the embryo. Despite his modern reputation, Spemann continued to entertain neo-vitalist "field" analyses similar to those of Hans Driesch, Gurwitsch and Harold Saxton Burr. However, the follow-up work of Johannes Holtfreter, Dorothy M. Needham and Joseph Needham, Conrad Waddington and others showed that organizers killed by boiling, fixing or freezing were also capable of causing induction. The conclusion was that the actual controllers were inert molecules, though little headway was made until the end of the 20th century in discovering how signalling took place. From 1919 Spemann was Professor of Zoology at the University of Freiburg-im-Breisgau, where he continued his line of enquiry until in 1937 he was relieved of his post to be replaced by one of his first students, Otto Mangold. In 1928 he was the first to perform somatic cell nuclear transfer using amphibian embryos – one of the first moves towards cloning. He was awarded the Nobel Prize in 1935. His theory of embryonic induction by organisers is described in his book Embryonic Development and Induction (1938). He died of heart failure on 12 September 1941. He never lost his love of classical literature and, throughout his life, organized evening gatherings of friends to discuss art, literature, and philosophy. Support of Nazism The commemoration of the 1923 death of Albert Leo Schlageter in Freiburg attracted particular attention. Hans Spemann suspended classes on June 6 and, with the deans in full regalia, went in a joint funeral procession with representatives of the student body and corporations to the train station, where they met with delegations of officers from Schlageter's former regiment and the German Officers' Association and students from Schlageter's former high school. Upon the train's arrival, Spemann laid two wreaths, which were stowed in the semi-open baggage car decorated with flowers and emblazoned with swastikas. To the sounds of “I had a comrade”, the crowd swore Schlageter's motto "Heil, Sieg und Rache". In 1935, at the end of Spemann’s acceptance speech for the Nobel Prize, he gave a Nazi salute. See also Theodor Boveri Developmental biology Morphogenesis August Weismann References External links Explanation of the Spemann-Mangold experiment from a Nature Reviews article including the Nobel Lecture, December 12, 1935 The Organizer-Effect in Embryonic Development 1869 births 1941 deaths German embryologists Academic staff of the Humboldt University of Berlin Nobel laureates in Physiology or Medicine German Nobel laureates Foreign associates of the National Academy of Sciences Physicians