But a part may be developed in the most unusual manner, like the wing of a bat, and yet not be more variable than any other structure, if the part be common to many subordinate forms, that is, if it has been inherited for a very long period; for in this case it will have been rendered constant by long-continued natural selection.
Baina atal bat erarik ezohikoenean gara daiteke, saguzarraren hegoa bezala adibidez, eta hala ere beste edozein egitura baino aldagarriagoa ez izan, baldin atal hori menpeko forma askok ez badauka, hau da, baldin aldi luzez heredatua izan bada, kasu honetan iraunkor bihurtu baita oso luzaro iraun duen hautespen naturalaz.