Radiograph of Nautilus Shell
Though it’s not a perfect golden spiral, the chambered nautilus shells (of both the extant and extinct species) are some of the finest natural examples of a logarithmic spiral.
Build thee more stately mansions, O my soul,
As the swift seasons roll!
Leave thy low-vaulted past!
Let each new temple, nobler than the last,
Shut thee from heaven with a dome more vast,
Till thou at length art free,
Leaving thine outgrown shell by life’s unresting sea!
- Oliver Wendell Holmes
On Growth and Form. D’Arcy Wentworth Thompson, 1945