Dr. Hatch is distinguished for his contributions to the pathway of carbon dioxide fixation in plants. His studies have established that in several species of tropical plants the metabolic steps leading to photosynthetic carbon dioxide assimilation differ in a major way from those previously thought to be universal in nature. The unique reactions of this modified process serve to fix carbon dioxide into c4-dicarboxylic acids, which then act to transport carbon dioxide to the site of operation of the Calvin cycle. These investigations have been the stimulus for many studies which are leading to an understanding of the unique physiological and ecological features of plants with the c4-pathway of photosynthesis.