We shall, when we come to our chapter on geology, have to refer again to this subject, and I think we shall then see that the diagram throws light on the affinities of extinct beings, which, though generally belonging to the same orders, families, or genera, with those now living, yet are often, in some degree, intermediate in character between existing groups; and we can understand this fact, for the extinct species lived at various remote epochs when the branching lines of descent had diverged less.
Berriro ere gai honetara etorri beharra izanen dugu Geologiari buruzko kapituluan, eta uste dut ikusiko dugula orduan diagramak ematen duela argia iraungiriko izakien antzekotasunez; izan ere, hauek, nahiz eta egun bizi direnen ordena, familia edo genero berekoak izan, iraungiriko taldeen bitartekoak dira ezaugarrietan; eta egitate hau hain zuzen honexagatik uler dezakegu, alegia, iraungiriko espezieak urruneko garai ezberdinetan, ondorengotza lerro abartuak elkarrengandik gutxiago aldendurik zeudenean, bizi izan zirelako.