The increasing importance for animals and bacteria of adenosine diphosphate (ADP) and adenosine triphosphate (ATP) in energy-transfer mechanisms involving such widely diverse processes as muscular contraction, nerve conduction, fire fly luminescence, coenzyme syntheses, tumor growth, polysaccharide synthesis and many other key reactions (McElroy and Glass, 1951, 1952) has focused attention, in recent years, on the possible role of similar compounds in higher plants. The main difficulties encountered in demonstrating these effects in plants have centered around the problem of isolating and characterizing these compounds from plants. Methods developed primarily for the isolation of these compounds from animal tissues, as will become apparent later, have proven unsatisfactory for the isolation of these compounds from plants.