ABSTRACT
Bees and various other insects must be directed by instinct to search flowers for nectar and pollen, as they act in this manner without instruction as soon as they emerge from the pupa state. That insects should visit the flowers of the same species as long as they can, is of great importance to the plant, as it favours the cross-fertilization of distinct individuals of the same species. The conspicuousness of the corolla does not suffice to induce repeated visits from insects, unless nectar is at the same time secreted, together perhaps with some odour emitted. The extraordinary industry of bees and the number of flowers which they visit within a short time, so that each flower is visited repeatedly, must greatly increase the chance of each receiving pollen from a distinct plant. The perforated flowers of those species, which are capable of fertilizing themselves, will yield only self-fertilized seeds, and the seedlings will in consequence be less vigorous.
