We have seen that it is the common, the widely diffused, and widely ranging species, belonging to the larger genera within each class, which vary most; and these tend to transmit to their modified offspring that superiority which now makes them dominant in their own countries.
Ikusi dugu espezie arruntak, oso zabalduak, hedadura handiak betetzen dituztenak eta klase bakoitzeko genero handietakoak direla gehien aldatzen direnak; eta beren herrialdeetan gailen izatera daramatzan nagusitasuna beren ondorengo eraldatuei transmitzeko joera dute.