My famous teacher, Rudolf Virchow, whom I had met at Würtzburg in 1852, and was soon associated with in the most friendly relations as special pupil and admiring assistant, played a very curious part in this great controversy. I am, I think, one of those elderly men who have followed Virchow's development, as man and thinker, with the greatest interest during the last fifty years. I distinguish three periods in his psychological metamorphoses. In the first decade of his academic life, from 1847 to 1858, mainly at Würtzburg, he effected the great reform of medicine that culminated brilliantly in his cellular pathology. In the following twenty years (1858-1877) he was chiefly occupied with politics and anthropology. He was at first favourable to Darwinism, then sceptical, and finally rejected it. His powerful and determined opposition to it dates from 1877, when, in is famous speech on "The Freedom of Science in the Modern State," he struck a heavy blow at that freedom, denounced the theory of evolution as dangerous to the State, and demanded its exclusion from the schools. This remarkable metamorphosis is so important, and has had so much influence, yet has been so erroneously described, that I will deal with it somewhat fully in the next chapter, especially as I have then to treat one chief problem, the descent of man from the ape. For the moment, I will merely recall the fact that in Berlin, the "metropolis of intelligence," as it has been called, the theory of evolution, now generally accepted, met with a more stubborn resistance than in most of our other leading educational centres, and that this opposition was due above all to the powerful authority of Virchow.