（8/39。’OrnamentalPoetry’bytheRev。E。S。Dixon1848page34。）Theinferiortail—covertsvaryinnumber，andaccordingtoaGermansuperstitionthehenlaysasmanyeggsasthecockhasfeathersofthiskind。（8/40。Bechstein’Naturgesch。Deutschlands’b。31793s。309。）Albinin1738，andTemminckwithinamuchlaterperiod，describeabeautifulbreed，dusky—yellowish，brownaboveandwhitebeneath，withalargetop—
knotofsoftplumosefeather。Thespursofthemalewererudimentary。ThisbreedhasbeenforalongtimeextinctinEurope;butalivingspecimenhaslatelybeenimportedfromtheeastcoastofAfrica，whichstillretainsthetop—knotandthesamegeneralcolouringandrudimentaryspurs。（8/41。Mr。
Bartlettin’LandandWater’October31，1868page233;andMr。Tegetmeierinthe’Field’July17，1869page46。）Mr。Wilmothasdescribed（8/42。
’Gardener’sChronicle’1852page699。）awhiteturkey—cockhavingacrestformedof"feathersaboutfourincheslong，withbarequills，andatuftofsoftwhitedowngrowingattheend。"Manyoftheyoungbirdsinheritedthiskindofcrest，butafterwardsitfellofforwaspeckedoutbytheotherbirds。Thisisaninterestingcase，aswithcareanewbreedmightprobablyhavebeenformed;andatop—knotofthisnaturewouldhavebeentoacertainextentanalogoustothatbornebythemalesinseveralalliedgenera，suchasEuplocomus，Lophophorus，andPavo。
Wildturkeys，believedineveryinstancetohavebeenimportedfromtheUnitedStates，havebeenkeptintheparksofLordsPowis，Leicester，Hill，andDerby。TheRev。W。D。Foxprocuredbirdsfromthetwofirst—namedparks，andheinformsmethattheycertainlydifferedalittlefromeachotherintheshapeoftheirbodiesandinthebarredplumageontheirwings。ThesebirdslikewisedifferedfromLordHill’sstock。SomeofthelatterkeptatOultonbySirP。Egerton，thoughprecludedfromcrossingwithcommonturkeys，occasionallyproducedmuchpaler—colouredbirds，andonethatwasalmostwhite，butnotanalbino。Thesehalf—wildturkeys，inthusdifferingslightlyfromeachother，presentananalogouscasewiththewildcattlekeptintheseveralBritishparks。Wemustsupposethatsuchdifferenceshaveresultedfromthepreventionoffreeintercrossingbetweenbirdsrangingoverawidearea，andfromthechangedconditionstowhichtheyhavebeenexposedinEngland。InIndiatheclimatehasapparentlywroughtastillgreaterchangeintheturkey，foritisdescribedbyMr。Blyth（8/43。
E。Blyth’AnnalsandMag。ofNat。Hist。’1847volume20page391。）asbeingmuchdegeneratedinsize，"utterlyincapableofrisingonthewing，"ofablackcolour，and"withthelongpendulousappendagesoverthebeakenormouslydeveloped。"
THEGUINEAFOWL。
ThedomesticatedGuineafowlisnowbelievedbysomenaturaliststobedescendedfromtheNumidaptilorhynca，whichinhabitsveryhot，and，inparts，extremelyariddistrictsinEasternAfrica;consequentlyithasbeenexposedinthiscountrytoextremelydifferentconditionsoflife。
Neverthelessithashardlyvariedatall，exceptintheplumagebeingeitherpalerordarker—coloured。ItisasingularfactthatthisbirdvariesmoreincolourintheWestIndiesandontheSpanishMain，underahotthoughhumidclimate，thaninEurope。（8/44。Roulinmakesthisremarkin’Mem。dediversSavans，1’Acad。desSciences’tome61835page349。Mr。
HillofSpanishTowninalettertomedescribesfivevarietiesoftheGuineafowlinJamaica。Ihaveseensingularpale—colouredvarietiesimportedfromBarbadoesandDemerara。）TheGuineafowlhasbecomethoroughlyferalinJamaicaandinSt。Domingo（8/45。ForSt。DomingoseeM。A。Salle，in’Proc。Zoolog。Soc。’1857page236。Mr。Hillremarkstome，inhisletter，onthecolourofthelegsoftheferalbirdsinJamaica。），andhasdiminishedinsize;thelegsareblack，whereasthelegsoftheaboriginalAfricanbirdaresaidtobegrey。Thissmallchangeisworthnoticeonaccountoftheoften—repeatedstatementthatallferalanimalsinvariablyrevertineverycharactertotheiroriginaltype。
