\"Allanimalsofsamespeciesareboundtogetherjustlikebudsofplants，whichdieatonetime，thoughproducedeithersoonerorlater。Proveanimalslikeplants——tracegradationbetweenassociatedandnon—associatedanimals——andthestorywillbecomplete。\"

　　Herewehavetheviewalreadyalludedtoofatermoflifeimpressedonaspecies。

　　Butinthefollowingnotewegetextinctionconnectedwithunfavourablevariation，andthusahintisgivenofnaturalselection:

　　\"Withrespecttoextinction，wecaneasilyseethat[a]varietyof[the]

　　ostrich（Petise），maynotbewelladapted，andthusperishout;or，ontheotherhand，likeOrpheus[aGalapagosbird]，beingfavourable，manymightbeproduced。Thisrequires[the]principlethatthepermanentvariationsproducedbyconfinedbreedingandchangingcircumstancesarecontinuedandproducedaccordingtotheadaptationofsuchcircumstance，andthereforethatdeathofspeciesisaconsequence（contrarytowhatwouldappearfromAmerica）ofnon—adaptationofcircumstances。\"

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