The work of the geologist and geophysicist has much in common with that of the physician. The work of both groups of men deals with a living body of which only the surface and such processes as are active on it are visible. Both want to know what goes on within, but must be content to base their diagnoses on indirect evidence. Both deal with the baffling complexity of unabstracted reality and look with envy on the basic sciences which achieve precision by lopping off all but the one process or property they are exploring. Both must go to the basic sciences for the understanding of what they observe, and both need men who bridge the gap between the concrete phenomena and the abstract processes ‐ geophysicists and geochemists on the one hand and biophysicists and biochemists on the othe