ABSTRACT
The exploration of a physical system can proceed in several ways. For the structuralist, the exploration will include a detailed examination and the recording of all of the physical features available to observation. For the neuroanatomist, for example, the examination may begin with the gross anatomy, holding the preserved brain in gloved hands and inspecting the surface, then move to the microscopic anatomy, the study of cell structure using light or electron microscopy. Finally, at the molecular level, techniques such as gel chromatography can analyze the protein composition of cells, or even parts of cells.
