the lymph hearts in amphibia; and also the results of his investigations on the coagulation of the blood.
Just and prompt recognition did not fail to follow in the train of these excellent results, and the consequent advancement and improvement in his material condition made possible for him other interesting journeys. In 1828 he visited Goethe. The spring of 1831 he spent in the Leiden Museum in Holland. In the autumn of 1831 we find him in Paris in the company of several of the great natural scientists, as Humboldt, Cuvier, Milne Edwards and others who were there at the time. One significant anecdote of this Paris trip should not be omitted. When for the first time Müller went to call upon Dumereil, the latter was very busy, and, since he did not know whom he had to meet, somewhat peevishly directed Müller to the door. Müller, however, as he was almost thrust out, pushed in his head and called out to Dumereil, "Yes, but the Coecilien in the young stages do have gill openings in their necks!" This thrust, it is needless to say, worked as a magic word to gain a long and pleasant interview between these two investigators.
In the year 1832 Rudolphi died at Berlin, thus leaving vacant the foremost position in anatomy and physiology in Germany. Negotiations were already in progress to secure as Rudolphi's successor Dr. Tiedermann from Heidelberg; but at this point in the proceedings Müller determined upon a unique step. He sent to his old friend and former benefactor, the Minister von Altenstein, copies of his works together with a letter in which he ("believing that the importance of the affair would furnish its own excuses") brought himself prominently into the proposition. He said, in part, that it was no more than right that the first and highest position of the kind in Germany should belong to the greatest among scholars; furthermore, that if this man were not Johann Friedrick Meckel, then he believed himself to be the foremost zoologist and physiologist in Germany.
This letter had results: the Minister von Altenstein at once ordered Müller's nomination; and on Easter, 1833, Müller, not yet thirty-three years old, entered upon his duties as "professor ordinary of anatomy, physiology and pathological anatomy, and director of the Anatomical Museums" in the University of Berlin.
The first fruit of Müller's residence in Berlin was the completion of his "Handbook of Physiology," which he had begun long before he left Bonn. Appearing in three parts, it was at last completed in 1840. These volumes represented a piece of work unparalleled in the field of physiological literature. The only work which could be compared with it was Haller's "Elementa." Müller's labors in preparation for this work included an immeasurable number of single observations with reference to the physiology of the voice, of speech, of hearing, of nerve physiology, of teachings on the blood—all of these rest,