Copy letter from Sir Michael Foster, to Professor Franz von Leydig The President and Council on behalf of all the Fellows send Leydig brotherly greetings on his eightieth birthday. They are mindful of his great contributions to the promotion of natural knowledge by his long and valuable labours in comparative anatomy. In token of their profound esteem, on 9 May they enrolled him among the small number of men whom they are proud to call Foreign Members of the Royal Society. 17 May 1901