaminingtheseremarkablefeathersthroughthekindnessofMr。Tegetmeier。）possessedanexcellentSebrightgold—lacedbantamhen，which，asshebecameold，grewdiseasedinherovaria，andassumedmalecharacters。Inthisbreedthemalesresemblethefemalesinallrespectsexceptintheircombs，wattles，spurs，andinstincts;henceitmighthavebeenexpectedthatthediseasedhenwouldhaveassumedonlythosemasculinecharacterswhicharepropertothebreed，butsheacquired，inaddition，well—archedtailsickle—feathersquiteafootinlength，saddle—feathersontheloins，andhacklesontheneck，——ornamentswhich，asMr。Hewittremarks，\"wouldbeheldasabominableinthisbreed。\"TheSebrightbantamisknown（13/65。’ThePoultryBook’byMr。Tegetmeier1866
page241。）tohaveoriginatedabouttheyear1800fromacrossbetweenacommonbantamandaPolishfowl，recrossedbyahen—tailedbantam，andcarefullyselected;hencetherecanhardlybeadoubtthatthesickle—feathersandhackleswhichappearedintheoldhenwerederivedfromthePolishfowlorcommonbantam;andwethusseethatnotonlycertainmasculinecharacterspropertotheSebrightbantam，butothermasculinecharactersderivedfromthefirstprogenitorsofthebreed，removedbyaperiodofabovesixtyyears，werelyinglatentinthishenbird，readytobeevolvedassoonasherovariabecamediseased。
Fromtheseseveralfactsitmustbeadmittedthatcertaincharacters，capacities，andinstincts，maylielatentinanindividual，andeveninasuccessionofindividuals，withoutourbeingabletodetecttheleastsignoftheirpresence。Whenfowls，pigeons，orcattleofdifferentcoloursarecrossed，andtheiroffspringchangecolourastheygrowold，orwhenthecrossedturbitacquiredthecharacteristicfrillafteritsthirdmoult，orwhenrarely—bredbantamspartiallyassumetheredplumageoftheirprototype，wecannotdoubtthatthesequalitieswerefromthefirstpresent，thoughlatent，intheindividualanimal，likethecharactersofamothinthecaterpillar。Now，iftheseanimalshadproducedoffspringbeforetheyhadacquiredwithadvancingagetheirnewcharacters，nothingismoreprobablethanthattheywouldhavetransmittedthemtosomeoftheiroffspring，whointhiscasewouldinappearancehavereceivedsuchcharactersfromtheirgrand—
parentsormoredistantprogenitors。Weshouldthenhavehadacaseofreversion，thatis，ofthereappearanceinthechildofanancestralcharacter，actuallypresent，thoughduringyouthcompletelylatent，intheparent;andthiswemaysafelyconcludeiswhatoccursinallreversionstoprogenitors，howeverremote。
Thisviewofthelatencyineachgenerationofallthecharacterswhichappearthroughreversion，isalsosupportedbytheiractualpresenceinsomecasesduringearlyyouthalone，orbytheirmorefrequentappearanceandgreaterdistinctnessatthisagethanduringmaturity。Wehaveseenthatthisisoftenthecasewiththestripesonthelegsandfacesoftheseveralspeciesofthehorsegenus。TheHimalayanrabbit，whencrossed，sometimesproducesoffspringwhichreverttotheparentsilver—greybreed，andwehaveseenthatinpurelybredanimalspale—greyfuroccasionallyreappearsduringearlyyouth。Blackcats，wemayfeelassured，wouldoccasionallyproducebyreversiontabbies;
andonyoungblackkittens，withapedigree（13/66。CarlVogt’LecturesonMan’Englishtranslation1864page411。）knowntohavebeenlongpure，fainttracesofstripesmayalmostalwaysbeseenwhichafterwardsdisappear。
HornlessSuffolkcattleoccasionallyproducebyreversionhornedanimals;andYouatt（13/67。’OnCattle’page174。）assertsthateveninhornlessindividuals\"therudimentofahornmaybeoftenfeltatanearlyage。\"
Nodoubtitappearsatfirstsightinthehighestdegreeimprobablethatineveryhorseofeverygenerationthereshouldbealatentcapacityandtendencytoproducestripes，thoughthesemaynotappearonceinathousandgenerations;thatineverywhite，black，orothercolouredpigeon，whichmayhavetransmitteditspropercolourduringcenturies，thereshouldbealatentcapacityintheplumagetobecomeblueandtobemarkedwithcertaincharacteristicbars;thatineverychildinasix—fingeredfamilythereshouldbethecapacityfortheproductionofanadditionaldigit;andsoinothercases。Nevertheless，thereisnomoreinherentimprobabilityinthisbeingthecasethaninauselessandrudimentaryorgan，oreveninonlyatendencytotheproductionofarudimentaryorgan，beinginheritedduringmillionsofgenerations，asiswellknowntooccurwithamultitudeoforganicbeings。
Thereisnomoreinherentimprobabilityineachdomesticpig，duringathousandgenerations，retainingthecapacityandtendencytodevelopgreattusksunderfittingconditions，thanintheyoungcalfhavingretained，foranindefinitenumberofgenerationsrudimentaryincisorteeth，whichneverprotrudethroughthegums。
