_Radioisotopes in the Service of Man_, Fernand Lot, National Agency for International Publications, 317 East 34th Street, New York 10016, 1958, 82 pp., $1.00. _Science and Cancer_, M. B. Shimkin, Public Health Service Publication No. 1162, Superintendent of Documents, U. S. Government Printing Office, Washington, D. C. 20402, 1964, 137 pp., $0.60. Motion Pictures _The Cell: Structural Unit of Life_, 10 minutes, sound, color or black and white, 1949, Coronet Films, Inc., 65 E. South Water Street, Chicago, Illinois 60601. _Continuity of Life: Characteristics of Plants and Animals_, 11 minutes, sound, color or black and white, 1954, Audio-Visual Center, Indiana University, Bloomington, Indiana 47405. _DNA: Molecule of Heredity_, 16 minutes, sound, color (No. 1825), black and white (No. 1826). 1960, Encyclopaedia Britannica Films, Inc., Wilmette, Illinois 60091. _The Science of Genetics_, AIBS Secondary School Film Series, No. 13280, 25 minutes, sound, color, 1962, McGraw-Hill Book Company, Inc., 330 West 42nd Street, New York 10036. Available for loan without charge from the AEC Headquarters Film Library, Division of Public Information, U. S. Atomic Energy Commission, Washington, D. C. 20545, and other AEC film libraries: _Tracing Living Cells_, Challenge Film No. 11, 29 minutes, sound, black and white, 1962. Produced by Ross-McElroy Productions for the National Educational Television and Radio Center under a grant from Argonne National Laboratory. This nontechnical film demonstrates some of the uses of radioisotopes in the study of cell division and in medical therapy. _The Eternal Cycle_, 12½ minutes, sound, black and white, 1954. Produced by the Handel Film Corporation. This nontechnical film illustrates the use of radioisotope tracers in biological research and is suitable for intermediate- through college-level audiences. _Chromosome Labeling by Tritium_, 15 minutes, sound, color, 1958. Produced by the Jam Handy Organization for the U. S. Atomic Energy Commission. This technical film discusses the advantages of tritium over other radioisotopes as labeling material in autoradiography. _A is for Atom_, 15 minutes, sound, color, 1953. Produced by the General Electric Company. This nontechnical film explains the structure of the atom, natural and artificially produced elements, stable and unstable atoms, principles and applications of nuclear reactors, and the benefits of atomic radiation to biology, medicine, industry, and agriculture. It is suitable for elementary- through high-school audiences. FOOTNOTES [1]An organism is a complete living plant or animal. [2]Metabolism is the sum of the life-sustaining activities in a living organism, including nutrition, production of energy, and synthesis (building) of new living material.