The greatest strides in the wonderful advances of modern clinical medicine have been made by virtue of investigations in chemistry and in physics, in some instances advances with which it has been impossible for pathologic anatomy and histology to keep pace. On the other hand, there are numerous well established conceptions in pathologic anatomy from which the clinical diagnosis must depart, the latter naming the condition in a fashion descriptive of its pathologic anatomy. Not infrequently, methods of functional diagnosis have been widely applied in the clinics after having been verified at the necropsy table in only a limited number of instances, a fact only too well known by critical readers of recent medical literature. It is not our intention to underestimate the value of clinical investigation, nor, on the other hand, to place too great a valuation on what may be learned from the postmortem study of patients, but