Ishallgiveattheendofthenextchapterasummaryofthethreeprecedingchapters;butasisolatedandstrikingcasesofreversionhaveherebeenchieflyinsistedon，Iwishtoguardthereaderagainstsupposingthatreversionisduetosomerareoraccidentalcombinationofcircumstances。Whenacharacter，lostduringhundredsofgenerations，suddenlyreappears，nodoubtsomesuchcombinationmustoccur;butreversions，totheimmediatelyprecedinggenerationsmaybeconstantlyobserved，atleast，intheoffspringofmostunions。Thishasbeenuniversallyrecognisedinthecaseofhybridsandmongrels，butithasbeenrecognisedsimplyfromthedifferencebetweentheunitedformsrenderingtheresemblanceoftheoffspringtotheirgrandparentsormoreremoteprogenitorsofeasydetection。Reversionislikewisealmostinvariablytherule，asMr。Sedgwickhasshown，withcertaindiseases。Hencewemustconcludethatatendencytothispeculiarformoftransmissionisanintegralpartofthegenerallawofinheritance。
MONSTROSITIES。
Alargenumberofmonstrousgrowthsandoflesseranomaliesareadmittedbyeveryonetobeduetoanarrestofdevelopment，thatis，tothepersistenceofanembryoniccondition。Butmanymonstrositiescannotbethusexplained;
forpartsofwhichnotracecanbedetectedintheembryo，butwhichoccurinothermembersofthesameclassofanimalsoccasionallyappear，andthesemayprobablywithtruthbeattributedtoreversion。As，however，IhavetreatedthissubjectasfullyasIcouldinmy’DescentofMan’（ch。12ndedition），I
willnothererecurtoit。
[Whenflowerswhichhavenormallyanirregularstructurebecomeregularorpeloric，thechangeisgenerallylookedatbybotanistsasareturntotheprimitivestate。ButDr。MaxwellMasters（13/68。’NaturalHist。Review’April1863page258。SeealsohisLecture，RoyalInstitution，March16，1860。OnsamesubjectseeMoquin—Tandon’ElementsdeTeratologie’1841pages184，352。
Dr。Peyritschhascollectedalargenumberofveryinterestingcases’Sitzb。
d。k。Akad。d。Wissensch。’Wienb。60andespeciallyb。661872page125。），whohasablydiscussedthissubject，remarksthatwhen，forinstance，allthesepalsofaTropaeolumbecomegreenandofthesameshape，insteadofbeingcolouredwithoneprolongedintoaspur，orwhenallthepetalsofaLinariabecomesimpleandregular，suchcasesmaybeduemerelytoanarrestofdevelopment;forintheseflowersalltheorgansduringtheirearliestconditionaresymmetrical，and，ifarrestedatthisstageofgrowth，theywouldnotbecomeirregular。If，moreover，thearrestweretotakeplaceatastillearlierperiodofdevelopment，theresultwouldbeasimpletuftofgreenleaves;andnooneprobablywouldcallthisacaseofreversion。Dr。
Mastersdesignatesthecasesfirstalludedtoasregularpeloria;andothers，inwhichallthecorrespondingpartsassumeasimilarformofirregularity，aswhenallthepetalsinaLinariabecomespurred，asirregularpeloria。Wehavenorighttoattributetheselattercasestoreversion，untilitcanbeshownthattheparent—form，forinstance，ofthegenusLinariahadhadallitspetalsspurred;forachanceofthisnaturemightresultfromthespreadingofananomalousstructure，inaccordancewiththelaw，tobediscussedinafuturechapter，ofhomologouspartstendingtovaryinthesamemanner。ButasbothformsofpeloriafrequentlyoccuronthesameindividualplantoftheLinaria（13/69。Verlot’DesVarietes’1865page89;Naudin’NouvellesArchivesduMuseum’tome1page137。），theyprobablystandinsomecloserelationtooneanother。Onthedoctrinethatpeloriaissimplytheresultofanarrestofdevelopment，itisdifficulttounderstandhowanorganarrestedataveryearlyperiodofgrowthshouldacquireitsfullfunctionalperfection;——howapetal，supposedtobethusarrested，shouldacquireitsbrilliantcolours，andserveasanenvelopetotheflower，orastamenproduceefficientpollen;yetthisoccurswithmanypeloricflowers。Thatpelorismisnotduetomerechancevariability，buteithertoanarrestofdevelopmentortoreversion，wemayinferfromanobservationmadebyCh。Morren（13/70。InhisdiscussiononsomecuriouspeloricCalceolariasquotedin’JournalofHorticulture’February24，1863page152。）namely，thatfamilieswhichhaveirregularflowersoften\"returnbythesemonstrousgrowthstotheirregularform;whilstweneverseearegularflowerrealisethestructureofanirregularone。\"
Someflowershavealmostcertainlybecomemoreorlesscompletelypeloricthroughreversion，asthefollowinginterestingcaseshows。Corydalistuberosaproperlyhasoneofitstwonectariescolourless，destituteofnectar，onlyhalfthesizeoftheother，andtherefore，toacertainextent，inarudimentarystate;thepistiliscurvedtowardstheperfectnectary，andthehood，formedoftheinnerpetals，slipsoffthepistilandstameninonedirectionalone，sothat，whenabeesuckstheperfectnectary，thestigmaandstamensareexposedandrubbedagainsttheinsect’sbody。Inseveralcloselyalliedgenera，asinDielytra，etc。，therearetwoperfectnectaries，thepistilisstraight，andthehoodslipsoffoneitherside，accordingasthebeesuckseithernectary。Now，IhaveexaminedseveralflowersofCorydalistuberosa，inwhichbothnectarieswereequallydevelopedandcontainednectar;
