But whenever we have the means of instituting a comparison, the same laws appear to have acted in producing the lesser differences between varieties of the same species, and the greater differences between species of the same genus.
Baina, konparatzeko modurik dugun guztian, badirudi lege berek ihardun izan dutela espezie beraren aldakien arteko alde txikiak eta genero bereko espezieen arteko alde handiagoak eragiten.