Why should the sepals, petals, stamens, and pistils, in each flower, though fitted for such distinct purposes, be all constructed on the same pattern? 查尔斯·达尔文.物种起源.
These organs are so proportioned in length to each other that half the stamens in two of the forms stand on a level with the stigma of the third form. 查尔斯·达尔文.物种起源.