inthisweseeonlytheredevelopmentofapartiallyabortedorgan;butwiththisredevelopmentthepistilbecomesstraight，andthehoodslipsoffineitherdirection，sothattheseflowershaveacquiredtheperfectstructure，sowelladaptedforinsectagency，ofDielytraanditsallies。Wecannotattributethesecoadaptedmodificationstochance，ortocorrelatedvariability;wemustattributethemtoreversiontoaprimordialconditionofthespecies。
ThepeloricflowersofPelargoniumhavetheirfivepetalsinallrespectsalike，andthereisnonectarysothattheyresemblethesymmetricalflowersofthecloselyalliedgenusGeranium;butthealternatestamensarealsosometimesdestituteofanthers，theshortenedfilamentsbeingleftasrudiments，andinthisrespecttheyresemblethesymmetricalflowersofthecloselyalliedgenusErodium。HencewemaylookatthepeloricflowersofPelargoniumashavingrevertedtothestateofsomeprimordialform，theprogenitorofthethreecloselyrelatedgeneraofPelargonium，Geranium，andErodium。
InthepeloricformofAntirrhinummajus，appropriatelycalledthe\"Wonder，\"
thetubularandelongatedflowersdifferwonderfullyfromthoseofthecommonsnapdragon;thecalyxandthemouthofthecorollaconsistofsixequallobes，andincludesixequalinsteadoffourunequalstamens。Oneofthetwoadditionalstamensismanifestlyformedbythedevelopmentofamicroscopicallyminutepapilla，whichmaybefoundatthebaseoftheupperlipoftheflowerofthecommonsnapdragonsinthenineteenplantsexaminedbyme。ThatthispapillaisarudimentofastamenwaswellshownbyitsvariousdegreesofdevelopmentincrossedplantsbetweenthecommonandthepeloricAntirrhinum。Again，apeloricGaleobdolonluteum，growinginmygarden，hadfiveequalpetals，allstripedliketheordinarylowerlip，andincludedfiveequalinsteadoffourunequalstamens;butMr。R。Keeley，whosentmethisplant，informsmethattheflowersvarygreatly，havingfromfourtosixlobestothecorolla，andfromthreetosixstamens。（13/71。ForothercasesofsixdivisionsinpeloricflowersoftheLabiataeandScrophulariaceaeseeMoquin—
Tandon’Teratologie’page192。）Now，asthemembersofthetwogreatfamiliestowhichtheAntirrhinumandGaleobdolonbelongareproperlypentamerous，withsomeofthepartsconfluentandotherssuppressed，weoughtnottolookatthesixthstamenandthesixthlobetothecorollaineithercaseasduetoreversion，anymorethantheadditionalpetalsindoubleflowersinthesesametwofamilies。ButthecaseisdifferentwiththefifthstameninthepeloricAntirrhinum，whichisproducedbytheredevelopmentofarudimentalwayspresent，andwhichprobablyrevealstousthestateoftheflower，asfarasthestamensareconcerned，atsomeancientepoch。Itisalsodifficulttobelievethattheotherfourstamensandthepetals，afteranarrestofdevelopmentataveryearlyembryonicage，wouldhavecometofullperfectionincolour，structure，andfunction，unlesstheseorganshadatsomeformerperiodnormallypassedthroughasimilarcourseofgrowth。HenceitappearstomeprobablethattheprogenitorofthegenusAntirrhinummustatsomeremoteepochhaveincludedfivestamensandborneflowersinsomedegreeresemblingthosenowproducedbythepeloricform。Theconclusionthatpeloriaisnotameremonstrosity，irrespectiveofanyformerstateofthespecies，issupportedbythefactthatthisstructureisoftenstronglyinherited，asinthecaseofthepeloricAntirrhinumandGloxiniaandsometimesinthatofthepeloricCorydalissolida。（13/72。Godronreprintedfromthe’Memoiresdel’Acad。deStanislas’1868。）
LastlyImayaddthatmanyinstanceshavebeenrecordedofflowers，notgenerallyconsideredaspeloric，inwhichcertainorgansareabnormallyaugmentedinnumber。Asanincreaseofpartscannotbelookedatasanarrestofdevelopment，norasduetotheredevelopmentofrudiments，fornorudimentsarepresent，andastheseadditionalpartsbringtheplantintocloserrelationshipwithitsnaturalallies，theyoughtprobablytobeviewedasreversionstoaprimordialcondition。]
Theseseveralfactsshowusinaninterestingmannerhowintimatelycertainabnormalstatesareconnectedtogether;namely，arrestsofdevelopmentcausingpartstobecomerudimentaryortobewhollysuppressed，——theredevelopmentofpartsnowinamoreorlessrudimentarycondition，——thereappearanceoforgansofwhichnotavestigecanbedetected，——andtothesemaybeadded，inthecaseofanimals，thepresenceduringyouth，andsubsequentdisappearance，ofcertaincharacterswhichoccasionallyareretainedthroughoutlife。Somenaturalistslookatallsuchabnormalstructuresasareturntotheidealstateofthegrouptowhichtheaffectedbeingbelongs;butitisdifficulttoconceivewhatismeanttobeconveyedbythisexpression。Othernaturalistsmaintain，withgreaterprobabilityanddistinctnessofview，thatthecommonbondofconnectionbetweentheseveralforegoingcasesisanactual，thoughpartial，returntothestructureoftheancientprogenitorofthegroup。Ifthisviewbecorrect，wemustbelievethatavastnumberofcharacters，capableofevolution，liehiddenineveryorganicbeing。Butitwouldbeamistaketosupposethatthenumberisequallygreatinallbeings。Weknow，forinstance，thatplantsofmanyordersoccasionallybecomepeloric;butmanymorecaseshavebeenobservedintheLabiataeandScrophulariaceaethaninanyotherorder;andinonegenusoftheScrophulariaceae，namelyLinaria，nolessthanthirteenspecieshavebeendescribedinthiscondition（13/73。Moquin—