THECANARYBIRD。
Asthisbirdhasbeenrecentlydomesticated，namely，withinthelast350
years，itsvariabilitydeservesnotice。IthasbeencrossedwithnineortenotherspeciesofFringillidae，andsomeofthehybridsarealmostcompletelyfertile;butwehavenoevidencethatanydistinctbreedhasoriginatedfromsuchcrosses。Notwithstandingthemoderndomesticationofthecanary，manyvarietieshavebeenproduced;evenbeforetheyear1718alistoftwenty—sevenvarietieswaspublishedinFrance（8/46。Mr。B。P。
Brent’TheCanary，BritishFinches’etc。pages21，30。），andin1779alongscheduleofthedesiredqualitieswasprintedbytheLondonCanarySociety，sothatmethodicalselectionhasbeenpractisedduringaconsiderableperiod。Thegreaternumberofthevarietiesdifferonlyincolourandinthemarkingsoftheirplumage。Somebreedshowever，differinshape，suchasthehoopedorbowedcanaries，andtheBelgiancanarieswiththeirmuchelongatedbodies。Mr。Brent（8/47。’CottageGardener’December11，1855
page184:anaccountisheregivenofallthevarieties。Formanymeasurementsofthewildbirds，seeMr。E。VernonHarcourtibidDecember25，1855page223。）measuredoneofthelatterandfounditeightinchesinlength，whilstthewildcanaryisonlyfiveandaquarterincheslong。
Therearetop—knottedcanaries，anditisasingularfactthat，iftwotop—
knottedbirdsarematched，theyoung，insteadofhavingveryfinetop—
knots，aregenerallybald，orevenhaveawoundontheirheads。（8/48。
Bechstein’Naturgesch。derStubenvogel’1840s。243;sees。252ontheinheritedsongofCanary—birds。WithrespecttotheirbaldnessseealsoW。
Kidd’TreatiseonSong—Birds。’）Itwouldappearasifthetop—knotwereduetosomemorbidcondition，whichisincreasedtoaninjuriousdegreewhentwobirdsinthisstatearepaired。Thereisafeather—footedbreed，andanotherwithakindoffrillrunningdownthebreast。Oneothercharacterdeservesnoticefrombeingconfinedtooneperiodoflife，andfrombeingstrictlyinheritedatthesameperiod;namely，thewingandtailfeathersinprizecanariesbeingblack，"butthiscolourisretainedonlyuntilthefirstmoult;oncemoulted，thepeculiarityceases。"（8/49。W。Kidd’TreatiseonSong—Birds’page18。）Canariesdiffermuchindispositionandcharacter，andinsomesmalldegreeinsong。Theyproduceeggsthreeorfourtimesduringtheyear。
GOLD—FISH。
Besidesmammalsandbirds，onlyafewanimalsbelongingtotheothergreatclasseshavebeendomesticated;buttoshowthatitisanalmostuniversallawthatanimals，whenremovedfromtheirnaturalconditionsoflife，vary，andthatracescanbeformedwhenselectionisapplied，itisnecessarytosayafewwordsongold—fish，bees，andsilk—moths。
Gold—fish（Cyprinusauratus）wereintroducedintoEuropeonlytwoorthreecenturiesago;buttheyhavebeenkeptinconfinementfromanancientperiodinChina。Mr。Blyth（8/50。The’IndianField’1858page255。）
suspects，fromtheanalogousvariationofotherfishes，thatgolden—
colouredfishdonotoccurinastateofnature。Thesefishesfrequentlyliveunderthemostunnaturalconditions，andtheirvariabilityincolour，size，andinsomeimportantpointsofstructureisverygreat。M。Sauvignyhasdescribedandgivencoloureddrawingsofnolessthaneighty—ninevarieties。（8/51。Yarrell’BritishFishes’volume1page319。）Manyofthevarieties，however，suchastripletail—fins，etc。，oughttobecalledmonstrosities;butitisdifficulttodrawanydistinctlinebetweenavariationandamonstrosity。Asgold—fisharekeptforornamentorcuriosity，andas"theChinesearejustthepeopletohavesecludedachancevarietyofanykind，andtohavematchedandpairedfromit"（8/52。
