Dr. Ernst Frederik Jacobi, who was a member of the Editorial Board of this journal for exactly 20 years, reached the age of 65 on September 11, 1973 and retired. Dr. Jacobi was appointed Director of the Amsterdam Zoo (officially: of the Royal Zoological Society “Natura Artis Magistra”) on April 1, 1953, in succession to Dr. A. L. J. Sunier. The function of Director of the Zoo automatically means also the membership of the Editorial Board of “Bijdragen tot de Dierkunde”. This periodical was published by the Royal Zoological Society until vol. 28 of 1949 (the last volume edited by Dr. Jacobi’s predecessor), but owing to the difficult financial situation of the Society, its publication was interrupted from 1949 to 1959, when vol. 29 appeared. From this volume onward, the “Bijdragen” appeared at regular periods, first once a year, later twice a year; also, the periodical was no longer published by the Royal Zoological Society solely, but by a committee (called so beautifully the “Board of Supervisors on the Management of the Artis Library”, the Artis Library being the library of the Society, though since 1938 chiefly managed by the University of Amsterdam).