Tandon’Teratologie’page186。）Onthisviewofthenatureofpeloricflowers，andbearinginmindcertainmonstrositiesintheanimalkingdom，wemustconcludethattheprogenitorsofmostplantsandanimalshaveleftanimpression，capableofredevelopment，onthegermsoftheirdescendants，althoughthesehavesincebeenprofoundlymodified。
Thefertilisedgermofoneofthehigheranimals，subjectedasitistosovastaseriesofchangesfromthegerminalcelltooldage，——incessantlyagitatedbywhatQuatrefageswellcallsthetourbillonvital，——isperhapsthemostwonderfulobjectinnature。Itisprobablethathardlyachangeofanykindaffectseitherparent，withoutsomemarkbeingleftonthegerm。Butonthedoctrineofreversion，asgiveninthischapter，thegermbecomesafarmoremarvellousobject，for，besidesthevisiblechangeswhichitundergoes，wemustbelievethatitiscrowdedwithinvisiblecharacters，propertobothsexes，toboththerightandleftsideofthebody，andtoalonglineofmaleandfemaleancestorsseparatedbyhundredsoreventhousandsofgenerationsfromthepresenttime:andthesecharacters，likethosewrittenonpaperwithinvisibleink，liereadytobeevolvedwhenevertheorganisationisdisturbedbycertainknownorunknownconditions。
CHAPTER2。XIV。
INHERITANCEcontinued。——FIXEDNESSOFCHARACTER——PREPOTENCY——SEXUALLIMITATION
——CORRESPONDENCEOFAGE。
FIXEDNESSOFCHARACTERAPPARENTLYNOTDUETOANTIQUITYOFINHERITANCE。
PREPOTENCYOFTRANSMISSIONININDIVIDUALSOFTHESAMEFAMILY，INCROSSED
BREEDSANDSPECIES;OFTENSTRONGERINONESEXTHANTHEOTHER;SOMETIMESDUETO
THESAMECHARACTERBEINGPRESENTANDVISIBLEINONEBREEDANDLATENTINTHE
OTHER。
INHERITANCEASLIMITEDBYSEX。
NEWLY—ACQUIREDCHARACTERSINOURDOMESTICATEDANIMALSOFTENTRANSMITTEDBYONE
SEXALONE，SOMETIMESLOSTBYONESEXALONE。
INHERITANCEATCORRESPONDINGPERIODSOFLIFE。
THEIMPORTANCEOFTHEPRINCIPLEWITHRESPECTTOEMBRYOLOGY;ASEXHIBITEDIN
DOMESTICATEDANIMALS:ASEXHIBITEDINTHEAPPEARANCEANDDISAPPEARANCEOF
INHERITEDDISEASES;SOMETIMESSUPERVENINGEARLIERINTHECHILDTHANIN
THEPARENT。
SUMMARYOFTHETHREEPRECEDINGCHAPTERS。
InthelasttwochaptersthenatureandforceofInheritance，thecircumstanceswhichinterferewithitspower，andthetendencytoReversion，withitsmanyremarkablecontingencies，werediscussed。Inthepresentchaptersomeotherrelatedphenomenawillbetreatedof，asfullyasmymaterialspermit。
FIXEDNESSOFCHARACTER。
Itisageneralbeliefamongstbreedersthatthelongeranycharacterhasbeentransmittedbyabreed，themorefullyitwillcontinuetobetransmitted。I
donotwishtodisputethetruthofthepropositionthatinheritancegainsstrengthsimplythroughlongcontinuance，butIdoubtwhetheritcanbeproved。Inonesensethepropositionislittlebetterthanatruism;ifanycharacterhasremainedconstantduringmanygenerations，itwillbelikelytocontinueso，iftheconditionsofliferemainthesame。So，again，inimprovingabreed，ifcarebetakenforalengthoftimetoexcludeallinferiorindividuals，thebreedwillobviouslytendtobecometruer，asitwillnothavebeencrossedduringmanygenerationsbyaninferioranimal。Wehavepreviouslyseen，butwithoutbeingabletoassignanycause，that，whenanewcharacterappears，itisoccasionallyfromthefirstconstant，orfluctuatesmuch，orwhollyfailstobetransmitted。Soitiswiththeaggregateofslightdifferenceswhichcharacteriseanewvariety，forsomepropagatetheirkindfromthefirstmuchtruerthanothers。Evenwithplantsmultipliedbybulbs，layers，etc。，whichmayinonesensebesaidtoformpartsofthesameindividual，itiswellknownthatcertainvarietiesretainandtransmitthroughsuccessivebud—generationstheirnewly—acquiredcharactersmoretrulythanothers。Innoneofthese，norinthefollowingcases，doesthereappeartobeanyrelationbetweentheforcewithwhichacharacteristransmittedandthelengthoftimeduringwhichithasbeentransmitted。Somevarieties，suchaswhiteandyellowhyacinthsandwhitesweet—peas，transmittheircoloursmorefaithfullythandothevarietieswhichhaveretainedtheirnaturalcolour。IntheIrishfamily，mentionedinthetwelfthchapter，thepeculiartortoiseshell—likecolouringoftheeyeswastransmittedfarmorefaithfullythananyordinarycolour。AnconandMauchampsheepandniatacattle，whichareallcomparativelymodernbreeds，exhibitremarkablystrongpowersofinheritance。Manysimilarcasescouldbeadduced。
