What was the title of Alan Turing's 1952 paper on biological pattern formation?

Alan Turing’s 1952 paper on biological pattern formation was titled “The Chemical Basis of Morphogenesis.” It proposed that chemical reactions and the movement of chemicals through developing tissue could generate organized biological patterns.

Turing imagined interacting substances called morphogens. One substance could promote a process while another inhibited it, and the two could diffuse through tissue at different rates. Under the right conditions, an initially uniform system could become unstable and produce stripes, spots, spirals, or other repeating forms.

This idea became known as a reaction-diffusion model, and the resulting structures are often called Turing patterns. The theory offered a mathematical explanation for how symmetry can break during development, helping explain why an embryo does not remain visually uniform as it grows.

The article was published in the Philosophical Transactions of the Royal Society of London B in 1952. It did not claim that every animal pattern had been experimentally proven to arise this way; rather, it supplied a powerful theoretical mechanism. “Morphogenetic fields” is a related concept, but it is not the paper’s title.