I am fully convinced that species are not immutable; but that those belonging to what are called the same genera are lineal descendants of some other and generally extinct species, in the same manner as the acknowledged varieties of any one species are the descendants of that species.
Erabat komentziturik nago espezieak ez direla aldaezinak eta genero bera deritzanekoak beste espezie eskuarki iraungi baten ondorengo zuzenak direla, espezie baten aldakitzat onarturikoak haren ondorengoak diren bezalaxe.