Letter: Cyclists' black holes

Sir: It is a pleasure to read Christian Wolmar's defence of cycling and his plea for better facilities (31 March). I, too, use similar strategies to survive, such as riding on occasion, with care, on the pavement. But one danger was left out. Potholes. As a biologist I regard them as probably a greater social danger than genetic engineering, since they are more likely to cause death or maiming and offer no rewards at all.

Yours sincerely,

LEWIS WOLPERT

University College and

Middlesex School of Medicine

London, W1