ABSTRACT
This chapter specifieds the various means by which cross-fertilization is favoured or ensured, namely, the separation of the sexes the maturity of the male and female sexual elements at different periods the heterostyled or dimorphic. And trimorphic condition of certain plants many mechanical contrivances the more or less complete inefficiency of a flower's own pollen on the stigma and the prepotency of pollen from any other individual over that from the same plant. The plants in these two lists are entomophilous, or adapted for fertilization by insects, with the exception of Zea and Beta, which are anemophilous or fertilized by the wind. The advantages derived from cross-fertilization throw a flood of light on most of the chief characters of flowers. All those who have long attended to hybridization, insist in the strongest terms on the liability of castrated flowers to be fertilized by pollen brought from distant plants of the same species.
