The Anaerobe Discussion Group (ADG) organised has four I-ntern-ational College, Symposia, all at Churchill Cambridge. The first was held in July 1979, the second in July 1981, the third in July 1983, and this, the fourth, on July 26-28th, 1985. The proceedings of each of these meetings have been published (see below). As on previous occasions, the scientific programme was designed appeal to the wide range to of interests represented by ADG members. The meeting was attended by delegates from allover the world, including medical mic- biologists, veterinarians, dentists, biochemists, gene- cists...