The Different Forms of Flowers on Plants of the Same Species
Encyclopedia
The Different Forms of Flowers on Plants of the Same Species by Charles Darwin is the fifth out of six books solely devoted to the study of plants, (excluding The Variation of Animals and Plants under Domestication). It was first published in 1877.
He conducted a wide range of experiments and observations and the results of these form the framework of the book. He was assisted in this work by his son, Francis Darwin who also wrote a preface for the second edition which was published two years after his father’s death in 1882.
Darwin states, ‘It will be shown that these heterostyled plants are adapted for reciprocal fertilisation; so that the two or three forms, though all are hermaphrodites, are related to one another almost like the males and females of ordinary unisexual animals....... Some plants have been supposed to be heterostyled merely from their pistils and stamens carrying greatly in length, and I have been myself more than once thus deceived. P.5
Darwin’s reflections indicate the economy of nature through a process of gradual modifications of plants, their structures being modified and degraded for the purpose of the large scale production of seed which is necessary and advantageous for survival. Darwin states: ‘Cleistogamic flowers ....are admirably fitted to yield a copious supply of seed at a wonderfully small cost to the plant. (p. 227).
Francis Darwin indicated that the work on heterostylism had given his father extreme pleasure, and especially as it had been one of the most puzzling bits of work he ever carried out. Darwin thought that hardly anyone had seen the full importance of heterostylism.
Context
These writings contributed to Darwin’s pursuit of evidence that would support his theory of Natural Selection. There were only two more books to follow: ‘The Power of Movement in Plants’ (1880) and ‘The Formation of Vegetable Mould through the Action of Worms’ (1881).He conducted a wide range of experiments and observations and the results of these form the framework of the book. He was assisted in this work by his son, Francis Darwin who also wrote a preface for the second edition which was published two years after his father’s death in 1882.
The Work
Using the four classifications established by Linnaeus (hermaphrodite, monoecious, dioecious, polygamous), Darwin concentrated on two divisions of the hermaphroditic class, namely the cleistogamic (Def: Of or relating to a flower that does not open and is self-pollinated in the bud) and heterostyled.Darwin states, ‘It will be shown that these heterostyled plants are adapted for reciprocal fertilisation; so that the two or three forms, though all are hermaphrodites, are related to one another almost like the males and females of ordinary unisexual animals....... Some plants have been supposed to be heterostyled merely from their pistils and stamens carrying greatly in length, and I have been myself more than once thus deceived. P.5
Darwin’s reflections indicate the economy of nature through a process of gradual modifications of plants, their structures being modified and degraded for the purpose of the large scale production of seed which is necessary and advantageous for survival. Darwin states: ‘Cleistogamic flowers ....are admirably fitted to yield a copious supply of seed at a wonderfully small cost to the plant. (p. 227).
Francis Darwin indicated that the work on heterostylism had given his father extreme pleasure, and especially as it had been one of the most puzzling bits of work he ever carried out. Darwin thought that hardly anyone had seen the full importance of heterostylism.