Asalldomesticatedanimalsandcultivatedplantshavevaried，andyetaredescendedfromaboriginallywildforms，whichnodoubthadretainedthesamecharacterfromanimmenselyremoteepoch，weseethatscarcelyanydegreeofantiquityensuresacharacterbeingtransmittedperfectlytrue。Inthiscase，however，itmaybesaidthatchangedconditionsoflifeinducecertainmodifications，andnotthatthepowerofinheritancefails;butineverycaseoffailure，somecause，eitherinternalorexternal，mustinterfere。Itwillgenerallybefoundthattheorgansorpartswhichinourdomesticatedproductionshavevaried，orwhichstillcontinuetovary，——thatis，whichfailtoretaintheirformerstate，——arethesamewiththepartswhichdifferinthenaturalspeciesofthesamegenus。As，onthetheoryofdescentwithmodification，thespeciesofthesamegenushavebeenmodifiedsincetheybranchedofffromacommonprogenitor，itfollowsthatthecharactersbywhichtheydifferfromoneanotherhavevaried，whilstotherpartsoftheorganisationhaveremainedunchanged;anditmightbearguedthatthesesamecharactersnowvaryunderdomestication，orfailtobeinherited，fromtheirlesserantiquity。Butvariationinastateofnatureseemstostandinsomecloserelationwithchangedconditionsoflife，andcharacterswhichhavealreadyvariedundersuchconditionswouldbeapttovaryunderthestillgreaterchangesconsequentondomestication，independentlyoftheirgreaterorlessantiquity。
Fixednessofcharacter，orthestrengthofinheritance，hasoftenbeenjudgedofbythepreponderanceofcertaincharactersinthecrossedoffspringbetweendistinctraces;butprepotencyoftransmissionherecomesintoplay，andthis，asweshallimmediatelysee，isaverydifferentconsiderationfromthestrengthorweaknessofinheritance。（14/1。See’YouattonCattle’pages92，69，78，88，163;and’YouattonSheep’page325。AlsoDr。Lucas’L’Hered。
Nat。’tome2page310。）Ithasoftenbeenobservedthatbreedsofanimalsinhabitingwildandmountainouscountriescannotbepermanentlymodifiedbyourimprovedbreeds;andastheselatterareofmodernorigin，ithasbeenthoughtthatthegreaterantiquityofthewilderbreedshasbeenthecauseoftheirresistancetoimprovementbycrossing;butitismoreprobablyduetotheirstructureandconstitutionbeingbetteradaptedtothesurroundingconditions。Whenplantsarefirstsubjectedtoculture，ithasbeenfoundthat，duringseveralgenerations，theytransmittheircharacterstruly，thatis，donotvary，andthishasbeenattributedtoancientcharactersbeingstronglyinherited:butitmaywithequalorgreaterprobabilitybeconsequentonchangedconditionsofliferequiringalongtimefortheircumulativeaction。Notwithstandingtheseconsiderations，itwouldperhapsberashtodenythatcharactersbecomemorestronglyfixedthelongertheyaretransmitted;
butIbelievethatthepropositionresolvesitselfintothis，——thatcharactersofallkinds，whetherneworold，tendtobeinherited，andthatthosewhichhavealreadywithstoodallcounteractinginfluencesandbeentrulytransmitted，will，asageneralrule，continuetowithstandthem，andconsequentlybefaithfullyinherited。
PREPOTENCYINTHETRANSMISSIONOFCHARACTER。
Whenindividuals，belongingtothesamefamily，butdistinctenoughtoberecognised，orwhentwowell—markedraces，ortwospecies，arecrossed，theusualresult，asstatedinthepreviouschapter，is，thattheoffspringinthefirstgenerationareintermediatebetweentheirparents，orresembleoneparentinonepartandtheotherparentinanotherpart。Butthisisbynomeanstheinvariablerule;forinmanycasesitisfoundthatcertainindividuals，races，andspecies，areprepotentintransmittingtheirlikeness。
ThissubjecthasbeenablydiscussedbyProsperLucas（14/2。’Hered。Nat。’
tome2pages112—120。），butisrenderedextremelycomplexbytheprepotencysometimesrunningequallyinbothsexes，andsometimesmorestronglyinonesexthanintheother;itislikewisecomplicatedbythepresenceofsecondarysexualcharacters，whichrenderthecomparisonofcrossedbreedswiththeirparentsdifficult。
Itwouldappearthatincertainfamiliessomeoneancestor，andafterhimothersinthesamefamily，havehadgreatpowerintransmittingtheirlikenessthroughthemaleline;forwecannototherwiseunderstandhowthesamefeaturesshouldsooftenbetransmittedaftermarriageswithmanyfemales，asinthecaseoftheAustrianEmperors;andsoitwas，accordingtoNiebuhr，withthementalqualitiesofcertainRomanfamilies。（14/3。SirH。Holland’ChaptersonMentalPhysiology’1852page234。）ThefamousbullFavouriteisbelieved（14/4。’Gardener’sChronicle’1860page270。）tohavehadaprepotentinfluenceontheshorthornrace。Ithasalsobeenobserved（14/5。Mr。N。H。
