The recruitment of young people into the teaching profession declined in Canada during the late 1970's and early 1980's. By 1985 the average age of teachers in most provinces rose to around 40. Three major papers presented at a 1985 seminar focused on the implications of this changing age structure for employment policies and services. In "The Teaching Business in Canada," John Holland and Saeed Quazi describe the factors affecting the average age of teachers and the rate of change in the average age, and comment on probable consequences of the changes. Teacher employment is examined in the context of (1) developments in the entire Canadian labor force, (2) population trends, (3) educational demand, (4) salary levels, and other factors. Statistical tables support the arguments."Aging Workers, Aging Teachers: What Do We Know about Them?" by Philippe Dupuis, identifies the determinants of aging, reviews research on older workers to distinguish myth from reality, and presents preliminary results from a study of the midlife and midcareer attitudes and perceptions of school principals and teachers. "Professional Development: Renewal Strategies," by May Maskow, suggests methods for ensuring the maintenance of effective teaching as the average age of teachers climbs. (PGD)