It makes sense as a mechanism that would have occurred to a computer scientist: on/off switches.

You can read the paper online: "The Chemical Basis of Morphogenesis" (1952).

I started reading David Quammen because he discussed the paper—along with slime mold—in an essay in his collection The Boilerplate Rhino (2001). I had never encountered anyone else who wanted to talk about Alan Turing and Dictyostelium discoideum. I went out and bought pretty much everything of his I could find.