Smith’ObservationsonBreeding’quotedin’Encyclop。ofRuralSports’page278。）withEnglishracehorsesthatcertainmareshavegenerallytransmittedtheirowncharacter，whilstothermaresofequallypurebloodhaveallowedthecharacterofthesiretoprevail。Afamousblackgreyhound，Bedlamite，asI
hearfromMr。C。M。Brown\"invariablygotallhispuppiesblack，nomatterwhatwasthecolourofthebitch;\"butthenBedlamite\"hadapreponderanceofblackinhisblood，bothonthesireanddamside。\"
[Thetruthoftheprincipleofprepotencycomesoutmoreclearlywhendistinctracesarecrossed。TheimprovedShorthorns，notwithstandingthatthebreediscomparativelymodern，aregenerallyacknowledgedtopossessgreatpowerinimpressingtheirlikenessonallotherbreeds;anditischieflyinconsequenceofthispowerthattheyaresohighlyvaluedforexportation。
（14/6。QuotedbyBronn’GeshichtederNatur’b。2s。170。SeeSturm’UeberRacen’1825s。104—107。Fortheniatacattleseemy’JournalofResearches’
1845page146。）Godinehasgivenacuriouscaseofaramofagoat—likebreedofsheepfromtheCapeofGoodHope，whichproducedoffspringhardlytobedistinguishedfromhimself，whencrossedwithewesoftwelveotherbreeds。Buttwoofthesehalf—bredewes，whenputtoamerinoram，producedlambscloselyresemblingthemerinobreed。GiroudeBuzareingues（14/7。Lucas’L’HerediteNat。’tome2page112。）foundthatoftworacesofFrenchsheeptheewesofone，whencrossedduringsuccessivegenerationswithmerinorams，yieldeduptheircharacterfarsoonerthantheewesoftheotherrace。SturmandGirouhavegivenanalogouscaseswithotherbreedsofsheepandwithcattle，theprepotencyrunninginthesecasesthroughthemaleside;butIwasassuredongoodauthorityinSouthAmerica，thatwhenniatacattlearecrossedwithcommoncattle，thoughtheniatabreedisprepotentwhethermalesorfemalesareused，yetthattheprepotencyisstrongestthroughthefemaleline。TheManxcatistaillessandhaslonghindlegs;Dr。WilsoncrossedamaleManxwithcommoncats，and，outoftwenty—threekittens，seventeenweredestituteoftails;butwhenthefemaleManxwascrossedbycommonmalecatsallthekittenshadtails，thoughtheyweregenerallyshortandimperfect。（14/8。Mr。
Orton’PhysiologyofBreeding’1855page9。）
Inmakingreciprocalcrossesbetweenpouterandfantailpigeons，thepouter—
raceseemedtobeprepotentthroughbothsexesoverthefantail。Butthisisprobablyduetoweakpowerinthefantailratherthantoanyunusuallystrongpowerinthepouter，forIhaveobservedthatbarbsalsopreponderateoverfantails。Thisweaknessoftransmissioninthefantail，thoughthebreedisanancientone，issaid（14/9。BoitardandCorbie’LesPigeons’1824page224。）
tobegeneral;butIhaveobservedoneexceptiontotherule，namely，inacrossbetweenafantailandlaugher。Themostcuriousinstanceknowntomeofweakpowerinbothsexesisinthetrumpeterpigeon。Thisbreedhasbeenwellknownforatleast130years:itbreedsperfectlytrue，asIhavebeenassuredbythosewhohavelongkeptmanybirds:itischaracterisedbyapeculiartuftoffeathersoverthebeak，byacrestonthehead，byasingularcooquiteunlikethatofanyotherbreed，andbymuch—featheredfeet。Ihavecrossedbothsexeswithturbitsoftwosub—breeds，withalmondtumblers，spots，andrunts，andrearedmanymongrelsandrecrossedthem;andthoughthecrestontheheadandfeatheredfeetwereinherited（asisgenerallythecasewithmostbreeds），Ihaveneverseenavestigeofthetuftoverthebeakorheardthepeculiarcoo。BoitardandCorbie（14/10。’LesPigeons’pages168，198。）assertthatthisistheinvariableresultofcrossingtrumpeterswithotherbreeds:
Neumeister（14/11。’DasGanze’etc。1837s。39。），however，statesthatinGermanymongrelshavebeenobtained，thoughveryrarely，whichwerefurnishedwiththetuftandwouldtrumpet:butapairofthesemongrelswithatuft，whichIimported，nevertrumpeted。Mr。Brentstates（14/12。’ThePigeonBook’
page46。）thatthecrossedoffspringofatrumpeterwerecrossedwithtrumpetersforthreegenerations，bywhichtimethemongrelshad7/8thsofthisbloodintheirveins，yetthetuftoverthebeakdidnotappear。Atthefourthgenerationthetuftappeared，butthebirdsthoughnowhaving15—16thstrumpeter’sbloodstilldidnottrumpet。Thiscasewellshowsthewidedifferencebetweeninheritanceandprepotency;forherewehaveawell—
establishedoldracewhichtransmitsitscharactersfaithfully，butwhich，whencrossedwithanyotherrace，hasthefeeblestpoweroftransmittingitstwochiefcharacteristicqualities。
Iwillgiveoneotherinstancewithfowlsandpigeonsofweaknessandstrengthinthetransmissionofthesamecharactertotheircrossedoffspring。TheSilkfowlbreedstrue，andthereisreasontobelieveisaveryancientrace;butwhenIrearedalargenumberofmongrelsfromaSilkhenbyaSpanishcock，notoneexhibitedevenatraceoftheso—calledsilkiness。Mr。Hewittalsoassertsthatinnoinstancearethesilkyfeatherstransmittedbythisbreedwhencrossedwithanyothervariety。ButthreebirdsoutofmanyraisedbyMr。
Ortonfromacrossbetweenasilkcockandabantamhenhadsilkyfeathers。
