As day care becomes a way of life for more and more Canadian children, the influence of William Blatz continues to spread. A pioneer in the study of children development and day care, Blatz’s work continues to spread. A pioneer in the study of child development and day care, Blatz’s work has influenced other specialists throughout the English speaking world. In this biography Jocelyn Motyer Raymond considers the man and his work. In 1925 Blatz established St George’s school for child study, associated with the University of Toronto. The school consisted of two divisions; one was Parent Education, a research program created to educate parents in the newest techniques of child-rearing. But by far the more famous division was the model nursery school. It served as a laboratory for the development of Blatz’s child study theories, and was so successful that demand for enrolment quickly became overwhelming. As his reputation grew he was asked to work with the Dionne quintuplets, which brought his name to a much wider audience, and to organize wartime day nurseries for factory workers in Canada and Britain. From the St. George’s School grew the Institute for child Study, still flourishing today. Blatz’s work in environmental influences on child development demonstrated the importance of adult-child relationships in making children emotionally secure. An architect of modern day-care standards, he greatly extended our understanding of the benefits for all when children in institutional and group settings receive care that is personal, positive, and sensitive to their developmental needs.