Compared to Jonathan and Marianna Kastner's Sleep: The Mysterious Third of Your Life (1968, p. 5.22, J-198), this looks moreelementary (larger type, fewer pages), sounds less sophisticated yet uses more technical language, and includes some additional information while omitting some very basic material. Singer and Martin ambitiously define the conditions sleep labs must establish to meet scientific research standards before they examine the findings--a preliminary that may discourage a browsing reader. The section on physiology--changes in pulse rate, etc.--is skimpy, inferior to the Kastners' treatment, but much of the material on REM research is similar. Further, the authors speculate on why babies may need so much more REM sleep than adults and suggest a possible connection between dreaming and the brain, stem, midbrain limbic system, and cortex (but not Olds' pleasure center). The explanation of dream symbolism is not as incisive as either the Kastners' presentation or Kettlekamp's Dreams (1968, p. 277, J-105) but it is adequate. Satisfactory then, but no sleeper, and the demanding vocabulary may be an obstacle.