attempted to cover metabolic matters already reviewed in Volumes I and II of The Biochemistry and Physiology of Protozoa (eds. Lwoff, and Lwoff and Hutner). To those interested in the broader aspects of photo synthesis and photoreception, reference is made to Photosynthesis and Related Processes, Volume I, and parts I and 2 of Volume II, by E. Rabinowitch; the Brookhaven Symposium on The Photochemical Ap paratus: Its Structure and Function (1959); the New York Academy of Sciences conference on Photoreception (1958), and to the many recent symposia, reviews, and current journal literature....