\"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。\"