In a study of the assimilation of a number of nucleic acid derivatives by Candida (Torulopsis) utilis, Di Carlo, Schultz, and McManus ('51) found that the nitrogen of all of the naturally occurring purines that were tested was utilized for growth. It was suggested that C . utilis contains the enzymes adenase, guanase, hypoxanthine oxidase, xanthine oxidase, and uricase. Following this suggestion, Roush ('54) found that adenine induces the formation of a specific adenase in C . utilis and noted that during the process of enzyme induction in an adenine medium the yeast accumulated dialyzable compounds with a high absorbancy at 260 mv. Subsequently, Roush and Domnas ('56) studied the uptake of uric acid by C . utilis, found an intracellular accumulation of uric acid by an active transport process, and demonstrated the induced biosynthesis of uricase in this yeast. In the above work, the purine served as the sole nitrogen source; in contrast, Cowie and Bolton ('57) have reported on the accumulation of adenine and guanine by exponentially growing yeast in a meditiaux (January, 1959) and A. J. Domnas (June, 1956) to the Graduate School of Illinois Institute of Technology in partial fulfilment of the requirements for the Ph.D. degree.