GRASS still occupies about 65% of the agricultural land of the islands that make up the United Kingdom. The research effort devoted to all aspects of its growth and utilization is considerable and is carried out by many official organizations, by large commercial firms, and by a few farmers. A review of the progress during the last decade, if confined to the limits of a single paper, is in consequence likely to be biased- in the direction of the writer's own interests. I confess at the start that this review is based largely on my experiences at the Grassland Research Institute at Hurley during the last five years and draws freely on the thoughts and recollections of several of my senior colleagues.