Mr。Blythinthe’IndianField’1858page255。），itmighthavebeenpredictedthatselectionwouldhavebeenlargelypractisedintheformationofnewbreeds;andthisisthecase。InanoldChineseworkitissaidthatfishwithvermilionscaleswerefirstraisedinconfinementduringtheSungdynasty（whichcommencedA。D。960），"andnowtheyarecultivatedinfamilieseverywhereforthesakeofornament。"Inanotherandmoreancientwork，itissaidthat"thereisnotahouseholdwherethegold—fishisnotcultivated，inRIVALRYastoitscolour，andasasourceofprofit，"etc。
（8/53。W。F。Mayers’ChineseNotesandQueries’August1868page123。）
Althoughmanybreedsexist，itisasingularfactthatthevariationsareoftennotinherited。SirR。Heron（8/54。’Proc。Zoolog。Soc。’May25，1842。）keptmanyofthesefishes，andplacedallthedeformedones，namely，thosedestituteofdorsalfinsandthosefurnishedwithadoubleanalfin，ortripletail，inapondbythemselves;buttheydid"notproduceagreaterproportionofdeformedoffspringthantheperfectfishes。"
Passingoveranalmostinfinitediversityofcolour，wemeetwiththemostextraordinarymodificationsofstructure。Thus，outofabouttwodozenspecimensboughtinLondon，Mr。Yarrellobservedsomewiththedorsalfinextendingalongmorethanhalfthelengthoftheback:otherswiththisfinreducedtoonlyfiveorsixrays:andonewithnodorsalfin。Theanalfinsaresometimesdouble，andthetailisoftentriple。Thislatterdeviationofstructureseemsgenerallytooccur"attheexpenseofthewholeorpartofsomeotherfin（8/55。Yarrell’BritishFishes’volume1page319。）;butBorydeSaint—Vincent（8/56。’Dict。Class。d’Hist。Nat。’tome5page276。）
sawatMadridgold—fishfurnishedwithadorsalfinandatripletail。Onevarietyischaracterisedbyahumponitsbacknearthehead;andtheRev。
L。Jenyns（Blomefield）（8/57。’ObservationsinNat。Hist。’1846page211。
Dr。Grayhasdescribedin’AnnalsandMag。ofNat。Hist。’1860page151anearlysimilarvarietybutdestituteofadorsalfin。）hasdescribedamostsingularvariety，importedfromChina，almostglobularinformlikeaDiodon，with"thefleshypartofthetailasifentirelycutaway？thecaudalfinbeingsetonalittlebehindthedorsalandimmediatelyabovetheanal。"Inthisfishtheanalandcaudalfinsweredouble;theanalfinbeingattachedtothebodyinaverticalline:theeyesalsowereenormouslylargeandprotuberant。
HIVE—BEES。
Beeshavebeendomesticatedfromanancientperiod;ifindeedtheirstatecanbeconsideredoneofdomestication，fortheysearchfortheirownfood，withtheexceptionofalittlegenerallygiventothemduringthewinter。
Theirhabitationisahiveinsteadofaholeinatree。Bees，however，havebeentransportedintoalmosteveryquarteroftheworld，sothatclimateoughttohaveproducedwhateverdirecteffectitiscapableofproducing。
ItisfrequentlyassertedthatthebeesindifferentpartsofGreatBritaindifferinsize，colour，andtemper;andGodron（8/58。’Del’Espece’1859
page459。WithrespecttothebeesofBurgundyseeM。Gerard，art。’Espece’
