Catholic Physiologist and comparative anatomist; founder of modern physiology and master of the science of morphology. Born Coblenz, Germany, 1801; died Berlin, Germany, 1858. After teaching medicine at Bonn and anatomy at Berlin, he devoted himself to research in physiology. He is considered the founder of modern physiology, because of his personal contributions to the science and his power of coordinating the results obtained by his predecessors, and of directing into new fields of investigation his own disciples. Developed the knowledge of voice mechanism and sense mechanism, and in this latter connection first formulated the principle which he called the law of specific energy of sense substance. Made valuable research on marine invertebrates. Loyal adherent of the Catholic Church.