The results obtained on survival, induction of mitoticrecombination, and on the induction of cytoplasmic "petite" mutations indicate that millimeter waves (under these conditions) do not induce lesions and genetic effects in DNA. Conventional heating had no deleterious effects until temperatures of specimens exceeded 50°C. Measurement of zygote formation permitted to determine effects of smaller changes in temperature on events at the cellular level. There was evidence of increased formation of zygotes as a function of power level. The ratio of the number of zygotes obtained in samples treated at different temperatures over the number of zygotes in the control sample increase as a function of the temperature.