As we ascend to the hierarchies of living matter, we find, even on the lowest level observable through the electron microscope, sub-cellular structures-organelles-of staggering complexity. And the most striking fact is that these minuscule parts of the cell function as self-governing wholes in their own right, each following its own statute-book of rules. One type of organelles look as quasi-independent agencies after the cell's growth; others after its energy supply, reproduction, communications, and so on.