During the fall last year the 6th International Congress on Spermatology was held in Siena. This Congress was subtitled: Comparative Spermatology, 20 years after.Pierre Favard and Daniel Sandoz had in fact participated in the first meeting held in Siena 20 years ago, and had disappeared since, Pierre nearly 2 years before, Daniel only a few months before the onset of the Congress.When we, at the Organizing Committee, were preparing the Congress, we had first asked Daniel Sandoz to evoke the memory of his friend and former boss, Pierre Favard. Of course he accepted this task with devotion, but alas, his illness inerrupted his life before he could do it.As they were both close friends to me, I asked for the privilege of commemorating their personalities. As they had been so close to each other — in their scientific life as well as in their editorial action of this Journal — I chose to let them united in the same praising oration.The text that follows has been pronounced in Siena, on August 30, 1