Indomitablepatience，thefinestpowersofdiscrimination，andsoundjudgmentmustbeexercisedduringmanyyears。Aclearlypredeterminedobjectmustbekeptsteadilyinview。Fewmenareendowedwithallthesequalities，especiallywiththatofdiscriminatingveryslightdifferences;judgmentcanbeacquiredonlybylongexperience;butifanyofthesequalitiesbewanting，thelabourofalifemaybethrownaway。Ihavebeenastonishedwhencelebratedbreeders，whoseskillandjudgmenthavebeenprovedbytheirsuccessatexhibitions，haveshownmetheiranimals，whichappearedallalike，andhaveassignedtheirreasonsformatchingthisandthatindividual。TheimportanceofthegreatprincipleofSelectionmainlyliesinthispowerofselectingscarcelyappreciabledifferences，whichneverthelessarefoundtobetransmissible，andwhichcanbeaccumulateduntiltheresultismademanifesttotheeyesofeverybeholder。

　　Theprincipleofselectionmaybeconvenientlydividedintothreekinds。

　　METHODICALSELECTIONisthatwhichguidesamanwhosystematicallyendeavourstomodifyabreedaccordingtosomepredeterminedstandard。UNCONSCIOUS

　　SELECTIONisthatwhichfollowsfrommennaturallypreservingthemostvaluedanddestroyingthelessvaluedindividuals，withoutanythoughtofalteringthebreed;andundoubtedlythisprocessslowlyworksgreatchanges。

　　Unconsciousselectiongraduatesintomethodical，andonlyextremecasescanbedistinctlyseparated;forhewhopreservesausefulorperfectanimalwillgenerallybreedfromitwiththehopeofgettingoffspringofthesamecharacter;butaslongashehasnotapredeterminedpurposetoimprovethebreed，hemaybesaidtobeselectingunconsciously。（20/1。Theterm\"unconsciousselection\"hasbeenobjectedtoasacontradiction;butseesomeexcellentobservationsonthisheadbyProf。Huxley（’Nat。Hist。Review’

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