We have seen how these sensitive instruments help to prove hypotheses difficult to verify otherwise and how they thereby may stimulate new and fruitful scientific experimentation. We have learned how whole body counters add to our knowledge of normal processes in healthy bodies and detect disease or abnormalities resulting from dangerous conditions. [Illustration: Figure 23 _A University of Illinois counter large enough to examine an adult steer, above. A Cornell University counter used for animal-parasite studies, below._] [Illustration: Figure 23, below] [Illustration: Figure 24 _A trailer-mounted whole body counter used for research. School children were examined in a project to determine possible pathways by which radioactivity may enter the human body._] Each fact uncovered by whole body counters seems to trigger more penetrating research. This is how science advances. And with the advance of science comes knowledge on which we may build intelligent behavior and find solutions to problems affecting our lives. SUGGESTED REFERENCES Books _Environmental Radioactivity_, Merril Eisenbud, McGraw-Hill Book Company, Inc., New York. 1963, 430 pp., $13.50. _Radioactivity in Man: Whole Body Counting and the Effects of Internal Gamma Ray-Emitting Radioisotopes_, George R. Meneely (Ed.). Charles C Thomas, Springfield, Illinois. 1965, 672 pp., $24.50. _Whole Body Counting_, Proceedings of the Symposium on Whole Body Counting Held by the International Atomic Energy Agency at the Neue Hofburg, Vienna (June 12-16, 1961), National Agency for International Publications, 317 East 34th Street, New York 10016, 1962, 535 pp., $10.00. _How to Detect and Measure Radiation_, Harold S. Renne, The Bobbs-Merrill Company, Inc., New York, 1963, 160 pp., $3.95. _An Introduction to Radiation Counters and Detectors_, C. C. H. Washtell, George Newnes Ltd., London, 1960, 115 pp., $7.50. _Liquid Scintillation Counting_, Proceedings of a Conference Held at Northwestern University (August 20-22, 1957), Carlos G. Bell, Jr., and F. Newton Hayes (Eds.), Pergamon Press, Inc., New York, 1958, 292 pp., $10.00. Reports _Fundamental Nuclear Energy Research, A Special Report of the United Stales Atomic Energy Commission_ (December 1963), Superintendent of Documents, U. S. Government Printing Office, Washington, D. C. 20402, 407 pp., $2.50. Whole Body Counters as Medical Aids, pp. 11-13; Acute Whole Body Irradiation Effects, pp. 35-41; Chronic Whole Body Irradiation Effects, pp. 42-48. _Radioactive Contamination of Materials Used in Scientific Research_, James R. DeVoe, Nuclear Science Series Report No. 34, National Academy of Sciences—National Research Council, Washington, D. C. 20418, 1961, $2.00. Appendix VIII, The Negotiations and Developmental Work on Low Activity Glasses for Use in Whole Body Counters, pp. 109-115. Articles