chunk: These flowers can be fertilised in eighteen distinct ways, necessitating a vast number of experiments, the result being, as in the case of the cowslip, that flowers fertilised by the pollen from stamens of the same length as the styles, gave on the average a larger number of capsules and a very much larger number of seeds than in any other case. The exact correspondence in the length of the style of each form with that of one set of stamens in the other form insures that the pollen attached to any part of the body of an insect shall be applied to a style of the same length on another plant, and there is thus a triple chance of the maximum of fertility....There is thus the clearest proof that these complex arrangements have the important end of securing both a more abundant and more vigorous offspring.â
  Observations and experiments still continue today to further the understanding of this phenomenon instigated by Darwin in this original and seminal work.