Experts now agree that Downe Bank encapsulates the species-rich setting that inspired Darwin’s poetic conclusion to The Origin of Species. The theme of an ‘entangled bank’ carries a universal message that has inspired ecologists and provided a model for our understanding of the natural world.
It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us .... and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved. Charles Darwin
This small nature reserve is owned and managed by the Kent Wildlife Trust. It lies in the Cudham Valley and is about ½ mile from Down House (Charles Darwin’s former home). It forms part of the Downe Bank and High Elms Site of Special Scientific Interest and comprises ancient woodland, known as ‘Hangrove’ and a chalk grassland clearing that was called ‘Rough Pell’ on the tithe map of 1840. It was a favourite place of the Darwins, who called the chalk grassland ‘Orchis Bank’, as many wild orchids grew there. In ‘Emma Darwin, Life and Letters’ (1904), Charles Darwin’s daughter, Henrietta Litchfield, described Hangrove as follows - ‘a wood, with hazel undergrowth cut down periodically, and in the hedges gnarled old beeches good for children to climb. It was carpetted with primroses, anemones and bluebells, and birds-nest orchis also grew in this wood. Just on the other side of the narrow steep little lane leading to the village of Cudham, perched high above the valley, was `Orchis Bank' where bee, fly, musk and butterfly orchises grew.’
There are numerous records of studies carried out here by Charles Darwin, both in the woodland and chalk grassland. Darwin’s observations of local orchids and their insect pollinators gave him evidence of co-evolution and led to the publication of his famous book Fertilisation of Orchids in 1862. He published a considerably expanded edition subsequently in 1877. On June 21st and June 24th 1862, after noting insects pollinating orchids 2 years earlier, Darwin recorded that his son George caught 4 species of moths that had visited Fragrant Orchids, Gymnadenia conopsea, that grow on Downe Bank; they had pollen sacs (pollinia) from fragrant orchid attached to them. He recorded how,
‘...pollinia attached, of course depressed; & these pollinia where <<nearly all>> attached rather on side of proboscis, so that the thick end of pollinia were lateral & fitted to strike the lateral stigmas. – Strap of course parallel in length to proboscis – (Cambridge University Library, DAR 7: 30) In Hangrove’s woodland areas he studied the structure of the flowers of spindle euonymus europaeus and wood sorrel Oxalis acetosella. Many of his studies here related to the struggle for existence between living organisms, their interdependence and adaptations for survival that provided him with evidence of ‘natural selection’ on which his theory of evolution was based. As one example below, Darwin recognised the fierce competition for food in early spring when he discovered bumblebees pillaging nectar before violet flowers opened.
‘April 15th 1863 Viola canina (true) Hangrove – saw Bombus hortorum sucking multitude of flowers, and biting holes in nectary…..Marked 6 flowers sucked by black thread’. (Darwin, Scientific papers, 1863)
For more information about Darwin’s work see www.darwin-online.org.uk.
Downe Bank Nature Reserve is quite small and the ecosystems it supports are quite fragile. There is no car parking; visitors can walk to the reserve by public footpath. To find out more this site and Kent Wildlife Trust’s other nature reserves go to www.kentwildlife.org.uk.