The Effects of Cross & Self-Fertilisation in the Vegetable Kingdom

There is weighty and abundant evidence that the ?owers of most kinds of plants are constructed so as to be occasionally or habitually cross-fertilised by pollen from another ?ower, produced either by the same plant, or generally, as we Shall hereafter see reason to believe, by a distinct plant. Cross-fertilisa tion is sometimes ensured by the sexes being separated, and in a large number of cases by the pollen and stigma of the same ?ower being matured at different times. Such plants are called dichogamous, and have. Been divided into two sub-classes: proterandrous species.