（14/13。’PhysiologyofBreeding’page22;Mr。Hewittin’ThePoultryBook’byTegetmeier1866page224。）Sothatitiscertainthatthisbreedveryseldomhasthepoweroftransmittingitspeculiarplumagetoitscrossedprogeny。Ontheotherhand，thereisasilksub—varietyofthefantailpigeon，whichhasitsfeathersinnearlythesamestateasintheSilkfowl:nowwehavealreadyseenthatfantails，whencrossed，possesssingularlyweakpowerintransmittingtheirgeneralqualities;butthesilksub—varietywhencrossedwithanyothersmall—sizedraceinvariablytransmitsitssilkyfeathers！
（14/14。BoitardandCorbie’LesPigeons’1824page226。）
Thewell—knownhorticulturist，Mr。Paul，informsmethathefertilisedtheBlackPrincehollyhockwithpollenoftheWhiteGlobeandtheLemonadeandBlackPrincehollyhocksreciprocally;butnotoneseedlingfromthesethreecrossesinheritedtheblackcolouroftheBlackPrince。So，again，Mr。Laxton，whohashadsuchgreatexperienceincrossingpeas，writestomethat\"wheneveracrosshasbeeneffectedbetweenawhite—blossomedandapurple—
blossomedpea，orbetweenawhite—seededandapurple—spotted，brownormaple—
seededpea，theoffspringseemstolosenearlyallthecharacteristicsofthewhite—floweredandwhite—seededvarieties;andthisresultfollowswhetherthesevarietieshavebeenusedasthepollen—bearingorseed—producingparents。\"
Thelawofprepotencycomesintoactionwhenspeciesarecrossed，aswithracesandindividuals。Gartnerhasunequivocallyshown（14/15。
’Bastarderzeugung’s。256，290，etc。Naudin’NouvellesArchivesduMuseum’
tome1page149givesastrikinginstanceofprepotencyinDaturastramoniumwhencrossedwithtwootherspecies。）thatthisisthecasewithplants。Togiveoneinstance:whenNicotianapaniculataandvincaefloraarecrossed，thecharacterofN。paniculataisalmostcompletelylostinthehybrid;butifN。
quadrivalvisbecrossedwithN。vincaeflora，thislatterspecies，whichwasbeforesoprepotent，nowinitsturnalmostdisappearsunderthepowerofN。
quadrivalvis。Itisremarkablethattheprepotencyofonespeciesoveranotherintransmissionisquiteindependent，asshownbyGartner，ofthegreaterorlessfacilitywithwhichtheonefertilisestheother。
Withanimals，thejackalisprepotentoverthedog，asisstatedbyFlourens，whomademanycrossesbetweentheseanimals;andthiswaslikewisethecasewithahybridwhichIoncesawbetweenajackalandaterrier。Icannotdoubt，fromtheobservationsofColinandothers，thattheassisprepotentoverthehorse;theprepotencyinthisinstancerunningmorestronglythroughthemalethanthroughthefemaleass;sothatthemuleresemblestheassmorecloselythandoesthehinny。（14/16。Flourens’LongeviteHumaine’page144oncrossedjackals。WithrespecttothedifferencebetweenthemuleandthehinnyIamawarethatthishasgenerallybeenattributedtothesireanddamtransmittingtheircharactersdifferently;butColin，whohasgiveninhis’TraitePhys。
Comp。’tome2pages537—539，thefullestdescriptionwhichIhavemetwithofthesereciprocalhybrids，isstronglyofopinionthattheasspreponderatesinbothcrosses，butinanunequaldegree。ThisislikewisetheconclusionofFlourens，andofBechsteininhis’NaturgeschichteDeutschlands’b。1s。294。
Thetailofthehinnyismuchmorelikethatofthehorsethanisthetailofthemule，andthisisgenerallyaccountedforbythemalesofbothspeciestransmittingwithgreaterpowerthispartoftheirstructure;butacompoundhybridwhichIsawintheZoologicalGardens，fromamarebyahybridass—
zebra，closelyresembleditsmotherinitstail。）Themalepheasant，judgingfromMr。Hewitt’sdescriptions（14/17。Mr。Hewittwhohashadsuchgreatexperienceinraisingthesehybridssays（’PoultryBook’byMr。Tegetmeier1866pages165—167）thatinall，theheadwasdestituteofwattles，comb，andear—lappets;andallcloselyresembledthepheasantintheshapeofthetailandgeneralcontourofthebody。Thesehybridswereraisedfromhensofseveralbreedsbyacock—pheasant;butanotherhybrid，describedbyMr。
Hewitt，wasraisedfromahen—pheasant，byasilver—lacedBantamcock，andthispossessedarudimentalcombandwattles。），andfromthehybridswhichI
haveseen，preponderatesoverthedomesticfowl;butthelatter，asfarascolourisconcerned，hasconsiderablepoweroftransmission，forhybridsraisedfromfivedifferentlycolouredhensdifferedgreatlyinplumage。I
formerlyexaminedsomecurioushybridsintheZoologicalGardens，betweenthePenguinvarietyofthecommonduckandtheEgyptiangoose（Anseraegyptiacus）;
andalthoughIwillnotassertthatthedomesticatedvarietypreponderatedoverthenaturalspecies，yetithadstronglyimpresseditsunnaturaluprightfigureonthesehybrids。
Iamawarethatsuchcasesastheforegoinghavebeenascribedbyvariousauthors，nottoonespecies，race，orindividualbeingprepotentovertheotherinimpressingitscharacteronitscrossedoffspring，buttosuchrulesasthatthefatherinfluencestheexternalcharactersandthemothertheinternalorvitalorgans。Butthegreatdiversityoftherulesgivenbyvariousauthorsalmostprovestheirfalseness。Dr。ProsperLucashasfullydiscussedthispoint，andhasshown（14/18。’L’Hered。Nat。’tome2book2
