At first sight, the brown-lipped snails look like buttons stitched on fence posts and nettle stems in a corner of the field. They appear passive and inanimate, yet they are quietly doing what they’ve done for millions of years – adapting.
The rain has brought them out. Although snails have adapted to dry land and to breathing air, they are still creatures of water. Much of their lives are spent conserving water and they spend 30% of their energy producing slime – a mucus membrane that is hygroscopic; it attracts water, allows them to wear a wetsuit and helps them travel on a film of lubricant.
I’ve seen some dotted trails recently that look as if the animal must have been jumping, but it’s due to the snail’s locomotion on a small part of the sole of its foot to conserve moisture.
The brown-lipped snails, Cepaea nemoralis, have nutty humbug shells. Far from sedentary, they are homing: hefted to this particular corner of the field they may well have travelled a 25-metre round trip in the past 24 hours, using sense organs to return to this post, this nettle.
Snail travel inspired Alfred Watkins in his book on ley lines. Here now, the snails aestivate; withdrawn into the shell, sealed up behind a membrane that glues them to the spot, they become ascetics, deep in meditation, connected to a past beyond imagination.
The calcium for their shells comes from lime in the soil and the rocks below, which 450m years ago were formed from the bodies of the snails’ ancestors. Wenlock limestone is made from the reefs and sediments of a shallow sea, long before life headed landward.
The fossils of corals, crinoids and molluscs persist because such delicate, vulnerable, animals evolved a way of drawing calcium from seawater to create a protective stone architecture. These structures are not only present under the fence post and nettle root, they are recycled into the body of the snail.
And so it goes on: the lines, circles and helixes, the weathering of upheavals and the quiet, contemplative, moments in the rain.
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