“Each morphogenetic field or organ primordium displays the holistic character of an automous unit, a self-regulating holon. If half of the field's tissue is cut away, the remainder will form not half an organ but a complete organ. If, at a certain stage of its development, the eye-cup is split into several isolated parts, each fragment will form a smaller, but normal, eye; and even the artificially scrambled and filtered cells of a tissue will, as we have seen (page 69), re-form again.”