This failure of Müller's to make a discovery of the first order can not, with justice, however, be made to count against him. As DuBois Reymond has said, "The most important discoveries can, and often do, play into the hands of insignificant investigators." "That Müller has no such discovery to his credit," continues DuBois Reymond, "can be called as little a failure as that a merchant, who becomes rich through industry and perseverance, should never have been visited by a great fortune." If, in the time when his productive strength stood at its maximum, instead of loosing his great power against a group of widely-extended activities, Müller had undertaken a course in a single definite direction, according to the view of Schiller, that strong stimulus would have been lost to the development of physiology.
Like Müller, Haller also, though he manifested an all-comprehensive knowledge of the field of physiology, failed in yielding an epoch-making discovery. Between these two men, as we have already noted, many points of similarity exist. But, notwithstanding the immense value which Haller rendered to science by his collection and ordering of the tag-ends of physiology up to his time (1775), his work as a whole is excelled by that of Müller with his over-weighing power of judgment and the massive comprehension which took in the whole realm of biological science. While Haller rendered an immense service by uniting the facts of physiology into a certain order and system, Müller took that system as he found it, worked it over, did away with every vestige of the false Naturphilosophie, deepened by his own exhaustive researches every channel of it, and turned into those channels the fresh spirit of a new physiology of comparative anatomy.
We come now, in closing, to a consideration of Müller's personality. From his father Müller inherited the strong and active body characteristic of the Müller line, which is traceable far back into German history. We can picture him a man of medium height; in his youth somewhat slim and of an elegant appearance; the breadth of his shoulders in good keeping with the well-shaped head, which was always held erect with a certain attitude of determination. Lithographs and photographs, pencil, pen and brush drawings presenting Müller's appearance at different times in life, have been given to the world; but, as one of his biographers has said, no picture could accurately repeat, now the sad, now the illuminating, splendor of that dusky countenance, with the dark locks of hair and brilliantly glowing eyes.
While we know that Müller received his physical characteristics from his father, it was from his mother that he appears to have inherited his mental qualities. Among these we may distinguish chiefly the strongly-developed sense of order and method, and the deep spirit of enterprise and of indefatigable activity. To these were added a thorough knowledge of men, a great gift of observation, a conscientious punctuality, and a firmness of purpose together with a knowl-