Fertilisation of Orchids is a book by English naturalist Charles Darwin published on 15 May 1862 under the full explanatory title On the Various Contrivances by Which British and Foreign Orchids Are Fertilised by Insects, and On the Good Effects of Intercrossing. Darwin's previous book, On the Origin of Species, had briefly mentioned evolutionary interactions between insects and the plants they fertilised, and this new idea was explored in detail. Field studies and practical scientific investigations that were initially a recreation for Darwin—a relief from the drudgery of writing—developed into enjoyable and challenging experiments. Aided in his work by his family, friends, and a wide circle of correspondents across Britain and worldwide, Darwin tapped into the contemporary vogue for growing exotic orchids.
The title page of the 1877 edition of Fertilisation of Orchids
Musk orchids (Herminium monorchis) in grassland
The bee orchid does not have nectar, but its labellum, imitating a female bee, attracts male bees. Darwin found that in northern Europe, it is mostly self-fertilising.
Head of a moth with its proboscis laden with seven pairs of pollinia from Orchis pyramidalis
In biology, coevolution occurs when two or more species reciprocally affect each other's evolution through the process of natural selection. The term sometimes is used for two traits in the same species affecting each other's evolution, as well as gene-culture coevolution.
The pollinating wasp Dasyscolia ciliata in pseudocopulation with a flower of Ophrys speculum
Honey bee taking a reward of nectar and collecting pollen in its pollen baskets from white melilot flowers
Purple-throated carib feeding from and pollinating a flower
A fig exposing its many tiny matured, seed-bearing gynoecia. These are pollinated by the fig wasp, Blastophaga psenes. In the cultivated fig, there are also asexual varieties.