When this is done, there is no apparent reason why they should not yield as many seeds as did their parents when legitimately fertilised. 查尔斯·达尔文.物种起源.
From this extreme degree of sterility we have self-fertilised hybrids producing a greater and greater number of seeds up to perfect fertility. 查尔斯·达尔文.物种起源.
I have come to this conclusion from finding it an invariable rule that when a flower is fertilised by the wind it never has a gaily-coloured corolla. 查尔斯·达尔文.物种起源.