Resulta imposible mejorar nada basándose sólo en la selección. La selección no es garantía de mejora. Así donde dice:   but that the native plants have not been improved by continued selection up to a standard of perfection   Debería decir:   but that the native plants have not been improved by continued breeding up to a standard of perfection         A large amount of change, thus slowly and unconsciously accumulated, explains, as I believe, the…