remarkable and unlooked-for deviations in the larval organization and habits of genera even of the same order. His inquiries respecting these animals have made us acquainted with the larval forms, with relations between the larva and future being; and with modes of existence, such as nature has not yet been found to present in any other part of the animal kingdom. Finally with the light thus derived from the study of their development, Professor Müller has subjected the organization of the entire class of Echinoderms, both recent and fossil, to a thorough revision, and has added much that was new, as well as cleared up much that was obscure in regard to their economy, structure and homologies. It is to their researches, which occupy seven memoirs of the Royal Academy of Sciences of Berlin, that more special reference is made in the award of the medal.
It was not long after his arrival at Berlin that Müller established the Archiv für Anatomie und Physiologie. Of this he continued the publication until the time of his death. This journal, during the period of its existence, formed a principal medium of publicity for the labors of the leading physiologists of Germany; and the establishment and continued superintendence of it by Müller, in the midst of other laborious employments, must be regarded as an important service rendered to science.
About this time, independent of Müller, his pupil Schwann, following apparently in the footsteps of Schleiden, made the discovery that the animal organism, just as the plant organism, was composed of elementary cells. Müller appears to have been the first to recognize the great significance of this discovery. He immediately employed the new fact for the explanation of certain disease phenomena and clearly pointed out the agreement between tumors and pathological and embryological development. His excellent work on the finer structure of morbid tumors signifies the beginning of all microscopical investigation in pathological anatomy, and here we see the fountain-head of that stimulus which, brought to bear upon the young investigator Virchow, gave rise to that well-known and comprehensive work on "Cellular Pathology."
Concerning the other events of Müller's life, during the Berlin period, it takes little time to relate. The routine work in the Berlin Anatomical Museum was interrupted only by the scientific expeditions which the desired investigation of the sea fauna afforded. The East and North Sea, Sweden, Norway, the coast of the Adriatic and Mediterranean, from Triest to Messina and Marseilles, formed the territory of Müller's scientific explorations. On one of these trips, in 1855, Müller experienced a serious danger. He was returning with two pupils from a journey to the coast of Norway, when at night the steamer Norge on which he sailed was rammed by another and speedily sank. Nearly fifty people lost their lives; and among them one of Müller's young companions. In a letter to a friend in England, in which Müller gives an account of the disaster, he says that upon finding himself in the water at first he kept himself up by swimming. But having his clothes on, he soon became exhausted and would have