T THE economic development in Southern Ontario since 1940 has surpassed that of all other regions of Canada. Expanding cities and towns have reduced the area of agricultural land and have increased the demand for agricultural produce. Approximately 20 per cent of the total area of the Palaeozoic lowland' (Fig. 2) is now urban land or is occupied by roads, railways, parks, cemeteries, and provincial forests. I n parts of the highly industrialized belt along Lake the area of agricultural land has declined as much as 20 per cent since 1940. most rapid urbanization is occurring in the areas with the highest proportion of good quality agricultural land. Land use planning on a regional basis is a prerequisite to future prosperity in this part of Canada. Basic to an understanding of present agricultural land use patterns is the reconstruction of the agricultural geography of the past. Oftentimes, such an investigation will greatly illuminate the dynamic forces that initiate and give impetus to the changes. purpose of this paper is to present the agricultural regions of 1880, to study the relation between these and those of 1951, and to explain the changes and to speculate regarding future trends. In 1880, practically all of the suitable land had been occupied and improved. acreage in wheat was three times what it was in 1950, though the livestock population was less than 40 per cent of the 1951 figure. era of diversified and specialized farming had begun while the period of rapid exploitation and increasing farm population was drawing to a close. map of the 1880 agricultural regions has been constructed after a careful study of census data, the Ontario Agricultural Commission Report, and all other relevant historical source materials (Fig. 4). Wheat was the dominant cash crop. There was a very large part of Southern Ontario which could be classified as a general or mixed farming region with an emphasis on wheat production. Specialization and diversification was in its infant stages and even in areas where the trend was in this direction, wheat was still one of the most important crops. traditional procedure in farming prior to 1880 was to clear as quickly as one could as much land as possible, and to grow wheat year after year, until yields or prices declined. This was the pattern everywhere throughout the Palaeozoic lowland on all soil types regardless of their texture, drainage, or inherent capabilities. Wheat was grown on *This paper was presented at the annual meeting of the Canadian Association of Geographers in Ottawa, June 5, 1957. It is based upon research carried out for a doctoral dissertation, The Agricultural Geography of Southern Ontario, submitted to the University of Toronto in 1955. 1 Palaeozoic lowland is that part of peninsular Ontario to the south and east of the Pre-Cambrian Shield.