in’Dict。Univers。d’Hist。Nat。’）saysthattheyaregenerallylargerinthesouththaninotherpartsofFrance;ithasalsobeenassertedthatthelittlebrownbeesofHighBurgundy，whentransportedtoLaBressebecomelargeandyellowinthesecondgeneration。Butthesestatementsrequireconfirmation。Asfarassizeisconcerned，itisknownthatbeesproducedinveryoldcombsaresmaller，owingtothecellshavingbecomesmallerfromthesuccessiveoldcocoons。Thebestauthorities（8/59。Seeadiscussiononthissubject，inanswertoaquestionofmine，in’JournalofHorticulture’1862pages225—242;alsoMr。BevanFoxinditto1862page284）concurthat，withtheexceptionoftheLigurianraceorspecies，presentlytobementioned，distinctbreedsdonotexistinBritainorontheContinent。Thereis，however，eveninthesamestock，somevariabilityincolour。Thus，Mr。Woodburystates（8/60。Thisexcellentobservermaybeimplicitlytrusted;see’JournalofHorticulture’July14，1863page39。）
thathehasseveraltimesseenqueenbeesofthecommonkindannulatedwithyellow—likeLigurianqueens，andthelatterdark—colouredlikecommonbees。
Hehasalsoobservedvariationsinthecolourofthedrones，withoutanycorrespondingdifferenceinthequeensorworkersofthesamehive。Thegreatapiarian，Dzierzon，inanswertomyqueriesonthissubject，says（8/61。’JournalofHorticulture’September9，1862page463;seealsoHerrKleineonsamesubjectNovember11page643，whosumsup，that，thoughthereissomevariabilityincolour，noconstantorperceptibledifferencescanbedetectedinthebeesofGermany。），thatinGermanybeesofsomestocksaredecidedlydark，whilstothersareremarkablefortheiryellowcolour。Beesalsoseemtodifferinhabitsindifferentdistricts，forDzierzonadds，"Ifmanystockswiththeiroffspringaremoreinclinedtoswarm，whilstothersarericherinhoney，sothatsomebee—keepersevendistinguishbetweenswarmingandhoney—gatheringbees，thisisahabitwhichhasbecomesecondnature，causedbythecustomarymodeofkeepingthebeesandthepasturageofthedistrict。Forexample，whatadifferenceinthisrespectonemayperceivetoexistbetweenthebeesoftheLuneburgheathandthoseofthiscountry！"……"Removinganoldqueenandsubstitutingayoungoneofthecurrentyearishereaninfalliblemodeofkeepingthestrongeststockfromswarmingandpreventingdrone—breeding;whilstthesamemeansifadoptedinHanoverwouldcertainlybeofnoavail。"I
procuredahivefullofdeadbeesfromJamaica，wheretheyhavelongbeennaturalised，and，oncarefullycomparingthemunderthemicroscopewithmyownbees，Icoulddetectnotatraceofdifference。
Thisremarkableuniformityinthehive—bee，whereverkept，mayprobablybeaccountedforbythegreatdifficulty，orratherimpossibility，ofbringingselectionintoplaybypairingparticularqueensanddrones，fortheseinsectsuniteonlyduringflight。Noristhereanyrecord，withasinglepartialexception，ofanypersonhavingseparatedandbredfromahiveinwhichtheworkerspresentedsomeappreciabledifference。Inordertoformanewbreed，seclusionfromotherbeeswould，aswenowknow，beindispensable;forsincetheintroductionoftheLigurianbeeintoGermanyandEngland，ithasbeenfoundthatthedroneswanderatleasttwomilesfromtheirownhives，andoftencrosswiththequeensofthecommonbee。
（8/62。Mr。Woodburyhaspublishedseveralsuchaccountsin’JournalofHorticulture’1861and1862。）TheLigurianbee，althoughperfectlyfertilewhencrossedwiththecommonkind，isrankedbymostnaturalistsasadistinctspecies，whilstbyothersitisrankedasavariety:butthisformneednotherebenoticed，asthereisnoreasontobelievethatitistheproductofdomestication。TheEgyptianandsomeotherbeesarelikewiserankedbyDr。Gerstacker（8/63。’AnnalsandMag。ofNat。Hist。’3rdseriesvolume11page339。）butnotbyotherhighlycompetentjudges，asgeographicalraces;hegroundshisconclusioninchiefpartonthefactthatincertaindistricts，asintheCrimeaandRhodes，theyvarysomuchincolour，thattheseveralge...完整阅读请扫描二维码下载丁香书院APP免费看：