It is particularly fitting, and I believe it would be most pleasing to Alexander Hollaender that the setting of an International Congress on Photobiology has been chosen in which to honor him. As I mentioned at the opening of this Congress, he was one of the founding fathers of the Comité International de Photobiologie in 1951. Later, he was its President from 1954 to 1960, and he was awarded the Finsen Medal in 1968 “for fundamental contributions in the early development of photobiology, in particular radiation genetics”. He was also a member of the U.S. Academy of Sciences (1957); he received the Enrico Fermi Award (1983). But, most of all, he headed the Oak Ridge National Laboratory’s Biology Division for 21 years, from 1946 to 1967.