Rare species, and each species will become rare if the number of species in any country becomes indefinitely increased, will, on the principal often explained, present within a given period few favourable variations;
Espezie bakanek-eta espezie oro bakan bilakatuko da, espezie kopurua mugagabeki gehitzen bada-, hainbat aldiz azaldu dugun hastapenaren arabera, aldi jakin baten barruan aldaketa faboragarri gutxi agertuko dute;