If species are only well-marked varieties, of which the characters have become in a high degree permanent, we can understand this fact; for they have already varied since they branched off from a common progenitor in certain characters, by which they have come to be specifically distinct from each other;
Espezieak, ezaugarriak oso iraunkor bihurtu zaizkien aldaki ongi markatuak besterik ez badira, uler dezakegu egitate hau; izan ere, arbaso komunarengandik abartu zirenetik aldatu dira jada zenbait ezaugarritan, eta bata bestearengandik espezifikoki ezberdinak izatera heldu dira;