Book contents
- Frontmatter
- Contents
- CHAPTER I INTRODUCTORY REMARKS
- CHAPTER II CONVOLVULACEÆ
- CHAPTER III SCROPHULARIACEÆ, GESNERIACEÆ, LABIATÆ, ETC
- IV CRUCIFERÆ, PAPAVERACEÆ, RESEDACEÆ, ETC
- CHAPTER V GERANIACEÆ, LEGUMINOSÆ, ONAGRACEÆ, ETC
- CHAPTER VI SOLANACEÆ PRIMULACEÆ, POLYGONEÆ, ETC
- CHAPTER VII SUMMARY OF THE HEIGHTS AND WEIGHTS OF THE CROSSED AND SELF-FERTILISED PLANTS
- CHAPTER VIII DIFFERENCE BETWEEN CROSSED AND SELF-FERTILISED PLANTS IN CONSTITUTIONAL VIGOUR AND IN OTHER RESPECTS
- CHAPTER IX THE EFFECTS OF CROSS-FERTILISATION AND SELF-FERTILISATION ON THE PRODUCTION OF SEEDS
- CHAPTER X MEANS OF FERTILISATION
- CHAPTER XI THE HABITS OF INSECTS IN RELATION TO THE FERTILISATION OF FLOWERS
- CHAPTER XII GENERAL RESULTS
- INDEX
CHAPTER I - INTRODUCTORY REMARKS
Published online by Cambridge University Press: 29 August 2010
- Frontmatter
- Contents
- CHAPTER I INTRODUCTORY REMARKS
- CHAPTER II CONVOLVULACEÆ
- CHAPTER III SCROPHULARIACEÆ, GESNERIACEÆ, LABIATÆ, ETC
- IV CRUCIFERÆ, PAPAVERACEÆ, RESEDACEÆ, ETC
- CHAPTER V GERANIACEÆ, LEGUMINOSÆ, ONAGRACEÆ, ETC
- CHAPTER VI SOLANACEÆ PRIMULACEÆ, POLYGONEÆ, ETC
- CHAPTER VII SUMMARY OF THE HEIGHTS AND WEIGHTS OF THE CROSSED AND SELF-FERTILISED PLANTS
- CHAPTER VIII DIFFERENCE BETWEEN CROSSED AND SELF-FERTILISED PLANTS IN CONSTITUTIONAL VIGOUR AND IN OTHER RESPECTS
- CHAPTER IX THE EFFECTS OF CROSS-FERTILISATION AND SELF-FERTILISATION ON THE PRODUCTION OF SEEDS
- CHAPTER X MEANS OF FERTILISATION
- CHAPTER XI THE HABITS OF INSECTS IN RELATION TO THE FERTILISATION OF FLOWERS
- CHAPTER XII GENERAL RESULTS
- INDEX
Summary
There is weighty and abundant evidence that the flowers of most kinds of plants are constructed so as to be occasionally or habitually cross-fertilised by pollen from another flower, produced either by the same plant, or generally, as we shall hereafter see reason to believe, by a distinct plant. Cross-fertilisation is sometimes ensured by the sexes being separated, and in a large number of cases by the pollen and stigma of the same flower being matured at different times. Such plants are called dichogamous, and have been divided into two sub-classes: proterandrous species, in which the pollen is mature before the stigma, and proterogynous species, in which the reverse occurs; this latter form of dichogamy not being nearly so common as the other. Cross-fertilisation is also ensured, in many cases, by mechanical contrivances of wonderful beauty, preventing the impregnation of the flowers by their own pollen. There is a small class of plants, which I have called dimorphic and trimorphic, but to which Hildebrand has given the more appropriate name of heterostyled; this class consists of plants presenting two or three distinct forms, adapted for reciprocal fertilisation, so that, like plants with separate sexes, they can hardly fail to be intercrossed in each generation. The male and female organs of some flowers are irritable, and the insects which touch them get dusted with pollen, which is thus transported to other flowers. Again, there is a class, in which the ovules absolutely refuse to be fertilised by pollen from the same plant, but can be fertilised by pollen from any other individual of the same species. There are also very many species which are partially sterile with their own pollen.
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- Publisher: Cambridge University PressPrint publication year: 2009First published in: 1876