commentation of Aristotle. A few years later we find him at the Gymnasium, where, in spite of the old scholastic system of teaching, he took a deep interest in the study of the animal and plant worlds—an interest which was no doubt stimulated by the reading of Goethe, whose works were a source of great delight to young Müller. During this period there also appears to have developed in him that rich gift of imagination which, as one of his biographers says, is so necessary not only to the poet, but also to the natural investigator. In his later work on the "Phantasmal Phenomena of Vision," Müller tells us how, as a boy, he perceived in the crumbling walls of a neighbor's house all sorts of odd and fantastic figures and faces.
At the age of seventeen, Müller left the Gymnasium and, having served one year in the army—as was customary with the youths of his station—he entered, at the age of eighteen, the University of Bonn, which had just been founded. As has been the case with so many natural scientists, here Müller at first hesitated in making his decision between the church and medicine. Born as he was of Roman Catholic parents and nurtured in the Catholic faith by a strongly believing mother, it is not strange that, even as a child, he manifested a desire to enter the priesthood. But the decision was soon made. For three days, so we are told, young Müller closeted himself in his room in order that he might deliberate. At the expiration of this time he made known his decision to a friend in these words: "I am determined. I shall study medicine; for I know what I have and whom I serve."
While at the University of Bonn, Müller's career was characterized by an intense application to study. He maintained, however, a constant exercise of independent thought, and manifested a keen relish for original investigation. Here he initiated, even in the first year of his studies, a series of experiments upon the "respiration of the fœtus," a subject in which a prize had been offered by the university. This prize Müller secured when at the age of nineteen. In connection with the work, a story which a friend of Müller has made known, is characteristic of the young investigator at this time. He had once started upon a journey on horse to Arrthal and was but a short distance on the way when, by the roadside, he espied a pregnant cat. He immediately gave chase, captured it and, for the time being postponing his journey, carried the animal back to the university, where, by Caesarian section, he deprived it of its young in order that he might consequently solve some point in his first problem of investigation.
During the early part of his period at Bonn, although as a student he was most intent upon his work, he was not wholly indifferent to the general yearning for constitutional freedom which was pervading the thought of the middle and lower classes throughout the German