Sea-shells and Tigers

• Life’s Other Secret: The New Mathematics of the Living World by Ian Stewart
  Penguin, 320 pp, £20.00, June 1998, ISBN 0 7139 9161 5

‘Each week I plot your equations dot for dot, xs against ys in all manner of algebraical relation, and every week they draw themselves as commonplace geometry, as if the world of forms were nothing but arcs and angles. God’s truth, Septimus, if there is an equation for a curve like a bell, there must be an equation for one like a bluebell, and if a bluebell, why not a rose?’ So says Lady Thomasina Coverly, the heroine of Tom Stoppard’s Arcadia, to her tutor Septimus Hodge. Her question was echoed a century after her (fictitious) life by the unorthodox biologist D’Arcy Wentworth Thompson, whose mathematical investigations of the living world were collected in On Growth and Form, published in 1917. Although they have excited the admiration of some important thinkers, including Alan Turing and the biologists John Tyler Bonner and Stephen Jay Gould, Thompson’s ideas do not figure prominently in the biological curriculum or the mainstream of research.