chapter1。）thatnoneoftherules（andIcouldaddotherstothosequotedbyhim）applytoallanimals。Similarruleshavebeenannouncedforplants，andhavebeenprovedbyGartner（14/19。’Bastarderzeugung’s。264—266。Naudin’NouvellesArchivesduMuseum’tome1page148hasarrivedatasimilarconclusion。）tobeallerroneous。Ifweconfineourviewtothedomesticatedracesofasinglespecies，orperhapseventothespeciesofthesamegenus，somesuchrulesmayholdgood;forinstance，itseemsthatinreciprocallycrossingvariousbreedsoffowlsthemalegenerallygivescolour（14/20。
’CottageGardener’1856pages101，137。）;butconspicuousexceptionshavepassedundermyowneyes。Itseemsthattheramusuallygivesitspeculiarhornsandfleecetoitscrossedoffspring，andthebullthepresenceorabsenceofhorns。
InthefollowingchapteronCrossingIshallhaveoccasiontoshowthatcertaincharactersarerarelyorneverblendedbycrossing，butaretransmittedinanunmodifiedstatefromeitherparent—form;Irefertothisfactherebecauseitissometimesaccompaniedontheonesidebyprepotency，whichthusacquiresthefalseappearanceofunusualstrength。InthesamechapterIshallshowthattherateatwhichaspeciesorbreedabsorbsandobliteratesanotherbyrepeatedcrosses，dependsinchiefpartonprepotencyintransmission。]
Inconclusion，someofthecasesabovegiven，——forinstance，thatofthetrumpeterpigeon，——provethatthereisawidedifferencebetweenmereinheritanceandprepotency。Thislatterpowerseemstous，inourignorance，toactinmostcasesquitecapriciously。Theverysamecharacter，eventhoughitbeanabnormalormonstrousone，suchassilkyfeathers，maybetransmittedbydifferentspecies，whencrossed，eitherwithprepotentforceorsingularfeebleness。Itisobvious，thatapurely—bredformofeithersex，inallcasesinwhichprepotencydoesnotrunmorestronglyinonesexthantheother，willtransmititscharacterwithprepotentforceoveramongrelisedandalreadyvariableform。（14/21。SeesomeremarksonthisheadwithrespecttosheepbyMr。Wilsonin’Gardener’sChronicle’1863page15。ManystrikinginstancesofthisresultaregivenbyM。Malingie—Nouel’Journ。R。Agricult。Soc。’volume141853page220withrespecttocrossesbetweenEnglishandFrenchsheep。HefoundthatheobtainedthedesiredinfluenceoftheEnglishbreedsbycrossingintentionallymongrelisedFrenchbreedswithpureEnglishbreeds。）Fromseveraloftheabove—givencaseswemayconcludethatmereantiquityofcharacterdoesnotbyanymeansnecessarilymakeitprepotent。Insomecasesprepotencyapparentlydependsonthesamecharacterbeingpresentandvisibleinoneofthetwobreedswhicharecrossed，andlatentorinvisibleintheotherbreed;andinthiscaseitisnaturalthatthecharacterwhichispotentiallypresentinbothbreedsshouldbeprepotent。Thus，wehavereasontobelievethatthereisalatenttendencyinallhorsestobedun—colouredandstriped;andwhenahorseofthiskindiscrossedwithoneofanyothercolour，itissaidthattheoffspringarealmostsuretobestriped。Sheephaveasimilarlatenttendencytobecomedark—coloured，andwehaveseenwithwhatprepotentforcearamwithafewblackspots，whencrossedwithwhitesheepofvariousbreeds，coloureditsoffspring。Allpigeonshavealatenttendencytobecomeslaty—blue，withcertaincharacteristicmarks，anditisknownthat，whenabirdthuscolourediscrossedwithoneofanyothercolour，itismostdifficultafterwardstoeradicatethebluetint。Anearlyparallelcaseisofferedbythoseblackbantamswhich，astheygrowold，developalatenttendencytoacquireredfeathers。Butthereareexceptionstotherule:
hornlessbreedsofcattlepossessalatentcapacitytoreproducehorns，yetwhencrossedwithhornedbreedstheydonotinvariablyproduceoffspringbearinghorns。
Wemeetwithanalogouscaseswithplants。Stripedflowers，thoughtheycanbepropagatedtrulybyseed，havealatenttendencytobecomeuniformlycoloured，butwhenoncecrossedbyauniformlycolouredvariety，theyeverafterwardsfailtoproducestripedseedlings。（14/22。Verlot’DesVarietes’1865page66。）Anothercaseisinsomerespectsmorecurious:plantsbearingpeloricflowershavesostrongalatenttendencytoreproducetheirnormallyirregularflowers，thatthisoftenoccursbybudswhenaplantistransplantedintopoorerorrichersoil。（14/23。Moquin—Tandon’Teratologie’page191。）NowI
crossedthepeloricsnapdragon（Antirrhinummajus），describedinthelastchapter，withpollenofthecommonform;andthelatter，reciprocally，withpeloricpollen。Ithusraisedtwogreatbedsofseedlings，andnotonewaspeloric。Naudin（14/24。’NouvellesArchivesduMuseum’tome1page137。）
obtainedthesameresultfromcrossingapeloricLinariawiththecommonform。