38i THE HISTORY OF BIOLOGY 



process. There are, indeed, still several of his discoveries that might well 

 be referred to here if space allowed. 



Contemporary with Purkinje there was working in Germany a scien- 

 tist who, in many respects, might be called his personal antithesis, but who 

 who was his equal in importance for science. 



Johannes Peter Muller was born in 1801 at Coblenz, on the Rhine, 

 the son of a shoemaker. He was of a well-to-do family and was able to indulge 

 his passion for study. After a brilliant career at school he went to Bonn, 

 where he settled down to the study of medicine. After having taken his doc- 

 tor's degree he spent three terms in Berlin, where he was welcomed with 

 paternal kindness by Rudolphi and received impressions that proved a de- 

 cisive factor in his further development. Having returned to Bonn, he became, 

 first, lecturer and afterwards, in 1830, professor at that university. When 

 Rudolphi died and the question of his successor arose, Muller submitted a 

 letter to the Prussian Minister of Education in which he applied for the ap- 

 pointment, at the same time drawing up an ambitious program for his future 

 work. He was accordingly appointed and held the professorship until his 

 death, in 1858. Both as a teacher and as a scientist he worked with unique 

 success; the circle of pupils he gathered around him has few parallels in the 

 history of science, as regards both results and the fame to which many of 

 them attained. Muller began by devoting himself to experimental and mi- 

 croscopical research; it was he who introduced experimental physiology into 

 Germany, and his services to microscopy were of no small value. During his 

 later years he applied himself chiefly to comparative anatomy and evolution, 

 and in connexion therewith to marine research, which had first been taken 

 up by Rathke. For this latter purpose he visited both the Mediterranean 

 and the Scandinavian coasts, everywhere enriching biology with his valu- 

 able observations. The violent exertions demanded by this many-sided 

 activity had, however, told upon not only his bodily powers, but also his 

 mind; anxieties of a practical nature also further weakened his health. He 

 was University Warden during the years of the Revolution of 1848 and, being 

 a conservative, came into repeated conflict with the revolutionary-minded 

 students. Some years later he was in a serious shipwreck, which cost the 

 life of one of his friends. These events seemed to have proved too much for 

 his powers. Ever since his youth his personality had been a curious com- 

 bination of nervous unrest, proud egotism, and deep melancholy; the last 

 gained the upper hand according as his worries increased and his powers 

 declined. One morning he was found dead in his bed without sickness's 

 having intervened; a common rumour, which was never contradicted, de- 

 clares that in despair he laid violent hands upon himself. 



Johannes Miiller's scientific career may be said to be typical of that of 

 contemporary German biology in general — it begins in natural philosophy 



