Page:Darwin - The various contrivances by which orchids are fertilized by insects (1877).djvu/197

. VI. by carrying them away, effect a union between two flowers, generally on distinct plants. This can hardly fail to occur in all the many cases in which the pollinia slowly change their position, when removed from the rostellum, in order to assume a proper direction for striking the stigma; for the insects during this interval will have had time to fly from the flowers on one plant which will serve as the male, to those on another plant which will serve as the female.