We are reminded by this latter fact of the extraordinary cases of Hippeastrum, Passiflora, etc., which seed much more freely when fertilised with the pollen of a distinct species than when fertilised with pollen from the same plant.
Egitate honek Hippeastrum, Passiflora eta abarren ezohiko kasuak gogorarazten dizkigu, landare horiek espezie diferente baten polenaz ernaltzean landare beraren polenaz ernaltzean baino askoz hazi gehiago ematen dituzte eta.