In studies of 5 vars. of Florida-grown pineapple fruits [long dash]Abachi, Cayenne, Natal, Red Spanish, Queen [long dash]in an effort to learn the fundamental causes of physiological breakdown, no striking varietal differences were observed in soluble solids, pH and acids in any instance except with Natal pineapples, which were higher than others in soluble solids. Abachi pineapples contained the highest quantities of ascorbic acid and the Red Spanish var. showed highest peroxidase activity. Disordered fruits contained less ascorbic acid than normal ones. Disordered tissue contained less ascorbic acid than did normal tissue in the same fruits. Tests made for ascorbic acid oxidase, peroxidase and phenolase, using a modified Guthrie method, gave negative results except in one instance.