theyhave，also，longbeenhabituatedtotheirconditionsoflife;butitcannotbesaidthattheyaresubjecttoquiteuniformconditions，andtheyareliabletoacertainamountofvariation。Thecircumstancesunderwhichourdomesticproductionsarerearedarewidelydifferent:theyareprotectedfromcompetition;theyhavenotonlybeenremovedfromtheirnaturalconditionsandoftenfromtheirnativeland，buttheyarefrequentlycarriedfromdistricttodistrict，wheretheyaretreateddifferently，sothattheyrarelyremainduringanyconsiderablelengthoftimeexposedtocloselysimilarconditions。Inconformitywiththis，allourdomesticatedproductions，withtherarestexceptions，varyfarmorethannaturalspecies。Thehive—bee，whichfeedsitselfandfollowsinmostrespectsitsnaturalhabitsoflife，istheleastvariableofalldomesticatedanimals，andprobablythegooseisthenextleastvariable;buteventhegoosevariesmorethanalmostanywildbird，sothatitcannotbeaffiliatedwithperfectcertaintytoanynaturalspecies。Hardlyasingleplantcanbenamed，whichhaslongbeencultivatedandpropagatedbyseed，thatisnothighlyvariable;commonrye（Secalecereale）hasaffordedfewerandlessmarkedvarietiesthanalmostanyothercultivatedplant（22/4。
Metzger’DieGetreidarten’1841s。39。）;butitmaybedoubtedwhetherthevariationsofthis，theleastvaluableofallourcereals，havebeencloselyobserved。
Bud—variation，whichwasfullydiscussedinaformerchapter，showsusthatvariabilitymaybequiteindependentofseminalreproduction，andlikewiseofreversiontolong—lostancestralcharacters。Noonewillmaintainthatthesuddenappearanceofamoss—roseonaProvence—roseisareturntoaformerstate，formossinessofthecalyxhasbeenobservedinnonaturalspecies;thesameargumentisapplicabletovariegatedandlaciniatedleaves;norcantheappearanceofnectarinesonpeach—treesbeaccountedforontheprincipleofreversion。Butbud—variationsmoreimmediatelyconcernus，astheyoccurfarmorefrequentlyonplantswhichhavebeenhighlycultivatedduringalengthoftime，thanonotherandlesshighlycultivatedplants;andveryfewwell—
markedinstanceshavebeenobservedwithplantsgrowingunderstrictlynaturalconditions。Ihavegivenoneinstanceofanash—treegrowinginagentleman’spleasure—grounds;andoccasionallytheremaybeseen，onbeechandothertrees，twigsleafingatadifferentperiodfromtheotherbranches。ButourforesttreesinEnglandcanhardlybeconsideredaslivingunderstrictlynaturalconditions;theseedlingsareraisedandprotectedinnursery—grounds，andmustoftenbetransplantedintoplaceswherewildtreesofthekindwouldnotnaturallygrow。Itwouldbeesteemedaprodigyifadog—rosegrowinginahedgeproducedbybud—variationamoss—rose，orawildbullaceorwildcherry—
treeyieldedabranchbearingfruitofadifferentshapeandcolourfromtheordinaryfruit。Theprodigywouldbeenhancedifthesevaryingbrancheswerefoundcapableofpropagation，notonlybygrafts，butsometimesbyseed;yetanalogouscaseshaveoccurredwithmanyofourhighlycultivatedtreesandherbs。