Page 649: A Universal Cellular Automaton
Details of how the universal cellular automaton emulates rule 254
Details of how the universal cellular automaton emulates rule 254 2
Details of how the universal cellular automaton emulates rule 254. Each of the blocks in the universal cellular automaton represents a single cell in rule 254, and encodes both the current color of the cell and the form of the rule used to update it.

From Stephen Wolfram: A New Kind of Science [citation]